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題名 Tumor phase recognition using cone‐beam computed tomography projections and external surrogate information 作者 洪英超
Hung, Y.C.
Tsai, P.F.;Yan, G.;Liu, C.;Kahler, D. L.;Park, J.Y.;Potter, N.;Li, J.G.;Lu, B.貢獻者 統計系 關鍵詞 lung ; tumor phase recognition ; principal component analysis ; singular ; spectrum ; analysis ; gating 日期 2020-05 上傳時間 22-Jan-2021 09:16:15 (UTC+8) 摘要 Purpose: Directly extracting the respiratory phase pattern of the tumor using cone-beam computed tomography (CBCT) projections is challenging due to the poor tumor visibility caused by the obstruction of multiple anatomic structures on the beams-eye view. Predicting tumor phase information using external surrogate also has intrinsic difficulties as the phase patterns between surrogates and tumors are not necessary to be congruent. In this work, we developed an algorithm to accurately recover the primary oscillation components of tumor motion using the combined information from both CBCT projections and external surrogates. Methods: The algorithm involved two steps. First, a preliminary tumor phase pattern was acquired by applying local principal component analysis (LPCA) on the cropped Amsterdam Shroud (AS) images. In this step, only the cropped image of the tumor region was used to extract the tumor phase pattern in order to minimize the impact of pattern recognition from other anatomic structures. Second, by performing multivariate singular spectrum analysis (MSSA) on the combined information containing both external surrogate signal and the original waveform acquired in the first step, the primary component of the tumor phase oscillation was recovered. For the phantom study, a QUASAR respiratory motion phantom with a removable tumor-simulator insert was employed to acquire CBCT projection images. A comparison between LPCA only and our method was assessed by power spectrum analysis. Also, the motion pattern was simulated under the phase shift or various amplitudes conditions to examine the robustness of our method. Finally, anatomic obstruction scenarios were simulated by attaching a heart model, PVC tubes, and RANDO® phantom slabs to the phantom, respectively. Each scenario was tested with five real-patient breathing patterns to mimic real clinical situations. For the patient study, eight patients with various tumor locations were selected. The performance of our method was then evaluated by comparing the reference waveform with the extracted signal for overall phase discrepancy, expiration phase discrepancy, peak, and valley accuracy. Results: In tests of phase shifts and amplitude variations, the overall peak and valley accuracy was -0.009± 0.18 seconds, and no time delay was found compared to the reference. In anatomical obstruction tests, the extracted signal had 1.6± 1.2 % expiration phase discrepancy, -0.12±0.28 second peak accuracy, and 0.01±0.15 second valley accuracy. For patient studies, the extracted signal using our method had -1.05±3.0 % overall phase discrepancy, -1.55±1.45% expiration phase discrepancy, 0.04±0.13 seconds peak accuracy, and -0.01±0.15 seconds valley accuracy, compared to the reference waveforms. Conclusions: An innovative method capable of accurately recognizing tumor phase information was developed. With the aid of extra information from the external surrogate, an improvement in prediction accuracy, as compared with traditional statistical methods, was obtained. It enables us to employ it as the ground truth for 4D-CBCT reconstruction, gating treatment, and other clinic implementations that require accurate tumor phase information. 關聯 Medical Physics, 47:10, 5077-5089 資料類型 article DOI https://doi.org/10.1002/mp.14298 dc.contributor 統計系 dc.creator (作者) 洪英超 dc.creator (作者) Hung, Y.C. dc.creator (作者) Tsai, P.F.;Yan, G.;Liu, C.;Kahler, D. L.;Park, J.Y.;Potter, N.;Li, J.G.;Lu, B. dc.date (日期) 2020-05 dc.date.accessioned 22-Jan-2021 09:16:15 (UTC+8) - dc.date.available 22-Jan-2021 09:16:15 (UTC+8) - dc.date.issued (上傳時間) 22-Jan-2021 09:16:15 (UTC+8) - dc.identifier.uri (URI) http://nccur.lib.nccu.edu.tw/handle/140.119/133661 - dc.description.abstract (摘要) Purpose: Directly extracting the respiratory phase pattern of the tumor using cone-beam computed tomography (CBCT) projections is challenging due to the poor tumor visibility caused by the obstruction of multiple anatomic structures on the beams-eye view. Predicting tumor phase information using external surrogate also has intrinsic difficulties as the phase patterns between surrogates and tumors are not necessary to be congruent. In this work, we developed an algorithm to accurately recover the primary oscillation components of tumor motion using the combined information from both CBCT projections and external surrogates. Methods: The algorithm involved two steps. First, a preliminary tumor phase pattern was acquired by applying local principal component analysis (LPCA) on the cropped Amsterdam Shroud (AS) images. In this step, only the cropped image of the tumor region was used to extract the tumor phase pattern in order to minimize the impact of pattern recognition from other anatomic structures. Second, by performing multivariate singular spectrum analysis (MSSA) on the combined information containing both external surrogate signal and the original waveform acquired in the first step, the primary component of the tumor phase oscillation was recovered. For the phantom study, a QUASAR respiratory motion phantom with a removable tumor-simulator insert was employed to acquire CBCT projection images. A comparison between LPCA only and our method was assessed by power spectrum analysis. Also, the motion pattern was simulated under the phase shift or various amplitudes conditions to examine the robustness of our method. Finally, anatomic obstruction scenarios were simulated by attaching a heart model, PVC tubes, and RANDO® phantom slabs to the phantom, respectively. Each scenario was tested with five real-patient breathing patterns to mimic real clinical situations. For the patient study, eight patients with various tumor locations were selected. The performance of our method was then evaluated by comparing the reference waveform with the extracted signal for overall phase discrepancy, expiration phase discrepancy, peak, and valley accuracy. Results: In tests of phase shifts and amplitude variations, the overall peak and valley accuracy was -0.009± 0.18 seconds, and no time delay was found compared to the reference. In anatomical obstruction tests, the extracted signal had 1.6± 1.2 % expiration phase discrepancy, -0.12±0.28 second peak accuracy, and 0.01±0.15 second valley accuracy. For patient studies, the extracted signal using our method had -1.05±3.0 % overall phase discrepancy, -1.55±1.45% expiration phase discrepancy, 0.04±0.13 seconds peak accuracy, and -0.01±0.15 seconds valley accuracy, compared to the reference waveforms. Conclusions: An innovative method capable of accurately recognizing tumor phase information was developed. With the aid of extra information from the external surrogate, an improvement in prediction accuracy, as compared with traditional statistical methods, was obtained. It enables us to employ it as the ground truth for 4D-CBCT reconstruction, gating treatment, and other clinic implementations that require accurate tumor phase information. dc.format.extent 2779282 bytes - dc.format.mimetype application/pdf - dc.relation (關聯) Medical Physics, 47:10, 5077-5089 dc.subject (關鍵詞) lung ; tumor phase recognition ; principal component analysis ; singular ; spectrum ; analysis ; gating dc.title (題名) Tumor phase recognition using cone‐beam computed tomography projections and external surrogate information dc.type (資料類型) article dc.identifier.doi (DOI) 10.1002/mp.14298 dc.doi.uri (DOI) https://doi.org/10.1002/mp.14298
