Clinical Toxicities and Dosimetric Parameters After Whole-Pelvis Versus Prostate-Only Intensity-Modulated Radiation Therapy for Prostate Cancer

Journal Article · Mon Nov 01 00:00:00 EDT 2010 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2009.08.043· OSTI ID:21438007

Deville, Curtiland ^[1]; Both, Stefan ^[1]; Hwang, Wei-Ting ^[2]; Tochner, Zelig; Vapiwala, Neha ^[1]

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1. Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, PA (United States)
2. Department of Biostatistics and Epidemiology, Hospital of the University of Pennsylvania, Philadelphia, PA (United States)

Purpose: To assess whether whole-pelvis (WP) intensity-modulated radiation therapy (IMRT) is associated with increased toxicity compared with prostate-only (PO) IMRT. Methods and Materials: We retrospectively analyzed all patients with prostate cancer undergoing definitive IMRT to 79.2 Gy with concurrent androgen deprivation at our institution from November 2005 to May 2007 with a minimum follow-up of 12 months. Thirty patients received initial WP IMRT to 45 Gy in 1.8-Gy fractions, and thirty patients received PO IMRT. Study patients underwent computed tomography simulation and treatment planning by use of predefined dose constraints. Bladder and rectal dose-volume histograms, maximum genitourinary (GU) and gastrointestinal (GI) Radiation Therapy Oncology Group toxicity grade, and late Grade 2 or greater toxicity-free survival curves were compared between the two groups by use of the Student t test, Fisher exact test, and Kaplan-Meier curve, respectively. Results: Bladder minimum dose, mean dose, median dose, volume receiving 5 Gy, volume receiving 20 Gy, volume receiving 40 Gy, and volume receiving 45 Gy and rectal minimum dose, median dose, and volume receiving 20 Gy were significantly increased in the WP group (all p values < 0.01). Maximum acute GI toxicity was limited to Grade 2 and was significantly increased in the WP group at 50% vs. 13% the PO group (p = 0.006). With a median follow-up of 24 months (range, 12-35 months), there was no difference in late GI toxicity (p = 0.884) or in acute or late GU toxicity. Conclusions: Despite dosimetric differences in the volume of bowel, bladder, and rectum irradiated in the low-dose and median-dose regions, WP IMRT results only in a clinically significant increase in acute GI toxicity, in comparison to PO IMRT, with no difference in GU or late GI toxicity.

• OSTI ID: 21438007
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Vol. 78, Issue 3; Other Information: DOI: 10.1016/j.ijrobp.2009.08.043; PII: S0360-3016(09)02992-7; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0360-3016
• Country of Publication: United States
• Language: English

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62 RADIOLOGY AND NUCLEAR MEDICINE
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PELVIS
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RADIOTHERAPY
RECTUM
SIMULATION
TOXICITY
BODY
DIAGNOSTIC TECHNIQUES
DIGESTIVE SYSTEM
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GASTROINTESTINAL TRACT
GLANDS
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LARGE INTESTINE
MALE GENITALS
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NUCLEAR MEDICINE
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