Oncology Vol 29 No 4_Suppl_1

(P001) Disparities in the Local Management of Breast Cancer in the United States According to Health Insurance Status

April 30, 2015

Patients with inadequate health insurance were more likely to receive mastectomy, omit RT following breast-conserving surgery, and receive PMRT. Differences in clinical presentation and demographics according to insurance status incompletely explain the variation in therapy. Further study is needed to validate and address these disparities and to evaluate the impact of health insurance legislative efforts in localized breast cancer.

(P002) Predictors of CNS Disease in Metastatic Melanoma: Desmoplastic Subtype Associated With Higher Risk

April 30, 2015

Desmoplastic histologic subtype is a strong predictor of brain metastasis development and decreased 2-year BMFS in patients with metastatic melanoma. Patients with desmoplastic melanoma, particularly thick lesions involving the H&N, should be imaged frequently during the first year after the diagnosis of stage IV disease.

(P003) Identification of Somatic Mutations Using Fine Needle Aspiration: Correlation With Clinical Outcomes in Patients With Locally Advanced Pancreatic Cancer

April 30, 2015

This is the first study to demonstrate the feasibility of genomic sequencing of FNAs from pancreatic tumors. We have been able to successfully identify unique genetic signatures in patients with LAPC; however, the small sample size limits our ability to identify generalizable patterns.

(S001) Tumor Control and Toxicity Outcomes for Head and Neck Cancer Patients Re-Treated With Intensity-Modulated Radiation Therapy (IMRT)-A Fifteen-Year Experience

April 30, 2015

Re-irradiation for H&N cancers with IMRT and concurrent chemotherapy results in promising local control and survival outcomes in selected patients. Treatment-related toxicity continues to be significant despite improvements in systemic therapy and radiation dose conformality, warranting careful patient selection and target volume delineation.

(S004) Combination of Radiotherapy and Cetuximab for Aggressive, High-Risk Cutaneous Squamous Cell Cancer of the Head and Neck: A Propensity Score Analysis

April 30, 2015

Although limited by small numbers, we found that there were more long-term survivors and less distant metastasis in the cetuximab group. This is the largest report of CSCC patients treated with cetuximab. In the absence of prospective data, we believe that these data reveal that the addition of cetuximab is well tolerated and reveal signs of efficacy in this typically poorly performing group of patients and should be pursued in clinical trials.

(S005) Radiotherapy for Carcinoma of the Hypopharynx Over Five Decades: Experience at a Single Institution

April 30, 2015

With similar 10-year follow-up, there is a trend for improved locoregional control if treated as of 1980. Our data suggest that overall survival is longer for patients treated with IMRT. The current study lends further support to the body of evidence suggesting that in contrast to squamous cell carcinoma of the larynx, overall survival is improving for patients with squamous cell carcinoma of the hypopharynx.

(P006) The Role of Sequential Imaging in Cervical Cancer Management

April 30, 2015

Despite uncertainty regarding the anatomic resolution of PET, sequential use of contrast-enhanced CT, PET-CT, and/or MRI had no impact on treatment planning that was not accomplished by the use of PET alone. Future work should focus on determining the optimal pretreatment imaging for women with cervical cancer and developing guidelines to optimize outcomes while minimizing cost and radiation exposure.

(P009) Monte Carlo Dosimetry Evaluation of Lung Stereotactic Body Radiosurgery

April 30, 2015

Without the use of MC planning, target structures were substantially underdosed. Local failures were associated with PTVmicro undercoverage, which suggests that delivering a therapeutic dose to this expanded microscopic disease target volume is beneficial. MC dosimetry is preferable for lung SBRT, while the PB algorithm is adequate for predicting pulmonary toxicity.

(P010) Stereotactic Body Radiotherapy for Treatment of Adrenal Gland Metastasis: Toxicity, Outcomes, and Patterns of Failure

April 30, 2015

SBRT is an effective treatment modality, achieving excellent local control with minimal toxicity for patients with adrenal metastases. The development of progressive distant metastasis is the predominant pattern of failure affecting patients’ survival outcomes.

(P011) Stereotactic Radiosurgery and BRAF Inhibitor Therapy for Melanoma Brain Metastases Is Associated With Increased Risk for Radiation Necrosis

April 30, 2015

Rates of symptomatic radiation necrosis appear to be higher for the BRAF inhibitor therapy group. Prospective studies investigating BRAF inhibitor therapy and SRS for melanoma brain metastases should consider incorporating methods to decrease potential radiation necrosis, including fractionating radiosurgery.

(P012) Characteristics of Mentorship During Radiation Oncology Residency

April 30, 2015

Almost half of current radiation oncology residents do not have a mentor. Of those with mentors, most established relationships early in their training, during PGY-2 or prior. Therefore, it is imperative to intervene early in the training process to produce successful mentorship experiences. Many residents require more than one active mentor, which enables multiple goals to be met, such as career development, increasing one’s research portfolio, networking, and coping with residency.

(P014) Absence of Infection From Injection of a Rectal Spacer Into the Anterior Perirectal Fat Space

April 21, 2015

With proper preparation and antibiotics, placement of the rectal spacer into the anterior perirectal fat is extremely safe, without any risk of infection, in our series. Also, infections were not found in patients who had rectal wall penetration with the rectal spacer applicator needle.

(P015) Radiation Biological Responses of MRI-Linac vs Linac in Human Head and Neck and Lung Cancer Cells

April 30, 2015

The 1.5-T MF generated by MRL had no effect on the viability or radioresponses of NSCLC or HNSCC cell lines in vitro. These results suggest that MRL, as a novel cancer treatment technology, has the potential not to influence the radiotherapy outcome of patients. Considering the complicated in vivo microenvironment, further in vivo study is warranted.

(P018) Accelerated Partial Breast Radiotherapy Using VMAT-A Preliminary Dosimetric Comparison to Single-Entry Brachytherapy

April 30, 2015

VMAT planning for the delivery of APBI in this preliminary dosimetric evaluation has been shown to be a viable option for APBI. VMAT planning gives acceptable lung and heart doses and appears to deliver lower doses to the heart and ipsilateral lung than APBI delivered with the single-entry SAVI applicator.

(P021) Improving Clinical Documentation and Prospectively Populating a Research Database Through an Electronic Data Capture System for Routine Clinical Care

April 30, 2015

We implemented an EDC system for routine clinical use in our breast RT service that resulted in significant time savings for clinical documentation and a prospective population of a database for future outcomes research. Additional follow-up is needed to determine how easily this system can be generalized to other RT disease sites and practices.

(P019) Predictors of Outcomes in Breast Cancer Patients With Oligometastases

April 30, 2015

Our study showed that oligometastatic breast cancer patients have improved 5-year survival after metastases compared with non-oligometastatic patients. In patients with oligometastases and HER2-positive disease or without triple-negative disease, survival after metastases was superior. Further studies are needed to identify a favorable subset of patients with oligometastases who would benefit from aggressive therapy.

(S015) Impact of Health Insurance Status on Prostate Cancer Treatment Modality Selection in the United States

April 30, 2015

Patients without insurance were less than half as likely to receive MIS and more than twice as likely to receive EBRT compared with patients with private insurance in our national cohort. Our findings suggest that with expanding access to private insurance under the Affordable Care Act, there may be significant shifts in the selection of treatment modality for men with prostate cancer in the United States.

(S013) Heterogeneity Within the Prostate and Risk-Adapting Dose-Volume Analysis With SBRT for Prostate Cancer

April 30, 2015

Greater intraprostatic heterogeneity was associated with late grade 2+ GU toxicity. Given the high correlation of prostate volume with toxicity, SBRT dose parameters should be individualized and risk-adapted based on normalized prostate volumes, including a V50 not to exceed 9% of the prostate. The urethra is an important organ at risk, and the 42-Gy dose-volume should be limited to 2 mL, while bladder dose-volumes appear to be poor predictors of GU grade 2+ toxicity.

(S012) Trends in the Selection of Definitive Treatment for Newly Diagnosed Prostate Cancer in Men < 60 Years Old

April 30, 2015

In this young patient population, no definitive treatment was selected in 22.5% of men with LR disease. For those with HR disease, 25.5% did not undergo active treatment, indicating that these men appear to be receiving less aggressive therapy than recommended by NCCN guidelines. In addition, African-American race is also associated with a decreased likelihood for receipt of definitive therapy.

