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Commissioning of a fluoroscopic-based real-time markerless tumor tracking system in a superconducting rotating gantry for carbon-ion pencil beam scanning treatment
https://repo.qst.go.jp/records/75673
https://repo.qst.go.jp/records/7567361432b40-f80b-4fd7-bf1a-f5805eae5400
| Item type | 学術雑誌論文 / Journal Article(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2019-01-22 | |||||
| タイトル | ||||||
| タイトル | Commissioning of a fluoroscopic-based real-time markerless tumor tracking system in a superconducting rotating gantry for carbon-ion pencil beam scanning treatment | |||||
| 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_6501 | |||||
| 資源タイプ | journal article | |||||
| 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 |
森, 慎一郎
× 森, 慎一郎× 坂田, 幸辰× 平井, 隆介× 古市, 渉× Shimabukuro, Kazuki× 河野, 良介× Woong Seop, Keum× 井関, 康× Kasai, Shigeru× Okaya, Keiko× Mori, Shinichiro× Sakata, Yukinobu× Hirai, Ryusuke× Furuichi, Wataru× Kohno, Ryosuke× Keum, WoongSeop× Iseki, Yasushi |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Purpose: To perform the final quality assurance of our fluoroscopic-based markerless tumor tracking for gated carbon-ion pencil beam scanning (C-PBS) radiotherapy using a rotating gantry system, we evaluated the geometrical accuracy and tumor tracking accuracy using a moving chest phantom with simulated respiration. Methods: The positions of the dynamic flat panel detector (DFPD) and X-ray tube are subject to changes due to gantry sag. To compensate for this, we generated a geometrical calibration table (gantry flex map) in 15° gantry angle steps by the bundle adjustment method. We evaluated five metrics: (i) Geometrical calibration was evaluated by calculating chest phantom positional error using 2D/3D registration software for each 5° step of the gantry angle. (ii) Moving phantom displacement accuracy was measured (± 10 mm in 1-mm steps) with a laser sensor. (iii) Tracking accuracy was evaluated with machine learning (ML) and multi-template matching (MTM) algorithms, which used fluoroscopic images and digitally reconstructed radiographic (DRR) images as training data. The chest phantom was continuously moved ± 10 mm in a sinusoidal path with a moving cycle of 4 s and respiration was simulated with ± 5 mm expansion/contraction with a cycle of 2 s. This was performed with the gantry angle set at 0°, 45°, 120°, and 240°. (iv) Four types of interlock function were evaluated: tumor velocity, DFPD image brightness variation, tracking anomaly detection, and tracking positional inconsistency in between the two corresponding rays. (v) Gate on/off latency, gating control system latency, and beam irradiation latency were measured using a laser sensor and an oscilloscope. Results: By applying the gantry flex map, phantom positional accuracy was improved from 1.03 mm/0.33° to < 0.45 mm/0.27° for all gantry angles. The moving phantom displacement error was 0.1 mm. Due to long computation time, the tracking accuracy achieved with ML was < 0.49 mm (= 95% confidence interval [CI]) for imaging rates of 15 fps and 7.5 fps; those at 30 fps were decreased to 1.84 mm (95% CI: 1.79 mm–1.92 mm). The tracking positional accuracy with MTM was < 0.52 mm (= 95% CI) for all gantry angles and imaging frame rates. The tumor velocity interlock signal delay time was 44.7 ms (= 1.3 frame). DFPD image brightness interlock latency was 34 ms (= 1.0 frame). The tracking positional error was improved from 2.27 ± 2.67 mm to 0.25 ± 0.24 mm by the tracking anomaly detection interlock function. Tracking positional inconsistency interlock signal was output within 5.0 ms. The gate on/off latency was < 82.7 ± 7.6 ms. The gating control system latency was < 3.1 ± 1.0 ms. The beam irradiation latency was < 8.7 ± 1.2 ms. Conclusions: Our markerless tracking system is now ready for clinical use. We hope to shorten the computation time needed by the ML algorithm at 30 fps in the future. |
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| 書誌情報 |
Medical Physics 巻 46, 号 4, p. 1561-1574, 発行日 2019-04 |
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| 出版者 | ||||||
| 出版者 | Wiley | |||||
| ISSN | ||||||
| 収録物識別子タイプ | ISSN | |||||
| 収録物識別子 | 0094-2405 | |||||
| DOI | ||||||
| 識別子タイプ | DOI | |||||
| 関連識別子 | 10.1002/mp.13403 | |||||
| 関連サイト | ||||||
| 識別子タイプ | URI | |||||
| 関連識別子 | https://aapm.onlinelibrary.wiley.com/doi/full/10.1002/mp.13403 | |||||
