Clinical study on quantitative evaluation of proton radiotherapy by off-line PET-CT in vivo biological validation
10.3760/cma.j.cn113030-20211215-00517
- VernacularTitle:离线PET-CT在体生物验证量化评估质子放疗精准度的临床研究
- Author:
Fuquan ZHANG
1
;
Zhengshan HONG
;
Jian'gang ZHANG
;
Yan LU
;
Xiangzi SHENG-YIN
;
Qing ZHANG
;
Dan YOU
;
Shaoli SONG
;
Guoliang JIANG
;
Yun SUN
;
Rong ZHOU
;
Jingyi CHENG
Author Information
1. 上海市质子重离子医院、上海市放射肿瘤学重点实验室（20 dz2261000）、上海质子重离子放射治疗工程技术研究中心核医学科，上海 201315
- Keywords:
Proton radiotherapy;
Off-line PET-CT;
In vivo verification;
Depth verification
- From:
Chinese Journal of Radiation Oncology
2022;31(11):1017-1021
- CountryChina
- Language:Chinese
-
Abstract:
Objective:Patients are breathing freely during adjuvant proton pencil beam radiotherapy after breast conserving surgery. Fluctuation of the thorax may affect the position of the end of the proton beam flow, which needs to be precisely evaluated on a millimeter scale.Methods:For 20 patients with breast cancer treated with proton radiotherapy after breast conserving surgery, PET-CT scan was performed approximately 10 min after the end of proton radiotherapy. The images of PET-CT were processed for ROI determination and sampling line (profile) extraction on a Raystation RV workstation to calculate the actual difference between the predicted and real radioactivity from the same spatial location as obtained by PET acquisition R50. Then, the differences in the spatial location between the actual process of proton irradiation and the planned process were obtained. Depth difference values for each pair of sampling lines were presented. Results:For 20 patients with breast cancer with a median follow-up of 22 months (range 12 - 46 months), all patients survived at the last follow-up, and no radiation pneumonitis was observed during the follow-up period. Among the verification results of 21 cases, the depth difference of evenly distributed was (-0.75±1.89) mm in the primary field and (-0.82±2.06) mm in the secondary field; The depth difference of sequential treatment was (1.81±1.87) mm in the primary field and (1.32±1.74) mm in the secondary field; The depth difference of synchronous addition in the primary field was (-1.47±1.44) mm, and the depth difference in the secondary field was (-1.48±2.11) mm.Conclusion:The results of off-line PET-CT in vivo biological verification show that the accuracy of the dose boundary cut-off was within 3 mm in breast cancer patients, which meets the clinical and physician requirement for the precision in breast cancer treatment.
