Rectal Hydrogel Spacer Improves Late Gastrointestinal Toxicity Compared to Rectal Balloon Immobilization After Proton Beam Radiation Therapy for Localized Prostate Cancer: A Retrospective Observational Study.

Autor:	Dinh TT; Department of Radiation Oncology, University of Washington, Seattle, Washington. Electronic address: tktdinh@uw.edu., Lee HJ Jr; Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts., Macomber MW; Sutter Health Radiation Oncology, Sacramento, California., Apisarnthanarax S; Department of Radiation Oncology, University of Washington, Seattle, Washington., Zeng J; Department of Radiation Oncology, University of Washington, Seattle, Washington., Laramore GE; Department of Radiation Oncology, University of Washington, Seattle, Washington., Rengan R; Department of Radiation Oncology, University of Washington, Seattle, Washington., Russell KJ; Department of Radiation Oncology, University of Washington, Seattle, Washington., Chen JJ; Department of Radiation Oncology, University of Washington, Seattle, Washington., Ellis WJ; Department of Urology, University of Washington, Seattle, Washington., Schade GR; Department of Urology, University of Washington, Seattle, Washington., Liao JJ; Department of Radiation Oncology, University of Washington, Seattle, Washington.
Jazyk:	angličtina
Zdroj:	International journal of radiation oncology, biology, physics [Int J Radiat Oncol Biol Phys] 2020 Nov 01; Vol. 108 (3), pp. 635-643. Date of Electronic Publication: 2020 Feb 06.
DOI:	10.1016/j.ijrobp.2020.01.026
Abstrakt:	Purpose: Our purpose was to compare dosimetric parameters and late gastrointestinal outcomes between patients treated with proton beam therapy (PBT) for localized prostate cancer with rectal balloon immobilization versus a hydrogel rectal spacer. Methods and Materials: Patients with localized, clinical stage T1-4 prostate adenocarcinoma were treated at a single institution using conventionally fractionated, dose-escalated PBT from 2013 to 2018. Patient-reported gastrointestinal toxicity was prospectively collected, and the incidence of rectal bleeding was retrospectively reviewed from patient records. Results: One hundred ninety-two patients were treated with rectal balloon immobilization, and 75 were treated with a rectal spacer. Rectal hydrogel spacer significantly improved rectal dosimetry while maintaining excellent target coverage. The 2-year actuarial rate of grade 2+ late rectal bleeding was 19% and 3% in the rectal balloon and hydrogel spacer groups, respectively (P = .003). In univariable analysis, the probability of grade 2+ rectal bleeding was significantly correlated with increasing rectal dose. In multivariable analysis, only receipt of spacer hydrogel (hazard ratio, 0.145; P = .010) and anticoagulation use (hazard ratio, 5.019; P < .001) were significantly associated with grade 2+ bleeding. At 2-year follow-up, patient-reported Expanded Prostate Cancer Index Composite bowel quality of life composite scores were less diminished in the hydrogel spacer group (absolute mean difference, 5.5; P = .030). Conclusions: Use of rectal hydrogel spacer for prostate PBT is associated with a significantly lower incidence of clinically relevant, late rectal bleeding and lower decrement in long-term, patient-reported bowel quality of life compared with rectal balloon immobilization. Our results suggest that hydrogel spacer may improve rectal sparing compared with rectal balloon immobilization during PBT for prostate cancer. (Copyright © 2020 Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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