Annual Report 2024
Division of Research and Development for Boron Neutron Capture Therapy
Hiroshi Igaki, Tairo Kashihara, Kimiteru Ito, Yoshitaka Narita, Seiichi Yoshimoto, Naoya Yamazaki, Satoshi Nakamura, Tetsu Nakaichi, Masamichi Ishiai, Akihiro Yanagihara, Hana Endo, Yasunori Shuto, Shuka Nishina, Homare Murata, Mitsuko Masutani, Shoji Imamichi, Hiroaki Kurihara, Mihiro Takemori.
Introduction
A linear accelerator-based neutron irradiation system for boron neutron capture therapy (BNCT) was developed using a solid lithium target, the first such system in the world, and installed in the National Cancer Center Hospital. A phase II clinical trial of BNCT for angiosarcoma and a phase I/II clinical trial for basket-type chest malignant tumors are ongoing to obtain regulatory approval as a neutron irradiation system. Patient enrollment is steadily progressing. In cooperation with the Japanese Society of Neutron Capture Therapy, activities are underway to establish guidelines for evaluation methods of neutron beam characteristics in medical devices.
The Team and What We Do
We are working to expand the clinical indications of BNCT and to be engaged in activities that contribute to the standardization of BNCT, such as the development of guidelines and international standards for the accelerator-based BNCT systems as medical devices in cooperation with the Japanese Society of Neutron Capture Therapy.
Research Activities
We are conducting clinical trials targeting angiosarcoma and chest malignant tumors using a neutron irradiation system for BNCT installed at the National Cancer Center Hospital. In addition, we have conducted basic research and preclinical trials aimed at expanding the indications of BNCT, and have reported research results such as [18F]FBPA PET, amino acid transporter LAT1 immunostaining, neutron generators using lithium targets, and improvement of the accuracy or the speed of BNCT treatment planning.
Clinical Trials
A phase II clinical trial of accelerator-based BNCT for angiosarcoma and a basket-type phase I/II clinical trial for chest malignant tumors are ongoing. Patient enrollment is progressing well.
Education
We are engaged in educating and training professionals for BNCT clinics and research. We actively accept overseas visitors and trainees and conduct exchanges of opinions with researchers from other institutions.
Future Prospects
With the hospital-based neutron irradiation system for BNCT, patient recruitment for BNCT clinical trials has been facilitated compared with the previous environment of the reactor-based BNCT era. In order to verify the efficacy of BNCT and establish its position in oncology, we will continue to conduct clinical trials to expand its applications. We will also collaborate with relevant academic institutions and societies to establish international standards and guidelines, and continue activities that contribute to the standardization of BNCT as a medical treatment. We will promote multi-center and international clinical trials to promote our purpose and missions.
List of papers published in 2024
Journal
1. Sekino Y, Sonoda Y, Shibahara I, Mizusawa J, Sasaki K, Sekita T, Ichikawa M, Igaki H, Kinoshita M, Kumabe T, Shibahara J, Ichimura K, Arakawa Y, Fukuda H, Narita Y. Protocol digest of a phase III randomized trial of gross total resection versus possible resection of fluid-attenuated inversion recovery-hyperintense lesion on MRI for newly diagnosed supratentorial glioblastoma: JCOG2209 (FLAMINGO). Japanese journal of clinical oncology, 55:75-79, 2025
2. Takada M, Yagi N, Nakamura S, Shimada K, Itami J, Igaki H, Nakamura M, Nunomiya T, Endo S, Kajimoto T, Tanaka K, Aoyama K, Narita M, Nakamura T. Development of an online neutron beam monitoring system for accelerator-based boron neutron capture therapy in a hospital. Medical physics, 52:605-618, 2025
3. Kashihara T, Nakamura S, Yamazaki N, Takahashi A, Namikawa K, Ogata D, Nakano E, Okuma K, Kaneda T, Mori T, Ito K, Itami J, Shimada K, Nakagama H, Igaki H. Boron neutron capture therapy for cutaneous angiosarcoma and malignant melanoma: First in-human phase I clinical trial. Radiotherapy and oncology, 202:110607, 2025
