[A five-year experience in conformational radiotherapy in the treatment of prostate cancer. Evaluation of acute toxicity in 131 patients]. / Radiothérapie conformationnelle dans le traitement du cancer de la prostate. Evaluation de la toxicité aiguë chez 131 patients.

ABSTRACT

PURPOSE: To evaluate the urinary and rectal toxicity secondary to 3D conformal radiotherapy for prostate cancer. MATERIAL AND METHODS: Between 1998 and 2003, 131 men with prostate cancer underwent 3D conformal radiotherapy with or without androgen deprivation. The different stages were 2 T1b ; 40 T1c; 19 T2a; 16 T2b; 18 T2c; 33 T3a; 1 T3b and 2 T3c with Gleason score 4-6 = 47%, 7 = 36% and 8-9 in 17% of the cases. The median patient age was 66 (48-87). Pretreatment PSA level was respectively < 10 ng/ml (41%). 10-20 ng/ml (30%) and > 20 ng/ml (29%). Of the 131 patients, 98 received androgen ablation therapy before radiation. The total radiation dose varied between 66 and 74 Gy, delivered with 18MV photons of the linear accelerator, the median follow up was 33 months (5-67). RESULTS: According to the RTOG grading (gr) for acute toxicity, we noticed 3gr 3 genitourinary (GU) toxicity and no gr3 gastro intestinal (GI) toxicity. There were 36 gr 1 and 12 gr 2 GI toxicity, 41 gr 1 and 22 gr 2 GU toxicity. The mean prostate volume was 41 cc for patients who received androgen ablation and 56 cc for the others (p < 0.002). The percentage of volume receiving more than 50 Gy (V50) was calculated, the median V50 was 32% (5-67) for the rectum and 35% (5-79) for the bladder CONCLUSION: The toxicity profile in this study is in the same range than those of the literature and of our previous study concerning our first 50 patients with prostate cancer treated with 3D conformal radiotherapy.