The feasibility of individualized primary CTV for lateralized nasopharyngeal carcinoma
10.3760/cma.j.cn113030-20221031-00365
- VernacularTitle:偏侧鼻咽癌原发灶CTV的个体化优化方案可行性探讨
- Author:
Siyu ZHANG
1
;
Wenxuan HUANG
;
Lijun WANG
;
Juying LIU
;
Lijun ZHAO
;
Lirong WU
;
Dejun WANG
;
Wenjing XU
;
Yesong GUO
;
Pengwei YAN
;
Lanfang ZHANG
;
Zhenyu ZHAI
;
Shengfu HUANG
;
Xia HE
Author Information
1. 江苏省肿瘤医院 江苏省肿瘤防治研究所 南京医科大学附属肿瘤医院放疗科，南京 210009
- Keywords:
Nasopharyngeal carcinoma;
Clinical target volume;
Target volume optimization;
Individualized target volume;
Reduced target volume
- From:
Chinese Journal of Radiation Oncology
2023;32(8):675-682
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the feasibility of individualized primary clinical target volume (CTV) delineation in intensity-modulated radiotherapy for nasopharyngeal carcinoma (NPC).Methods:Clinical data of 87 consecutive patients newly diagnosed with lateralized NPC in Jiangsu Cancer Hospital between October 2016 and February 2018 were retrospectively analyzed. Lateralized NPC is defined as tumor invasion not exceeding the contralateral wall. According to the tumor spread, the primary CTV was optimized as follows: CTV2 only covered the medial part of the contralateral pterygopalatine fossa, whereas the contralateral foramen oval was not included; on the level of parapharyngeal space, the contralateral side of CTV only covered the posterior lateral lymph nodes, whereas the contralateral internal jugular vein was not regularly covered. Failure patterns and 5-year survival [local control rate (LCR), progression-free survival (PFS) and overall survival (OS)] were evaluated by Kaplan-Meier method. Paired t-test and rank-sum test were used to analyze the dose variation in the optimized region and adverse reactions. Results:The median follow-up time was 59.5 months. The 5-year LCR, PFS, and OS were 98.9%, 86.5% and 92.1%, respectively. There was no local recurrence in the optimized area of CTV. Dosimetric comparison results showed that the doses of parotid gland, temporal lobe, cochlea and middle ear on the contralateral side were reduced by 13.45%, 9.14%, 38.83%, and 29.36%, respectively. Four cases (4.6%) developed grade 3 hearing loss, all on the ipsilateral side. The optimized scheme significantly alleviated the hearing loss on the contralateral side compared to that on the ipsilateral side ( P<0.001). Other grade 3 late adverse reactions included cranial nerve injury, subcutaneous fibrosis in the neck and visual impairment, with 1 case each. Conclusion:Individualized primary CTV for lateralized NPC is feasible and safe, with obvious dosimetric advantages and reduced adverse reaction rate, which is worthy of clinical promotion.
