High-dose-rate interstitial brachytherapy as a monotherapy for localized prostate cancer: treatment description and preliminary results of a phase I/II clinical trial.
OBJECTIVE
To improve results for localized prostate cancer, a prospective clinical trial of hyperfractionated Iridium-192 high-dose-rate (HDR) brachytherapy as a monotherapy was initiated.


METHODS
Between May 1995 and September 1998, 22 implants were performed on 22 patients with localized prostate cancer (T1:T2:T3:T4 = 4:6:9:3) at Osaka University Hospital. Nineteen patients, who had T3-T4 tumors or pretreatment PSA >/= 20.0 ng/mL, received hormone therapy. No patient had external beam radiation. Transperineal needle implants using real-time ultrasound guidance were performed, followed by dose optimization program. Patients were irradiated twice a day, with a time interval of more than 6 h. Total dose was 48 Gy/8 fractions/5 days or 54 Gy/9 fractions/5 days. Acute toxicity was scored using the Radiation Therapy Oncology Group (RTOG) radiation morbidity scoring criteria. Median follow-up time was 31 months.


RESULTS
HDR brachytherapy as a monotherapy was well-tolerated. No significant intra- or peri-operative complications occurred. No patient experienced acute toxicity of grade 3 or more. PSA levels normalized in 95% of patients within 20 months after irradiation. Four-year clinical and biochemical relapse-free rates were 95% and 55%, respectively.


CONCLUSIONS
Acute toxicity with this method was acceptable. Further patient accrual and longer follow-up will allow comparison to other techniques.
Yoshioka
Y
Y
Division of Multidisciplinary Radiotherapy, Biomedical Research Center, Osaka University Graduate School of Medicine, Suita, Osaka, Japan. yoshioka@radonc.med.osaka-u.ac.jp
Nose
T
T
Yoshida
K
K
Inoue
T
T
Yamazaki
H
H
Tanaka
E
E
Shiomi
H
H
Imai
A
A
Nakamura
S
S
Shimamoto
S
S
Inoue
T
T
D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D018572:Disease-Free Survival; D005240:Feasibility Studies; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D018084:Ultrasonography, Interventional; D001749:Urinary Bladder Neoplasms / Q000473:pathology
D017430:Prostate-Specific Antigen