[Impact of neoadjuvant hormonal therapy on the permanent ¹²⁵I-seed brachytherapy for localized high-risk prostate cancer].

Objective To evaluate the impact of neoadjuvant hormonal therapy on the permanent transperineal 125I-seed brachytherapy for localized high-risk prostate cancer. Methods Ten patients with T1-T2, localized high-risk prostate cancer were reviewed. The mean level of PSA was (29. 4 ± 12. 6) μg/L (20-50 μg/L) and the mean prostate volume (54 ± 33 ) ml. All cases were sequentially treated on a neoadjuvant hormonal therapy with 1 week of Casodex (50 mg/d) and 3 -10 months( median: 6 months)of Casodex (50 mg/d) with Zoladex (3.6 mg per 4 weeks, SC). Then all patients received the transperineal permanent interstitial 125I-seed implantation brachytherapy by template method. The matched peripheral dose of seed implantation was 145 Gy (median number of 125I seeds: 46), urethral peripheral dose ≤80 Gy and rectal peripheral dose ≤ 60 Gy. The mean operative duration was 1. 75 hours (range: 1 -2. 5 hours ).Results After neoadjuvant hormonal therapy for 3 - 10 months, the PSA level decreased to ( 1. 4 ± 0. 7 )g/L in all patients. The mean prostate volume significantly decreased to (25 ± 10) ml(t-test, P ＜0. 01 ).The Foley tube extracted at Days 3-5 post-brachytherapy. Side effects of mild dysuria (n = 1 ) and urethral irritation ( n = 1 ) were effectively managed by symptomatic treatment. After a median follow-up of 13 months (range: 3 -24), the PSA level was (0.9 ±0.7) μg/L. Conclusion A combination of neoadjuvant hormonal therapy with brachytherapy may lower the PSA level and shrink the prostate volume so as to ensure an effective dose in the target tumor and improve the therapeutic efficacy for localized high-risk prostate cancer. Key words: Prostate neoplasms; Neoadjuvant therapy; 125I-seed; Brachytherapy