Interstitial Brachytherapy With or Without External-Beam Radiation Therapy in Treating Patients With Prostate Cancer
Interstitial Brachytherapy With or Without External-Beam Radiation Therapy in Treating Patients With Prostate Cancer
RATIONALE: Radiation therapy uses high-energy x-rays and other sources to damage tumor cells.
 Interstitial brachytherapy uses radioactive material placed directly into or near a tumor to
 kill tumor cells. Combining interstitial brachytherapy with external-beam radiation therapy
 may kill more tumor cells. It is not yet known whether interstitial brachytherapy is more
 effective with or without external-beam radiation therapy in treating prostate cancer.

 PURPOSE: Randomized phase III trial to compare the effectiveness of interstitial
 brachytherapy with or without external-beam radiation therapy in treating patients who have
 prostate cancer.
OBJECTIVES:

 -  Compare the 5-year freedom from progression in patients with intermediate-risk prostate
 cancer treated with interstitial brachytherapy with or without external beam
 radiotherapy (EBRT).

 -  Compare biochemical (i.e., prostate-specific antigen) failure, biochemical failure by
 the Phoenix definition, disease-specific survival, local progression, and distant
 metastases in patients treated with these regimens.

 -  Compare morbidity and quality of life of patients treated with these regimens.

 -  Determine the feasibility of collecting Medicare data in a large Radiation Therapy
 Oncology Group (RTOG) prostate cancer clinical trial for cost effectiveness and cost
 utility analysis of combined treatment with interstitial brachytherapy and EBRT.

 -  Prospectively collect diagnostic biopsy samples from these patients for future biomarker
 analyses.

 OUTLINE: This is a randomized, multicenter study. Patients are stratified according to
 disease stage (T1c vs T2a or T2b), Gleason score (≤ 6 vs 7), prostate-specific antigen (< 10
 ng/mL vs 10-20 ng/mL), and prior neoadjuvant hormonal therapy (yes vs no). Patients are
 randomized to 1 of 2 treatment arms.

 -  Arm I: Patients undergo external beam radiotherapy 5 days a week for 5 weeks. Within 2-4
 weeks of radiotherapy, patients undergo interstitial brachytherapy with iodine I 125 or
 palladium Pd 103 seeds.

 -  Arm II: Patients undergo interstitial brachytherapy only, as in arm I. Quality of life
 is assessed at baseline, at 4, 12, and 24 months, and then annually for 3 years.

 After completion of study treatment, patients are followed at 3-5 weeks, at 4, 6, 9, and 12
 months, every 6 months for 4 years, and then annually thereafter.
DISEASE CHARACTERISTICS:

 -  Histologically confirmed adenocarcinoma of the prostate

 -  T1c-T2b, N0, M0

 -  Intermediate-risk disease, as defined by 1 of the following:

 -  Gleason score < 7 AND prostate-specific antigen (PSA) 10-20 ng/mL

 -  Gleason score 7 AND PSA < 10 ng/mL

 -  No evidence of distant metastases

 -  Prostate volume ≤ 60 cc by transrectal ultrasonography

 -  American Urological Association voiding symptom score no greater than 15 (alpha
 blockers allowed)

 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

 -  Patients must use effective contraception

 -  No other malignancy within the past 5 years except basal cell or squamous cell skin
 cancer or carcinoma in situ at any other site

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

 -  No hip prosthesis

 PRIOR CONCURRENT THERAPY:

 Biologic therapy

 -  Not specified

 Chemotherapy

 -  No prior chemotherapy

 Endocrine therapy

 -  Prior neoadjuvant hormonal therapy allowed provided the following are true:

 -  Therapy was initiated within 2-6 months of study enrollment

 -  Therapy was no more than 6 months in duration

 -  Use of 5-alpha reductase inhibitors (e.g., finasteride) is discontinued before
 registration

 -  No concurrent hormonal therapy

 Radiotherapy

 -  No prior pelvic radiotherapy

 Surgery

 -  No prior radical surgery for prostate cancer

 -  No prior transurethral resection of the prostate

 -  No prior cryosurgery

 Other

 -  No prior transurethral needle ablation of the prostate

 -  No prior transurethral microwave thermotherapy of the prostate