Dosimetric differences between 6 MV flatten-filter free MC and CCC algorithms for the same machine model
10.3969/j.issn.1005-202X.2025.05.003
- VernacularTitle:相同机器模型6MV非均整模式MC和CCC算法剂量差异研究
- Author:
Yong SANG
1
;
Jian'an WU
1
;
Man ZHAO
1
;
Zhen DING
1
;
Jiajun CAI
1
Author Information
1. 国家癌症中心/国家肿瘤临床医学研究中心/中国医学科学院北京协和医学院肿瘤医院深圳医院放射治疗科,广东 深圳 518116
- Publication Type:Journal Article
- Keywords:
Monte Carlo algorithm;
collapse cone convolution algorithm;
treatment planning system;
dosimetric difference
- From:
Chinese Journal of Medical Physics
2025;42(5):571-576
- CountryChina
- Language:Chinese
-
Abstract:
Objective To analyze the dosimetric differences between Monaco Monte Carlo(MC)algorithm and Pinnacle collapse cone convolution(CCC)algorithm for the same machine model using the 6 MV flatten-filter free(FFF)mode,thus providing a reference for the clinical application of these two treatment planning systems.Methods According to the MPPG5 and TRS430 reports,the acceptance and commissioning of Monaco MC algorithm model and Pinnacle CCC algorithm model in Department of Radiation Oncology,Shenzhen Hospital,Cancer Hospital of Chinese Academy of Medical Sciences were performed.A retrospectively analysis was conducted on 30 cases,including 10 cases of nasopharyngeal cancer,6 cases of lung cancer,4 cases of esophageal cancer,and 10 cases of cervical cancer.For each case,a 6 MV FFF plan was designed in Pinnacle using CCC algorithm.A 2.5 mm dose grid was selected for plan optimization and dose calculation.The plan was then exported to Monaco,where dose to medium was calculated using MC algorithm and a 2.5 mm dose grid with a 1%uncertainty for each control point.Both calculations in Pinnacle and Monaco took into account the impact of the treatment couch and immobilization devices on dose attenuation.The dose differences to the target volumes and major organs at risk between Pinnacle and Monaco for 3 different body parts including the head,chest and abdomen were compared.Results(1)For nasopharyngeal cancer,compared with Pinnacle CCC algorithm,Monaco MC algorithm lowered the Vpd of PTVp,PTVn,PTVrpn,PTV1 and PTV2 by 9.98%,2.64%,15.0%,1.93%and 8.01%,elevated the Dmax of PTVp,PTVn and PTVrpn by 2.98%,5.62%and 2.39%,increased the Dmean of PTVn and PTV1 by 1.87%and 0.72%,respectively;and the Dmax of the brainstem,the Dmax of the optic chiasm,and the Dmean of the right parotid gland were 3.83%lower,7.03%higher and 1.32%higher in Monaco MC algorithm as compared with Pinnacle CCC algorithm,respectively.(2)For lung cancer and esophageal cancer,Monaco MC algorithm showed increases of 2.37%,4.18%,15.30%,6.36%and 1.04%in the Dmax of PGTV,the V20,V5 and Dmean of lungs,and the V30 of heart as compared with Pinnacle CCC algorithm,respectively.(3)For cervical cancer,the Vpd of PTV_LR,Dmax of PTV_LR,the V40 of the rectum,the Dmax of the small intestine,and the Dmean of humeral head were 7.70%lower,3.70%higher,4.31%lower,3.05%higher and 2.07%higher in Monaco MC algorithm than in Pinnacle CCC algorithm,respectively.These differences were statistically significant(P<0.05).Conclusion For the above 3 treatment sites,significant differences are found in dose calculations for target areas and organs at risk between Monaco MC algorithm and Pinnacle CCC algorithm for the same treatment plan.Attention should be paid to the differences in dose algorithms for different treatment planning systems in clinical applications,which may have impacts on patient survival rates and organ toxicity.
