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.
(P115) The Experience of a Radiation Oncology Center in Gauging the Use of Single-Fraction Radiotherapy for Painful Bone Metastases
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.
(P135) Quantitative Assessment of Target Delineation Variability for Thymic Cancers: Agreement Evaluation of a Prospective Segmentation Challenge
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.
(P063) Can Some High-Risk Prostate Cancer Patients Be Treated With a Shorter Course of Androgen Deprivation Therapy (ADT)?
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.
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.
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.
(P004) A Retrospective Study to Assess Disparities in the Utilization of Intensity-Modulated Radiotherapy (IMRT) and Proton Therapy (PT) in the Treatment of Prostate Cancer (PCa)
Disparities exist in PT utilization compared with IMRT by age, race, and SES and merit further investigation.
(P016) The Cell Cycle Inhibitor P21 Regulates Langerhans Cell Radiation Resistance and PromotesT Regulatory Cell Induction Upon Exposure to Radiotherapy
Future analyses will seek to elaborate the functional implications of LCs and IR-sensitive DC IR-exposure as it relates to the priming and development of graft-versus-host disease (GVHD) and local antitumor immunity following radiation therapy.
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.
(S033) Predictive Capacity of Three Comorbidity Indices in Estimating Survival Endpoints in Women With Early-Stage Endometrial Carcinoma
While all three comorbidity indices correlated significantly with OS in women with early-stage EC, AACCI was the only independent predictor of OS and should be considered for evaluating comorbidity in future endometrial cancer patients.