Purpose: To report our experience with 3D conformal radiotherapy for prostate cancer.
Material and methods: We reviewed our first 50 patients diagnosed with prostate cancer. Median follow-up was 27 months (16-40 m). Median age 68 (52-74). T stage was: T1c = 12 ; T2a = 14; T2b = 10; T2c = 2; T3a = 10; T3b = 1 and T3c = 1. Gleason score (GS) 4-6 50% and GS 7-8 50%. Pretreatment PSA value of < 10 ng/ml 36%, 10-20 ng/ml 32% and > 20 ng/ml 32%. Forty patients received androgen ablation therapy 2 to 6 months before radiation. 3D conformal radiotherapy was used to allow a smaller amount of rectum and bladder to be in the high dose volume. An 18 Mv linear accelerator was used. The first 21 patients received 66 Gy, 28 patients received 70 Gy and one 74 Gy.
Results: The mean prostate volume was 45 cc for patients who received androgen ablation and 54 for the others (p = 0.02). The percentage of volume receiving more than 50 Gy (V50) was calculated for the rectum and bladder. The median V50 was 30% (10-55) for the rectum and 36% (5-70) for the bladder. Based on the RTOG grading (gr) for acute toxicity, there was no gr 3 gastrointestinal (GI) toxicity and only 1 gr 3 genitourinary (GU) toxicity. There were 9 gr 1 and 5 gr 2 GI toxicity, 10 gr 1 and 5 gr 2 GU toxicity. With our actual follow-up we have 2 late morbidities: gr 2 GU and one erectile failure.
Conclusion: 3D conformal radiotherapy for prostate cancer has a good toxicity profile. Longer follow-up is needed to assess late toxicity and clinical outcome in this series.