High-dose-rate iridium-192 afterloading therapy combined with external beam radiotherapy for T1c-T3bN0M0 prostate cancer.
OBJECTIVE
To determine the efficacy of radiotherapy (RT) for T1c-T3bN0M0 prostate cancer in a prospective clinical trial of concurrent external beam RT and fractionated iridium-192 high-dose-rate brachytherapy.


METHODS
Included in the study were 98 patients with T1c-T3bN0M0 prostate cancer who were diagnosed between October 1997 and September 2002 and underwent high-dose-rate brachytherapy with external beam RT. Treatment consisted of external beam RT (four ports) to the prostate of 16 fractions of 2.3 Gy to a total dose of 36.8 Gy and high-dose-rate brachytherapy of 4 fractions of 6.0 Gy within 30 hours to a total dose of 24.0 Gy. No patient received adjuvant hormonal therapy after RT.


RESULTS
The most recent prostate-specific antigen level was 0.0 to 3.9 ng/mL (median 0.4). Seven patients (7.1%) developed recurrence and treatment was considered a failure (bone metastasis in two and biochemical failure in five). The overall biochemical disease-free survival (bDFS) rate was 95.9% at 2 years and 92.9% at 5 years. The bDFS rate by T stage was 98.6% at 2 years and 95.9% at 5 years for Stage T1c-T2b and 88.0% and 84.0% for Stage T3a-b, respectively (P = 0.047). The 2-year and 5-year bDFS rate was better in patients with an initial prostate-specific antigen level of less than 20 ng/mL compared with 20 ng/mL or greater (98.6% and 97.1% versus 93.1% and 82.8%, respectively, P = 0.0261). Acute toxicity was mild to moderate (Radiation Therapy Oncology Group grade 1-2) and consisted of cystourethritis or proctitis in 29 (29.6%) of 98 patients.


CONCLUSIONS
With a low complication rate and satisfactory bDFS rates, this combination therapy can be considered an alternative method for clinical Stage T1c-T3b prostate cancer and is expected to improve patient quality of life. Additional long-term follow-up is needed to confirm this treatment.
Jo
Yoshimasa
Y
Department ofUrology, Kawasaki Medical School, Kurashiki-city, Okayama, Japan.
Hiratsuka
Junichi
J
Fujii
Tomohiro
T
Takenaka
Atsushi
A
Fujisawa
Masato
M
D000230:Adenocarcinoma / Q000188:drug therapy / Q000532:radiotherapy*; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000097:blood; D001918:Brachytherapy / Q000009:adverse effects; D003131:Combined Modality Therapy; D003556:Cystitis / Q000209:etiology; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D006801:Humans; D007496:Iridium Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009363:Neoplasm Proteins / Q000097:blood; D009364:Neoplasm Recurrence, Local; D011349:Proctitis / Q000209:etiology; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000209:etiology; D011882:Radiotherapy, High-Energy / Q000009:adverse effects; D016896:Treatment Outcome
D018931:Antineoplastic Agents, Hormonal; D014408:Biomarkers, Tumor; D007496:Iridium Radioisotopes; D009363:Neoplasm Proteins; D017430:Prostate-Specific Antigen