(S011) Hypofractionated vs Standard Fractionated Proton Beam Therapy for Early-Stage Prostate Cancer: Interim Results of a Randomized Prospective Trial

April 30, 2015

Patients tolerated proton therapy in this randomized trial well, with excellent QoL scores, persistent low IPSS, and no grade ≥ 3 AEs in either arm. Thus far, there is no apparent clinical difference in outcomes with hypofractionated proton beam therapy compared to standard fractionation.

(S010) A Phase III Randomized Trial of MRI-Mapped Dose-Escalated Salvage Radiotherapy Post-Prostatectomy: The MAPS Trial-Feasibility and Acute Toxicity

April 30, 2015

This study demonstrates that even though most MRI-identified GTVs are located in close proximity to critical structures, dose escalation is achievable without exceeding rectal constraints in all cases, and bladder constraints in the majority of cases. These variations are in cases with small bladders encompassed in the CTV and are not associated with increased acute toxicity.

(S008) The Impact of HPV, HIV, and Smoking on Oncologic and Functional Outcomes in Patients With Head and Neck Cancer

April 30, 2015

HIV+ patients with HNC have inferior oncologic and functional outcomes compared to HIV− patients. HPV positivity and smoking did not have a statistically significant impact on clinical outcomes. Innovative treatment modalities and approaches with better efficacy and less morbidity need to be developed for this growing patient population.

(S007) Intensity of Follow-Up After Radiotherapy for HPV-Positive Oropharyngeal Cancer

April 30, 2015

Following radiotherapy +/− chemotherapy for HPV+ oropharynx cancer, there is a low risk of disease recurrence or late grade ≥ 3 toxicity. As most events occur within 6 months of treatment completion, it may be reasonable to reduce the intensity of follow-up appointments to an every-6-month basis beyond this window.

(S014) pN+ Prostate Cancer (CaP) Does Not Imply Incurable Disease

April 30, 2015

When corrected for comorbid conditions in this patient cohort, CaP patients with less than 10% %LN+ have almost 14 years before their disease becomes incurable. Progressively larger %LN+ yields smaller windows of such time. Above 50% LN+, the inflection point is only about 4 years. While better therapies for pN+ CaP must be defined, this patient cadre is not homogenous and should be stratified by %LN+ in future clinical trials.

(S016) Intermediate-Risk Prostate Cancer: A Medicare-Based Cost Comparison of Five Radiotherapy Regimens

April 30, 2015

Under current Medicare-allowable reimbursements, the cost of proton therapy relative to the cost of other therapeutic options is highly dependent on the number of radiotherapy fractions delivered. Ultimately, the cost of proton therapy will need to be weighed against tumor control probabilities, as well as the economic and quality of life benefits associated with reduced normal tissue exposure.

(S017) Factors Associated With Regional Recurrence Following Lymphadenectomy for Penile Squamous Cell Carcinoma

April 30, 2015

The presence of cN3 disease, ENE, and > 3 lymph nodes at lymphadenectomy and the presence of pT4 disease at penile surgery were associated with increased risk of early RR, while adjuvant chemotherapy decreased RR. Since RR portends a dismal prognosis with few salvage options, men with these adverse factors should be considered for adjuvant therapy, including radiation therapy, to reduce RR.

(S019) Radiation-Induced Liver Disease Following Liver SBRT for Primary Hepatic Malignancies: Analysis of a Prospective Institutional Study 

April 30, 2015

Primary hepatic malignancies that are not amenable to surgical resection portend a poor prognosis, despite available treatment options. Though RILD is rare following SBRT, this study demonstrates a risk, despite close adherence to standard dose and volume constraints. Further analysis of this prospective study will seek to elicit patient parameters that may increase susceptibility to toxicities, such as RILD.

(S020) Predictors of Local-Regional Failure and the Impact on Overall Survival in Patients With Resected Exocrine Pancreatic Cancer

April 30, 2015

In our analysis of 458 patients with resected pancreatic cancer and adjuvant therapy, elevated preoperative CA 19.9 and no adjuvant RT were associated with increased risk of LRF. LRF was associated with poor OS. As such, RT should be considered as an adjunctive LR treatment modality for patients undergoing pancreatic cancer resection.

(S022) Experimental Insight Into the Preferential Cytotoxicity of Cancerous vs Noncancerous Cells of Metformin

April 30, 2015

Metformin was demonstrated to increase ROS levels, cytotoxicity, and radiosensitization in A549 and MCF-7 cancer cells under oxic, hypoxic, glucose-full, and glucose-free conditions. Normal MCF-10A cells did not show increased toxicity with metformin. The preferential metformin-induced increase in ROS levels found in cancer cells, particularly hypoxic cells, may provide some explanation for the therapeutic benefit seen in diabetic patients taking metformin while undergoing cancer treatment.

(S023) Ultrasound Tissue Characterization of Breast Fibrosis Following Hypofractionated Breast Radiotherapy

April 30, 2015

This is the first prospective imaging study to objectively document normal-tissue toxicity in patients treated with hypofractionation breast RT using ultrasonography tissue characterization. Contrary to the criticism, patients receiving hypofractionation RT recovered better and experienced less late toxicity at the 1-year follow-up.

(S024) Impact of Pelvic Radiotherapy on Sexuality Reported by Women Surviving Cancer

April 30, 2015

Reports of sexual changes in women after cancer treatment are highest in patients receiving pelvic radiation, particularly brachytherapy. Rates of sexual changes are higher than expected in patients receiving radiation elsewhere and/or chemotherapy alone. These findings support the need for both adequate patient counseling prior to treatment and support for late-effect management afterwards.

(S025) Discovery and Validation of Predictive Factors for Safety Incident Reports in Patients Receiving Radiation Therapy: Comparative Results From a Large Safety Variance Database

April 30, 2015

We determined several patient and treatment-specific characteristics that predicted for treatment incident events. Children were more susceptible to incident alerts, possibly related to increased staff vigilance or more frequent use of complex modalities. Patients with head and neck tumors, greater number of fractions, treatment on protocol, and use of IMRT also predicted for incidents.

(S027) Novel Mechanisms of Adaptive Resistance in Head and Neck Cancer

April 30, 2015

Targeted combinatorial therapy with XRT is necessary to overcome adaptive radioresistance. RPPA is a powerful proteomic platform, suggesting alterations in energy metabolism following XRT that are targetable by inhibition of the enzyme glutaminase. Further in vivo experiments with glutaminase inhibition and xenograft models to assess combinatorial efficacy with radiation are warranted.

(S028) Patient-Level DNA Damage and Repair Pathway Profiles Are Prognostic After Prostatectomy for High-Risk Prostate Cancer

April 30, 2015

Patient-level DDR pathway profiling revealed distinct clusters. Individual DDR pathways and a composite biomarker showed strong prognostic performance with the long-term outcomes of metastatic progression and OS, which may be useful for risk stratification of high-risk prostate cancer patients aged < 70 years.

(S030) Breast Conservation in Young Women in the Modern Era

April 30, 2015

Outcomes for women with breast cancer aged ≤ 40 years undergoing BCT and M have improved significantly over time, likely reflecting the advent of improved local and systemic therapies. In addition, for women treated after 2000, BCT appears to be safe and equivalent to M at 10 years in terms of FFLR, OS, and RFS.

(S031) Dosimetric Analysis of Left-Sided Breast Cancer Treatment With Tomotherapy IMRT, IMRT, VMAT, and 3D-CRT

April 30, 2015

Our analysis of this single-institution population of women with left-sided breast cancer treated to the whole breast demonstrates that differing radiation treatment techniques have statistically significant impacts on dosimetric parameters of the heart, left ventricle, and LAD.

(S032) Complications of Contralateral Prophylactic Mastectomy With Tissue Expander Reconstruction and Potential Impact on Adjuvant Oncologic Therapy

April 30, 2015

CPM with TER resulted in a complication in 25% of patients, half of which occurred within 6 months of surgery. However, adjuvant chemotherapy or radiotherapy was delayed by acute complications in only 3% after CPM. Delayed complication rates were higher on the therapeutic side, possibly due to effects of radiotherapy. These data may better inform patients considering bilateral mastectomies with TER.

