Recommendation for a contouring method and atlas of organs at risk in nasopharyngeal carcinoma patients receiving intensity-modulated radiotherapy.
OBJECTIVE
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
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.
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China.
Ying
Y
Sun
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China.
Xiao-Li
XL
Yu
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China.
Wei
W
Luo
Department of Clinical Oncology, The University of Hong Kong-Shenzhen Hospital, People's Republic of China.
Anne W M
AW
Lee
Department of Radiation Oncology, National Cancer Center Singapore, Singapore.
Joseph Tien Seng
JT
Wee
Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, USA.
Nancy
N
Lee
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China.
Guan-Qun
GQ
Zhou
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China.
Ling-Long
LL
Tang
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China.
Chang-Juan
CJ
Tao
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China.
Rui
R
Guo
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China.
Yan-Ping
YP
Mao
Imaging Diagnosis and Interventional Center, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China.
Rong
R
Zhang
Department of Medical Statistics and Epidemiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China.
Ying
Y
Guo
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China. Electronic address: majun2@mail.sysucc.org.cn.
Jun
J
Ma
D000328:Adult; D000368:Aged; D002277:Carcinoma; D005260:Female; D006801:Humans; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000532:radiotherapy*; D058958:Organs at Risk; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D013116:Spinal Cord / Q000528:radiation effects; D013702:Temporal Lobe / Q000473:pathology / Q000528:radiation effects
Atlas; Intensity modulated radiotherapy; Nasopharyngeal carcinoma; Organs at risk