Details of the Researcher

PHOTO

Shohei Tanaka
Section
Tohoku University Hospital
Job title
Assistant Professor
Degree
  • 博士(医学)(東北大学)

  • 修士(医科学)(東北大学)

e-Rad No.
90883330

Research History 2

  • 2024/04 - Present
    Tohoku University Hospital University Hospital Therapeutic Radiology

  • 2020/04 - 2024/03
    Tohoku University Hospital University Hospital Therapeutic Radiology Assistant

Education 3

  • Tohoku University Graduate School of Medicine Department of Medical Sciences, Doctoral course

    2020/04 - 2024/03

  • Tohoku University Graduate School of Medicine Department of Medical Sciences, Master's course

    2018/04 - 2020/03

  • Tohoku University Faculty of Medicine School of Health Sciences, School of Medicine

    2014/04 - 2018/03

Professional Memberships 4

  • Japan Society of Medical Physics

    2018/05 - Present

  • Japan Society for Radiation Oncology

    2018/04 - Present

  • Medical Imaging and Information Sciences

    2019/08 - 2022/03

  • Japan Radiological Society

    2018/06 - 2020/03

Research Interests 5

  • MR-Linac

  • Machine learning

  • Radiotherapy

  • Deep learning

  • Radiomics

Research Areas 1

  • Life sciences / Tumor diagnostics and therapeutics /

Awards 2

  1. President's Award Silver

    2019/04 The 117th Scientific Meeting of the Japan Society of Medical Physics Homology as novel radiomic features for prediction of the prognosis of lung cancer based on CT-based radiomics

  2. 座長推薦優秀研究発表

    2018/12 第46回日本放射線技術学会秋季学術大会 胸部領域のCT-based Radiomicsにおける施設 毎のロバストなRadiomic特徴量の新たな絞り 込み法の開発

Papers 30

  1. Evaluation of deliverable artificial intelligence-based automated volumetric arc radiation therapy planning for whole pelvic radiation in gynecologic cancer. International-journal

    Yushan Xiao, Shohei Tanaka, Noriyuki Kadoya, Kiyokazu Sato, Yuto Kimura, Rei Umezawa, Yoshiyuki Katsuta, Kazuhiro Arai, Haruna Takahashi, Taichi Hoshino, Keiichi Jingu

    Scientific reports 15 (1) 15219-15219 2025/04/30

    DOI: 10.1038/s41598-025-99717-y  

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    This study aimed to develop a deep learning (DL)-based deliverable whole pelvic volumetric arc radiation therapy (VMAT) for patients with gynecologic cancer using a prototype DL-based automated planning support system, named RatoGuide, to evaluate its clinical validity. In our hospital, 110 patients with gynecologic cancer were registered. The prescribed dose was 50.4 Gy/28 fr. A DL-based three-dimensional dose prediction model was first trained by the dose distribution and structure data of whole pelvic VMAT (n = 100) created on the Monaco treatment planning system (TPS). The structure data of the test data (n = 10) were then input to RatoGuide, and RatoGuide predicted the dose distribution of the whole pelvic VMAT plan (PreDose). We established deliverable plans with Monaco and Eclipse TPS (DeliDose) based on PreDose and vendor-supplied optimization objectives. Medical physicists then manually developed plans (CliDose) for the test data. Finally, we evaluated and compared the dose distribution and dose constraints of PreDose, DeliDose, and CliDose. DeliDose, in both Eclipse and Monaco, was comparable to PreDose in most Dose constraints, planning target volume (PTV) coverage, and Dmax of the bladder, rectum, and bowel bag were better for DeliDose than for PreDose. Additionally, DeliDose demonstrated no significant difference from CliDose in most dose constraints. The blinded average scores of radiation oncologists for DeliDose and CliDose were 4.2 ± 0.4 and 4.3 ± 0.5, respectively, in Eclipse, and 4.0 ± 0.6 and 3.9 ± 0.5, respectively, in Monaco (5 is the max score and 3 is clinically acceptable). We indicated that RatoGuide can eliminate variations in plan quality between hospitals in whole pelvic VMAT irradiation and help develop VMAT plans in a short time.

  2. Radiomics and dosiomics approaches to estimate lung function after stereotactic body radiation therapy in patients with lung tumors.

    Yoshiro Ieko, Noriyuki Kadoya, Shohei Tanaka, Koyo Kikuchi, Takaya Yamamoto, Hisanori Ariga, Keiichi Jingu

    Radiological physics and technology 2025/01/14

    DOI: 10.1007/s12194-024-00877-9  

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    Lung function assessment is essential for determining the optimal treatment strategy for radiation therapy in patients with lung tumors. This study aimed to develop radiomics and dosiomics approaches to estimate pulmonary function test (PFT) results in post-stereotactic body radiation therapy (SBRT). Sixty-four patients with lung tumors who underwent SBRT were included. Models were created to estimate the PFT results at 0-6 months (Cohort 1) and 6-24 months (Cohort 2) after SBRT. Radiomics and dosiomics features were extracted from the computed tomography (CT) images and dose distributions, respectively. To estimate the PFT results, Models A (dose-volume histogram [DVH] + radiomics features) and B (DVH + radiomics + dosiomics features) were created. In the PFT results, the forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were estimated using each model, and the ratio of FEV1 to FVC (FEV1/FVC) was calculated. The Pearson's correlation coefficient (Pearson r) and area under the curve (AUC) for FEV1/FVC (< 70%) were calculated. The models were evaluated by comparing them with the conventional calculation formulae (Conventional). The Pearson r (FEV1/FVC) values were 0.30, 0.64, and 0.69 for Conventional and Models A and B (Cohort 2), respectively, and the AUC (FEV1/FVC < 70%) values were 0.63, 0.80, and 0.78, respectively. This study demonstrates the possibility of estimating lung function after SBRT using radiomics and dosiomics features based on planning CT images and dose distributions.

  3. Investigation of intrafractional spinal cord and spinal canal movement during stereotactic MR-guided online adaptive radiotherapy for kidney cancer

    Takaya Yamamoto, Shohei Tanaka, Noriyoshi Takahashi, Rei Umezawa, Yu Suzuki, Keita Kishida, So Omata, Kazuya Takeda, Hinako Harada, Kiyokazu Sato, Yoshiyuki Katsuta, Noriyuki Kadoya, Keiichi Jingu

    PLOS ONE 2024/10/30

    DOI: 10.1371/journal.pone.0312032  

  4. Assessing knowledge about medical physics in language-generative AI with large language model: using the medical physicist exam.

    Noriyuki Kadoya, Kazuhiro Arai, Shohei Tanaka, Yuto Kimura, Ryota Tozuka, Keisuke Yasui, Naoki Hayashi, Yoshiyuki Katsuta, Haruna Takahashi, Koki Inoue, Keiichi Jingu

    Radiological physics and technology 2024/09/10

    DOI: 10.1007/s12194-024-00838-2  

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    This study aimed to evaluate the performance for answering the Japanese medical physicist examination and providing the benchmark of knowledge about medical physics in language-generative AI with large language model. We used questions from Japan's 2018, 2019, 2020, 2021 and 2022 medical physicist board examinations, which covered various question types, including multiple-choice questions, and mainly focused on general medicine and medical physics. ChatGPT-3.5 and ChatGPT-4.0 (OpenAI) were used. We compared the AI-based answers with the correct ones. The average accuracy rates were 42.2 ± 2.5% (ChatGPT-3.5) and 72.7 ± 2.6% (ChatGPT-4), showing that ChatGPT-4 was more accurate than ChatGPT-3.5 [all categories (except for radiation-related laws and recommendations/medical ethics): p value < 0.05]. Even with the ChatGPT model with higher accuracy, the accuracy rates were less than 60% in two categories; radiation metrology (55.6%), and radiation-related laws and recommendations/medical ethics (40.0%). These data provide the benchmark for knowledge about medical physics in ChatGPT and can be utilized as basic data for the development of various medical physics tools using ChatGPT (e.g., radiation therapy support tools with Japanese input).