(S034) Pilot Phase II Trial of “Sandwich” Radiation and Combination Carboplatin and Paclitaxel Chemotherapy in Patients With High-Risk Endometrial Cancer

April 30, 2015

Sandwich chemotherapy and radiation therapy is a tolerable treatment modality for patients with high-risk endometrial cancer. Rates of hematologic toxicities are acceptable, and nonhematologic toxicities are uncommon. Further enrollment of patients is underway to determine efficacy.

(S035) Cervical Cancer Outcome Prediction to High-Dose-Rate Brachytherapy Using Quantitative Magnetic Resonance Imaging Analysis of Tumor Response to External Beam Radiotherapy

April 30, 2015

Aside from the known benefits of IGBT, MRI-based planning allows for assessment of tumor regression and prognosticates patients, as shown in the present study. If these findings are replicated in prospective trials, alternative methods, such as dose escalation and surgical salvage, should be considered to offset poor prognoses.

(S042) Factors Influencing Brain Recurrence After PCI Among Patients With Limited Small-Cell Lung Cancer

April 30, 2015

Tumor size appears to be a significant prognostic factor for brain recurrence in patients with limited-stage SCLC after PCI. Further investigation is warranted to in order to best individualize treatment for limited-stage SCLC patients with large tumors.

(S041) The Role of Chemoradiation in Elderly Limited-Stage Small-Cell Lung Cancer Patients

April 30, 2015

With modern treatment, there appears to be a significant benefit to the use of combined modality therapy in elderly patients with LS-SCLC, even in those with medical comorbidities. For patients who would be expected to tolerate the acute effects of concurrent chemo-RT, there appears to be a significant long-term survival benefit over sequential therapy.

(S038) Pulmonary Dose-Volume Predictors of Radiation Pneumonitis Following Stereotactic Body Radiation Therapy

April 30, 2015

Symptomatic RP occurred in 23.1% of our patients treated with SBRT. Lung V10 was the strongest predictor of grade ≥ 2 RP on multivariate logistic regression, associated with a 30% decrease in risk for patients with V10 < 10.9 Gy compared with ≥ 10.9 Gy. Further research is needed to validate these findings and the importance of lung V10 in predicting symptomatic RP following SBRT.

(S037) Phenotypic Diversity Measured in PET/CT Scans Predicts Overall Survival in Early-Stage Lung Adenocarcinoma

April 30, 2015

These results suggest that within-tumor phenotypic diversity, as quantified in PET-CT scans, can predict OS in patients with early-stage lung adenocarcinoma. Quantification of within-tumor heterogeneity in this routine clinical imaging may provide a noninvasive method for identifying a high-risk subset of patients with early-stage non–small-cell lung cancer.

(S036) Circulating Tumor DNA and Implications for Clinical Decision-Making in Stage I NSCLC

April 30, 2015

Our model suggests that ctDNA could improve clinical decision-making for stage I NSCLC. Prospectively identified high-risk patients could benefit from systemic therapy. We assumed that occult micrometastases and ctDNA had clinical significance, which is supported in published literature.

(S046) Prognosis for Patients With Metastatic Breast Cancer Who Achieve ‘No-Evidence-of-Disease’ Status After Systemic or Local Therapy

April 30, 2015

Achieving NED status correlates strongly with outcome in MBC, making this a potentially valuable short-term clinical trial endpoint akin to pathologic complete response. MBC patients who attain NED have prolonged survival, with perhaps up to one-third achieving complete remission.

(S048) Identification of Excellent and Poor Prognostic Groups After Stereotactic Radiosurgery for Spinal Metastasis: Secondary Analyses of Mature Prospective Trials

April 30, 2015

We present a survival prediction model that has identified patient subgroups with poor (Group 4) to excellent (Group 1) prognoses. In addition, pretreatment symptoms were predictive of survival and correlated with the prediction of the model. If validated, we believe that this model, possibly in conjunction with patient symptoms, may aid in determining optimal treatment strategies.

(S049) Salvage Stereotactic Radiosurgery for Locally Recurrent Brain Metastases Treated Previously With Stereotactic Radiosurgery

April 30, 2015

Repeat SRS represents a potential salvage therapy for patients with locally recurrent brain metastases, providing additional tumor control with acceptable toxicity, even in the setting of prior SRS, surgical resection, and/or WBRT. Repeat SRS may also be reasonable to use to either avoid or delay the treatment of WBRT.

(S052) Inverse Optimization for Correlating 4DCT Ventilation Imaging and Radiation Dose

April 30, 2015

A numerical method for computing a DIR transformation according to a target ventilation image was used to generate a ventilation image that correlates precisely with the dose distribution while maintaining high DIR spatial accuracy. Thus, by employing this approach, the focus of future CT ventilation studies that are designed to assess radiation dose response is reduced to assessing the physical feasibility of the DIR transformation that generates the ventilation image predicted by the dose-response model.

(S051) The Role of Temozolomide in the Treatment of Low-Grade Glioma

April 30, 2015

Our preliminary results suggest that the use of temozolomide in the management of low-grade glioma is neither deleterious nor beneficial in terms of PFS. In comparison with the PFS reported by the EORTC 22844/22845 and RTOG 9802 trials, our PFS is markedly worse. This finding is likely attributable to the high median age of our patient population, which is noticeably older and thus assumed to have a poorer prognosis.

(S054) Long-Term Survival and Racial Differences in Pediatric Hodgkin Lymphoma Patients From the State of Florida: Three Decades of Experience

April 30, 2015

This is the largest retrospective review with the longest outcome to specifically evaluate pediatric Hodgkin lymphoma patients. Furthermore, this is the first analysis to find that AA patients have inferior OS when compared with whites and Hispanics. These differences remained significant over the course of 30 years, indicating that modern treatment modalities have not improved this racial disparity.

(S021) The Role of Neoadjuvant Stereotactic Body Radiation Therapy in Pancreatic Cancer

April 30, 2015

Selected patients who are initially deemed unresectable may now undergo resection after receiving neoadjuvant induction chemotherapy and SBRT. Furthermore, improved surgical outcomes are observed with neoadjuvant SBRT in comparison with neoadjuvant chemotherapy alone. Longer follow-up is needed to validate its impact on survival.

(S026) A Novel Method for Detecting Serious Cardiac Device Errors in Patients Receiving Radiotherapy Using Daily Pulse Checks

April 30, 2015

A novel method for monitoring CIEDs during radiotherapy is presented, which we report as effective, easy, and lacking adverse side effects. This simple technique is a cost-effective alternative to frequent device interrogations during the course of radiotherapy and allows for consistent daily monitoring.

(P023) Dosimetric Evaluation of Accelerated Partial Breast Irradiation Utilizing the ViewRay Magnetic Resonance Image-Guided Radiation Therapy System

April 30, 2015

MRI-guided EBRT using the ViewRay system is a novel approach to deliver APBI. ViewRay APBI is noninvasive yet maintains a high degree of precision by using prefraction MR imaging, thus allowing a reduction in the PTV margin. The resultant decrease in the ipsilateral breast dose may reduce acute skin toxicity and improve cosmetic outcomes. Thus, the ViewRay system is an attractive alternative to existing APBI techniques.

(P025) T3 Tumors and Breast Conservation

April 30, 2015

For patients with tumors greater than 5 cm, survival in the Medicare population remains similar between breast conservation and mastectomy, as it does for smaller primaries. Despite the exclusion from prospective randomized trials, breast conservation should remain a standard option for women with larger tumors when deemed clinically and cosmetically amenable to resection.

(P024) Predictors of Radiation-Induced Skin Toxicity: Data From a Prospective Cohort Receiving Breast Radiation

April 30, 2015

In this prospectively followed cohort of breast cancer patients receiving RT to the intact breast, novel predictors for more severe skin toxicity were identified, including PR-negative status, invasive ductal histology, and receipt of chemotherapy, as well as known risk factors, including BMI and fractionation scheme.

