Intensity-Modulated Radiation Therapy With or Without Decreased Radiation Dose to Erectile Tissue in Treating Patients With Stage II Prostate Cancer

Intensity-Modulated Radiation Therapy With or Without Decreased Radiation Dose to Erectile Tissue in Treating Patients With Stage II Prostate Cancer

Outcomes Following Intensity Modulated Radiation Therapy With And Without Erectile Tissue Dose Sparing For Favorable To Intermediate Risk Prostate Cancer

RATIONALE: Radiation therapy uses high-energy x-rays to damage tumor cells. Intensity-modulated radiation therapy (radiation directed at the tumor more precisely than in standard radiation therapy) may reduce damage to healthy tissue near the tumor. It is not yet known whether reducing the dose of radiation to erectile tissue will help prevent erectile dysfunction. PURPOSE: This randomized phase III trial is studying intensity-modulated radiation therapy alone to see how well it works compared to intensity-modulated radiation therapy with reduced doses to erectile tissue in treating patients with stage II prostate cancer.

OBJECTIVES: Primary Compare erectile dysfunction in patients with stage T1b-T2c adenocarcinoma of the prostate after treatment with intensity-modulated radiotherapy with vs without dose sparing for erectile tissue. Secondary Compare biochemical freedom from failure rates, as a measure of prostate cancer control, in patients treated with these regimens. Compare the quality of life of patients treated with these regimens. Determine the association of molecular markers and biochemical freedom from failure rate and other endpoints in patients treated with these regimens. OUTLINE: This is a randomized, single-blind study. Patients are stratified according to age (≤ 65 vs > 65), prescription radiotherapy dose (74 Gy vs 76 Gy), and frequency of erection during sexual activity within the past 4 weeks (a few times vs sometimes vs most times to always). Patients are randomized to 1 of 2 treatment arms. Arm I: Patients undergo conventional intensity-modulated radiotherapy (IMRT) once daily 5 days a week for approximately 7.5 weeks. Arm II: Patients undergo IMRT with dose restriction to erectile tissue once daily 5 days a week for approximately 7.5 weeks. Treatment in both arms continues in the absence of unacceptable toxicity or disease metastasis. Quality of life is assessed at baseline, at 6 and 12 months, and then annually for 4 years Patients are followed at 3 months and then every 6 months thereafter. PROJECTED ACCRUAL: A total of 200 patients (100 per treatment arm) will be accrued for this study within 2.5 years.

sexual dysfunction, sexuality and reproductive issues, adenocarcinoma of the prostate, stage IIB prostate cancer, stage IIA prostate cancer

Patients undergo conventional intensity-modulated radiotherapy (IMRT) once daily 5 days a week for approximately 7.5 weeks.

Patients undergo IMRT with dose restriction to erectile tissue once daily 5 days a week for approximately 7.5 weeks.

Patients undergo conventional intensity-modulated radiotherapy (IMRT) once daily 5 days a week for approximately 7.5 weeks.

Postage Stamp Test -A row of stamps is placed around the base of the penis and the ends are moistened and joined. If the circle is broken in the morning then the subject was recorded as having had a nocturnal erection International Index of Erectile Function (IIEF) Questionnaire 15-item questionnaire that measures erectile function Includes companion questionnaire which measures how the partner feels her sexual relationship with the patient has changed since his cancer diagnosis and therapy

Patients without documented failure will undergo needle biopsy of the prostate. A minimum of 12 core biopsies will be taken and additional biopsies will be taken from any suspicious areas (ultrasound or palpation) and/or the original site of biopsy confirmation of prostate cancer at diagnosis. The 12 biopsy sites include sextant, bilateral lateral base, bilateral lateral mid-gland and bilateral transition zone. These data will enable us to evaluate the extent of disease eradication, as well as the prognostic significance of positive biopsies in otherwise palpably normal prostate glands after treatment.

DISEASE CHARACTERISTICS: Histologically confirmed adenocarcinoma of the prostate Clinical stage T1b-T2c by palpation Pretreatment prostate-specific antigen ≤ 20 ng/mL Gleason score ≤ 7 Suitable erectile function, defined as a response ≥ score 2 in question #1 of the International Index of Erectile Function Questionnaire No clinical, radiographic, or pathologic evidence of nodal or distant metastatic disease PATIENT CHARACTERISTICS: Age Not specified Performance status Zubrod 0-1 Life expectancy Not specified Hematopoietic Not specified Hepatic Not specified Renal Not specified Other Fertile patients must use effective contraception No other active malignancy within the past 5 years except nonmetastatic skin cancer or early-stage chronic lymphocytic leukemia (well-differentiated small cell lymphocytic lymphoma) No other medical condition that would preclude study participation PRIOR CONCURRENT THERAPY: Biologic therapy Not specified Chemotherapy Not specified Endocrine therapy Prior androgen-ablation therapy allowed provided total calculated duration ≤ 4 months Radiotherapy No prior pelvic radiotherapy Surgery No prior or planned radical prostate surgery