Rates of rectal toxicity in patients treated with high dose rate brachytherapy as monotherapy compared to dose-escalated external beam radiation therapy for localized prostate cancer. (June 2020)

• Record Type: Journal Article
• Authors: Parzen, Jacob S.; Ye, Hong; Gustafson, Gary; Yan, Di; Martinez, Alvaro; Chen, Peter Y.; Ghilezan, Michel; Sebastian, Evelyn; Limbacher, Amy; Krauss, Daniel J.
• Is Part Of: Radiotherapy and oncology. Volume 147(2020)
• Page Start: 123
• Page End: 129
• Publication Date: 2020-06
• Subjects: Prostate cancer -- High-dose-rate brachytherapy -- Dose-escalated external beam radiation therapy -- Rectal toxicity; Oncology -- Periodicals; Radiotherapy -- Periodicals; Tumors -- Periodicals; Medical Oncology -- Periodicals; Neoplasms -- radiotherapy -- Periodicals; Radiotherapy -- Periodicals; Radiothérapie -- Périodiques; Cancérologie -- Périodiques; Tumeurs -- Périodiques; Electronic journals; 616.9940642
• DOI: 10.1016/j.radonc.2020.03.033
• Languages: English
• ISSNs: 0167-8140

Abstract

Highlights: High dose rate brachytherapy reduces rectal toxicity in prostate cancer treatment. Rectal toxicity lower with brachytherapy than external beam radiotherapy. Biochemical control similar for brachytherapy and external beam radiotherapy. Abstract: Background: Using a prospectively collected institutional database, we compared rectal toxicity following high dose rate (HDR) brachytherapy as monotherapy relative to dose-escalated external beam radiotherapy (EBRT) for patients with localized prostate cancer. Methods: 2683 patients treated with HDR or EBRT between 1994 and 2017 were included. HDR fractionation was 38 Gy/4 fractions ( n = 321), 24 Gy/2 ( n = 96), or 27 Gy/2 ( n = 128). EBRT patients received a median dose of 75.6 Gy in 1.8 Gy fractions [range 70.2–82.8 Gy], using either 3D conformal or intensity modulated radiotherapy (IMRT). EBRT patients underwent 3D image guidance via an off-line adaptive process. Results: Median follow-up was 7.5 years (7.4 years for EBRT and 7.9 years for HDR). 545 patients (20.3%) received HDR brachytherapy and 2138 (79.7%) EBRT. 69.1% of EBRT patients received IMRT. Compared to EBRT, HDR was associated with decreased rates of acute grade ≥2 diarrhea (0.7% vs. 4.5%, p < 0.001), rectal pain/tenesmus (0.6% vs. 7.9%, p < 0.001), and rectal bleeding (0% vs. 1.6%, p = 0.001). Rates of chronic grade ≥2 rectal bleeding (1.3% vs. 8.7%, p < 0.001) and radiation proctitis (0.9% vs. 3.3%, p = 0.001) favored HDR over EBRT. Rates of any chronic rectal toxicity grade ≥2 were 2.4% vs. 10.5% ( p < 0.001) for HDR versus EBRT, respectively. In those treated with IMRT, acute and chronic rates of any grade ≥2 GI toxicity were significantly reduced but remained significantly greater than those treated with HDR. Conclusions: In appropriately selected patients with localized prostate cancer undergoing radiation therapy, HDR brachytherapy as monotherapy is an effective strategy for reducing rectal toxicity.