| Abstract: |
PURPOSE: This study evaluated outcomes associated with a high-dose-rate (HDR) brachytherapy boost combined with stereotactic body radiation therapy (SBRT) for patients with higher-risk localized prostate cancer. MATERIALS AND METHODS: We identified 101 patients with National Comprehensive Cancer Network high-risk, unfavorable intermediate-risk, or favorable intermediate-risk with probable extra-prostatic extension treated with HDR brachytherapy (15 Gy x 1 fraction) followed by SBRT (5 Gy x 5 daily fractions to the prostate and/or seminal vesicles and/or pelvic lymph nodes). Androgen deprivation therapy was used in 55.4% of all patients (90% of high-risk, 33% of intermediate-risk). Toxicities according to Common Terminology Criteria for Adverse Events (CTCAE) v4.0 and International Prostate Symptom Scores were prospectively documented at each followup visit. Biochemical relapse was defined as PSA nadir +2ng/mL. RESULTS: The median follow-up time after SBRT was 24.1 months. No grade >= 3 toxicities were observed. The incidence of acute and late grade 2 gastrointestinal toxicities was both 0.99%. Acute and late grade 2 genitourinary (GU) toxicities were observed in 5.9% and 9.9%, respectively. Median time to a grade 2 GU toxicity was 6 months with a 14% 2-year actuarial rate of grade 2 GU toxicity. Median International Prostate Symptom Scores at 24 months was not significantly different than baseline (6 vs. 5; p = 0.24). Inclusion of pelvic lymph nodes and absence of a rectal spacer were significantly associated with more frequent grade >= 1 GU toxicity, but not grade >= 2 GU or gastrointestinal toxicity. The 2-year biochemical relapse free survival was 97%. CONCLUSIONS: HDR brachytherapy combined with SBRT was associated with a favorable early toxicity profile and encouraging cancer control outcomes. (C) 2021 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved. |
| Keywords: |
survival; prostate cancer; prostate-specific antigen; intensity-modulated radiotherapy; radiosurgery; boost; therapy; failure; quality-of-life; external-beam radiotherapy; randomized-trial; clinical target volume; composite; high dose rate brachytherapy; stereotactic; escalation; ascende-rt; toxicity. abbreviations: adt, androgen deprivation; ctcae, common terminology criteria for adverse events; ctv,; ebrt, external beam radiation therapy; epe,; extra-prostatic extension; epic, expanded prostate cancer index; gi, gastrointestinal; gu, genitourinary; hdr, high-dose rate; imrt, intensity-modulated radiation therapy; ipss, international; prostate symptom score; ldr, low-dose rate; nccn, national comprehensive; cancer network; oars, organs at risk; pet, positron emission tomography; pfs, progression-free survival; pro, patient-reported outcomes; psa,; psma, prostate-specific membrane antigen; ptv, planning target volume; sbrt, stereotactic body radiation therapy
|
