Effect of 125I permanent implant brachytherapy on clinically localized prostate cancer / 肿瘤研究与临床

ABSTRACT

Objective To analyze oncological outcomes of 125I permanent implant brachytherapy (125I-PIB) in clinically localized prostate cancer. Methods Between June 2008 and June 2015, 121 patients with clinically localized prostate cancer were treated with 125I-PIB, and their average age was 72.37 years old. Before treatment, the average prostate-specific antigen (PSA) level was 17.7 ng/ml, prostate volume was (51.4 ±15.0) cm3, the International Prognostic Scoring System (IPSS) score was (21.6 ±2.4) scores. The intermediate-risk and high-risk patients were treated with adjuvant endocrine or supplemental external beam radiotherapy. All patients were followed-up. Biochemical recurrence was defined as the PSA nadir plus 2.0 ng/ml. Results Average follow-up time of the 121 patients was 41.81 months. The prostate volume was (23.1 ± 10.2) cm3, and the IPSS score was (9.7±3.3) scores. Rates of 5-year overall survival, biochemical recurrence-free survival and cancer-specific survival were 86.7 %, 76.7 % and 96.5 %, respectively. 5-year biochemical recurrence-free survival rates were 88.5 %, 67.5 % and 65.2 % in the low-, intermediate-, and high-risk groups, respectively. Biochemical recurrence-free survival did not differ significantly by three risk groups (P=0.103), but the difference between high-risk and low-risk groups was statistically significant (P=0.028). According to multivariate analysis, higher prostate-specific antigen (P=0.021), higher Gleason score (P=0.023) and higher clinical T stage (P=0.037) were the significant covariates associated with biochemical recurrence-free survival. The addition of hormonal therapy or external beam radiation therapy was associated with significantly better outcomes than brachytherapy monotherapy (P=0.036, P=0.027). As for complications, there were 4 cases of surgery (trans-urethral resection of the prostate) and 4 cases of cardiovascular complications. Conclusions The 125I-PIB can bring excellent oncological outcomes and acceptable complications in patients. Adjuvant endocrine or external beam radiotherapy for the intermediate-risk and high-risk patients may improve the outcome. Factors influencing efficacy include the high PSA, Gleason score and clinical T stage.