H Kato

National Institute of Radiological Sciences, Tiba, Chiba, Japan

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Publications (29)51.51 Total impact

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    ABSTRACT: The features of relativistic carbon-ion beams are attractive from the viewpoint of radiotherapy. They exhibit not only a superior physical dose distribution but also an increase in biological efficiency with depth, because energy loss of the beams increases as they penetrate the body. This paper reviews clinical aspects of carbon-beam radiotherapy using the experience at the National Institute of Radiological Sciences. The paper also outlines the dosimetry related to carbon-beam radiotherapy, including absolute dosimetry of the carbon beam, neutron measurements and radiation protection measurements.
    No preview · Article · Oct 2009 · Radiation Protection Dosimetry
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    ABSTRACT: A total of 193 patients with HCC were enrolled on the clinical trials with carbon ion beams. In the first and second phase I/II clinical trials, dose escalation experiments were carried out in incremental steps of 10%, resulting in the confirmation of both the safety and the effectiveness in a short-course regime of 12, 8 and 4 fractions. Based on the results, a phase II clinical study with fixed fractionation, that is. 52.8 GyE/4 fractions, was performed, where forty-seven patients were treated with low toxicity, high local control rate of 95% at 5 years. We can conclude that because of the low toxicity and high local control rate, carbon ion radiotherapy has a promising potential as a new, radical, and minimally invasive therapeutic option for HCC.
    No preview · Article · Jan 2009

  • No preview · Article · Sep 2008 · International Journal of Radiation OncologyBiologyPhysics

  • No preview · Article · Sep 2008 · International Journal of Radiation OncologyBiologyPhysics
  • S. Yamada · T. Yanagi · R. Hara · H. Kato · T. Kamada · H. Tsujii

    No preview · Article · Sep 2008 · International Journal of Radiation OncologyBiologyPhysics

  • No preview · Article · Sep 2008 · International Journal of Radiation OncologyBiologyPhysics
  • S. Yasuda · H. Kato · H. Tsujii
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    ABSTRACT: Charged particles such as protons and heavier ions have unique properties in terms of dose distributions. In contrast to photons, charged particles deposit most of their energy in a narrow Bragg peak at a specific depth inside the tissue depending on the energy of the particles. Because of this unique property, it is possible that high-radiation doses can be delivered to the tumor with less irradiation to the surrounding normal tissue. Protons and heavier charged particles therefore provide the opportunity to improve the therapeutic ratio by increasing the tumor cure probability while simultaneously reducing the risk of normal tissue complications. The radiation dose can thus be safely concentrated in the target volume even in the presence of critical organs in the vicinity of the lesion. The radiobiology of protons is similar to that of photons. Photons and protons are considered low linear energy transfer (LET), and biologically equivalent, radiation. We can therefore adopt protons for the treatment of cancer using prior experience with photons. On the other hand, heavier charged particles such as neon and carbon are considered high-LET radiation. High-LET radiation response in tissue is less influenced by oxygenation and less sensitive to variations in the cell cycle and DNA repair. Heavier ion beams therefore have a larger relative biological effectiveness (RBE). Accordingly, heavy ion radiotherapy is potentially effective for such tumors that are resistant to low-LET radiation therapy. Since June 1994, clinical studies on cancer treatment using carbon ion beams have been carried out at the National Institute of Radiological Sciences (NIRS). As of February 2008, a total of 3,819 patients with malignant tumors were treated with carbon ion radiotherapy and then analyzed for toxicities and tumor response. It has been possible to confirm the anticipated effect of carbon ion radiotherapy in the treatment of cancers intractable to any other treatment modalities. Utilizing therapeutically favorable dose distribution of carbon ion beams, it has also been possible to develop short-course hypofractionated irradiation regimens for almost all types of tumors. Particle therapy will play a more important role in cancer treatment in our aging society.
    No preview · Article · May 2008
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    Full-text · Article · Jan 2008 · Molecular imaging and biology: MIB: the official publication of the Academy of Molecular Imaging

