Brachytherapy versus external beam radiotherapy boost for prostate cancer: Systematic review with meta-analysis of randomized trials.

BACKGROUND: Brachytherapy boost after external beam radiotherapy for intermediate and high-risk prostate cancer is presented as an attractive technique in numerous retrospective and prospective studies. Currently, three randomized controlled trials comparing brachytherapy versus external beam radiotherapy boost used non-homogenous irradiation features. Therefore, we analyzed the oncological outcomes by a systematic review with meta-analysis of the randomized controlled trials.

METHODS: We performed a systematic literature review of MEDLINE and COCHRANE databases up to 30/04/10 and we considered all published randomized controlled trials comparing brachytherapy versus external beam radiotherapy boost for intermediate and high-risk prostate cancer according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. The review was assessed using Assessing the Methodological Quality of Systematic Reviews (AMSTAR) tool and the identified reports were reviewed according to the Consolidated Standards of Reporting Trials (CONSORT). Eight publications from 3 RCTs were selected.

RESULTS: There was a significant benefit in 5-year biochemical-progression-free survival in favor of BT versus EBRT boost (HR: 0.49 [95% CI, 0.37-0.66], p < 0.01). There was no difference at 5 years in overall survival (HR: 0.92 [95% CI, 0.64-1.33], p = 0.65), ≥ grade 3 late genito-urinary (RR: 2.19 [95%CI, 0.76-6.30], p = 0.15) and late gastro-intestinal toxicities (RR: 1.85 [95%CI, 1.00-3.41] p = 0.05).

CONCLUSION: This meta-analysis provides further evidence in favor of BT boost for intermediate and high-risk prostate cancer in terms of b-PFS improvement, leading to suggest BT boost as level I and grade A recommendation. However, the risk of grade ≥ 3 late toxicity must be carefully investigated.