Igaku butsuri : Nihon Igaku Butsuri Gakkai kikanshi = Japanese journal of medical physics : an official journal of Japan Society of Medical Physics最新文献

Since the Fukushima Daiichi Nuclear Power Station accident (hereinafter referred to as the "Fukushima Daiichi accident") occurred in March 2011, many experts around the world have conducted the assessments on radiation doses and health effects attributed to the Fukushima Daiichi accident. During the months soon after the accident while the state of the nuclear reactor was not accurately grasped, the radiation exposure of the residents was estimated based on the predicted environmental behavior of various radionuclides. However, there were significant differences in the estimated doses and effects presented by different researchers and research institutes. As investigations on the causes and progress of the Fukushima Daiichi accident have progressed in last 10 years, now we know better the situation and consequence of the accident. In this article, the contents of relevant papers and reports published during the three years (-2014) after the Fukushima Daiichi accident are briefly reviewed and then compared with the relatively new scientific information obtained in 2015 or later. Through these analyses, the author tries to look back on how correct or incorrect the initial estimates were.

A charged particle therapy was proposed by Robert R. Wilson in 1946 and a clinical study of proton radiotherapy had been started at Lawrence Berkeley National Laboratory in 1954. Clinical studies have been promoted mainly in the United States and Europe. However, in Japan as well, the University of Tsukuba (KEK Campus) and the National Institute of Radiological Sciences (NIRS) started proton radiotherapy around 1980, and NIRS started carbon-ion radiotherapy in 1994. Following pioneering clinical studies, now in Japan, many proton and carbon-ion radiotherapy facilities are in operation, and some vendors are supplying equipment. Among them, charged particle therapy technologies originating in Japan have been developed, such as a respiratory-gated irradiation technology, a spot scanning irradiation technology, and a clinical dose design for ion radiotherapy. I look back on them and discuss the future direction of research and development of the charged particle therapy.

Stereotactic body radiation therapy (SBRT) is a high-precision radiation therapy technique that enables to deliver a high ablative biological dose in 1 to 5 high dose-fractions despite sparing the high dose of adjacent organs at risk. SBRT has emerged as an alternative to conventional radiation therapy for spinal metastases and has been applied to patients with non-spine bone metastases as well. Since bone SBRT is the technique of high biologically effective dose to the local lesion, quality assurance (QA) of the entire treatment process is an essential for performing SBRT. This report provides QA procedures for performing bone SBRT.

In Japan, mammography was introduced in 2000 for the early detection of breast cancer. In quality control of mammography, dosimetry is one of the most important items. For accurate dosimetry, calibration of dosimeters is necessary because radiation quality (target-filter combination) of mammography x-ray is different from that of general radiography. Therefore, development of dosimetry standard based on radiation quality of mammography x-ray was required. AIST/NMIJ developed an air-kerma standard for mammography x-rays and started its dissemination in 2009. Since then, the air-kerma standard has been extended to various radiation qualities that have come to be used in digital mammography. In this paper, an overview of the air-kerma standard for mammography x-ray together with a future plan is briefly presented.

The International System of Units (SI) is recommended for the practical system of units of measurement. The decision of redefining the seven base units of the SI (the second, the meter, the kilogram, the ampere, the kelvin, the mole and the candela) was made at the 26th meeting of the General Conference on Weights and Measures on 16 November 2018. This redefinition came into force starting 20 May 2019, and it became a big historic turning point for the metrology society. This is because the kilogram, the unit of mass, was defined only by an artifact as the international prototype of the kilogram, has been kept for 130 years since its determination in 1889, and was finally changed to the new definition by taking the fixed numerical value of the Planck constant on that day.It is easily imagined that the redefinition of the SI base units has a strong impact on our daily life or the field of science. The reason why the SI redefinition had to be adapted is introduced firstly. Then, how the new definitions are applied now after a year from the redefinition and future prospective of the new definitions are discussed. In the last, the impacts of the SI redefinition in the field of the ionizing radiation, especially in the fields of the medical application of the ionizing radiation, are discussed.

This is a review on biological fingerprint for radiologic technology and forensic pathology by JSRT and JSMP (https://www.jsmp.org/en).