Radiation Therapy in Treating Patients With Stage II or Stage III Prostate Cancer

OBJECTIVES:

Primary

- Determine the rate of late grade 3 or greater genitourinary and gastrointestinal
toxicity after treatment with external beam radiotherapy and high-dose rate
brachytherapy in patients with stage II or III adenocarcinoma of the prostate.

Secondary

- Determine acute grade 3 or greater genitourinary and gastrointestinal toxicity in
patients treated with this regimen.

- Determine freedom from biochemical failure in patients treated with this regimen.

- Determine overall survival of patients treated with this regimen.

- Determine disease-specific survival of patients treated with this regimen.

- Determine clinical relapse (local and/or distant) in patients treated with this
regimen.

- Develop a quality assurance process for high-dose rate prostate brachytherapy.

OUTLINE: This is a multicenter study. Patients are stratified according to prostate-specific
antigen (≤ 10 ng/mL vs 11-20 ng/mL), T stage (T1c-T2c vs T3a-T3b), combined Gleason score
(2-6 vs 7 vs 8-10), prior hormonal therapy (no vs yes), and timing of high-dose rate
brachytherapy (before external beam radiotherapy vs after external beam radiotherapy).

Patients undergo external beam radiotherapy over approximately 15 minutes once daily 5 days
a week for 5 weeks. Patients also receive two fractions (within a 24-hour period) of
high-dose rate brachytherapy (delivered through an implant inserted into the prostate) over
approximately 5-30 minutes either before or after external beam radiotherapy. Treatment
continues in the absence of disease progression or unacceptable toxicity.

Patients are followed at 3, 7, 9, and 12 months, every 6 months for 5 years, and then
annually thereafter.

PROJECTED ACCRUAL: A total of 110 patients will be accrued for this study within 1 year.

DISEASE CHARACTERISTICS:

- Histologically confirmed adenocarcinoma of the prostate

- Clinical stage T1c-T3b

- No clinically or pathologically involved lymph nodes (N0 by pelvic CT scan or
MRI)

- No distant metastases (M0 by negative bone scan)

- Meets one of the following combination criteria:

- Clinical stage T1c-T2c, Gleason score 2-6, and prostate-specific antigen (PSA) >
10 but ≤ 20 ng/mL

- Clinical stage T3a-T3b, Gleason score 2-6, and PSA ≤ 20 ng/mL

- Clinical stage T1c-T3b, Gleason score 7-10, and PSA ≤ 20 ng/mL

PATIENT CHARACTERISTICS:

Age

- 18 and over

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 hip prosthesis

- No major medical or psychiatric illness that would preclude study participation

- No prior invasive malignancy except nonmelanomatous skin cancer (e.g., carcinoma in
situ of the oral cavity or bladder) or any other malignancy with a disease-free
status ≥ 3 years

PRIOR CONCURRENT THERAPY:

Biologic therapy

- Not specified

Chemotherapy

- No prior chemotherapy for prostate cancer

Endocrine therapy

- Prior induction hormonal therapy allowed provided therapy was initiated within 90
days before study enrollment

Radiotherapy

- No prior pelvic or prostate radiotherapy

- No concurrent intensity-modulated radiotherapy

Surgery

- No prior radical surgery for prostate cancer

- No prior transurethral resection of the prostate