Dose escalation in locally advanced carcinoma of the prostate

Radiotherapeutic management of advanced prostate cancer is challenging. Several retrospective analyses showed a dose response for local tumor control before the availability of conformal radiation therapy. Attempts to escalate dose without the benefit of modern treatment planning was commonly fraught with high rates of bowel or bladder complications. The advent of image-guided or computed tomography-based treatment planning has allowed safe delivery of high-dose radiation therapy in men with prostate cancer with an acceptable rate of side effects and complications. Several prospective clinical trials have been conducted both at single institutions and in the cooperative group setting. Early evidence suggests that patients with high-risk factors such as advanced clinical stage, high initial prostate-specific antigen, or poorly differentiated tumors may benefit from high-dose 3-dimensional conformal radiation therapy with improved biochemical and local tumor control. A published randomized trial with conformal radiation therapy shows that a modest escalation of radiation dose leads to improved biochemical disease-free survival for a select group of patients. A confirmatory trial within the Radiation Therapy Oncology Group is underway to determine if dose escalation will improve overall survival in men without compromising quality of life.