The purpose of this study is to determine the feasibility and late toxicity of dose escalated radiation therapy to the pelvic lymph nodes and prostate and seminal vesicles in the treatment of high risk prostate cancer. All eligible patients with high risk prostate cancer who are going to have primary radiation therapy to the pelvic lymph nodes and prostate seminal vesicles with or without concurrent hormonal therapy will be approached regarding study entry.

Prostate cancer is now the most commonly diagnosed cancer in Canadian men and is the third most common cause of cancer death.1 Locally advanced prostate cancer (clinical T3/T4) is uncommon in North America because of earlier diagnosis following widespread PSA testing and patient information campaigns. However, in the past decade the term high-risk prostate cancer has been developed to include the previous locally advanced disease and patient with T1/T2 disease with poor prognostic features (either a high Prostate Specific Antigen or high Gleason score). The risk of involvement of pelvic lymph nodes by prostate cancer for certain subgroups of intermediate risk and most high risk prostate cancer may be substantial. The long term results of conventional dose (66-70 Gy) external beam radiation therapy for intermediate and locally advanced prostate cancer have been disappointing. The combination of hormonal therapy and radiation therapy or radiation therapy dose escalation are the two strategies which have been evaluated and are now used to improve these results.

Inclusion Criteria:

• A histologic diagnosis of adenocarcinoma of the prostate within six months of entry.
• Clinical Stage T1-T2 with (PSA >20 or Gleason score >7)
• Clinical Stage T3, T4
• Bone scan reported as negative for metastases within 6 months of study entry.
• All patients must have a CT scan of the abdomen and pelvis reported as negative for nodal metastases within 12 wks of study entry.
• The patient must not have received greater than 6 months of hormonal therapy.
• The patient must not have received cytotoxic anticancer therapy prior to study entry.
• Patients must have an ECOG performance status of 2 or less.
• Age 80 years old or less
• Signed informed consent

Exclusion Criteria:

• Patients with history of inflammatory bowel disease or other contraindication to radical radiation therapy
• Patients with prior colorectal surgery
• Patients with prior or active malignancy except non-melanoma skin carcinoma within 5 years of the diagnosis of prostate cancer