Analysis of dosimetric characteristics of proton radiotherapy in 3 cases of lung cancer
10.3760/cma.j.cn371439-20250217-00112
- VernacularTitle:肺癌3例质子放疗剂量学特点分析
- Author:
Cheng TAO
1
;
Bingjie FAN
;
Chengqiang LI
;
Shizhang WU
;
Jinghao DUAN
;
Tianyuan DAI
;
Tong BAI
;
Jinhu CHEN
;
Jian ZHU
Author Information
1. 山东省肿瘤防治研究院（山东省肿瘤医院）放射物理技术科，山东第一医科大学（山东省医学科学院），济南 250117
- Keywords:
Lung neoplasms;
Radiotherapy;
Proton therapy;
Radiotherapy dosage
- From:
Journal of International Oncology
2025;52(10):653-658
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the dosimetric characteristics of intensity modulated proton therapy (IMPT) and intensity modulated radiation therapy (IMRT) for lung cancers.Methods:Three lung cancer patients (central-lower, central, and peripheral types) admitted to Shandong Cancer Hospital and Institute from January 2024 to May 2024 were selected as the research subjects. IMPT and IMRT plans were designed for each case based on the anatomical location of the clinical target volume and the dose constraints for organs at risk (OARs). Dosimetric parameters, including conformity index (CI), homogeneity index (HI), and gradient index (GI) for target coverage, as well as OARs dosimetric parameters were evaluated. The volume of additional dose deposition in the body was compared by assessing regions receiving 10%, 30%, and 50% of the prescription dose.Results:For all three cases, IMRT plans demonstrated higher CI values (0.80, 0.60, and 0.79) compared to IMPT plans (0.61, 0.57, and 0.34). IMPT plans yielded lower HI values (0.07, 0.06, and 0.06) than IMRT plans (0.09, 0.15, and 0.09) and lower GI values (2.84, 2.47, and 4.56 vs. 4.91, 3.09, and 4.99 for IMRT plans). Compared with the IMRT plans, the low-dose region in the ipsilateral lung was significantly reduced in IMPT plans (V 5 of the IMPT plans were 20.59%, 46.29%, 10.94%, respectively; V 5 of the IMRT plans were 48.91%, 60.63%, 19.92%, respectively), but there was no significant advantage in the high-dose region compared to IMRT plans (V 20 of the IMPT plans were 12.88%, 34.75%, 5.21%, respectively; V 20 of the IMRT plans were 21.70%, 36.50%, 5.31%, respectively). The dose to the contralateral lung and heart was significantly reduced in IMPT plans [the D mean of the contralateral lung in the IMPT plans were 0.08, 0.04, and 0.00 Gy (RBE), respectively, and those in the IMRT plans were 3.25, 1.18, and 0.55 Gy, respectively; the heart D mean in the IMPT plans were 6.23, 7.04, and 0.00 Gy (RBE), respectively, while those of the IMRT plans were 18.33, 10.27, and 0.08 Gy, respectively). IMPT plans significantly reduced the volumes receiving 10% of the prescription dose by 65.94%, 25.57% and 72.47%, respectively, compared to IMRT plans. The volumes IMPT plans occupied by 30% of the prescription dose area in the body were reduced by 54.97%, 26.47% and 39.04%, respectively, compared to the IMRT plans. The volumes IMPT plans occupied by 50% of the prescription dose area in the body were reduced by 54.49%, 30.43% and 28.89%, respectively, compared to the IMRT plans. Conclusions:IMPT plan significantly reduces the V 5 of the ipsilateral lung, the D mean of the contralateral lung and the heart, while maintaining target coverage compared with IMRT plan for lung cancers. However, IMPT plan does not show much more advantage than IMRT plan in the ipsilateral lung V 20. IMPT can reduce the additional exposure volume within the body.