(P026) Is Cause-Specific Survival Similar for Estrogen Receptor- and Progesterone Receptor-Negative Early-Stage Invasive Lobular and Invasive Ductal Cancers? A National Registry SEER Database Study

April 30, 2015

For early-stage breast cancer cases with ER+ and PR+ status, histology was not associated with a difference in BCSS. Alternatively, ILC cases that were ER− or PR− had an increased BCSS compared with receptor-matched IDC cases. These findings add to the growing evidence supporting ILC as a more favorable histology, which is important for guiding treatment and prognostication.

(P029) A Comparison of CT- and MRI-Defined Lumpectomy Cavity for Radiotherapy Planning of Breast Cancer

April 30, 2015

MRI substantially improves the visibility and accuracy of lumpectomy cavity definition as compared with CT. Although the LC and PTV volumes that are delineated from an individual MRI sequence are generally smaller as compared with those from CT, the volumes, shapes, and locations for the PTV-MRI, defined by the union of T1, T2, and STIR, were comparable with PTV-CT for most of the cases studied. It is feasible to use MRI to replace CT in RT simulations for breast-conserving RT.

(P030) Metaplastic Breast Carcinoma at a Single Institution: Clinical-Pathologic Characteristics and Outcome

April 30, 2015

Similar to other reported series, the majority of our patients had triple-negative disease, and our patient population did not express the HER2/neu oncoprotein. Our predominant histology was squamous differentiation, whereas heterogeneity in histology is described in the literature. Despite high-grade disease, the outcomes in our study are favorable in comparison with previously reported series, although the follow-up is short.

(P031) Effects of Oncoplastic Surgery on Delivery of Standard Adjuvant Radiotherapy

April 30, 2015

The standard patterns of care for breast conservation therapy include A-RT with a boost to the surgical bed. For the PubMed and Medline articles, 71% of the 1,180 patients without clips and clear margins did not receive a boost. These results correspond with the ROs’ survey, which showed that 65.4% of them did not give a boost to the patients systematically. While OBS was perceived by the surgeons as a technique to remove more tissue and improve cosmesis, our review demonstrated that it negatively impacts radiotherapy techniques that are proven to achieve adequate local control. OBS is clearly changing patterns of delivery of adjuvant RT, without long-term outcomes supporting its safety.

(P032) Current Management of Low-Grade Central Nervous System Glioma

April 30, 2015

Currently, low-grade glioma is commonly treated in the community setting by RT alone. A relatively high rate of local failure is noted (28%), and long-term survival appears to be shorter than might be expected. A number of patients are treated based on imaging alone without a detriment to survival. Low-grade glioma appears to be a more aggressive disease than usually considered, and efforts to improve the outcome would be served through clinical trials.

(P033) MRI Resection Cavity Dynamics Following Brain Metastasis Resection and Permanent Iodine-125 Brachytherapy

April 30, 2015

Surgical resection with 125I brachytherapy is an effective strategy for local control of brain metastases. Although metastasis volume significantly influences resection cavity size and remodeling, volumetric parameters do not appear to influence local control or necrosis.

(P035) Prognostic Factors of Early Deaths in Patients With Craniopharyngioma From the SEER Registry

April 30, 2015

Craniopharyngioma-related death represents the most common cause of early deaths in both pediatric and adult patients. GTR and adjuvant RT do not appear to have a significant impact on OS within 5 years of diagnosis. Older age, black race, and adamantinomatous/papillary histologies are significant prognostic factors for early deaths after the diagnosis.

(P036) Patterns of Care and Outcomes of Adjuvant Radiotherapy for Meningiomas: A Surveillance, Epidemiology, and End Results and Medicare-Linked Analysis

April 30, 2015

Utilization of adjuvant XRT and SRS remained stable between 2000 and 2010. Male sex, young age, marriage, partial resection, grade II/III tumors, and large tumors predicted for use of adjuvant therapy. For all patients, SRS improved survival compared with craniotomy alone. For patients with incomplete resection, SRS improved survival compared with craniotomy alone and adjuvant XRT. Randomized, prospective clinical trials are needed to better define the role of adjuvant XRT or SRS.

(P037) Analysis of Survival Outcomes in Patients With Multifocal Glioblastoma

April 30, 2015

Median survival of multifocal GBM is incredibly short, even compared with the already short median survival of single-lesion GBM. The majority of our patients had biopsy alone, likely due to the nature of multifocal GBM. This most likely contributes to a worse MS.

(P038) Leukoencephalopathy Following Stereotactic Radiosurgery for Brain Metastases

April 30, 2015

Our results establish that WBRT + SRS produces leukoencephalopathy at a much higher rate than SRS alone. Surprisingly, an SRS integral dose of over only 3 J predicts for leukoencephalopathy in patients treated with SRS alone. Our data define a dosimetric threshold at which radiation-induced leukoencephalopathy is likely to occur following SRS. As the survival of patients with CNS metastases increases and as the neurotoxicity of chemotherapeutic and targeted agents becomes established, the threshold of 3 J may influence the therapeutic management of patients with multiple brain metastases.

(P040) Radiosurgery for Primary Central Nervous System Lymphoma

April 30, 2015

SRS appears to be a reasonable treatment option for focally persistent or recurrent PCNSL in select patients, especially in the setting of focal neurologic deficits. As a radiosensitive entity, all PCNSL lesions had a substantial volumetric reduction with at least 14 Gy, and all patients with a focal neurologic deficit at treatment experienced symptomatic improvement with SRS. Further investigation should be completed regarding the benefits of SRS for focally appearing PCNSL as a potential way to avoid neurotoxicity and improve symptoms in selected patients.

(P041) Clinical Outcomes of Gamma Knife Stereotactic Radiosurgery (GK-SRS) for Painful Trigeminal Neuropathy (TNP) 

April 30, 2015

SRS is both safe and efficacious for PTN. Additionally, prior to treatment, PTN patients who characterize their facial pain as dull and not exacerbated by daily activities are more likely to receive therapeutic benefit, with a mean response time of 1 month.

(P042) Toxicity and Treatment Outcomes in Single vs Multifractionated Radiotherapy for Acoustic Neuromas

April 30, 2015

FSRT and SRS in treatment for acoustic neuromas had similar outcomes and toxicity at our institution. Both modalities appear to be successful at providing high tumor control with acceptable toxicities in the noninvasive treatment of acoustic neuromas.

(P043) Central Neurocytoma: Impact of Resection Extent and Adjuvant Radiotherapy on Survival Outcomes 

April 30, 2015

Adjuvant RT was delivered to a minority of CNC patients after either GTR or STR in this national database, though patients were more likely to receive RT after STR. Long-term OS was excellent for all subgroups, and there was no clear evidence of resection extent or adjuvant RT influencing survival outcomes. Since our database is subject to selection bias and limited by a lack of information regarding local recurrence, salvage therapies, exact extent of STR, and RT technique, further research is needed to validate our findings.

(P044) Treatment Outcomes of WHO Grade III Malignant Meningioma With and Without Postoperative Radiation Therapy

April 30, 2015

Our study showed that patients with primary malignant meningioma had better outcomes after maximal resection followed by postoperative radiation. In contrast, transformed meningiomas demonstrated more aggressive behavior, with lower median survival despite RT. Further multi-institutional or randomized studies are required to evaluate the effectiveness of postoperative RT to determine the best approach to managing these tumors.

(P045) Multimodality Therapy With Intensity-Modulated Radiotherapy for Locally Advanced Esophageal Cancer

April 30, 2015

Patients who undergo surgery after chemoradiotherapy demonstrate improved survival; however, this may be related to underlying comorbidities that preclude surgery. IMRT appears to be a reasonable treatment option that may reduce complications from radiotherapy. Careful attention should be given to heart dose during treatment planning.

(P047) The Role of Radiation Therapy Following Adjuvant Chemotherapy in Pancreatic Adenocarcinoma

April 30, 2015

We discerned no significant improvements with the addition of radiation therapy in these patients with resected pancreatic adenocarcinoma treated with modern adjuvant chemotherapy, but statistical power was limited. The eventual results of the ongoing Radiation Therapy Oncology Group (RTOG) study RTOG 0848 will provide definitive data regarding the appropriate role for radiation in the era of modern adjuvant chemotherapy.

