Reduced acute toxicity associated with the use of volumetric modulated arc therapy for the treatment of adenocarcinoma of the prostate

• Type of Material: Article
• Authors: William A Hall, Emory University; Lauren Colbert, Emory University; Dana Nickleach, Emory University; Joseph Shelton, Emory University; David M Marcus, Emory University; Jeffrey Switchenko, Emory University; Peter Rossi, Emory University; Karen Godette, Emory University; Sherrie Cooper, Emory University; Ashesh B Jani, Emory University
• Language: English
• Date: 2013-10-01
• Publisher: Elsevier Inc
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2013 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.prro.2013.01.003
• Title of Journal or Parent Work: Practical Radiation Oncology
• Volume: 3
• Issue: 4
• Start Page: e157
• End Page: e164
• Grant/Funding Information: This work was supported in part by a grant from the Georgia Cancer Coalition and in part by the National Center for Advancing Translational Sciences of the National Institutes of Health under Award Numbers UL1TR000454 and TL1TR000456. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
• Keywords: volumetric modulated arc therapy (VMAT).; adenocarcinoma of the prostate (ACP); genitourinary (GU); intensity modulated radiation therapy (IMRT); gastrointestinal (GI)
• Research Categories: Biology, Biostatistics; Biology, Radiation; Health Sciences, Oncology

Abstract

Purpose: Novel techniques to deliver intensity modulated radiation therapy (IMRT) have resulted in improved treatment efficiency and dosimetric endpoints. We aimed to compare acute gastrointestinal (GI) and genitourinary (GU) toxicity in patients treated for adenocarcinoma of the prostate (ACP) using volumetric modulated arc therapy (VMAT). Methods and Materials: A total of 122 (71 IMRT and 51 VMAT) ACP patients treated from 2004 to 2011 with definitive external beam radiation therapy were analyzed. Dose-volume histogram endpoints (V40, V65, V70, and V75 of the bladder and rectum) were collected for each patient. Median follow-up for patients treated with VMAT was 269 days versus IMRT was 1121 days. Acute Common Toxicity Criteria for Adverse Events (CTCAE) GI and GU toxicity scores, obtained during each weekly treatment check, were compared across cohorts. The univariate (UV) association between the covariates and outcomes was assessed and multivariable (MV) cumulative logit models were fit for each outcome. Results: Median patient age was 68 years and median prostate-specific antigen was 8.3. Both bladder and rectal V40, V65, V70, and V75 were all higher in the IMRT group versus the VMAT group (P < .05), which was likely influenced by larger planning target volumes in the IMRT group. The VMAT group had significantly lower rates of acute GU and acute GI CTCAE toxicity on UV association analysis. On MV analysis, VMAT remained independently associated with acute GU (odds ratio [OR], 0.18; 95% confidence interval [CI], 0.07-0.44; P < .001) and GI (OR, 0.16; 95% CI, 0.07-0.41; P < .001) toxicity. Conclusions: VMAT appears to be independently associated with lower rates of acute GI and GU toxicity when compared with traditional IMRT. Further exploration of toxicity improvements associated with VMAT use in the definitive treatment of ACP is needed. © 2013 American Society for Radiation Oncology.