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Experimental PET/CT study of imaging the small amount of positron emitters generated by carbon ion beam irradiation
https://repo.qst.go.jp/records/70601
https://repo.qst.go.jp/records/706016bf3851e-ea01-40dc-a8ea-802b92d249f4
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2011-11-02 | |||||
| タイトル | ||||||
| タイトル | Experimental PET/CT study of imaging the small amount of positron emitters generated by carbon ion beam irradiation | |||||
| 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 object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Shiraishi, Takahiro
× Shiraishi, Takahiro× Yoshikawa, Kyosan× Fukumura, Akifumi× Mizuno, Hideyuki× Tanimoto, Katsuyuki× Ishii, Noriyuki× Inagaki, Eri× Omatsu, Mika× Ohashi, Seiya× Toubaru, Sachiko× Kamada, Tadashi× Ando, Yutaka× Tsuji, Hiroshi× Watanabe, Kazuhiro× et.al× 白石 貴博× 吉川 京燦× 福村 明史× 水野 秀之× 谷本 克之× 石井 徳幸× 稲垣 枝里× 尾松 美香× 大橋 靖也× 桃原 幸子× 鎌田 正× 安藤 裕× 辻 比呂志× 渡邊 和洋 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | [Purpose] Detecting the distribution of positron emitter generated by nuclear fragmentation reaction in carbon ion beam therapy (auto-activation) applied at Heavy Ion Medical Accelerator in Chiba (HIMAC) by means of positron emission tomography (PET) is novel method for therapy quality assurance especially assessing irradiated area. Since a new 3D irradiation system with pencil-beam scanning (fast- scanning system) has been developed at NIRS, and we are planning to assess the accuracy of the delivered dose distribution by clinical auto-activation PET study. In preparation for this purpose, we performed some phantom experiments for determine optimal scan duration and compare PET image quality of auto-activation PET study between conventional irradiation system and fast scanning system. \n[Materials and Methods] A SET-3000GCT/X (PET/CT; Shimadzu Corp.) dedicated to the 3D-acquisition mode is used for auto-activation PET imaging. It uses gadolinium oxyorthosilicate (GSO) detectors and provides 99 sections with a center-to-center distance of 2.6mm. To determine the optical scan duration, the phantom irradiated with carbon-ion beam is scanned for 60min in list-mode, then a 5min transmission scan with a 137Cs point source is performed. Before reconstruction, list-mode events are histogrammed as PET raw data obtained at each acquisition time (10, 20, 30, 40, 50 and 60min). The emission images are reconstructed with the manufacturer software using Fourier rebinning followed by 2D-dynamic-RAMLA. Reconstructed images are evaluated visually and normal mean square error (NMSE) is assessed. In addition, image noise is derived from region-of-interest (ROI) analysis. Image noise was defined as the coefficient of variation (COV, 100 x SD/mean [%]) of the pixel values within a homogeneous ROI. \n[Results] There is no obvious difference of image quality between 40min acquisition and 60min acquisition by visually evaluation. Based on statistical analysis, NMSE value and COV are 0.0017 and 12% at 40min acquisition, respectively, while NMSE value and COV are 0.0023 and 14% at 30 min acquisition, respectively. According to these results, we conclude the 40min acquisition as optimal scan duration for clinical auto-activation PET study. The distribution of positron emitters generated by carbon ion beam for a clinical target volume (CTV) is slightly larger in fast-scanning system compared with conventional irradiation system. The difference is all explained by presence of penumbra in fast-scanning system. These results show that auto-activation PET method can visualize precisely the absorbed radiation area. \n[Conclusions] According to our analysis, it is clarified that auto-activation PET method can detect precisely absorbed radiation area and it plays an important role in quality assurance of heavy ion beam therapy. |
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| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | EANM Annual Congress 2011 | |||||
| 発表年月日 | ||||||
| 日付 | 2011-10-19 | |||||
| 日付タイプ | Issued | |||||
