Overview of treatment plan quality in a high dose rate prostate brachytherapy workflow

PURPOSE: High dose rate brachytherapy (HDR-BT) has been shown to be an effective treatment for prostate cancer, with treatment plan quality dependent on a number of factors. In this work, we report on the overall performance of our ultrasound (US)-based workflow and the impact of several treatment-specific variables. METHODS AND MATERIALS: Patients who underwent HDR-BT (boost, monotherapy, and retreatment) using Varian Bravos/US from 2021 to 2023 were sampled for this study. Treatment plan quality was analyzed and plans were categorized with regard to a number of metrics, including: prostate volume, treating physician, planning physicist, number of needles included, estimated planning time, rectum-prostate separation, and bladder-prostate separation. The performance of this program was compared to the performance of our program using previously used RESULTS: Plan quality for our Bravos/US workflow was shown to be consistently above acceptability criteria for all personnel involved; on average: prostate V100%: 98.9% f 0.1%, rectum V75%: 0.04 f 0.01 cc, bladder V75%: 0.06 f 0.01cc, urethra V125%: 0.00 f 0.00 cc. Prostate coverage was statistically improved with this workflow compared to that using our previous modalities. There was a statistical correlation between organ-at-risk sparing/prostate coverage ratio and prostate volume, number of needles/prostate volume, bladder-prostate separation, and rectum-prostate separation. There was no correlation between plan quality and planning time. CONCLUSIONS: Our US-based HDR-BT program led to target coverage and organ-at-risk sparing that exceeded department thresholds. Results were acceptable regardless of the personnel involved and improved plan quality was obtained using more needles/prostate volume and increased spacing between the prostate and the rectum and bladder. (c) 2024 American Brachytherapy Society. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.