  • No preview · Article · Nov 2007 · International Journal of Radiation OncologyBiologyPhysics

  • No preview · Article · Sep 2007 · EJC Supplements
  • H Kato · M Ohto · H Tsujii

    No preview · Article · Nov 2001 · Nippon rinsho. Japanese journal of clinical medicine
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    ABSTRACT: We investigated the potential role of mitochondrial manganese superoxide dismutase (Mn-SOD) in protective activity against irradiation by analyzing cell viability by a colony formation assay and by detecting apoptosis in stably human Mn-SOD gene-transfected HLE, a hepatocellular carcinoma cell line. We found that overexpression of Mn-SOD reduced the levels of reactive oxygen species in the mitochondria and intracellular phospholipid peroxidation product (4-hydroxy-2-nonenal) and prevented cell death. The production of intracellular nitric oxide after irradiation was not changed by Mn-SOD overexpression. The results suggested that Mn-SOD might play an important role in protecting cells against radiation-induced cell death by controlling the generation of mitochondrial reactive oxygen species and intracellular lipid peroxidation.
    Full-text · Article · Aug 2001 · Cancer Research

  • No preview · Article · Apr 2001 · European Journal of Cancer
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    ABSTRACT: The phase I/II clinical study of carbon beam therapy was undertaken for 31 cases of advanced cervical cancer of stages IIIB and IVA from June 1995 to November 1997. The main purpose was to determine clinically useful fraction doses without severe acute reaction of normal tissues and to assess tumor control dose levels achievable without significant normal tissue toxicity. The treatment was given with four fixed fractions per week (24 fractions over 6 weeks) and was initiated with a fraction dose of 2.2 Gray equivalent (GyE), and the dose was increased as 2.4 GyE, 2.6 GyE, 2.8 GyE, and 3.0 GyE. Consequently, the total dose initiated was 52.8 GyE, to increase up to 72.0 GyE in 4.8-GyE increments in the dose-escalation fashion. Thirty patients with eligible advanced cervical cancers consisting of 27 squamous cell carcinomas and three adenocarcinomas were analyzed. Acute response of normal tissues was less than with photon treatment until fraction doses of 2.8 GyE were administered, and patients finished treatment with comfortable conditions. Severe late complications occurred in the two patients who received more than 67.2 GyE. The 2-year cumulative survival rate and the local control rate of 27 patients with squamous cell carcinoma were 61.5% and 59.3%, respectively. According to stages, the 2-year survival rates of stage IIIB and IVA patients were 54.4% and 75.0%, respectively. The 2-year local control rates of stage IIIB and IVA patients were 52.6% and 75.0%, respectively. These results indicated that the disease control seems to be relatively better for very advanced disease and with dose escalation treatment. Local control was not significantly correlated with total dose and tumor volume. The results of the present study, despite small numbers and short observation, suggest that an adequate fraction dose for pelvis fields is 2.8 to 3.0 GyE and that the carbon beam therapy might be advantageous for advanced cervical cancer.
    No preview · Article · Nov 1999 · The cancer journal from Scientific American
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    ABSTRACT: Since 1994, heavy ion therapy has been carried out at the National Institute of Radiological Sciences (NIRS) using carbon-ions generated by a medically dedicated accelerator (HIMAC: Heavy Ion Medical Accelerator in Chiba). The purpose of this project is to evaluate whether differential effects could exist between therapeutically resistant neoplasms and normal tissues that favor the latter. Based on analysis of physical as well as biological properties of heavy ions, we chose carbon ions for cancer therapy. The RBE value of the carbon-ions was estimated to be 3.0 for acute skin reactions at the distal region of the SOBP. Interdisciplinary working groups were organized to design protocols for phase I/II dose-escalation study in various tumor sites including the head and neck, brain, lung, liver, uterine cervix, prostate, bone and soft tissue, and esophagus. The initial dose employed was 10-20% lower than the tolerable dose for musculo-connective tissues. The dose was esclated by 10% increments for every 3 to 5 patients based on careful observation of the normal tissue response. As of February 1997, a total of 230 patients were treated. So far, none of them experienced major morbidities. Our preliminary judgment that the carbon-ion therapy would be effective for those tumors with non-squamous histology such as adenocarcinoma, adenoid cystic carcinoma, malignant melanoma, and bone/soft tissue sarcoma. The heavy-ion clinical trials are still in premature status, and numerous developments have to be achieved for more successful performance.