(P048) Mutational Analysis by Next-Generation Sequencing in Patients With Pancreatic Adenocarcinoma

April 30, 2015

Novel mutations were identified in the majority of patients, including mutations within a number of genes that have the potential to influence KRAS-mediated signaling, as well as other prominent signaling pathways. These results could potentially serve to identify targets for novel chemotherapeutic agents and guide personalized, combinatorial therapy in appropriately selected patients.

(P049) Increased Portal Venous Enhancement of Hepatocellular Carcinoma Following Transcatheter Arterial Chemoembolization

April 30, 2015

The majority of cases exhibited increased enhancement on portal venous phase following treatment with TACE, demonstrating the importance of surveillance with proper multiphase imaging to assess for recurrence, especially in light of a decrease in arterial phase enhancement following treatment.

(P052) Human Papillomavirus in Esophageal Cancer: An Institutional Retrospective Analysis

April 30, 2015

There was no HPV oncogene expression in our patient cohort, which corresponds with a low-to-no prevalence of esophageal HPV infection in a population of patients in the United States. However, further studies including a larger patient cohort with pretreatment tissue analysis would still be helpful in determining the true prevalence of HPV in esophageal cancer. Patients who are treated with trimodality therapy experienced a high rate of pathologic response.

(P053) Esophageal Cancer Pathologic Complete Response Rate After Neoadjuvant Chemoradiation: Is There a Difference Between Academic Centers vs Community Centers

April 30, 2015

Pathologic outcomes after neoadjuvant chemoradiation for esophageal cancer were similar between patients treated at an academic center and community setting, although patients treated in the community tended to be older than patients treated at our academic center. These results will need to be validated with a larger dataset. The pCR rate after neoadjuvant chemoradiation at our institution was 21%, consistent with published data.

(P054) Carbon Ion Therapy for Chinese Patients With Prostate Cancer: Primary Reports

April 30, 2015

This is the first report about a Chinese population with prostate cancer treated with carbon ion therapy. Our primary data showed that carbon ion therapy was well tolerated, and the immediate effect was encouraging. Long-term follow-up is needed for the analysis of final treatment responses and toxicities.

(P051) Intraductal Papillary Neoplasm of the Bile Duct: Prognostic Factors in SEER Outcomes of Benign and Malignant Cases

April 30, 2015

Both benign and malignant cases had outcomes dependent upon the location and extent of surgical resection. In malignant cases that are not amenable to surgery, radiation offers a survival benefit. Given the cohort in this analysis, selection bias likely plays a significant role. Further study is required to define the optimal management of IPNB.

(S029) Evaluating the Role of a 21-Gene Expression Assay in Directing Adjuvant Radiotherapy Decisions for Elderly Women With Early-Stage Breast Cancer

April 30, 2015

We observed a wide range of RSs among elderly ESBC patients in the NCDB. Further research is needed to determine if gene expression assays are capable of risk-stratifying within this population, as a means for directing adjuvant RT recommendations after BCS. Should this be proven, our findings would suggest that ODX-directed decision-making is theoretically cost-effective at a conservative willingness-to-pay threshold of $50,000/QALY.

(P094) Treatment Outcomes of Sinonasal Neuroendocrine Cancer: A Retrospective Review

April 30, 2015

Sinonasal neuroendocrine tumors are a challenging group of diseases to manage, due to their rarity and heterogeneous natural histories. New multimodality strategies need to be explored to potentially enhance outcomes, especially in non-ONB histologies.

(P096) Late Radiation-Associated Dysphagia (Late-RAD) With Lower Cranial Neuropathy After Oropharyngeal IMRT

April 30, 2015

Although the majority of oropharyngeal cancer survivors enjoy functional recovery in early survivorship, almost 10% suffer severe, late deterioration of swallowing abilities. Delayed lower cranial neuropathies often precipitate late-RAD.

(P098) Dosimetric Predictors of Pulmonary Toxicity in Patients With Malignant Pleural Mesothelioma Receiving Radiation Therapy to the Intact Lungs

April 30, 2015

Sparing the ipsilateral lung of at least a finite functional unit per 1 L of the ipsilateral lung is a predictor of the development of radiation pneumonitis. This represents a new dosimetric measure in plan evaluation and correlates significantly with the development of toxicity in patients with malignant pleural mesothelioma receiving radiation to the ipsilateral lung. This factor might be a more effective and useful parameter in these challenging cases.

(P099) Influence of Surveillance PET/CT on Detection of Early Recurrence Following Definitive Radiation in Stage III Non–Small-Cell Lung Cancer

April 30, 2015

In stage III NSCLC patients treated with definitive radiation, increased frequency of PET-CT scan surveillance did not result in decreased time to detection of locoregional or distant recurrence or improved survival. If validated, further investigation is warranted to elucidate the benefit, if any, of NSCLC posttreatment surveillance with PET-CT scan.

(P097) Tumor Density, Size, and Histology in the Outcome of Stereotactic Body Radiation Therapy for Early-Stage Non–Small-Cell Lung Cancer: A Single-Institution Experience

April 30, 2015

Our institutional experience confirmed that SBRT to primary NSCLC is well tolerated and provides excellent LC, regardless of tumor size or histology. Tumor density did not appear to have a significant effect on PTC, but denser tumors were more likely to have poorer outcomes, likely owing to associated larger tumor burden.

(P102) Surgery Improves Survival in 14,228 Patients With Malignant Pleural Mesothelioma

April 30, 2015

Despite developments in surgery, perioperative management, and radiotherapy, the prognosis for MPM patients has not improved over the past four decades. In this SEER study of 14,228 patients over 36 years, cancer-directed surgery was associated with better survival in MPM, independent of other prognostic factors. These data support the role of surgery-based therapy as the cornerstone of treatment for this challenging disease.

(P103) A New Score Predicts Survival in Patients With Non–Small-Cell Lung Cancer

April 30, 2015

Prognostic factors that were significantly associated with survival on both UV and MV analyses were used to construct a valid scoring system that can be used to predict survival of NSCLC patients. The score can be used for trial stratification or for choosing patients specifically for high-risk trials. Optimally, this score will be helpful when counseling patients and designing future trials.

(P104) Esophagus- and Contralateral Lung–Sparing IMRT for Locally Advanced Lung Cancer in the Community Hospital Setting

April 30, 2015

These data provide proof of principle that suboptimal radiation dose distributions are associated with significant acute and late lung and esophageal toxicity that may result in hospitalization or even premature mortality. We propose a relatively simple four-field IMRT technique with strict attention to commonly accepted lung and esophageal dose-volume constraints as a preferred approach for the majority of locally advanced lung cancers.

(P105) Community-Based Early-Stage Treatment (BEST) Outcomes for NSCLC

April 30, 2015

LC, survival, and toxicity of stage I NSCLC treated with SBRT in this community setting are comparable to those reported in university and multi-institutional trials. The efficacy, safety, and convenience of SBRT have been translated to a large cohort of patients in an outpatient community cancer center. These results also indicate that doses < 60 Gy delivered in five fractions may be less effective at achieving LC. As lower doses are examined in central lesions, it will be important to closely evaluate any possible reduction in LC.

(P106) Dosimetric Comparisons of Treatment by Different Radiotherapy Techniques for Stage III Non–Small-Cell Lung Cancer

April 30, 2015

For both the 60-Gy and 74-Gy dose levels, significant dosimetric advantages (normal tissue sparing) were observed with IMRT, and a larger benefit was observed for 74-Gy dose plans. The dose to the esophagus, heart, and lung are likely to be clinically meaningful in terms of toxicity. VMAT provided benefit over conventional IMRT at the 60-Gy dose level. Additional studies are warranted to further investigate the impact of advanced radiotherapy techniques for the delivery of high-dose thoracic radiotherapy.

(P107) Vero SBRT Treatment of Moving Lung Tumors

April 30, 2015

Overall, 40%-thresholded 18F-FDG PET contours nonsignificantly enlarge PTVs when multiphase free-breathing, inspiration, and expiration breath-hold scans are used for Vero SBRT. Whether 18F-FDG PET contours improve local control of moving lung tumors treated by Vero SBRT needs further study.