  5. Beginning of clinical treatment using the 1.5 Tesla MR-Linac system in Japan: a narrative review. International-journal

    Noriyoshi Takahashi, Shohei Tanaka, Rei Umezawa, Takaya Yamamoto, Yu Suzuki, Keita Kishida, So Omata, Kazuhiro Arai, Yoshiyuki Katsuta, Noriyuki Kadoya, Keiichi Jingu

    Translational cancer research 13 (2) 1131-1138 2024/02/29

    DOI: 10.21037/tcr-23-1649  

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    BACKGROUND AND OBJECTIVE: In the field of radiation therapy, image-guided radiotherapy (IGRT) technology has been gradually improving and highly accurate radiation treatment has been possible. Research on IGRT using 1.5 Tesla magnetic resonance imaging (MRI) began in 1999, and a radiation therapy device called 1.5 Tesla magnetic resonance linear accelerator (MR-Linac), which combines a linear accelerator with 1.5 Tesla MRI, was developed in Europe. The aim of this review is to present an overview of 1.5 Tesla MR-Linac with a review of the literature and our experience. METHODS: Reports related to 1.5 Tesla MR-Linac were searched for in PubMed and are discussed in relation to our experience. KEY CONTENT AND FINDINGS: The 1.5 Tesla MR-Linac enables IGRT using 1.5 Tesla MRI, further enhancing the precision of radiation therapy. Position verification by cone-beam computed tomography (CBCT) is performed in many institutions, but soft tissue contrast is often unclear in CBCT images of the abdomen and mediastinal organs. Since the 1.5 Tesla MR-Linac allows position verification using MRI, position verification can be performed using clear MRI even in regions where CBCT is unclear. With the 1.5 Tesla MR-Linac, it is possible to perform online adaptive radiotherapy (ART) using 1.5 Tesla MRI. Online ART is a method in which images are acquired while the patient is on the treatment table. The method is based on the current condition of the organs in the body on that day and an optimal treatment field is recreated. Additionally, it allows monitoring of tumor motion using cine images obtained by 1.5 Tesla MRI during the delivery of X-ray radiation. A previous report showed that patients with prostate cancer who received radiotherapy by MR-Linac had fewer side effects than those in patients who received conventional CBCT radiation therapy. CONCLUSIONS: The 1.5 Tesla MR-Linac obtained CE-mark certification in Europe in August 2018 and it has been used for clinical treatment. In Japan, clinical treatment using this device started in 2021. By using 1.5 Tesla MR-Linac, patients can be provided with higher precision radiotherapy. In this review, we provide an overview of 1.5 Tesla MR-Linac.

  6. 【IGRT今後の展開】エレクタUnityの装置導入と1年半の臨床経験

    角谷 倫之, 田中 祥平, 佐藤 清和, 新井 一弘, 高橋 紀善, 梅澤 玲, 神宮 啓一

    Rad Fan 21 (13) 48-52 2023/11

    Publisher: (株)メディカルアイ

    ISSN: 1348-3498

  7. Evaluation of deep learning-based deliverable VMAT plan generated by prototype software for automated planning for prostate cancer patients. International-journal

    Noriyuki Kadoya, Yuto Kimura, Ryota Tozuka, Shohei Tanaka, Kazuhiro Arai, Yoshiyuki Katsuta, Hidetoshi Shimizu, Yuto Sugai, Takaya Yamamoto, Rei Umezawa, Keiichi Jingu

    Journal of radiation research 64 (5) 842-849 2023/09/22

    DOI: 10.1093/jrr/rrad058  

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    This study aims to evaluate the dosimetric accuracy of a deep learning (DL)-based deliverable volumetric arc radiation therapy (VMAT) plan generated using DL-based automated planning assistant system (AIVOT, prototype version) for patients with prostate cancer. The VMAT data (cliDose) of 68 patients with prostate cancer treated with VMAT treatment (70-74 Gy/28-37 fr) at our hospital were used (n = 55 for training and n = 13 for testing). First, a HD-U-net-based 3D dose prediction model implemented in AIVOT was customized using the VMAT data. Thus, a predictive VMAT plan (preDose) comprising AIVOT that predicted the 3D doses was generated. Second, deliverable VMAT plans (deliDose) were created using AIVOT, the radiation treatment planning system Eclipse (version 15.6) and its vender-supplied objective functions. Finally, we compared these two estimated DL-based VMAT treatment plans-i.e. preDose and deliDose-with cliDose. The average absolute dose difference of all DVH parameters for the target tissue between cliDose and deliDose across all patients was 1.32 ± 1.35% (range: 0.04-6.21%), while that for all the organs at risks was 2.08 ± 2.79% (range: 0.00-15.4%). The deliDose was superior to the cliDose in all DVH parameters for bladder and rectum. The blinded plan scoring of deliDose and cliDose was 4.54 ± 0.50 and 5.0 ± 0.0, respectively (All plans scored ≥4 points, P = 0.03.) This study demonstrated that DL-based deliverable plan for prostate cancer achieved the clinically acceptable level. Thus, the AIVOT software exhibited a potential for automated planning with no intervention for patients with prostate cancer.

  8. Evaluation of Unity 1.5 T MR-linac plan quality in patients with prostate cancer. International-journal

    Shohei Tanaka, Noriyuki Kadoya, Miyu Ishizawa, Yoshiyuki Katsuta, Kazuhiro Arai, Haruna Takahashi, Yushan Xiao, Noriyoshi Takahashi, Kiyokazu Sato, Ken Takeda, Keiichi Jingu

    Journal of applied clinical medical physics e14122 2023/08/10

    DOI: 10.1002/acm2.14122  

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    The Unity magnetic resonance (MR) linear accelerator (MRL) with MR-guided adaptive radiotherapy (MRgART) is capable of online MRgART where images are acquired on the treatment day and the radiation treatment plan is immediately replanned and performed. We evaluated the MRgART plan quality and plan reproducibility of the Unity MRL in patients with prostate cancer. There were five low- or moderate-risk and five high-risk patients who received 36.25 Gy or 40 Gy, respectively in five fractions. All patients underwent simulation magnetic resonance imaging (MRI) and five online adaptive MRI. We created plans for 5, 7, 9, 16, and 20 beams and for 60, 100, and 150 segments. We evaluated the target and organ doses for different number of beams and segments, respectively. Variation in dose constraint between the simulation plan and online adaptive plan was measured for each patient to assess plan reproducibility. The plan quality improved with the increasing number of beams. However, the proportion of significantly improved dose constraints decreased as the number of beams increased. For some dose parameters, there were statistically significant differences between 60 and 100 segments, and 100 and 150 segments. The plan of five beams exhibited limited reproducibility. The number of segments had minimal impact on plan reproducibility, but 60 segments sometimes failed to meet dose constraints for online adaptive plan. The optimization and delivery time increased with the number of beams and segments. We do not recommend using five or fewer beams for a reproducible and high-quality plan in the Unity MRL. In addition, many number of segments and beams may help meet dose constraints during online adaptive plan. Treatment with the Unity MRL should be performed with the appropriate number of beams and segments to achieve a good balance among plan quality, delivery time, and optimization time.