4. Matsubayashi N, Hu N, Takata T, Sasaki A, Kumada H, Nakamura S, Masuda A, Tanaka H. Characterization of acrylic phantom for use in quality assurance of BNCT beam output procedure. Journal of radiation research, 66:10-15, 2025
5. Takahashi K, Kagami Y, Yoshimura R, Morota M, Murakami N, Nakamura S, Okamoto H, Nagao A, Sakuramachi M, Kashihara T, Kaneda T, Inaba K, Okuma K, Nakayama Y, Itami J, Igaki H. Prospective study of once-daily accelerated partial breast irradiation using 3-dimensional conformal external beam radiotherapy for Japanese women: 12-year outcomes, toxicity, and cosmesis. Breast cancer (Tokyo, Japan), 32:197-207, 2025
6. Ota S, Yasui K, Ogata T, Mori Y, Nishio T, Tohyama N, Okamoto H, Kurooka M, Shimomura K, Kojima T, Onishi H. Clinical workload profile of medical physics professionals at particle therapy Centers: a National Survey in Japan. Journal of radiation research, 66:52-64, 2025
7. Ozeki Y, Honda-Kitahara M, Yanagisawa S, Takahashi M, Ohno M, Miyakita Y, Kikuchi M, Nakano T, Hosoya T, Sugino H, Satomi K, Yoshida A, Igaki H, Kubo Y, Ichimura K, Suzuki H, Masutomi K, Kondo A, Narita Y. Early progressive disease within 2 years in isocitrate dehydrogenase (IDH)-mutant astrocytoma may indicate radiation necrosis. Japanese journal of clinical oncology, 55:106-112, 2025
8. Green S, Phoenix B, Nakamura S, Liu YH, Shu D, Hu N, Suzuki S, Koivunoro H, Kumada H, Tanaka H. Accelerator neutron sources for BNCT: Current status and some pointers for future development. Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine, 217:111656, 2025
9. Imamichi S, Ito T, Tong Y, Gao Z, Arai Y, Fujimori H, Chen L, Sanada Y, Nakamura S, Murakami Y, Ishiai M, Suzuki M, Itami J, Igaki H, Masunaga S, Masutani M. Transcriptome analysis of human oral squamous cancer SAS cells as an early response after boron neutron capture therapy. Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine, 218:111648, 2025
10. Igaue S, Yamamoto S, Shiraishi K, Itoyama M, Imazeki H, Yokoyama K, Honma Y, Kashihara T, Kurita D, Ishiyama K, Oguma J, Daiko H, Kato K. Correlation Between Histopathological Response of Esophageal Squamous Cell Carcinoma to Neoadjuvant DCF Therapy and the Clinical Efficacy of Palliative Chemotherapy for Recurrence. Journal of gastrointestinal cancer, 56:60, 2025
11. Takada M, Yagi N, Shimada K, Fujii R, Nakamura M, Nakamura S, Kato S, Nunomiya T, Aoyama K, Narita M, Nakamura T. Novel approach to long-term monitoring of accelerator-based boron neutron capture therapy. Medical physics, 52:3298-3308, 2025
12. Kobayashi Y, Nakamura S, Takemori M, Nakaichi T, Shuto Y, Ito K, Takahashi K, Kashihara T, Yonemura M, Endo H, Kunito K, Okamoto H, Chiba T, Nakayama H, Oshika R, Kishida H, Itami J, Kurihara H, Igaki H. Comparison of dose distribution with and without reflecting heterogeneous boron distribution using (18)F-BPA positron emission tomography in boron neutron capture therapy. Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine, 219:111720, 2025
13. Yoshimura RI, Toda K, Watanabe H, Miura M, Notake R, Murakami N, Igaki H, Nakamura S, Umezawa R, Kadoya N, Jingu K, Itami J. Efficacy and safety of diffusing alpha-emitter radiation therapy (DaRT) for head and neck cancer recurrence after radiotherapy. International journal of clinical oncology, 30:893-903, 2025
14. Kashihara T, Nakamura S, Igaki H. Response to 'Pioneering BNCT: Refining strategies for complex cutaneous malignancies. Radiotherapy and oncology, 206:110787, 2025
15. Kawauchi D, Ohno M, Sugino H, Ito K, Fuse K, Yoshida A, Kubo Y, Honda-Kitahara M, Yanagisawa S, Ohmura T, Aoki T, Kawanishi A, Sakuramachi M, Igaki H, Narita Y. Utility of [18F]fluciclovine PET/MRI for identifying the optimal biopsy target region, helping to avoid underdiagnosis in patients with glioblastoma: illustrative case. Journal of neurosurgery. Case lessons, 9:CASE24677, 2025
