Abstract

Info

Title:: Effects of carotid sheath-sparing intensity-modulated radiotherapy for locally advanced nasopharyngeal carcinoma on doses of target areas and organs-at-risk

Author(s):: LEI Huaiyu; ZHANG Shuxu; ZHANG Guoqian; WANG Linjing; WANG Ruihao; ZHANG Quanbin; LI Ping; LIN Xiaohui; Radiotherapy Center, Cancer Center of Guangzhou Medical University, Guangzhou 510095, China

Keywords:: ; Keywords: nasopharyngeal carcinoma; intensity-modulated radiotherapy; carotid sheath-sparing; radiotherapy dose

Abstract:: Abstract: Objective To investigate the effects of carotid sheath-sparing intensity-modulated radiotherapy (IMRT) on the doses of target areas and organs-at-risk (OAR) in patients with locally advanced nasopharyngeal carcinoma (NPC). Methods A retrospective dosimetric analysis was performed on 10 patients with locally advanced NPC. Two plans, namely routine IMRT plan and carotid sheath-sparing IMRT plan, were designed for each patient. The mean dose (Dmean), D98%, D50%, D5%, D2%, conformity index and homogeneity index of planning gross target volume (PGTVnx) and planning clinical target volume (PCTV1) as well as the doses of the carotid sheath and OAR were evaluated. Results The conformity index and homogeneity index of PGTVnx, D50% and Dmean of PCTV1, Dmax and Dmean of carotid sheath, Dmean of spinal cord, and V40 and Dmean of brain stem in carotid sheath-sparing IMRT plan were significantly lower than those in routine IMRT plan, with statistical differences (P<0.05). No statistical differences were found in other dosimetric indexes. Conclusion Carotid sheath-sparing IMRT plan for locally advanced NPC can significantly reduce the doses of carotid sheath and brain stem without affecting target coverage, and achieve a superior dose distribution.