ONCOLOGY Vol 19 No 11_Suppl_4

Percutaneous radiofrequency ablation (RFA) of osteoid osteomashas replaced surgical excision as the preferred method for treatment ofthese benign lesions, due to high effectiveness and low morbidity. BothRFA and cryoablation are safe and effective for palliation of pain dueto metastatic disease in patients who have failed conventional therapies.These image-guided treatments can be performed precisely, allowingsafe treatment of complex metastatic tumors. A single ablationtreatment is effective in most patients, is well tolerated, and provides along duration of pain relief.

Although resection currently remains the standard of care for renalcarcinoma, the search for less invasive treatments has led to alternativesurgical approaches. Even less invasive, and appropriate for manygroups of patients, is percutaneous radiofrequency ablation, which inducestumor necrosis via lethal hyperthermia. Multiple series of renaltumors treated with percutaneous ablation in vivo and left in situ havebeen published; these series reveal that for small renal tumors,radiofrequency ablation results in complete necrosis at imaging in 79%to 100% of cases. Because current results come from tumors left in situwith short postablation follow-up, long-term results are necessary tocompare outcomes to surgical standards. Complication rates are lowerthan those following partial nephrectomy. Future reports will shed lighton the long-term outcomes of percutaneous ablation and the relativeadvantages and disadvantages of various technologies for thermal ablation.

Imagine destroying a tumor in 6minutes with a small needle electrodeplaced through the skin intoa tumor deep in the human body-thepatient is cured after spending only afew hours in the hospital and leaveswith just a small bandage. This maysound like science fiction, but it isreality in many medical centers aroundthe world.

Assessing outcome after ablation is difficult because few studies with good long-term followup have evaluated local recurrence, disease-free survival, and overall survival after ablation. This and other limitations make it difficult to draw meaningful conclusions.

Only about 15% of patients diagnosed with lung carcinoma eachyear are surgical candidates, either due to advanced disease orcomorbidities. The past decade has seen the emergence of minimallyinvasive therapies using thermal energy sources: radiofrequency,cryoablation, focused ultrasound, laser, and microwave; radiofrequencyablation (RFA) is the best developed of these. Radiofrequency ablationis safe and technically highly successful in terms of initial ablation.Long-term local control or complete necrosis rates drop considerablywhen tumors are larger than 3 cm, although repeat ablations can beperformed. Patients with lung metastases tend to fare better with RFlung ablation than those with primary lung carcinoma in terms of localcontrol, but it is unclear if this is related to smaller tumor size at time oftreatment, lesion size uniformity, and sphericity with lung metastases,or to differences in patterns of pathologic spread of disease. The effectsof RFA on quality of life, particularly dyspnea and pain, as well aslong-term outcome studies are generally lacking. Even so, the resultsregarding RF lung ablation are comparable to other therapies currentlyavailable, particularly for the conventionally unresectable or high-risklung cancer population. With refinements in technology, patient selection,clinical applications, and methods of follow-up, RFA will continueto flourish as a potentially viable stand-alone or complementarytherapy for both primary and secondary lung malignancies in standardand high-risk populations.