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アイテム
FIRST CLINICAL TRIAL ON WASHOUT-BASED TUMOR DIAGNOSIS USING RANGE-VERIFICATION OPENPET INCARBON-ION THERAPY
https://repo.qst.go.jp/records/2003332
https://repo.qst.go.jp/records/2003332477a7f0a-437d-48a4-b635-9362b9ec1369
| アイテムタイプ | 会議発表用資料 / Presentation(1) | |||||||
|---|---|---|---|---|---|---|---|---|
| 公開日 | 2026-05-20 | |||||||
| タイトル | ||||||||
| タイトル | FIRST CLINICAL TRIAL ON WASHOUT-BASED TUMOR DIAGNOSIS USING RANGE-VERIFICATION OPENPET INCARBON-ION THERAPY | |||||||
| 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 | Tumor blood flow provides important information for estimating hypoxic and proliferative regions, and maycontribute to adaptive treatment‑planning and prognosis prediction. Those conditions fluctuate during thecourse of particle therapy, and are an important predictor of treatment response; therefore, frequentmonitoring is required. However, positron emission tomography (PET) using hypoxia-specific radioligands isimpractical to perform in every fractionated irradiation. Alternatively, tumor blood flow can be evaluated bymeasuring washout rates of irradiation-induced positron-emitters in range-verification PET. In the last PTCOG,we reported tumor rat irradiation with carbon-ion beam, which demonstrated clear correlation between thewashout rate map and18 F-FAZA hypoxia PET. This study aimed to translate the analysis methodestablished in animal studies into clinical practice.MethodsSince 2023, a clinical study (jRCTs032220746) has been underway at HIMAC for the range-verification ofcarbon‑ion therapy using OpenPET, an online PET system developed by our laboratory. Patients with H&Ncancer received a total of 64 Gy (RBE weighted) in 16 fractions over 4 weeks, during which a range-verificationOpenPET scan was performed four times, once during each of consecutive 4 fractions. The range-verificationOpenPET was performed for 10 minutes following horizontal beam irradiation. To derive the washout-rateconstant (k₂), the single-tissue compartment model, which is common in nuclear medicine, was applied on avoxel-by-voxel basis.ResultsThe range-verification OpenPET images showed appropriate results consistent with the treatment planthroughout the 4‑week period. On the other hand, the washout-rate constant (k₂‑Map) exhibited weeklyvariations, suggesting changes in tumor blood flow. These findings may be explained by thehypothesis that areas showing slow washout rates at the beginning of treatment, typically indicative of poorperfusion and hypoxia, may become re-perfused in response to the radiation therapy.ConclusionsThe feasibility of tumor diagnosis without PET radioligands was clinically demonstrated throughrange‑verification OpenPET measurements. Our future task is to analyze the clinical data from 20 upcomingpatients and investigate the relationship between temporal changes in the k₂‑Maps and follow‑up outcomes. | |||||||
| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||||
| 内容記述 | 64th Annual PTCOG Conference | |||||||
| 発表年月日 | ||||||||
| 日付 | 2026-06-10 | |||||||
