WEKO3
アイテム
Radiopharmaceutical-free hypoxia imaging in particle therapy by means of range-verification PET: a feasibility rat study
https://repo.qst.go.jp/records/2002062
https://repo.qst.go.jp/records/200206220ad1fdd-c0fe-41bd-8fac-b5e2da488773
| アイテムタイプ | 会議発表用資料 / Presentation(1) | |||||||
|---|---|---|---|---|---|---|---|---|
| 公開日 | 2025-04-22 | |||||||
| タイトル | ||||||||
| タイトル | Radiopharmaceutical-free hypoxia imaging in particle therapy by means of range-verification PET: a feasibility rat study | |||||||
| 言語 | en | |||||||
| 言語 | ||||||||
| 言語 | eng | |||||||
| 資源タイプ | ||||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||||
| 資源タイプ | conference presentation | |||||||
| 著者 |
Toramatsu Chie
× Toramatsu Chie
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| 抄録 | ||||||||
| 内容記述 | Background and aimsTumor oxygen status provides important information to optimize particle therapy. However, tumor oxygen status may constantly change during a treatment period of several weeks, and it is impractical to perform hypoxia PET such as using 18F-FAZA for every fraction. For this issue, our hypothesis is that range-verification PET, which is based on the detection of positron (β+)-emitting nuclides produced through nuclear fragmentation reactions in tissue, may provide tumor hypoxia information. In the last PTCOG, we reported that the washout rate of the produced β+-emitting nuclides obtained by rat irradiation reflects the tumor vascular status measured by MR angiography. In this study, we compared the range-verification PET directly with 18F-FAZA PET.MethodsC6 glioma cancer cells were implanted into the left thigh of a nude rat. After tumors grew in two weeks, two experiments were carried out sequentially. (a) Range-verification PET experiment: A whole tumor was irradiated with the 12C ion beam, and from PET data obtained by 30-min scan of our custom-made high-sensitivity small-animal PET system, the voxel-by-voxel washout rate constants (k2,m) were derived. (b) Hypoxia PET experiment on the next day: 18F-FAZA was injected to the same rat and hypoxia-PET imaging was performed for 30 mins. ResultsThe washout-rate image of the range-validation PET image, a k2,m image, had three regions: a faster washout rate (k2,m=0.26/min) mostly at the edge of the tumor, a slower washout rate (k2,m=0.05/min) at the core of the tumor, and a middle washout rate (k2,m=0.13/min) between them, which agreed with a typical structure of most solid tumors. The middle washout-rate area appears to be consistent with the 18F-FAZA uptake, which means hypoxia. The tumor peripheral area (faster washout-rate) is considered to be a viable area with low 18F-FAZA accumulation, and the core (slower washout-rate) is considered as necrosis.Conclusion The feasibility of radiopharmaceutical-free hypoxia imaging in carbon ion therapy by means of range-verification PET was shown by the rat irradiation. | |||||||
| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||||
| 内容記述 | 63nd Annual Meeting of the Particle Therapy Cooperative Group (PTCOG 63) | |||||||
| 発表年月日 | ||||||||
| 日付 | 2025-06-04 | |||||||
