Journal of International Oncology ›› 2025, Vol. 52 ›› Issue (7): 455-461.doi: 10.3760/cma.j.cn371439-20250217-00079

• Dosimetric characteristics of proton radiotherapy • Previous Articles     Next Articles

Analysis of dosimetric characteristics of proton radiotherapy in 3 cases of abdominal and pelvic tumors

Duan Jinghao1,2, Yue Jinbo3, Tao Cheng1,2, Wu Shizhang1,2, Li Chengqiang1,2, Dai Tianyuan1,2, Chen Jinhu1,2, Bai Tong1,2, Zhu Jian1,2()   

  1. 1Department of Radiological Physics,Shandong Cancer Hospital and Institute,Shandong First Medical University and Shandong Academy of Medical Sciences,Jinan 250117,China
    2Shandong Provincial Key Medical and Health Laboratory of Pediatric Cancer Precision Radiotherapy (Shandong Cancer Hospital),Jinan 250117,China
    3Department of Radiation Oncology (Abdominal Section 1),Shandong Cancer Hospital and Institute,Shandong First Medical University and Shandong Academy of Medical Sciences,Jinan 250117,China
  • Received:2025-02-17 Revised:2025-05-05 Online:2025-07-08 Published:2025-07-23
  • Contact: Zhu Jian E-mail:zhujian@sdfmu.edu.cn
  • Supported by:
    National Science and Technology Major Project of China(2024ZD0519901);National Natural Science Foundation of China(12105160);National Natural Science Foundation of China(82172072);Key R&D Program of Shandong Province,China(2024CXPT084);Natural Science Foundation of Shandong Province of China(ZR2021QA099);Natural Science Foundation of Shandong Province of China(ZR2022QH188);Youth Innovation Team Development Plan of Shandong Universities(2024KJJ013);Shandong Provincial Young Science and Technology Talent Support Project(SDAST2024QTB034)

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 Dmean of normal liver tissues and right kidney by 37.8% and 78.5%,respectively,and decreased the Dmax of spinal cord by 13.2%. For cervical cancer,IMPT plan reduced the V30 of the small bowel by 22.0%,Dmean of the bladder,rectum and bone marrow by 15.7%,14.3% and 12.6%,and spinal cord Dmax by 4.8%. In prostate cancer,IMPT plan lowered bladder and rectal Dmean by 14.9% and 36.5%,respectively,but resulted in an increase of 35.3% and 6.1% in the Dmean and V40 of the left femoral head,respectively,and an increase of 23.6% and 10.8% in the Dmean and V40 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.

Key words: Abdominal neoplasms, Pelvic neoplasms, Radiotherapy, Proton therapy, Radiotherapy dosage