Establishing an isodose assignment model for 125I brachytherapy using γ-ray photon counts detected by SPECT/CT
10.3760/cma.j.cn112271-20240730-00290
- VernacularTitle:建立SPECT/CT探测γ射线光子计数值与 125I近距离治疗等剂量赋值模型
- Author:
Wenfei WANG
1
;
Chuan TIAN
;
Xueda LI
;
Hongtao ZHANG
;
Congxiao WANG
;
Shifeng LIU
;
Xiaokun HU
;
Teng LI
Author Information
1. 青岛大学附属医院介入医学中心，青岛 266003
- Publication Type:Journal Article
- Keywords:
SPECT/CT;
γ-ray photon count;
Dose;
125I;
Brachytherapy
- From:
Chinese Journal of Radiological Medicine and Protection
2025;45(7):674-678
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To employ single-photon emission computed tomography (SPECT)/CT for isodose assignment in 125I brachytherapy, assess the correlation between photon counts and dose values, and develop a clinical γ-ray visualization model for 125I brachytherapy. Methods:125I radioactive seeds were filled into a self-made 3D printed stereotactic template to build a stereotactic model. The model was scanned by SPECT/CT for photon counts at 0.5, 1.0, 1.5, 2.0 cm from the outermost peripheral seeds, and the corresponding dose values were measured using the Treatment Planning System (TPS). The fitting curve for the photon counts and the dose values was plotted using SPSS 27.0 software. Results:The photon counts of γ rays at distances of 0.5, 1.0, 1.5, and 2.0 cm from the peripheral particles were 7 603.57±1 806.35, 4 018.26±1 315.72, 2 074.04±791.53, and 1 080.34±424.79, respectively, showing a significant difference ( F=743.72, P<0.01). The dose values (in Gy) in the TPS at distances of 0.5, 1.0, 1.5, and 2.0 cm from the peripheral particles were 208.05±37.57, 125.43±17.74, 86.76±17.67, and 61.55±14.39, respectively, which were significantly different ( F=930.46, P<0.01). The photon counts were linearly correlated with the dose values ( y=0.02 x+ 46.45, R2=81.2%, P<0.01). Conclusions:SPECT/CT-based γ-ray photon count detection can be used to assign doses for 125I brachytherapy, enabling the visualization of γ rays in 125I brachytherapy. This approach has a distinct advantage over TPS, laying the foundation for the establishment of an alternative system to TPS.