16. Kurokawa S, Okamoto H, Nakaichi T, Mikasa S, Nakamura S, Iijima K, Chiba T, Nakayama H, Kashihara T, Inaba K, Igaki H. Machine learning prediction for lung dose in locally advanced esophageal cancer using volumetric modulated arc therapy. Medical dosimetry, S0958-3947(25)00011-1, 2025
17. Maebayashi T, Mizowaki T, Ishikawa H, Nakamura K, Inaba K, Asakura H, Iwata H, Itasaka S, Wada H, Sakaguchi M, Jingu K, Akiba T, Tomita N, Nakamura K. Prostate dose escalation may positively impact survival in patients with clinically node-positive prostate cancer definitively treated by radiotherapy: surveillance study of the Japanese Radiation Oncology Study Group (JROSG). Journal of radiation research, 66:157-166, 2025
18. Ono T, Uto M, Mineharu Y, Arakawa Y, Nakamura M, Nishio T, Igaki H, Nihei K, Ishikura S, Narita Y, Mizowaki T. Dummy run study for outlining and plan quality of intensity-modulated radiotherapy in elderly patients with newly diagnosed glioblastoma: The Japan clinical oncology group study JCOG1910 (AgedGlio-PIII). Radiation oncology (London, England), 20:32, 2025
19. Murofushi KN, Tsujino K, Ito Y, Okamoto M, Doi H, Ogawa H, Onozawa M, Kawamoto T, Katoh N, Jingu K, Takeda A, Nihei K, Makishima H, Mayahara H, Yamazaki H, Igaki H. Contouring atlas and essential points for radiotherapy in rectal cancer. Journal of radiation research, 66:203-211, 2025
20. Cho H, Abe S, Nonaka S, Suzuki H, Yoshinaga S, Okuma K, Yamamoto S, Daiko H, Kato K, Sekine S, Boku N, Saito Y. Long-term outcomes after non-curative endoscopic resection for esophageal squamous cell carcinoma followed by additional chemoradiotherapy. Diseases of the esophagus, 37:doae004, 2024
21. Watanabe Y, Chen YW, Igaki H, Arakawa A, Tao K, Sugiyama M, Nakajima M, Shirakawa N, Yanagisawa S, Miyakita Y, Yoshida A, Isohashi K, Ono K, Narita Y, Ogawa C. Boron neutron capture therapy prolongs survival in a patient with a recurrent malignant peripheral nerve sheath tumor-A case report. Pediatric blood & cancer, 71:e31011, 2024
22. Nakamura K, Nihei K, Saito Y, Shikama N, Noda SE, Hara R, Imagumbai T, Mizowaki T, Akiba T, Kunieda E, Someya M, Ohga S, Kawamori J, Kozuka T, Ota Y, Inaba K, Kodaira T, Itoh Y, Funakoshi K, Kagami Y. A Japanese multi-institutional phase II study of moderate hypofractionated intensity-modulated radiotherapy with image-guided technique for prostate cancer. International journal of clinical oncology, 29:847-852, 2024
23. Kashihara T, Urago Y, Okamoto H, Takemori M, Nakayama H, Mikasa S, Nakaichi T, Iijima K, Chiba T, Kuwahara J, Nakamura S, Chang W, Matsui Y, Igaki H. A preliminary study on rectal dose reduction associated with hyaluronic acid implantation in brachytherapy for prostate cancer. Asian journal of urology, 11:286-293, 2024
24. Nakamura S, Takemori M, Nakaichi T, Shuto Y, Kashihara T, Iijima K, Chiba T, Nakayama H, Urago Y, Nishina S, Kobayashi Y, Kishida H, Imamichi S, Takahashi K, Masutani M, Okamoto H, Nishio T, Itami J, Igaki H. A method for delivering the required neutron fluence in an accelerator-based boron neutron capture therapy system employing a lithium target. Scientific reports, 14:11253, 2024
25. Nagao A, Murakami N, Sakuramachi M, Kashihara T, Takahashi K, Kaneda T, Inaba K, Okuma K, Okamoto H, Nakayama Y, Yonemori K, Igaki H. Role of the gel spacer in safely delivering whole pelvic radiation therapy without central shielding in computed tomography-based image-guided adaptive brachytherapy for uterine cervical cancer patients. Brachytherapy, 23:595-603, 2024
26. Okamoto H, Sakuramachi M, Yatsuoka W, Ueno T, Katsura K, Murakami N, Nakamura S, Iijima K, Chiba T, Nakayama H, Shuto Y, Takano Y, Kobayashi Y, Kishida H, Urago Y, Nishitani M, Nishina S, Arai K, Igaki H. A novel method for determining dose distribution on panoramic reconstruction computed tomography images from radiotherapy computed tomography. Imaging science in dentistry, 54:129-137, 2024
