Comparative study of dose distributions calculated by dual optimization modes of Monaco system by volumetric modulated arc therapy of nasopharyngeal carcinoma
10.13491/j.issn.1004-714X.2021.03.013
- VernacularTitle:Monaco系统鼻咽癌VMAT计划两种优化方式的剂量学对比
- Author:
Ruixin HE
1
;
Wei YUAN
1
;
Chao XU
1
;
Yuemei ZHANG
1
;
Yangpeng HAN
1
;
Fengwen TANG
1
;
Tuotuo GONG
1
;
Huitao WANG
2
Author Information
1. The First Affiliated Hospital of Xi’an Jiaotong University, Xi'an 710061 China.
2. Anyang Tumor Hospital, Anyang 455001 China.
- Publication Type:DiagnosisandTreatment/OriginalArticles
- Keywords:
Nasopharyngeal Carcinoma;
VMAT;
Optimization Mode;
Dosimetric Comparison
- From:
Chinese Journal of Radiological Health
2021;30(3):321-325
- CountryChina
- Language:Chinese
-
Abstract:
Objective To compare the dosimetric differences in volumetric modulated arc therapy (VMAT) of Monaco planning system for nasopharyngeal carcinoma between Pareto and Constrained optimization in order to provide a reference for future mode selection. Methods Select 20 patients with nasopharyngeal carcinoma whom were calculated by Pareto and Constrained modes in the same CT image. Prescription dose of target PGTV, PTV1 and PTV2 was 70.29、60.39 and 54.45 Gy with 33 fractions, 5 times a week. The differences in target dose, organs at-risk dose, monitor units and segments were compared in the condition of 95% of the target volume reached the prescribed dose. Results Compared with Pareto group, Constrained group achieved a better HI and CI. CI of PGTV and PTV1 signed statistical differences (P < 0.05). Dose of OARs in Constrained group were all lower than those in Pareto group except Optical-l and lens-l. The differences of spinal cord prv dose and V30 of Parotid-r between two groups was significant (P < 0.05) while the differences of monitor units and segments between two groups was not significant (P > 0.05). Conclusion The length of middle turbinate is negatively correlated with the occurrence and severity of CMS. There is no significant correlation between the degree of curling and the occurrence of CMS, but patients with lower degree of curling of middle turbinate may have more serious CMS.