(P110) Hodgkin Lymphoma and Pregnancy: Treatment Patterns and Survival Outcomes of Women Treated With Modern Chemotherapy and Radiotherapy

April 30, 2015

Overall, outcomes in patients diagnosed with HL in pregnancy in the modern era of chemotherapy and radiation are good. As in HL not diagnosed during pregnancy, outcomes are better in patients with a complete response following initial therapy. Delaying all therapy until the postpartum period is appropriate in properly selected patients and is not associated with poorer outcomes.

(P119) Electronic Brachytherapy Management of Atypical Fibroxanthoma: Report of Seven Cases

April 30, 2015

This is the largest reported series of AFX treated with radiation therapy in the literature. No contraindication to the use of radiation is found in the literature. Prior series all utilized surgery, likely due to the clinically rapid progression of this tumor. Risk of recurrence is mitigated with surgical debulking prior to brachytherapy. Electronic brachytherapy appears to be a safe and effective treatment for AFX.

(P118) Radiotherapeutic Care Within the Veterans Health Administration of US Veterans With Metastatic Cancer to the Brain: Part 2 Clinical Treatment Patterns

April 30, 2015

ROs in practice less than 5 years, with academic appointments, or with an FT status had statistically significant associations with WBRT/SRS choice. In poor-prognosis patients, consideration of best supportive care measures is done, and short-course RT is often recommended. For patients with good KPS and limited small brain metastases, SRS with or without WBRT is recommended by most practitioners in accordance with ASTRO guidelines.

(P117) Outcomes, Patterns of Failures, and Toxicity for Patients Diagnosed With Pulmonary Metastases Treated With Stereotactic Body Ablative Radiotherapy (SABR)

April 30, 2015

SABR is an effective treatment modality for patients with pulmonary metastases, with excellent local control. Further studies are warranted to elucidate which patients with pulmonary metastases would benefit from the local control with SABR and determine when to treat with systemic therapy due to quick progression of distant metastases.

(P114) Radiotherapeutic Care Within the Veterans Health Administration of US Veterans With Metastatic Cancer to the Brain: Supportive Measures (Part 1 of 2 Reports)

April 30, 2015

Veterans with brain metastases treated at VHA radiation oncology centers receive appropriate care. Still, the use of prognostic indices in treatment decision-making is statistically significantly more likely in cases treated by recent training program graduates. Given the relatively recent development of these scoring systems, educational efforts need to be devoted to increasing their use in the clinic.

(P113) Posttreatment Sequelae for Long-Term Survivors of Brain Metastases

April 30, 2015

For patients with brain metastases, long-term survival is possible, but the majority of long-term survivors will still experience intracranial progression and require salvage therapies after initial treatment. While salvage therapies may control disease, the development of new metastasis seems to adversely affect survival. RN risk increases over time and may affect a significant portion of long-term survivors.

(P112) Spine Stereotactic Radiosurgery in the Treatment of Metastatic Pheochromocytoma: A Case Series

April 30, 2015

Our data suggest that SSRS is an effective, safe, and durable treatment option. Given the robust tumor control of SSRS and the possibility for metastatic foci to serve as sources for further systemic spread, proactive treatment of spinal metastasis earlier in the disease course may offer therapeutic benefit to these patients.

(P115) The Experience of a Radiation Oncology Center in Gauging the Use of Single-Fraction Radiotherapy for Painful Bone Metastases

April 30, 2015

We observed an increase in the use of SFRT for bone metastases over the time period covered. Tracking the encounters by ICD codes and CPT codes, when properly coded, served as a useful tool in providing a snapshot view of SFRT usage. Additionally, physician education is a prerequisite for the proper use of a CPT 77431 to capture the true rate of usage of SFRT in clinical practice.

(P121) Image-Guided Radiation Therapy Utilization and Practice Patterns: Results From a National Survey of ASTRO Membership

April 30, 2015

IGRT use is widespread, without standardization of pretreatment imaging modality, frequency, or verification process. Additionally, PTV margin size selection does not appear to be based on IGRT frequency or method of verification. Further research aimed at optimizing IGRT techniques is needed to ensure accurate, safe, timely, and cost-effective treatment delivery.

(P122) Older African Americans’ Use of Religious Music to Cope With Cancer

April 30, 2015

Religion and particularly the use of religious songs are important aspects of coping with the cancer experience among older African Americans. During diagnosis and treatment, a religious song is likely to be a viable complement to therapies for symptom reduction and mood elevation among this population.

(P123) Reducing Time From Patient CT Simulation (CT SIM) Appointment Time to Start of Actual CT Scan: Lean Thinking in the VA System

April 30, 2015

By applying Lean thinking, we were able to reduce the time for CT image acquisition for prostate cancer patients requiring radiotherapy planning by 22%. By reducing the time for CT SIM, veterans’ experiences and satisfaction were improved, flow through the radiation oncology department was optimized, and capacity for CT SIMs was increased.

(P125) Glioblastoma Multiforme Outcome Comparison Between Pediatrics and Adults: Is There a Difference?

April 30, 2015

This is the first report to directly compare pediatric and adult patients with GBM. Pediatric patients had significantly superior OS and CSS when compared with adults, and these differences remained significant over time and on multivariate analysis. The underlying cause of these survival differences between pediatrics and adults requires exploration, with attention to molecular biological tumor differences.

(P126) Long-Term Volumetric Follow-Up of Juvenile Pilocytic Astrocytomas Treated With Proton Beam Radiotherapy

April 30, 2015

Pediatric patients with PAs can have extended survival following proton beam radiotherapy. This volumetric study illustrates that responders are declared within 6 months, but vigilant surveillance is necessary due to the potential need for postradiotherapy interventions.

(P127) Stereotactic Accelerated Partial Breast Irradiation (SAPBI) for Early-Stage Breast Cancer: Rationale, Feasibility, and Early Experience Using the CyberKnife Radiosurgery Delivery Platform

April 30, 2015

SAPBI via CyberKnife is a suitable platform for partial breast irradiation, offering improvements over existing APBI techniques, with excellent normal tissue-sparing. Our early findings indicate that CyberKnife SAPBI delivered in five fractions is a feasible, well-tolerated, and reliable platform for delivering PBI.

(P129) Bone Marrow Aspiration Under CT Guidance: Technique and Value

April 30, 2015

Bone marrow aspiration under CT guidance is a safe procedure that has become commonplace at our institution. Pain is minimal, even in the absence of sedation. All biopsies performed at our institution with participation from the pathology department have resulted in diagnostic specimens, and relationships with healthcare stakeholders have improved.

(P130) An Exploratory Pilot Study of Perfusion Patterns in Locoregionally Advanced Head and Neck Cancer Using a Novel Analysis Technique of Dynamic Contrast-Enhanced (DCE)-MRI

April 30, 2015

UPR is a novel technique that has been developed in a preclinical tumor model and that is potentially applicable in HNCs. This exploratory study appears consistently to identify subvolumes within the GTV that may have therapeutic implications and that may be promising areas for further research (eg, correlation with hypoxia and clinical outcome).

(P131) Improved Prostate Delineation in Prostate HDR Brachytherapy With TRUS-CT Deformable Registration Technology

April 30, 2015

We have developed a novel TCDR-based approach to improve prostate delineation utilizing intraoperative TRUS-based prostate volume in prostate HDR brachytherapy and demonstrated its improvement in prostate volume accuracy over the standard CT-defined prostate volumes. Integration of TRUS into the HDR brachytherapy treatment planning workflow has the potential to enable accurate dose planning and delivery and enhance prostate HDR treatment outcome.

(P132) Evaluation of the Chest Wall Skin Dose Associated With Bolus Application in Postmastectomy Radiation Therapy (PMRT) Using Nanodot OSLD

April 30, 2015

Skin dose is dependent on patient anatomy, the incident beam geometry, and planning techniques. For example, RapidArc plans with tissue expanders should be monitored for skin dose coverage. In conclusion, the skin dose should be measured to ensure that the clinically desired dose is obtained for the various bolus applications in patients undergoing PMRT.