  9. Evaluation of the MVCT-based radiomic features as prognostic factor in patients with head and neck squamous cell carcinoma. International-journal

    Kota Abe, Noriyuki Kadoya, Kei Ito, Shohei Tanaka, Yujiro Nakajima, Shimpei Hashimoto, Yuhi Suda, Takashi Uno, Keiichi Jingu

    BMC medical imaging 23 (1) 102-102 2023/08/01

    DOI: 10.1186/s12880-023-01055-w  

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    BACKGROUND: Megavoltage computed tomography (MVCT) images acquired during each radiotherapy session may be useful for delta radiomics. However, no studies have examined whether the MVCT-based radiomics has prognostic power. Therefore, the purpose of this study was to examine the prognostic power of the MVCT-based radiomics for head and neck squamous cell carcinoma (HNSCC) patients. METHODS: 100 HNSCC patients who received definitive radiotherapy were analyzed and divided into two groups: training (n = 70) and test (n = 30) sets. MVCT images obtained using TomoTherapy for the first fraction of radiotherapy and planning kilovoltage CT (kVCT) images obtained using Aquilion LB CT scanner were analyzed. Primary gross tumor volume (GTV) was propagated from kVCT to MVCT images using rigid registration, and 107 radiomic features were extracted from the GTV in MVCT and kVCT images. Least absolute shrinkage and selection operator (LASSO) Cox regression model was used to examine the association between overall survival (OS) and rad score calculated for each patient by weighting the feature value through the coefficient when features were selected. Then, the predictive values of MVCT-based and kVCT-based rad score and patient-, treatment-, and tumor-specific factors were evaluated. RESULTS: C-indices of the rad score for MVCT- and kVCT-based radiomics were 0.667 and 0.685, respectively. The C-indices of 6 clinical factors were 0.538-0.622. The 3-year OS was significantly different between high- and low-risk groups according to the MVCT-based rad score (50% vs. 83%; p < 0.01). CONCLUSIONS: Our results suggested that MVCT-based radiomics had stronger prognostic power than any single clinical factor and was a useful prognostic factor when predicting OS in HNSCC patients.

  10. Development of a prediction model for head and neck volume reduction by clinical factors, dose-volume histogram parameters and radiomics in head and neck cancer Peer-reviewed

    Ishizawa M, Tanaka S, Takagi H, Kadoya N, Sato K, Umezawa R, Jingu K, Takeda K

    J Radiat Res 2023/07/18

    DOI: 10.1093/jrr/rrad052  

  11. Development of a collapsed cone convolution/superposition dose calculation algorithm with a mass density-specific water kernel for magnetic resonance-guided radiotherapy

    Kengo ITO, Yojiro Ishikawa, Satoshi Teramura, Noriyuki Kadoya, Yoshiyuki Katsuta, Shohei Tanaka, Ken Takeda, Keiichi Jingu, Takayuki Yamada

    Journal of Radiation Research 2023/03/21

    Publisher: Oxford University Press (OUP)

    DOI: 10.1093/jrr/rrad011  

    ISSN: 0449-3060

    eISSN: 1349-9157

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    Abstract This study aimed to develop and validate a collapsed cone convolution for magnetic resonance-guided radiotherapy (CCCMR). The 3D energy deposition kernels (EDKs) were generated in water in a 1.5-T transverse magnetic field. The CCCMR corrects the inhomogeneity in simulation geometry by referring to the EDKs according to the mass density between the interaction and energy deposition points in addition to density scaling. Dose distributions in a water phantom and in slab phantoms with inserted inhomogeneities were calculated using the Monte Carlo (MC) and CCCMR. The percentage depth dose (PDD) and off-axis ratio (OAR) were compared, and the gamma passing rate (3%/2 mm) was evaluated. The CCCMR simulated asymmetric dose distributions in the simulation phantoms, especially the water phantom, and all PDD and OAR profiles were in good agreement with the findings of the MC. The gamma passing rates were &amp;gt;99% for each field size and for the entire region. In the inhomogeneity phantoms, although the CCCMR underestimated dose in the low mass density regions, it could reconstruct dose changes at mass density boundaries. The gamma passing rate for the entire region was &amp;gt;95% for the field size of 2 × 2 cm2, but it was 68.9–86.7% for the field sizes of ≥5 × 5 cm2. Conclusively, in water, the CCCMR can obtain dose distributions comparable to those with the MC. Although the dose differences between them were mainly in inhomogeneity regions, the possibility of the effective use of the CCCMR in small field sizes was demonstrated.

  12. Development and validation of an [18F]FDG-PET/CT radiomic model for predicting progression-free survival for patients with stage II – III thoracic esophageal squamous cell carcinoma who are treated with definitive chemoradiotherapy

    Noriyoshi Takahashi, Shohei Tanaka, Rei Umezawa, Kentaro Takanami, Kazuya Takeda, Takaya Yamamoto, Yu Suzuki, Yoshiyuki Katsuta, Noriyuki Kadoya, Keiichi Jingu

    Acta Oncologica 62 (2) 159-165 2023/02/01

    Publisher: Informa UK Limited

    DOI: 10.1080/0284186x.2023.2178859  

    ISSN: 0284-186X

    eISSN: 1651-226X

  13. Dosimetric impact of deformable image registration using radiophotoluminescent glass dosimeters with a physical geometric phantom. International-journal

    Siwaporn Sakulsingharoj, Noriyuki Kadoya, Shohei Tanaka, Kiyokazu Sato, Mitsuhiro Nakamura, Keiichi Jingu

    Journal of applied clinical medical physics e13890 2023/01/07

    DOI: 10.1002/acm2.13890  

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    PURPOSE: To study the dosimetry impact of deformable image registration (DIR) using radiophotoluminescent glass dosimeter (RPLD) and custom developed phantom with various inserts. METHODS: The phantom was developed to facilitate simultaneous evaluation of geometric and dosimetric accuracy of DIR. Four computed tomography (CT) images of the phantom were acquired with four different configurations. Four volumetric modulated arc therapy (VMAT) plans were computed for different phantom. Two different patterns were applied to combination of four phantom configurations. RPLD dose measurement was combined between corresponding two phantom configurations. DIR-based dose accumulation was calculated between corresponding two CT images with two commercial DIR software and various DIR parameter settings, and an open source software. Accumulated dose calculated using DIR was then compared with measured dose using RPLD. RESULTS: The mean ± standard deviation (SD) of dose difference was 2.71 ± 0.23% (range, 2.22%-3.01%) for tumor-proxy and 3.74 ± 0.79% (range, 1.56%-4.83%) for rectum-proxy. The mean ± SD of target registration error (TRE) was 1.66 ± 1.36 mm (range, 0.03-4.43 mm) for tumor-proxy and 6.87 ± 5.49 mm (range, 0.54-17.47 mm) for rectum-proxy. These results suggested that DIR accuracy had wide range among DIR parameter setting. CONCLUSIONS: The dose difference observed in our study was 3% for tumor-proxy and within 5% for rectum-proxy. The custom developed physical phantom with inserts showed potential for accurate evaluation of DIR-based dose accumulation. The prospect of simultaneous evaluation of geometric and dosimetric DIR accuracy in a single phantom may be useful for validation of DIR for clinical use.

