Analysis of dosimetric characteristics of proton radiotherapy in 3 cases of abdominal and pelvic tumors
10.3760/cma.j.cn371439-20250217-00079
- VernacularTitle:腹盆部肿瘤3例质子放疗剂量学特点分析
- Author:
Jinghao DUAN
1
;
Jinbo YUE
;
Cheng TAO
;
Shizhang WU
;
Chengqiang LI
;
Tianyuan DAI
;
Jinhu CHEN
;
Tong BAI
;
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:
Abdominal neoplasms;
Pelvic neoplasms;
Radiotherapy;
Proton therapy;
Radiotherapy dosage
- From:
Journal of International Oncology
2025;52(7):455-461
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore the dosimetric characteristics of intensity modulated proton therapy (IMPT) and intensity modulated radiation therapy (IMRT) for typical abdominal and pelvic tumors.Methods:Three patients with abdominal and pelvic tumors (one case each of liver cancer, cervical cancer, and prostate cancer) admitted to Shandong Cancer Hospital and Institute from January to June 2024 were selected as the research subjects. IMPT and IMRT plans were designed for each case based on clinical target volume (CTV) and organs at risk (OARs) constraints. Dosimetric parameters, including conformity index (CI), homogeneity index (HI), and gradient index (GI) for target coverage, as well as OARs dose metrics, 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 plan demonstrated higher CI values (0.82, 0.81, and 0.86) compared to IMPT plan (0.61, 0.62, and 0.43). IMPT plan yielded lower HI values (0.053, 0.075, and 0.020) than IMRT plan (0.060, 0.120, and 0.080) and lower GI values (3.45, 2.63, and 3.80 vs. 7.28, 4.76, and 4.66 for IMRT plan). In liver cancer, IMPT plan reduced the D mean of normal liver tissues and right kidney by 37.8% and 78.5%, respectively, and decreased the D max of spinal cord by 13.2%. For cervical cancer, IMPT plan reduced the V 30 of the small bowel by 22.0%, D mean of the bladder, rectum and bone marrow by 15.7%, 14.3% and 12.6%, and spinal cord D max by 4.8%. In prostate cancer, IMPT plan lowered bladder and rectal D mean by 14.9% and 36.5%, respectively, but resulted in an increase of 35.3% and 6.1% in the D mean and V 40 of the left femoral head, respectively, and an increase of 23.6% and 10.8% in the D mean and V 40 of the right femoral head, respectively. IMPT plan reduced the volumes receiving 10%, 30%, and 50% of the prescription dose by 48.9%-64.8%, 22.0%-47.0%, and 22.0%-57.7%, respectively, compared to IMRT plan. Conclusions:Comparison between IMPT and IMRT plans for abdominopelvic tumors: IMPT plan offers advantages in reducing doses to normal organs such as the liver, kidneys, spinal cord, small intestine, rectum, and bladder. However, its advantage is less pronounced regarding the dose to the femoral heads. IMPT plan notably minimizes additional dose deposition within the body.
