Experimental study of range verification of proton radiotherapy using off-line PET/CT
Zhang Jiangang, Zhang Junyu, Lu Yan, Sheng Yinxiangzi, Ren Wei, Shi Leijun, Sun Yun, Zhang Yingjian, Hsi Wenchien, Zhou Rong, Jiang Guoliang, Lu Jiade, Cheng Jingyi
Abstract
ObjectiveTo 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.
MethodsProton 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.
ResultsThe 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 (ΔR50 between 1 mm and -1 mm with a standard deviation <1 mm).
ConclusionsThe 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.
Key words:
Radiotherapy; Protons; Positron-emission tomography; Tomography; X-ray computed
Contributor Information
Zhang Jiangang
Department of Nuclear Medicine, Shanghai Proton and Heavy Ion Center, Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201321, China
Zhang Junyu
School of Physics, Sichuan University, Chengdu 610065, China
Lu Yan
Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201321, China
Sheng Yinxiangzi
Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201321, China
Ren Wei
Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201321, China
Shi Leijun
Department of Nuclear Medicine, Shanghai Proton and Heavy Ion Center, Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201321, China
Sun Yun
Department of Nuclear Medicine, Shanghai Proton and Heavy Ion Center, Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201321, China
Zhang Yingjian
Department of Nuclear Medicine, Shanghai Proton and Heavy Ion Center, Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201321, China
Department of Nuclear Medicine, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, Shanghai 201321, China
Center for Biomedical Imaging, Fudan University, Shanghai 200032, China
Shanghai Engineering Research Center of Molecular Imaging Probes, Shanghai 200032, China
Hsi Wenchien
University Florida Health Proton Therapy Institue and Radiation Oncology of University, Jacksonville, Florida FL32819, US
Zhou Rong
School of Physics, Sichuan University, Chengdu 610065, China
Jiang Guoliang
Department of Radiotherapy, Shanghai Proton and Heavy Ion Center, Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201321, China
Lu Jiade
Department of Radiotherapy, Shanghai Proton and Heavy Ion Center, Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201321, China
Cheng Jingyi
Department of Nuclear Medicine, Shanghai Proton and Heavy Ion Center, Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201321, China
Department of Nuclear Medicine, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, Shanghai 201321, China
Center for Biomedical Imaging, Fudan University, Shanghai 200032, China
Shanghai Engineering Research Center of Molecular Imaging Probes, Shanghai 200032, China