  14. Radiation pneumonitis prediction model with integrating multiple dose-function features on 4DCT ventilation images

    Yoshiyuki Katsuta, Noriyuki Kadoya, Tomohiro Kajikawa, Shina Mouri, Tomoki Kimura, Kazuya Takeda, Takaya Yamamoto, Nobuki Imano, Shohei Tanaka, Kengo Ito, Takayuki Kanai, Yujiro Nakajima, Keiichi Jingu

    Physica Medica 105 102505-102505 2023/01

    Publisher: Elsevier BV

    DOI: 10.1016/j.ejmp.2022.11.009  

    ISSN: 1120-1797

  15. Comparison of acute gastrointestinal toxicities between 3-dimensional conformal radiotherapy and intensity-modulated radiotherapy including prophylactic regions in chemoradiotherapy with S-1 for pancreatic cancer-importance of dose volume histogram parameters in the stomach as the predictive factors. International-journal Peer-reviewed

    Rei Umezawa, Kei Nakagawa, Masamichi Mizuma, Yoshiyuki Katsuta, Shohei Tanaka, Noriyuki Kadoya, Yu Suzuki, Kazuya Takeda, Noriyoshi Takahashi, Takaya Yamamoto, Michiaki Unno, Keiichi Jingu

    Journal of radiation research 63 (6) 856-865 2022/12/06

    DOI: 10.1093/jrr/rrac049  

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    The purpose of this study was to compare acute gastrointestinal (GI) toxicities in patients who underwent 3-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT) in chemoradiotherapy (CRT) with S-1 including prophylactic regions for pancreatic cancer. We also investigated the predictive factor of acute GI toxicities in dose volume histogram (DVH) parameters. Patients who received CRT with S-1 for pancreatic cancer between January 2014 and March 2021 were included. Radiotherapy (RT) with a total dose of 50-54 Gy was delivered. We examined the differences in the frequencies of acute GI toxicity of grade 2 or higher and DVH parameters of the stomach (ST) and duodenum (DU) between the 3DCRT group and the IMRT group. The RT-related predictive factors of acute GI toxicities were investigated by univariate and multivariate analyses. There were 25 patients in the 3DCRT group and 31 patients in the IMRT group. The frequencies of acute GI toxicity of G2 or higher were 36% in the 3DCRT group and 9.7% in the IMRT group (p = 0.035). ST V50 was the most predictive factor (p = 0.001), and the incidences of acute GI toxicity of G2 or higher in ST V50 ≥ 4.1 cc and < 4.1cc were 43.7% and 7.7%, respectively. ST V40 was also a significant predictive factor of acute GI toxicity (p = 0.002). IMRT could reduce acute GI toxicities in CRT with S-1 including prophylactic regions for pancreatic cancer. Acute GI toxicities may be affected by moderate to high doses to the ST.

  16. 胸部領域における新規開発した治療計画支援ソフトウェアの非剛体レジストレーションの精度評価

    高橋 春奈, 角谷 倫之, 勝田 義之, 田中 祥平, 新井 一弘, 山本 貴也, 梅澤 玲, 神宮 啓一

    日本放射線技術学会雑誌 78 (10) 1187-1193 2022/10

    Publisher: (公社)日本放射線技術学会

    ISSN: 0369-4305

    eISSN: 1881-4883

  17. Assessment of a computed tomography-based radiomics approach for assessing lung function in lung cancer patients. International-journal Peer-reviewed

    Yoshiro Ieko, Noriyuki Kadoya, Yuto Sugai, Shiina Mouri, Mariko Umeda, Shohei Tanaka, Takayuki Kanai, Kei Ichiji, Takaya Yamamoto, Hisanori Ariga, Keiichi Jingu

    Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB) 101 28-35 2022/09

    Publisher: Elsevier BV

    DOI: 10.1016/j.ejmp.2022.07.003  

    ISSN: 1120-1797

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    PURPOSE: We aimed to assess radiomics approaches for estimating three pulmonary function test (PFT) results (forced expiratory volume in one second [FEV1], forced vital capacity [FVC], and the ratio of FEV1 to FVC [FEV1/FVC]) using data extracted from chest computed tomography (CT) images. METHODS: This retrospective study included 85 lung cancer patients (mean age, 75 years ±8; 69 men) who underwent stereotactic body radiotherapy between 2012 and 2020. Their pretreatment chest breath-hold CT and PFT data before radiotherapy were obtained. A total of 107 radiomics features (Shape: 14, Intensity: 18, Texture: 75) were extracted using two methods: extraction of the lung tissue (<-250 HU) (APPROACH 1), and extraction of small blood vessels and lung tissue (APPROACH 2). The PFT results were estimated using the least absolute shrinkage and selection operator regression. Pearson's correlation coefficients (r) were determined for all PFT results, and the area under the curve (AUC) was calculated for FEV1/FVC (<70 %). Finally, we compared our approaches with the conventional formula (Conventional). RESULTS: For the estimated FEV1/FVC, the Pearson's r were 0.21 (P =.06), 0.69 (P <.01), and 0.73 (P <.01) for Conventional, APPROACH 1, and APPROACH 2, respectively; the AUCs for FEV1/FVC (<70 %) were 0.67 (95 % confidence interval [CI]: 0.55, 0.79), 0.82 (CI: 0.72, 0.91; P =.047) and 0.86 (CI: 0.78, 0.94; P =.01), respectively. CONCLUSIONS: The radiomics approach performed better than the conventional equation and may be useful for assessing lung function based on CT images.

  18. [Evaluation of Accuracy of Deformable Image Registration with Newly Developed Treatment Planning Support Software for Thoracic Images].

    Haruna Takahashi, Noriyuki Kadoya, Yoshiyuki Katsuta, Shohei Tanaka, Kazuhiro Arai, Takaya Yamamoto, Rei Umezawa, Keiichi Jingu

    Nihon Hoshasen Gijutsu Gakkai zasshi 78 (10) 1187-1193 2022/08/24

    DOI: 10.6009/jjrt.2022-1308  

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    This study evaluated accuracy of deformable image registration (DIR) with twelve parameter settings for thoracic images. We used peak-inhale and peak-exhale images for ten patients provided by DIR-lab. We used a prototype version of iCView software (ITEM Corporation) with DIR to perform intensity, structure, and hybrid-based DIR with the twelve parameter settings. DIR accuracy was evaluated by a target registration error (TRE) using 300 bronchial bifurcations and the Dice similarity coefficient (DSC) of the lungs. For twelve parameter settings, TRE ranged from 2.83 mm to 5.27 mm, whereas DSC ranged from 0.96 to 0.98. These results demonstrated that DIR accuracy differed among parameter settings and show that appropriate parameter settings are required for clinical practice.

  19. Brachytherapy for primary nasal vestibule cancer using Au-198 grains. International-journal

    Hinako Harada, Yojiro Ishikawa, Shohei Tanaka, Keita Kishida, Rei Umezawa, Takaya Yamamoto, Noriyoshi Takahashi, Kazuya Takeda, Yu Suzuki, Keiichi Jingu

    International cancer conference journal 11 (3) 184-187 2022/07

    DOI: 10.1007/s13691-022-00546-x  

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    Radiation therapy (RT) is one of the definitive treatments for early-stage nasal vestibular carcinoma and has similar local control rates to resection surgery. There are various methods, including external beam RT and brachytherapy. This report describes a case who showed local control for more than 5 years after brachytherapy alone using Au-198 grains for nasal vestibular carcinoma. A 68-year-old Japanese man complained of swelling and pain in his left nasal cavity. He was diagnosed with squamous cell carcinoma (SCC) (cT1N0M0, stage I). An elevated mass of 8 mm in long diameter was found inside the left nasal cavity. Since the patient selected brachytherapy, nine Au-198 grains 185 mBq were permanently injected percutaneously under local anesthesia, and 85 Gy was prescribed. Grade three dermatitis was observed as an acute adverse event. After 2 years, mild telangiectasia of the left nasal skin and epilation of nasal hair in the left nasal cavity was regarded as late adverse events. The patient continues to keep a complete response for 5 years. For small nasal vestibular SCC, brachytherapy with Au-198 grains might be a good option.