(P133) Spinal Cord Dose Comparison With and Without Contrast Density Correction on CT Myelogram Simulations for Patients Treated With Stereotactic Body or Conventional Radiotherapy

April 30, 2015

These data suggest that the use of a CT myelogram with simulation significantly underestimates the spinal cord maximum and mean doses. The clinical significance of this finding is uncertain, and this study is limited by its small sample size. Density correction should be further investigated in a larger study, given the high doses used in SBRT and potential morbidity of spinal cord injury.

(P144) Radiation-Associated Toxicities in Obese Women With Endometrial Cancer: More Than Just BMI?

April 30, 2015

The impact of obesity on adjuvant treatment is poorly understood. Increasing BMI was associated with increased frequency of gynecologic and cutaneous radiation-associated toxicities. Additional studies to critically evaluate the radiation treatment dosing and treatment fields in obese EC patients are warranted to identify strategies to mitigate the radiation-associated toxicities in these women.

(P135) Quantitative Assessment of Target Delineation Variability for Thymic Cancers: Agreement Evaluation of a Prospective Segmentation Challenge

April 30, 2015

Expert agreement for definitive-case volumes was exceptionally high, although significantly lower agreement was noted postoperatively. Technique and dose prescription between experts were substantively consistent, and these preliminary results will be utilized to create an expert-consensus contouring atlas to aid the nonexpert radiation oncologist in the planning of these challenging, rare tumors.

(P139) Clinical Outcomes and Patient-Reported Outcomes After Local Treatment for High-Risk, Localized Prostate Cancer

April 30, 2015

Long-term CaP-specific survival is equally high after RT + ADT and RP + RT in clinically high-risk CaP patients. Further investigation should be aimed at integrating quality of life measures when considering the optimal treatment for men with high-risk CaP.

(P140) Clinical Predictors of Survival for Patients With Stage IV Cancer Referred to Radiation Oncology

April 30, 2015

These data suggest that a model that considers performance status, extent of disease, serum albumin, mental status, and primary tumor site represents a clinically relevant tool in radiation oncology to predict survival for patients with stage IV cancer.

(P143) Multisite Review of Twenty-Six Head and Neck Cancer Patients Who Have Developed Osteoradionecrosis: Location, Etiology, and Treatment

April 30, 2015

All patients in this review developed ORN in the posterior aspect of the mandible. Neither the specific systemic agent (Erbitux or chemotherapy) nor the manner in which the agent was delivered (induction vs concurrent) appeared to increase the risk of ORN. It is hoped that having a better understanding as to the location, etiology, and treatment of ORN will help to minimize this potentially devastating complication for future generations of head and neck cancer patients.

(P142) Older Patients Derive Greater Benefit From Adjuvant and Neoadjuvant Radiotherapy in Diverse Solid Malignancies

April 30, 2015

This is the largest analysis to date examining the effects of RT in a broad population of solid tumor patients. Although we were unable to control for chemotherapy use in this cohort, RT was associated with superior oncologic outcome compared with surgery alone among patients with multiple solid malignancies. This positive effect was most pronounced in older patients with breast and rectal cancer, suggesting age-dependent effects of RT.

(P056) Ten-Year Outcomes of Patients With Gleason Score 9/10 Prostate Cancer Treated With Trimodality Therapy

April 30, 2015

In this large, retrospective series, we report very good long-term oncologic outcomes and minimal toxicity in patients with GS 9/10 prostate cancer treated with combination EBRT, LDRBT, and ADT. Trimodality therapy is a well-tolerated and effective treatment for these very-high-risk patients.

(P059) Trends in the Utilization of Radiotherapy in the Management of Renal Cell Carcinoma

April 30, 2015

There has been a decrease in the use of radiotherapy for patients with localized RCC, although patients with more aggressive disease were more likely to receive radiation. Modern trials are needed to better identify the role of radiation in the management of these patients.

(P060) Impact of Major Psychiatric Disorders on Tolerance and Outcomes for Men With Prostate Cancer Undergoing Dose-Escalated Radiation Therapy

April 30, 2015

This study did not find any significant differences in treatment tolerance or any outcome endpoints between men with and without psychiatric disorders undergoing definitive radiation treatment for prostate cancer. This finding suggests that early diagnosis and reduced barriers to definitive treatment will alleviate the decreased cancer-specific mortality in this patient population.

(P063) Can Some High-Risk Prostate Cancer Patients Be Treated With a Shorter Course of Androgen Deprivation Therapy (ADT)?

April 30, 2015

This study suggests that certain patients with high-risk prostate cancer may be effectively treated with a shorter course of hormone ablation therapy. Longer follow-up and more patients will be needed to verify the efficacy of a shorter course of hormone ablation therapy in this patient population.

(P064) Outcomes After Adjuvant Radiation Therapy for Prostate Cancer at a Comprehensive Cancer Center

April 30, 2015

At a comprehensive cancer center, men who are referred for adjuvant RT often have margin involvement and/or ECE. Patients did well overall, with high 5- and 10-year freedom from failure. Only Gleason 8/9 disease was associated with increased failure after adjuvant RT.

(P065) Lack of Variation in Pathologic Upgrading and Upstaging by Race Among Patients With Low-Risk Prostate Cancer

April 30, 2015

Our analysis of this large, population-based database demonstrates that after accounting for other demographics and clinical factors at diagnosis, race does not predict for pathologic upgrading or pathologic upstaging at the time of prostatectomy among patients with low-risk prostate cancer. As such, race by itself should not be used to select potential candidates for active surveillance or treatment.

(S044) Patient-Reported Quality of Life After Stereotactic Body Radiotherapy (SBRT), Intensity-Modulated Radiotherapy (IMRT), and Brachytherapy

April 30, 2015

There were slightly smaller declines in bowel QoL after SBRT and slightly larger declines in urinary QoL after brachytherapy. While QoL after SBRT, IMRT, or brachytherapy is largely similar and supports SBRT as a reasonable radiotherapy option for localized prostate cancer, a randomized comparison is needed for the strongest evidence.

(P116) Pain and Radiographic Control After Stereotactic Radiosurgery for Spinal Metastases From Hepatocellular Carcinoma: A Comparison With Other Radioresistant Histologies

April 30, 2015

When treated with SRS to the spine, metastatic HCC has worse pain and radiographic control than other highly radioresistant histologies, suggesting that HCC should be included in the category of highly radioresistant tumors. Whether these lesions may benefit from further dose escalation and/or alternate treatment strategies will be the subject of future studies.

(P066) Dosimetric Analysis of Proton Therapy for Prostate Cancer: A Single Institutional Experience

April 30, 2015

Proton therapy for prostate cancer typically generates treatment plans that are below dose constraints defined in the photon literature, with the exception of a small subset of patients. In order to promote the best possible proton treatment plans, lower dose constraints for OARs should be considered.

(P067) The Role of Offline PET-CT Imaging in Evaluating the Particle Beam Range and Beam Stop for Prostate Cancer Treated With Heavy Ion Therapy

April 30, 2015

Posttreatment offline PET-CT imaging has the potential to evaluate the particle beam range and beam stop for prostate cancer patients treated with heavy ion therapy, which might overcome the pitfalls of simple bone structure fusions with two-dimensional imaging, and provides another approach to monitor the treatment accuracy of prostate cancer treated with carbon ion therapy. Further investigation needs to be performed.

(P069) Gleason 7 Prostate Adenocarcinoma Treated With High- or Low-Dose-Rate Brachytherapy: Impact of External Beam Radiotherapy and/or Androgen Deprivation Therapy

April 30, 2015

nPSA has been related to biochemical progression–free survival, freedom from metastasis, and death from prostate cancer. BT with either EBRT or HT achieves a lower PSA nadir. There was no difference in disease failure. Longer follow-up may be necessary to see differences in disease failure in this population.

(P071) Socioeconomic Disparities in Baseline Magnetic Resonance Imaging (MRI) Utilization and Imaging Characteristics for Prostate Cancer (PCa) Patients Undergoing Radiotherapy

April 30, 2015

In this urban, academic center cohort, PCa patients of lower SES were significantly less likely to undergo staging MRI, particularly in the low-risk group. No differences were found in dominant IPL presence, area, ECE, or SVI, except in the low-risk group. Further investigation is required to better understand trends in pretreatment MRI utilization and dominant IPL characteristics differing by SES.

