Experimental study of range verification of proton radiotherapy using off-line PET/CT
10.3760/cma.j.cn321828-20191113-00257
- VernacularTitle:离线模式下PET/CT显像验证质子放疗精准度的模型实验
- Author:
Jiangang ZHANG
1
;
Junyu ZHANG
;
Yan LU
;
Yinxiangzi SHENG
;
Wei REN
;
Leijun SHI
;
Yun SUN
;
Yingjian ZHANG
;
Wenchien HSI
;
Rong ZHOU
;
Guoliang JIANG
;
Jiade LU
;
Jingyi CHENG
Author Information
1. 上海市质子重离子医院、上海质子重离子放射治疗工程技术研究中心核医学科 201321
- From:
Chinese Journal of Nuclear Medicine and Molecular Imaging
2020;40(10):603-608
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To test the usefulness of PET-range verification (RV) method for proton radiation accuracy verification in poly (methyl methacrylate) (PMMA) phantom using off-line PET/CT scanning.Methods:Proton irradiation dose of 2 Gy and 4 Gy were delivered in PMMA phantom. Given the difference of clinical target volume (CTV), 7 subgroups with different depth (5.0, 7.5, 10.0, 12.5, 15.0, 17.5, 20.0 cm) were set for each dose (14 radiation plans or radiation fields). PET/CT scan was performed 10 min after irradiation of 48-221 MeV proton beam. A co-registration between CT from treatment planning system and PET/CT was performed, as well as the smoothing and normalization of PET/CT data. The region of interest (ROI) and profile lines were drawn with the Raystation PET-RV software. The predictive induced radioactivity and the measured induced radioactivity profile lines were analyzed to evaluate the Δ R50, namely, the error at the position corresponding to 50% of the maximum predictive induced radioactivity at the end of both curves. Results:The size of each ROI was 5.0 cm×5.0 cm×2.5 cm. Profile lines were evenly distributed with the interval of 3 mm, and totally 289 pairs of profile lines were drew. The 2 Gy- and 4 Gy-dose groups yielded similar mean depth errors (Δ R50 between 1 mm and -1 mm with a standard deviation <1 mm). Conclusions:The off-line PET/CT scanning of PMMA phantom reveals a good agreement between predicted and measured PET data, with error of ±1 mm. The PET-RV method can be extended to clinical cases′ verification in human body treatment with further investigation.