  20. Feasibility of Differential Dose-Volume Histogram Features in Multivariate Prediction Model for Radiation Pneumonitis Occurrence. International-journal Peer-reviewed

    Yoshiyuki Katsuta, Noriyuki Kadoya, Yuto Sugai, Yu Katagiri, Takaya Yamamoto, Kazuya Takeda, Shohei Tanaka, Keiichi Jingu

    Diagnostics (Basel, Switzerland) 12 (6) 1354-1354 2022/05/31

    Publisher: MDPI AG

    DOI: 10.3390/diagnostics12061354  

    eISSN: 2075-4418

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    The purpose of this study is to introduce differential dose–volume histogram (dDVH) features into machine learning for radiation pneumonitis (RP) prediction and to demonstrate the predictive performance of the developed model based on integrated cumulative dose–volume histogram (cDVH) and dDVH features. Materials and methods: cDVH and dDVH features were calculated for 153 patients treated for non-small-cell lung cancer with 60–66 Gy and dose bins ranging from 2 to 8 Gy in 2 Gy increments. RP prediction models were developed with the least absolute shrinkage and selection operator (LASSO) through fivefold cross-validation. Results: Among the 152 patients in the patient cohort, 41 presented ≥grade 2 RP. The interdependencies between cDVH features evaluated by Spearman’s correlation were significantly resolved by the inclusion of dDVH features. The average area under curve for the RP prediction model using cDVH and dDVH model was 0.73, which was higher than the average area under curve using cDVH model for 0.62 with statistically significance (p &lt; 0.01). An analysis using the entire set of regression coefficients determined by LASSO demonstrated that dDVH features represented four of the top five frequently selected features in the model fitting, regardless of dose bin. Conclusions: We successfully developed an RP prediction model that integrated cDVH and dDVH features. The best RP prediction model was achieved using dDVH (dose bin = 4 Gy) features in the machine learning process.

  21. A deep learning-based radiomics approach to predict head and neck tumor regression for adaptive radiotherapy. International-journal Peer-reviewed

    Shohei Tanaka, Noriyuki Kadoya, Yuto Sugai, Mariko Umeda, Miyu Ishizawa, Yoshiyuki Katsuta, Kengo Ito, Ken Takeda, Keiichi Jingu

    Scientific reports 12 (1) 8899-8899 2022/05/27

    Publisher: Springer Science and Business Media LLC

    DOI: 10.1038/s41598-022-12170-z  

    eISSN: 2045-2322

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    Abstract Early regression—the regression in tumor volume during the initial phase of radiotherapy (approximately 2 weeks after treatment initiation)—is a common occurrence during radiotherapy. This rapid radiation-induced tumor regression may alter target coordinates, necessitating adaptive radiotherapy (ART). We developed a deep learning-based radiomics (DLR) approach to predict early head and neck tumor regression and thereby facilitate ART. Primary gross tumor volume (GTVp) was monitored in 96 patients and nodal GTV (GTVn) in 79 patients during treatment. All patients underwent two computed tomography (CT) scans: one before the start of radiotherapy for initial planning and one during radiotherapy for boost planning. Patients were assigned to regression and nonregression groups according to their median tumor regression rate (ΔGTV/treatment day from initial to boost CT scan). We input a GTV image into the convolutional neural network model, which was pretrained using natural image datasets, via transfer learning. The deep features were extracted from the last fully connected layer. To clarify the prognostic power of the deep features, machine learning models were trained. The models then predicted the regression and nonregression of GTVp and GTVn and evaluated the predictive performance by 0.632 + bootstrap area under the curve (AUC). Predictive performance for GTVp regression was highest using the InceptionResNetv2 model (mean AUC = 0.75) and that for GTVn was highest using NASNetLarge (mean AUC = 0.73). Both models outperformed the handcrafted radiomics features (mean AUC = 0.63 for GTVp and 0.61 for GTVn) or clinical factors (0.64 and 0.67, respectively). DLR may facilitate ART for improved radiation side-effects and target coverage.

  22. Prediction of radiation pneumonitis with machine learning using 4D-CT based dose-function features. International-journal Peer-reviewed

    Yoshiyuki Katsuta, Noriyuki Kadoya, Shina Mouri, Shohei Tanaka, Takayuki Kanai, Kazuya Takeda, Takaya Yamamoto, Kengo Ito, Tomohiro Kajikawa, Yujiro Nakajima, Keiichi Jingu

    Journal of radiation research 63 (1) 71-79 2022/01/20

    Publisher: Oxford University Press (OUP)

    DOI: 10.1093/jrr/rrab097  

    ISSN: 0449-3060

    eISSN: 1349-9157

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    Abstract In this article, we highlight the fundamental importance of the simultaneous use of dose-volume histogram (DVH) and dose-function histogram (DFH) features based on functional images calculated from 4-dimensional computed tomography (4D-CT) and deformable image registration (DIR) in developing a multivariate radiation pneumonitis (RP) prediction model. The patient characteristics, DVH features and DFH features were calculated from functional images by Hounsfield unit (HU) and Jacobian metrics, for an RP grade ≥ 2 multivariate prediction models were computed from 85 non-small cell lung cancer patients. The prediction model is developed using machine learning via a kernel-based support vector machine (SVM) machine. In the patient cohort, 21 of the 85 patients (24.7%) presented with RP grade ≥ 2. The median area under curve (AUC) was 0.58 for the generated 50 prediction models with patient clinical features and DVH features. When HU metric and Jacobian metric DFH features were added, the AUC improved to 0.73 and 0.68, respectively. We conclude that predictive RP models that incorporate DFH features were successfully developed via kernel-based SVM. These results demonstrate that effectiveness of the simultaneous use of DVH features and DFH features calculated from 4D-CT and DIR on functional image-guided radiotherapy.

  23. Evaluation of the electron transport algorithm in magnetic field in EGS5 Monte Carlo code. International-journal Peer-reviewed

    Kengo Ito, Noriyuki Kadoya, Yoshiyuki Katsuta, Shohei Tanaka, Suguru Dobashi, Ken Takeda, Keiichi Jingu

    Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB) 93 46-51 2022/01

    Publisher: Elsevier BV

    DOI: 10.1016/j.ejmp.2021.12.001  

    ISSN: 1120-1797

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    PURPOSE: To evaluate the accuracy of electron transport in the magnetic field of Electron Gamma Shower version 5 (EGS5) by using the special Fano cavity test. METHODS: To simulate electron transport in the magnetic field, the trajectory of the electron was reconstructed with a short step length to restrict fractional energy loss, and the maximum user step length (mxustep) was set at 0.01 cm or 0.001 cm. For the special Fano cavity test, three-layer slab Fano test geometry was used, and uniform and isotropic per unit mass mono-energetic electrons with 0.01, 0.1, 1.0, and 10 MeV were permitted from the central axis of geometry in 0.35 T and 1.5 T. Furthermore, the magnetic field strength was scaled based on the mass density of the material. The relative difference between the calculated dose to gap and the theoretical value was evaluated. Furthermore, the special Fano cavity test was also performed using EGSnrc with the electron-enhanced electric and magnetic field macros under the same conditions, and the results were compared with those of EGS5. RESULTS: Deviations in 0.35 T were within 0.3% regardless of the parameter settings. In 1.5 T, stable results within 0.3% were obtained using 0.001 cm as the mxustep, except for one at 10 MeV. Further, the accuracy of EGSnrc was within 0.2%, except for 10 MeV for a 0.2-cm gap in 1.5 T. CONCLUSIONS: EGS5 with the appropriate parameter settings enable electron transport in magnetic fields similar with the accuracy of EGSnrc.

