3D-Conformal Radiation vs Helical Tomotherapy in Prostate Cancer

In this study we are comparing two forms of radiotherapy. This study is being done because it is not clear at present time whether intensity modulated radiotherapy (IMRT) can reduce side effects of radiotherapy compared to standard radiotherapy (called 3D-Conformal Radiotherapy).

Radical radiation therapy plays an important role in the management of prostate cancer, yielding comparable long-term outcomes to surgery. Unfortunately, long term disease free survival data using PSA criteria have shown that less than 50% of high-risk patients are free of disease at 10 years. To improve on the results of conventional dose radiotherapy dose escalation with three-dimensional conformal radiation has been employed. Due to the irregular shape of the prostate and the variable motion of this organ there is substantial radiation of adjacent normal surrounding tissue during treatment which results in radiation-induced toxicity. Intensity-modulated radiation therapy (IMRT) is a new form of radiation therapy. Preliminary evidence suggests that IMRT improves the dose distribution during radiation therapy of the prostate. The hypothesis of this study is that IMRT delivered using Helical Tomotherapy can reduce late toxicity of radical radiotherapy as compared to three-dimensional conformal radiation (3DCRT) in high-risk prostate cancer patients.