    No preview · Article · Jan 1998 · Physica Medica
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    ABSTRACT: In 1994, the clinical trial of heavy ion therapy was begun at the National Institute of Radiological Sciences using carbon ions generated by a medically dedicated accelerator (HMAC, Heavy Ion Medical Accelerator in Chiba, Japan). The HIMAC is the world's only heavy ion accelerator complex dedicated to medical use in a hospital environment. There are three treatment rooms with fixed apertures as well as rooms for physics and biological research studies. Judging from the results of preparatory experiments as well as Lawrence Berkeley Laboratory (LBL) experiences, we decided to use carbon ions in the initial clinical studies. Preparatory to clinical application, preclinical studies were performed on five human cell lines cultured in vitro and mouse skin to estimate relative biological effectiveness (RBE) values relative to photons and to fast neutrons as well. The RBE values of carbon ions for acute or subacute skin reactions were estimated to be 3.0 at the distal part of the SOBP. Interdisciplinary working groups were organized to design protocols for phase I/II carbon-ion therapy, in which the main purpose was to investigate normal tissue toxicities as well as tumor response in HIMAC carbon-ion therapy. The protocols were designed for various tumor sites including the head and neck, brain, lung, liver, uterine cervix, and prostate. In the phase I/II studies for these tumors, the initial doses used were assumed to be 10% to 20% lower than those possibly tolerable for musculoconnective tissues. The doses have been escalated by 10% increments based on careful observation of the normal tissue morbidity as well as tumor response. During June 1994 to August 1995, a total of 55 patients were treated. As with carbon-related toxicities, none of the patients experienced major morbidities at six months or later posttreatment. The preliminary results appear to demonstrate promising effects of carbon ions in selected tumors. Despite using relatively conservative doses for cancer control, the local control rates were adequate in those tumors other than malignant gliomas.
    No preview · Article · Jan 1997
  • H Kato · T Yamaguchi · H Saisho · H Tsujii
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    ABSTRACT: According to a nation-wide annual report on pancreatic cancer patients in 1992, 70 percent of patients with pancreatic cancer underwent operations. Thirty percent of them, along with 10 percent of patients who did not undergo operations, underwent radiation therapy. The result of external radiation monotherapy for local advanced pancreatic cancer is so poor that the 2-year survival rate and the median survival time have been reported in some papers to be approximately 10% and at most 13 months, respectively. Our results indicated that the 1-, 2- and 3-year survival rates and the median survival time after external radiation monotherapy for local advanced pancreatic cancer were 21%, 11%, 5% and 11.3 months, respectively. The reasons for the poor results are thought to be as follows: pancreatic cancer is very malignant, invades the surrounding tissues and metastasizes distantly in its earliest stages; it is mostly adenocarcinoma resistant to radiation therapy; and the pancreas borders closely the stomach and duodenum, which are very sensitive to radiation. Therefore, charged particle radiotherapy, especially heavy ion radiotherapy, is expected to bring about advances in the field of radiation therapy for pancreatic cancer because of its excellent potential for dose distribution and biological effect.
    No preview · Article · Nov 1996 · Gan to kagaku ryoho. Cancer & chemotherapy
  • H Kato · I Sobue

    No preview · Article · Jun 1978 · Nippon rinsho. Japanese journal of clinical medicine
  • H Kato · I Sobue

    No preview · Article · Feb 1977 · Nippon rinsho. Japanese journal of clinical medicine
  • I Sobue · M Saito · H Kato

    No preview · Article · Jan 1977 · Rinsho shinkeigaku = Clinical neurology