  24. Evaluation of the dosimetric impact of heart function-based volumetric modulated arc therapy planning in patients with esophageal cancer. Peer-reviewed

    Shohei Tanaka, Noriyuki Kadoya, Rei Umezawa, Hikaru Nemoto, Yoshiyuki Katsuta, Kengo Ito, Ken Takeda, Keiichi Jingu

    Radiological physics and technology 14 (3) 279-287 2021/09

    Publisher: Springer Science and Business Media LLC

    DOI: 10.1007/s12194-021-00623-5  

    ISSN: 1865-0333

    eISSN: 1865-0341

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    Radiotherapy for esophageal cancer entails high-dose irradiation of the myocardium owing to its close anatomical proximity to the esophagus. This study aimed to evaluate the dosimetric impact of functional avoidance planning for the myocardium with volumetric-modulated arc therapy (VMAT) in patients with esophageal cancer and determine the feasibility of functional planning. Ten patients with early stage esophageal cancer were included in this study. The prescribed dose was 60 Gy administered in 30 fractions. An experienced physician contoured the left ventricle (LV) of the myocardium. For each patient, an anatomical plan (non-LV-sparing plan) and a functional plan (LV-sparing plan) were created using the VMAT. In the functional plan, the mean percentage of LV volume receiving a dose of ≥ 30 and ≥ 40 Gy was 6.0% ± 6.7% and 2.4% ± 2.7%, respectively, whereas in the anatomical plan, they were 11.7% ± 13.1% and 4.9% ± 6.5%, respectively. There were no significant differences with respect to the dose to the hottest 1 cm3 of the planning target volume (PTV) and the minimum dose of the gross tumor volume and the dosimetric parameters of other normal tissues between the anatomical and functional plans. We compared the anatomical and functional plans of patients with esophageal cancer undergoing VMAT. Our results demonstrated that the functional plan reduced the dose to the LV with no significant differences in the organs at risk and PTV, indicating that avoidance planning can be safely performed when administering VMAT in patients with esophageal cancer.

  25. Impact of feature selection methods and subgroup factors on prognostic analysis with CT-based radiomics in non-small cell lung cancer patients. International-journal Peer-reviewed

    Yuto Sugai, Noriyuki Kadoya, Shohei Tanaka, Shunpei Tanabe, Mariko Umeda, Takaya Yamamoto, Kazuya Takeda, Suguru Dobashi, Haruna Ohashi, Ken Takeda, Keiichi Jingu

    Radiation oncology (London, England) 16 (1) 80-80 2021/04/30

    Publisher: Springer Science and Business Media LLC

    DOI: 10.1186/s13014-021-01810-9  

    eISSN: 1748-717X

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    Abstract Background Radiomics is a new technology to noninvasively predict survival prognosis with quantitative features extracted from medical images. Most radiomics-based prognostic studies of non-small-cell lung cancer (NSCLC) patients have used mixed datasets of different subgroups. Therefore, we investigated the radiomics-based survival prediction of NSCLC patients by focusing on subgroups with identical characteristics. Methods A total of 304 NSCLC (Stages I–IV) patients treated with radiotherapy in our hospital were used. We extracted 107 radiomic features (i.e., 14 shape features, 18 first-order statistical features, and 75 texture features) from the gross tumor volume drawn on the free breathing planning computed tomography image. Three feature selection methods [i.e., test–retest and multiple segmentation (FS1), Pearson's correlation analysis (FS2), and a method that combined FS1 and FS2 (FS3)] were used to clarify how they affect survival prediction performance. Subgroup analysis for each histological subtype and each T stage applied the best selection method for the analysis of All data. We used a least absolute shrinkage and selection operator Cox regression model for all analyses and evaluated prognostic performance using the concordance-index (C-index) and the Kaplan–Meier method. For subgroup analysis, fivefold cross-validation was applied to ensure model reliability. Results In the analysis of All data, the C-index for the test dataset is 0.62 (FS1), 0.63 (FS2), and 0.62 (FS3). The subgroup analysis indicated that the prediction model based on specific histological subtypes and T stages had a higher C-index for the test dataset than that based on All data (All data, 0.64 vs. SCCall, 060; ADCall, 0.69; T1, 0.68; T2, 0.65; T3, 0.66; T4, 0.70). In addition, the prediction models unified for each T stage in histological subtype showed a different trend in the C-index for the test dataset between ADC-related and SCC-related models (ADCT1–ADCT4, 0.72–0.83; SCCT1–SCCT4, 0.58–0.71). Conclusions Our results showed that feature selection methods moderately affected the survival prediction performance. In addition, prediction models based on specific subgroups may improve the prediction performance. These results may prove useful for determining the optimal radiomics-based predication model.

  26. Comparison of predictive performance for toxicity by accumulative dose of DVH parameter addition and DIR addition for cervical cancer patients Peer-reviewed

    Yuya Miyasaka, Noriyuki Kadoya, Rei Umezawa, Yoshiki Takayama, Kengo Ito, Takaya Yamamoto, Shohei Tanaka, Suguru Dobashi, Ken Takeda, Kenji Nemoto, Takeo Iwai, Keiichi Jingu

    Journal of Radiation Research 62 (1) 155-162 2021/01/01

    Publisher: Oxford University Press ({OUP})

    DOI: 10.1093/jrr/rraa099  

    ISSN: 0449-3060 1349-9157

    eISSN: 1349-9157

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    Abstract We compared predictive performance between dose volume histogram (DVH) parameter addition and deformable image registration (DIR) addition for gastrointestinal (GI) toxicity in cervical cancer patients. A total of 59 patients receiving brachytherapy and external beam radiotherapy were analyzed retrospectively. The accumulative dose was calculated by three methods: conventional DVH parameter addition, full DIR addition and partial DIR addition. ${D}_{2{cm}^3}$, ${D}_{1{cm}^3}$ and ${D}_{0.1{cm}^3}$ (minimum doses to the most exposed 2 cm3, 1cm3 and 0.1 cm3 of tissue, respectively) of the rectum and sigmoid were calculated by each method. V50, V60 and V70 Gy (volume irradiated over 50, 60 and 70 Gy, respectively) were calculated in full DIR addition. The DVH parameters were compared between toxicity (≥grade1) and non-toxicity groups. The area under the curve (AUC) of the receiver operating characteristic (ROC) curves were compared to evaluate the predictive performance of each method. The differences between toxicity and non-toxicity groups in ${D}_{2{cm}^3}$ were 0.2, 5.7 and 3.1 Gy for the DVH parameter addition, full DIR addition and partial DIR addition, respectively. The AUCs of ${D}_{2{cm}^3}$ were 0.51, 0.67 and 0.57 for DVH parameter addition, full DIR addition and partial DIR addition, respectively. In full DIR addition, the difference in dose between toxicity and non-toxicity was the largest and AUC was the highest. AUCs of V50, V60 and V70 Gy were 0.51, 0.63 and 0.62, respectively, and V60 and V70 were high values close to the value of ${D}_{2{cm}^3}$ of the full DIR addition. Our results suggested that the full DIR addition may have the potential to predict toxicity more accurately than the conventional DVH parameter addition, and that it could be more effective to accumulate to all pelvic irradiation by DIR.

  27. Dose distribution correction for the influence of magnetic field using a deep convolutional neural network for online MR-guided adaptive radiotherapy Peer-reviewed

    Kajikawa, T., Kadoya, N., Tanaka, S., Nemoto, H., Takahashi, N., Chiba, T., Ito, K., Katsuta, Y., Dobashi, S., Takeda, K., Yamada, K., Jingu, K.

    Physica Medica 80 186-192 2020/12

    Publisher: Elsevier BV

    DOI: 10.1016/j.ejmp.2020.11.002  

    ISSN: 1120-1797

  28. Multi-atlas–based auto-segmentation for prostatic urethra using novel prediction of deformable image registration accuracy Peer-reviewed

    Takagi, H., Kadoya, N., Kajikawa, T., Tanaka, S., Takayama, Y., Chiba, T., Ito, K., Dobashi, S., Takeda, K., Jingu, K.

