Brachytherapy based microboosting to the dominant intraprostatic lesion in prostate cancer: A systematic review on treatment outcomes and toxicities.

Whether brachytherapy based microboosting of the dominant intraprostatic lesion (DIL) improves outcomes over standard approaches is not known. The purpose of this study is to perform a systematic review on brachytherapy microboosting of the DIL to evaluate clinical outcomes and toxicities with this treatment approach.

This review was performed according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Databases including Pubmed, Embase, and Google Scholar were queried. About 16 studies met our inclusion criteria. These studies reported PSA control and/or toxicities based on standardized scales.

There were 10 studies (two monotherapy, eight combination) that used HDR microboosting on a total of 516 patients. HDR dose (EQD2 assuming alpha/beta of 1.5) to the DIL ranged from 90 to 180 Gy. Most patients were low/intermediate risk. PSA control rates at 5-8 years ranged from 69% to 100%. Acute/late G3-G4 GU/GI toxicities ranged from 0% to 12%. There were six studies (five monotherapy, one combination) that used LDR microboosting on a total of 1041 patients. Studies performed a microboost of 130-150% of the whole gland prescription to the DIL. Most patients were low/intermediate risk. PSA control rates at 5 years ranged from 69% to 98%. Acute/late G3-4 GU/GI toxicities ranged from 0% to 4%.

Over 1000 patients have been treated with a brachytherapy based microboost in published series. Severe acute/late toxicities appear limited. PSA control rates with more than 5 years of follow-up are limited. Longer-term follow-up is needed to determine ideal utilization of this approach.

Brachytherapy. 2024 Jul 29 [Epub ahead of print]

Mehdi Kazemi, Andrew Barsoum, Katelyn M Atkins, Leslie Ballas, Mitchell Kamrava

Department of Internal Medicine, Southwest Healthcare Medical Education Consortium, Temecula, CA. Electronic address: ., Department of Internal Medicine, Southwest Healthcare Medical Education Consortium, Temecula, CA., Cedars Sinai Medical Center, Department of Radiation Oncology, Los Angeles, CA.