27. Okamoto H, Nonaka M, Chiba T, Kaneda T, Kobayashi Y, Nakamura S, Nakayama H, Iijima K, Shuto Y, Yonemura M, Oshika R, Kishida H, Urago Y, Nishitani M, Nishina S, Sakamoto T, Shibata Y, Goka T, Igaki H. Dosimetric impact of the respiratory motion of the liver dome in stereotactic body radiotherapy for spine metastasis: A planning study. Journal of applied clinical medical physics, 25:e14403, 2024
28. Kawaguchi Y, Watanabe Y, Miyakita Y, Ohno M, Ogawa C, Takahashi M, Yanagisawa S, Mukai T, Igaki H, Sugino H, Yoshida A, Narita Y. Successful treatment of pediatric patients with high-grade gliomas featuring leptomeningeal metastases by targeting BRAF V600E mutations with dabrafenib plus trametinib: two illustrative cases. International cancer conference journal, 13:256-262, 2024
29. Uezono H, Onoe T, Shikama N, Ono Y, Hirata H, Ito Y, Yasuda K, Imano N, Kikuchi K, Kashihara T, Kawamoto T, Nakamura N. Uptake of ultra-hypofractionated radiation therapy following breast-conserving surgery among patients with early-stage breast cancer: a multi-institutional questionnaire survey. Breast cancer (Tokyo, Japan), 31:1071-1079, 2024
30. Murata S, Horinouchi H, Morishita M, Kaku S, Shinno Y, Okuma Y, Yoshida T, Goto Y, Yamamoto N, Kashihara T, Okuma K, Kusumoto M, Ohe Y. Impact of Durvalumab on the Duration and Complexity of Corticosteroid Therapy for Pneumonitis After Chemoradiotherapy. Clinical lung cancer, 25:e369-e378.e3, 2024
31. Ohno M, Takahashi M, Yanagisawa S, Osawa S, Tsuchiya T, Fujita S, Igaki H, Narita Y. Development of a scoring system to predict local recurrence in brain metastases following complete resection and observation. Journal of neuro-oncology, 170:297-305, 2024
32. Tsuchiya T, Ohno M, Watanabe Y, Fujita S, Miyazaki B, Sugino H, Igaki H, Yoshida A, Takahashi M, Yanagisawa S, Osawa S, Ogawa C, Narita Y. Pediatric atypical teratoid/rhabdoid tumor in the cauda equina with rapid tumor progression: illustrative case. Journal of neurosurgery. Case lessons, 8:CASE24219, 2024
33. Nakamura S, Tanaka H, Kato T, Akita K, Takemori M, Kasai Y, Kashihara T, Takai Y, Nihei K, Onishi H, Igaki H. A national survey of medical staffs' required capability and workload for accelerator-based boron neutron capture therapy. Journal of radiation research, 65:712-724, 2024
34. Zenda S, Kashihara T, Saito T, Okamoto H, Kadoya N, Chiba T, Noda SE, Kawaguchi T, Jingu K, Shibuya K, Uno T, Igaki H. Two-fractionated stereotactic magnetic resonance-guided adaptive radiation therapy for patients with prostate cancer (SMART PRO trial): protocol for a confirmatory clinical trial. BMJ open, 14:e082899, 2024
35. Iijima K, Nakayama H, Nakamura S, Chiba T, Shuto Y, Urago Y, Nishina S, Kishida H, Kobayashi Y, Takatsu J, Kuwahara J, Aikawa A, Goka T, Kaneda T, Murakami N, Igaki H, Okamoto H. Analysis of human errors in the operation of various treatment planning systems over a 10-year period. Journal of radiation research, 65:603-618, 2024
36. Ohno M, Takahashi M, Yanagisawa S, Osawa S, Tsuchiya T, Fujita S, Igaki H, Narita Y. Correction to: Development of a scoring system to predict local recurrence in brain metastases following complete resection and observation. Journal of neuro-oncology, 170:307, 2024
37. Ishikawa A, Tanaka H, Nakamura S, Kumada H, Sakurai Y, Watanabe K, Yoshihashi S, Tanagami Y, Uritani A, Kiyanagi Y. Effect of neutron beam properties on dose distributions in a water phantom for boron neutron capture therapy. Journal of radiation research, 65:765-775, 2024
38. Kojima T, Okamoto H, Kurooka M, Tohyama N, Tsuruoka I, Nemoto M, Shimomura K, Myojoyama A, Ikushima H, Ohno T, Ohnishi H. Current status of the working environment of brachytherapy in Japan: a nationwide survey-based analysis focusing on radiotherapy technologists and medical physicists. Journal of radiation research, 65:851-861, 2024
39. Nishitani M, Okamoto H, Nakamura S, Iijima K, Chiba T, Nakayama H, Nakaichi T, Takemori M, Urago Y, Chang W, Igaki H. A new approach to assess transit dose impact in gynecological and prostate brachytherapy with effective transit time. Journal of contemporary brachytherapy, 16:449-456, 2024