    Medical Physics 47 (7) 3023-3031 2020/07

    Publisher: Wiley

    DOI: 10.1002/mp.14154  

    ISSN: 0094-2405

    eISSN: 2473-4209

  29. Homology-based radiomic features for prediction of the prognosis of lung cancer based on CT-based radiomics. International-journal Peer-reviewed

    Noriyuki Kadoya, Shohei Tanaka, Tomohiro Kajikawa, Shunpei Tanabe, Kota Abe, Yujiro Nakajima, Takaya Yamamoto, Noriyoshi Takahashi, Kazuya Takeda, Suguru Dobashi, Ken Takeda, Kazuaki Nakane, Keiichi Jingu

    Medical physics 47 (5) 2197-2205 2020/06

    Publisher: Wiley

    DOI: 10.1002/mp.14104  

    ISSN: 0094-2405

    eISSN: 2473-4209

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    PURPOSE: Radiomics is a new technique that enables noninvasive prognostic prediction by extracting features from medical images. Homology is a concept used in many branches of algebra and topology that can quantify the contact degree. In the present study, we developed homology-based radiomic features to predict the prognosis of non-small-cell lung cancer (NSCLC) patients and then evaluated the accuracy of this prediction method. METHODS: Four datasets were used: two to provide training and test data and two for the selection of robust radiomic features. All the datasets were downloaded from The Cancer Imaging Archive (TCIA). In two-dimensional cases, the Betti numbers consist of two values: b0 (zero-dimensional Betti number), which is the number of isolated components, and b1 (one-dimensional Betti number), which is the number of one-dimensional or "circular" holes. For homology-based evaluation, computed tomography (CT) images must be converted to binarized images in which each pixel has two possible values: 0 or 1. All CT slices of the gross tumor volume were used for calculating the homology histogram. First, by changing the threshold of the CT value (range: -150 to 300 HU) for all its slices, we developed homology-based histograms for b0 , b1 , and b1 /b0 using binarized images. All histograms were then summed, and the summed histogram was normalized by the number of slices. 144 homology-based radiomic features were defined from the histogram. To compare the standard radiomic features, 107 radiomic features were calculated using the standard radiomics technique. To clarify the prognostic power, the relationship between the values of the homology-based radiomic features and overall survival was evaluated using LASSO Cox regression model and the Kaplan-Meier method. The retained features with nonzero coefficients calculated by the LASSO Cox regression model were used for fitting the regression model. Moreover, these features were then integrated into a radiomics signature. An individualized rad score was calculated from a linear combination of the selected features, which were weighted by their respective coefficients. RESULTS: When the patients in the training and test datasets were stratified into high-risk and low-risk groups according to the rad scores, the overall survival of the groups was significantly different. The C-index values for the homology-based features (rad score), standard features (rad score), and tumor size were 0.625, 0.603, and 0.607, respectively, for the training datasets and 0.689, 0.668, and 0.667 for the test datasets. This result showed that homology-based radiomic features had slightly higher prediction power than the standard radiomic features. CONCLUSIONS: Prediction performance using homology-based radiomic features had a comparable or slightly higher prediction power than standard radiomic features. These findings suggest that homology-based radiomic features may have great potential for improving the prognostic prediction accuracy of CT-based radiomics. In this result, it is noteworthy that there are some limitations.

  30. Investigation of thoracic four-dimensional CT-based dimension reduction technique for extracting the robust radiomic features Peer-reviewed

    Tanaka, S., Kadoya, N., Kajikawa, T., Matsuda, S., Dobashi, S., Takeda, K., Jingu, K.

    Physica Medica 58 141-148 2019/02

    Publisher: Elsevier BV

    DOI: 10.1016/j.ejmp.2019.02.009  

    ISSN: 1120-1797

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Misc. 7

  1. 非小細胞肺がんに対する肺換気画像とレディオミクスによる機械学習ベース放射線肺臓炎予測モデルの開発

    毛利詩菜, 角谷倫之, 勝田義之, 田中祥平, 武田一也, 山本貴也, 金井貴幸, 中島祐二朗, 武田賢, 神宮啓一

    日本放射線腫瘍学会高精度放射線外部照射部会学術大会プログラム・抄録集 35th 2022

  2. 最新医用画像技術 AIと放射線治療

    角谷 倫之, 松田 匠平, 竹内 孝至, 梶川 智博, 田中 祥平, 田邊 俊平, 勝田 義之, 伊藤 謙吾, 神宮 啓一

    臨床放射線 65 (2) 163-171 2020/02

    Publisher: 金原出版(株)

    ISSN: 0009-9252

  3. 体幹部定位放射線治療における視認下能動的呼吸停止システム基盤の開発研究

    石川 陽二郎, 角谷 倫之, 梶川 智博, 田中 祥平, 松下 晴雄, 梅澤 玲, 山本 貴也, 武田 一也, 片桐 佑, 田坂 俊, 福井 勝哉, 鈴木 友, 川端 広聖, 岸田 桂太, 寺村 聡司, 尾股 聡, 神宮 啓一

    Japanese Journal of Radiology 38 (Suppl.) 3-3 2020/02

    Publisher: (公社)日本医学放射線学会

    ISSN: 1867-1071

    eISSN: 1867-108X

  4. CT画像における肺癌患者の予後予測解析-ホモロジーによる新たな挑戦

    田中祥平, 角谷倫之, 梶川智博, 松田匠平, 土橋卓, 武田賢, 神宮啓一, 中根和昭

    Japanese Journal of Radiology 38 (Supplement) 9 2020/02

    ISSN: 1867-1071

  5. ディープラーニングレディオミクスを用いた肺がんの放射線治療の予後予測

    角谷倫之, 田中祥平, 田邊俊平

    Medical Imaging Technology 38 (1) 4-9 2020/01

    DOI: 10.11409/mit.38.4  

  6. The Feasibility of MVCT-Based Radiomics for Delta-Radiomics in Head and Neck Cancer

    K Abe, N Kadoya, S Tanaka, Y Nakajima, S Hashimoto, T Kajikawa, K Karasawa, K Jingu

    Medical Physics 46 (6) e142-e142 2019/06

    Publisher: Wiley

    DOI: 10.1002/mp.13589  

    ISSN: 0094-2405

    eISSN: 2473-4209

  7. 胸部領域のCT-based Radiomicsにおける施設毎のロバストなRadiomic特徴量の新たな絞り込み法の開発

    田中祥平, 角谷倫之, 佐藤慎哉, 梶川智博, 松田匠平, 土橋卓, 武田賢, 神宮啓一

    日本放射線技術学会雑誌 74 (9) 9 2018

    ISSN: 0369-4305

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Books and Other Publications 1