(P072) Analysis of Composite EQD2 Dose Distribution in Radiotherapy for Cervical Cancer Using Central Shielding Technique

April 30, 2015

Three-dimensional composite dose distribution analysis plays a significant role in the correct understanding of the dose distribution of the combination of EBRT and ICBT for cervical cancer. The use of CS in radiotherapy for cervical cancer provided tumor doses higher than those referred by the Point-A dose in previous reports, with no irregularly “cold” regions around the central target.

(P073) Optimal Epidural Analgesia During Interstitial Brachytherapy for Treatment of Gynecological Cancer

April 30, 2015

Epidural analgesia provides safe and effective pain control in patients undergoing ISBT. Epidural delivery of narcotics with ropivacaine improves pain control and lowers oral and intravenous narcotic requirements without increased risk of adverse effects.

(P074) The Use of Stereotactic Body Radiotherapy in Lieu of Brachytherapy in Patients With Cervical or Endometrial Cancer

April 30, 2015

SBRT boost appears to be an effective and well-tolerated alternative treatment method for patients with gynecologic malignancies who cannot undergo brachytherapy. Target coverage and dose to organs at risk with SBRT appear to be comparable with those of brachytherapy. Acute toxicity is minimal. These initial clinical results substantiate the need for further evaluation of this treatment approach and its long-term efficacy and safety.

(P075) Management of Nodal Recurrences of Endometrial Cancer With IMRT

April 30, 2015

Long-term survival can be achieved following salvage radiation for nodal recurrence of endometrial cancer. However, central and distant recurrences remain a challenge. Chemotherapy prior to radiation was associated with an increased rate of central recurrences and reduced survival, while the use of concurrent chemotherapy was associated with higher rates of survival.

(P076) Postoperative Treatment Recommendations for Stage I Endometrial Cancer: A Survey of Society of Gynecologic Oncology Members

April 30, 2015

BT is the most common AT modality recommended by SGO members in the postoperative management of stage I EC. CT was recommended in a substantial number of scenarios and even exceeded the use of EBRT in G3 disease. Although there was generally agreement about the management of low-risk EC, there was much more variability in high-intermediate–risk patients. Further studies are needed to compare these SGO members’ recommendations with those of radiation oncologists and to determine optimal management.

(P077) Defining the Pendulum Swing From Whole-Pelvic Radiation Therapy (WPRT) Alone to Vaginal Brachytherapy (VB) in the Adjuvant Setting for Endometrial Cancer: A SEER-Based Analysis From Years 2000–2011

April 30, 2015

This SEER study demonstrates the pronounced increase in the utilization of VB over WPRT alone in the adjuvant setting for endometrial cancer. This observation may spark critical evaluation of US practice patterns seen from 2000 to 2011 and its potential impact on cost, new policies, and the patient’s quality of life.

(P080) Favorable Outcomes Using Radiation Therapy After Chemotherapy in the Management of Primary, Recurrent, and Metastatic Ovarian Cancer

April 30, 2015

The use of RT for primary or recurrent ovarian cancer is well tolerated, with durable rates of FFP. RT with palliative intent achieved high rates of symptom palliation without much additional toxicity. RT should be considered for patients with advanced ovarian cancer.

(P083) Concurrent Chemotherapy + IMRT in Locally Advanced Squamous Cell Carcinoma of Head and Neck: What Is the Appropriate Chemotherapy?

April 30, 2015

Cetuximab may be considered as an alternative to cisplatin with concurrent RT, particularly for patients with locally advanced head and neck squamous cell carcinoma who are not candidates for platinum therapy. These results indicate no difference in patterns of local or distant failure between cetuximab, low-dose weekly cisplatin, or q3 weekly high-dose cisplatin in this patient population.

(P082) Outcomes of Definitive Radiotherapy for T2N0 Squamous Cell Carcinoma of the Glottis: A Single-Institution Retrospective Study

April 30, 2015

Excellent 5-year oncologic and functional outcomes were achieved for patients presented in the study. The use of altered fractionation, concurrent chemotherapy, and different radiation techniques did not show any significant differences in outcomes. However, the reduced radiation dose delivered to the carotid arteries using IMRT suggests that it is potentially advantageous for reduction of long-term vascular toxicity and is therefore recommended as the treatment of choice.

(P078) Radiation Therapy in the Management of Carcinosarcoma of the Uterus

April 30, 2015

Pelvic radiation reduces the risk of pelvic relapse in patients with MMMT and may be indicated with patients at high risk for pelvic recurrence, including patients with cervical involvement, heterologous elements, and stage III disease.

(P091) Sarcopenia/Cachexia Is Associated With Reduced Survival and Locoregional Control in Head and Neck Cancer Patients Receiving Radiotherapy: Results From Quantitative Imaging Analysis of Lean Body Mass

April 30, 2015

We confirm that analysis of routine CT scans for sarcopenia can predict outcomes for HNSCC patients. Pre-RT sarcopenia is associated with more poor outcomes for nonoperated patients and post-RT sarcopenia for all HNSCC patients. Post-RT sarcopenia, as measured by routine CT, outperformed simple weight loss and BMI-derived cachexia metrics, because loss of lean muscle mass can occur independently of BMI status. These findings suggest the potential benefit for investigating intervention with aggressive nutritional and physiatric methods to prevent sarcopenia during RT and to study how these interventions might affect outcomes in nonoperated, pre-RT sarcopenia patients.

(P090) Pediatric Metastatic Odontogenic Ghost Cell Carcinoma: A Multimodal Treatment Approach

April 30, 2015

OGCC can exhibit aggressive progression, warranting investigation into multimodal therapy. Given that adjuvant chemoradiation and immunotherapy are associated with improved outcomes in primary head and neck cancer, a similar application in OGCC may help guide optimal treatment. This approach was well tolerated in our pediatric patient, and he remains disease-free at 14 months.

(P084) Long-Term Functional and Oncologic Outcomes of Esthesioneuroblastoma

April 30, 2015

ENB is a rare malignancy, with optimal management remaining uncertain. Our experience suggests that aggressive management seems successful in providing sustained LRC with acceptable long-term toxicity. The role of elective nodal irradiation to the upper neck remains unclear.

(P086) Proton vs Photon/Electron-Based Therapy in the Treatment of Pediatric Salivary Gland Tumors: A Comparison of Dosimetric Data and Acute Toxicities

April 30, 2015

This report of adjuvant RT for pediatric salivary gland tumors is one of the largest to date and the only one to document outcomes following proton therapy. Compared with conventional photon/electron-based therapy, proton therapy significantly reduced doses to multiple normal tissues. Moreover, clinically, no grade 3 toxicities were observed in the proton group vs 45% in the photon/electron cohort. Continued follow-up is required to determine long-term outcomes.

(P088) Nonadherence to NCCN Guidelines Negatively Impacts Survival in Early-Stage Squamous Cell Carcinoma of the Larynx

April 30, 2015

NCCN guidelines were not followed in 9.4% of patients with early-stage LSCC in 2011, because chemotherapy was added to their RT-based regimen. In these patients, the addition of chemotherapy reduced patient survival by 18%. These results indicate the importance of adherence to NCCN guidelines when prescribing RT-based regimens in the early-stage LSCC setting.

(P089) p16 as a Complementary Prognostic Marker for EBV-Positive Nasopharyngeal Carcinoma

April 30, 2015

Our results suggest that p16 overexpression can act as a marker for PFS and LRC in EBV-positive nasopharyngeal carcinoma patients. This interesting finding raises the possibility of further stratifying more aggressive phenotypes within EBV-positive tumors. Therefore, molecular testing of p16 expression may complement EBV status to provide more detailed and comprehensive guidance in determining the prognosis and predicting treatment outcomes for patients diagnosed with nasopharyngeal carcinoma.

(P092) Definitive Chemoradiotherapy or Radiotherapy for Unresectable, Very Locally Advanced, or Medically Inoperable Paranasal Sinus and Nasal Cavity Cancer

April 30, 2015

Definitive CRT or RT is feasible for unresectable, very locally advanced, or medically inoperable PNS/NC cancer with minimal late toxicity. Local disease control is encouraging, with acceptable treatment-related complications, when treating with the described two-phase IMRT treatment technique.