Recommendation for a contouring method and atlas of organs at risk in nasopharyngeal carcinoma patients receiving intensity-modulated radiotherapy.

Abstract

BACKGROUND AND PURPOSE:

To recommend contouring methods and atlas of organs at risk (OARs) for nasopharyngeal carcinoma (NPC) patients receiving intensity-modulated radiotherapy, in order to help reach a consensus on interpretations of OARs delineation.

METHODS AND MATERIALS:

Two to four contouring methods for the middle ear, inner ear, temporal lobe, parotid gland and spinal cord were identified via systematic literature review; their volumes and dosimetric parameters were compared in 41 patients. Areas under the receiver operating characteristic curves for temporal lobe contouring were compared in 21 patients with unilateral temporal lobe necrosis (TLN).

RESULTS:

Various contouring methods for the temporal lobe, middle ear, inner ear, parotid gland and spinal cord lead to different volumes and dosimetric parameters (P<0.05). For TLN, D1 of PRV was the most relevant dosimetric parameter and 64Gy was the critical point. We suggest contouring for the temporal lobe, middle ear, inner ear, parotid gland and spinal cord. A CT-MRI fusion atlas comprising 33 OARs was developed.

CONCLUSIONS:

Different dosimetric parameters may hinder the dosimetric research. The present recommendation and atlas, may help reach a consensus on subjective interpretation of OARs delineation to reduce inter-institutional differences in NPC patients.

• Authors: Ying Sun, Xiao-Li Yu, Wei Luo, Anne W M Lee, Joseph Tien Seng Wee, Nancy Lee, Guan-Qun Zhou, Ling-Long Tang, Chang-Juan Tao, Rui Guo, Yan-Ping Mao, Rong Zhang, Ying Guo, Jun Ma
• Journal: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology (Radiother Oncol) Vol. 110 Issue 3 Pg. 390-7 (Mar 2014) ISSN: 1879-0887 [Electronic] Ireland
• PMID: 24721546 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Topics

• Adult
• Aged
• Carcinoma
• Female
• Humans
• Middle Aged
• Nasopharyngeal Carcinoma
• Nasopharyngeal Neoplasms (radiotherapy)
• Organs at Risk
• Radiotherapy Dosage
• Radiotherapy, Intensity-Modulated (adverse effects, methods)
• Retrospective Studies
• Spinal Cord (radiation effects)
• Temporal Lobe (pathology, radiation effects)