  1. レディオミクス入門

    有村, 秀孝, 角谷, 倫之

    オーム社 2021/10

    ISBN: 9784274226380

Presentations 13

  1. 前立腺がんにおける累積線量の最適なタイミングと急性尿路毒性に関連する因子

    田中祥平, 高橋紀善, 角谷倫之, Wingyi Lee, 星野大地, 勝田義之, 新井一弘, 肖玉杉, 鈴木友, 神宮啓一

    第4回日本MR画像誘導適応放射線治療研究会 2025/06/21

  2. MR-Linacにおける照射中の臓器の移動量と投与線量分布への影響

    田中 祥平, 角谷 倫之, 勝田 義之, 新井 一弘, 高橋 紀善, 肖 玉杉, 星野 大地, Wingyi Lee, 神宮 啓一

    第3回日本MR画像誘導適応放射線治療研究会 2024/07/06

  3. 1.5T MR-Linac (Unity) における適応放射線治療の実際 Invited

    田中祥平

    第126回 日本医学物理学会学術大会 2023/09/16

  4. 1.5 T MR-Linacにおける ビーム数とセグメント数の違いがプランの質に与える影響

    田中祥平, 角谷倫之, 石澤美優, 勝田義之, 新井一弘, 高橋春奈, 肖玉杉, 高橋紀善, 佐藤清和, 武田賢, 神宮啓一

    第126回 日本医学物理学会学術大会 2023/09/16

  5. Planningの工夫:前立腺 Invited

    田中祥平, 高橋紀善

    第1回日本MR画像誘導適応放射線治療研究会 2022/06/25

  6. Deep learning based;radiomicsアプローチによる頭頚部腫瘍縮小の予測

    田中祥平, 角谷倫之, 菅井裕斗, 梅田真梨子, 石澤美優, 勝田義之, 伊藤謙吾, 武田賢, 神宮啓一

    日本放射線腫瘍学会第34回学術大会 2021/11/12

  7. A Deep Learning-Based Radiomics Approach to Identify Patient with Early Tumor Regression Utilizing Planning CT Images for Adaptive Radiotherapy

    S Tanaka, N Kadoya, Y Sugai, M Umeda, Y Katsuta, K Ito, T Yamamoto, N Takahashi, K Takeda, S Dobashi, K Takeda, K Jingu

    The American Association of Physicists in Medicine 63th Annual Meeting & Exhibition 2021/07/25

  8. Dosimetric impact of heart functional based planning in esophageal cancer patients.

    S Tanaka, N Kadoya, H Nemoto, T Chiba, Y Katsuta, S Matsuda, K Ito, S Dobashi, K Takeda, R Umezawa, K Jingu

    19st Asia-Oceania Congress of Medical Physics (AOCMP-2019) 2019/10/29

  9. Prognosis prediction with homology-based radiomic features quantifying the lung tumor malignancy in CT-based radiomics.

    S Tanaka, N Kadoya, T Kajikawa, K Abe, S Dobashi, K Takeda, K Nakane, K Jingu

    The American Association of Physicists in Medicine 61th Annual Meeting 2019/07/16

  10. Homology as novel radiomic features for prediction of the prognosis of lung cancer based on CT-based radiomics.

    S Tanaka, N Kadoya, K Nakane, T Kajikawa, K Abe, S Dobashi, K Takeda, K Jingu

    The 117th Scientific Meeting of the Japan Society of Medical Physics 2019/04/13

  11. Homology as a novel radiomic feature for prediction of the prognosis of lung cancer based on CT-based radiomics.

    S Tanaka, N Kadoya, K Nakane, S Sato, T Kajikawa, K Abe, K Jingu

    18st Asia-Oceania Congress of Medical Physics (AOCMP-2018) 2018/11/12

  12. 胸部領域のCT-based radiomicsにおける新たなロバストなradiomic特徴量の絞り込み法

    田中祥平, 角谷倫之, 佐藤慎哉, 梶川智博, 松田匠平, 武田賢, 土橋卓, 神宮啓一

    日本放射線腫瘍学会第31回学術大会 2018/10/13

  13. 胸部領域のCT-based radiomicsにおける施設毎のロバストなradiomic特徴量の新たな絞り込み法の開発

    田中祥平, 角谷倫之, 梶川智博, 佐藤慎哉, 松田匠平, 土橋卓, 武田賢, 神宮啓一

    第46回日本放射線技術学会秋季学術大会 2018/10/05

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Industrial Property Rights 3

  1. 【発明の名称】磁場影響を考慮した線量分布作成プログラム、磁場影響を考慮した線量分 布作成方法、および線量分布作成装置

    角谷倫之, 梶川智博, 田中祥平, 土橋卓, 神宮啓一

    Property Type: Patent

  2. 位相幾何学を用いた高精度な放射線治療予後予想システム

    角谷倫之, 田中祥平, 梶川智博, 神宮啓一,中根 和昭

    Property Type: Patent

  3. 非剛体画像レジストレーション調整支援装置、非剛体画像レジストレーション調整支援方法及びプログラム

    角谷 倫之, 根本 光, 阿部 幸太, 田中 祥平, 細谷 祐里, 神宮 啓一, 中村 光宏

    Property Type: Patent

Research Projects 3

  1. 深層学習技術による照射中の動きを考慮した本当の線量分布の作成

    田中 祥平

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業 基盤研究(C)

    Category: 基盤研究(C)

    Institution: 東北大学

    2023/04/01 - 2028/03/31

  2. 体内に⼈⼯物を配置する密封⼩線源治療計画を⾃ 動かつ迅速に⾏う⼈⼯知能モデルの開発

    武田賢, 高城久道, 高橋季莉華, 田中祥平, 新井一弘, 勝田義之, 角谷倫之, 高橋紀善, 山本貴也, 梅澤玲, 神宮啓一

    Offer Organization: 独立行政法人 日本学術振興会

    System: 科学研究費助成事業

    Category: 基盤研究(C)

    Institution: 東北大学

    2024/04 - 2027/03

  3. 患者個別化医療に向けた治療前の医療画像のみから腫瘍の縮小を予測する手法の開発

    田中 祥平

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 研究活動スタート支援

    Institution: 東北大学

    2020/09/11 - 2023/03/31

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    頭頚部癌患者の治療計画前のCT画像を62人を用いて、治療計画中の腫瘍の縮小をディープラーニングで予測を行った。方法としては、治療計画前の原発巣の肉眼的腫瘍体積とリンパ節転移の腫瘍体積を算出し、それから2週間ほど経過した原発巣とリンパ節の肉眼的腫瘍体積を算出し、その差分を計算する。この差分が大きいほど治療期間中に腫瘍が縮小する患者ということになる。まずは、全62人の患者の中央値の差分を使用して、腫瘍縮小群と非縮小群に患者を分類した。 そこから、治療計画前のCT画像を様々な事前学習済みのディープラーニングのモデルに入力して、そこからさまざまなパターンの特徴量を抽出した。この特徴量に関しては1000個ほどあるため、そこからCT画像のノイズに強い特徴量や冗長性のない特徴量や腫瘍の縮小に関係のある特徴量のみに絞り込みを行い、最終的には10個まで有用な特徴量を絞り込んだ。絞り込んだ特徴量を機械学習(ランダムフォレストやサポートベクトルマシーン、k-nearest neighborなど)で学習を行い、パラメータのチューニングを行った。さらに学習された機械学習のモデルに未知のデータの特徴量を入力して、腫瘍の縮小と非縮小を予測した。本研究のディープラーニングアプローチは現在のところ未知のデータに対して、AUC=0.89(1が最大値)で予測ができている。今までの臨床的因子(年齢、性別、化学療法の有無、腫瘍の組織型、ステージ分類、腫瘍体積など)ではAUC=0.64ほどであった。またレディオミクスと呼ばれる画像からさまざまな特徴量を抽出する方法では、AUC=0.70であったため、本研究のディープラーニングアプローチは従来の方法よりも超える結果を出すことができた。

Media Coverage 2

  1. 放射線治療の個別化医療実現へ 深層学習で頭頸部癌の放射線治療による腫瘍縮小効果の予測に成功

    東北大学医学系研究科 プレスリリース

    2022/06

    Type: Internet

  2. コップ=輪っか?:ホモロジー解析技術による新規画像診断法- 機械学習を用いてCT画像のみから放射線治療後の経過予測に成功-

    東北大学医学系研究科 プレスリリース

    2020/03

    Type: Internet