@thmssllvn, thank you for your suggestion! You are right! Brachytherapy is an attractive alternative and was my first considered alternative to gated SBRT because the seeds are placed in the prostate and travel with it as it moves. Exposure of OAR to radiation toxicity due to prostate movement isn't an issue. I discussed brachytherapy as an option with two radiation oncologists at Mayo Rochester and got mixed recommendations because of my history of moderate LUTS (lower urinary tract symptoms). One didn't think brachytherapy would be a problem with my level of LUTS (14-15 on AUA / IPSS Urinary Symptom Score). One expressed concern. A 2023 study (https://doi.org/10.3390/curroncol30060426) demonstrated an average increase in IPSS scores of 7-13 points for months 3-9 after brachytherapy, gradually reducing to +3-7 points above baseline at 18-24 months. During that period, a patient with pre-treatment moderate to high-moderate lower urinary tract symptoms (LUTS) would have an International Prostate Symptom Score (IPSS) score in the low to upper 20s (Severe) and be at moderate risk for prolonged catheterization. My understanding is that patients with pre-treatment severe LUTS (IPSS scores > 20) are not candidates for brachytherapy without first addressing LUTS. Additionally, my understanding is that the surgical address for LUTS (TURP, HOLEP, TULSA) often precludes brachytherapy in prostates less than 60-70 g because there is not enough remaining prostate tissue to place brachy seeds safely. I may revisit brachytherapy, pending my investigation into gated EBRT.

For others reading this, I am not a doctor. I am educating myself as a patient about treatment options so that I can make the best choice, given my diagnostic classification (Gleason 3/4, grade 2, with no apparent extracapsular involvement) and quality of life (QOL) considerations.