Publications by authors named "Hideo Tatsuzaki"
Accidental inhalation intake of plutonium isotopes and 241Am occurred at a Pu research facility in Japan in 2017, and the five workers involved in this accident were treated by the administration of Ca/Zn-diethylenetriaminepentaacetic acid (DTPA). For the worker who was most internally exposed, the therapy was continued over 1 y after the accident. Urinary samples collected before and after each administration were subject to bioassay to evaluate the efficacy of the dose reduction.
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- - Seven nuclear workers exposed to radionuclides, especially I-131, during the Fukushima accident in March 2011 were evaluated at the National Institute of Radiological Sciences over a 10-year follow-up period.
- - They received estimated thyroid doses ranging from 3.2 to 1.2 × 10 Sv but reported no symptoms of abnormal thyroid function.
- - Despite no immediate health issues or abnormalities detected in tests, ongoing monitoring of their thyroid status is recommended for the future.
In Japan, the radiation-dose limit for the lens of the eye was revised in April 2021. Consequently, for workers, the numerical values of the equivalent dose to the lens of the eye are equal to those of the effective dose. Radiation workers, radiation safety officers and licensees must comply with regulations related to radiation protection and optimize protection.
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- The assessment of thyroid radiation doses for Fukushima residents after the 2011 nuclear accident is crucial but challenging due to limited direct data, with only about 1,300 iodine (I) measurement points available from post-accident screenings.* -
- Researchers reassessed doses for 1,080 individuals aged 15 or younger using updated conversion factors, finding that most thyroid doses were less than 30 mSv, indicating a similar iodine intake across different age groups in three municipalities.* -
- Results revealed that despite varying iodine concentrations in tap water, the thyroid doses for residents in Iitate Village and Iwaki City were comparable, suggesting ingestion was the main intake route rather than inhalation, although the exact intake method remains
Article Synopsis
- * Researchers conducted numerical simulations using individual voxel phantoms based on MRI scans of six of the seven workers, focusing on their thyroid sizes which were generally smaller than standard reference values.
- * The study found that individual thyroid size significantly impacts dose estimation, with results showing absorbed doses could vary widely, and confirmed the accuracy of direct thyroid measurements from the National Institute for Radiological Sciences.
Article Synopsis
- A screening survey was conducted on 1080 children after the 2011 Fukushima nuclear disaster to check for thyroid exposure to radioiodine using handheld survey meters.
- A practical exercise was carried out to train personnel in measuring radiation levels using manikin heads with controlled radiation sources.
- Results showed that measurements were mostly unaffected by background radiation, with deviations within 10-20% for higher dose rates, indicating reliability of readings during a nuclear accident.
This article introduces the first accident of internal contamination with plutonium (Pu) or americium (Am) in Japan for which treatment was carried out. An accident of internal contamination with Pu and Am occurred at a Pu research facility at Oarai-town of Ibaraki prefecture in Japan. A plastic bag containing these radionuclides ruptured when five workers were inspecting a storage container in a hood.
View Article and Find Full Text PDFSince the International Commission on Radiological Protection recommended reducing the occupational equivalent dose limit for the lens of the eye in 2011, there have been extensive discussions in various countries. This paper reviews the current situation in radiation protection of the ocular lens and the discussions on the potential impact of the new lens dose limit in Japan. Topics include historical changes to the lens dose limit, the current situation with occupational lens exposures (e.
View Article and Find Full Text PDFHazardous chemical, radiological, and nuclear materials threaten public health in scenarios of accidental or intentional release which can lead to external contamination of people. Without intervention, the contamination could cause severe adverse health effects, through systemic absorption by the contaminated casualties as well as spread of contamination to other people, medical equipment, and facilities. Timely decontamination can prevent or interrupt absorption into the body and minimize opportunities for spread of the contamination, thereby mitigating the health impact of the incident.
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- * The cooling systems at the NPP failed during subsequent aftershocks, causing hydrogen explosions and core meltdowns, and contaminating both first responders and the environment with radioactive isotopes such as ¹³¹I, ¹³⁴Cs, and ¹³⁷Cs.
- * The local hospital system was overwhelmed, as facilities designated for radiation emergencies were damaged, preventing them from treating contaminated patients while evacuation orders hindered local fire department personnel.
Article Synopsis
- - On March 11, 2011, a massive earthquake hit Japan's northeast coast, triggering a tsunami with waves up to 15 meters and causing significant damage, particularly to the Fukushima nuclear power plant, which released radioactive materials.
- - The disaster affected around 170,000 people who had to evacuate or remain indoors and rendered local hospitals and emergency services dysfunctional due to their proximity to the nuclear plant and damage from the tsunami.
- - This event highlighted the need for improved disaster preparedness, emphasizing the importance of comprehensive evacuation plans for hospitals and better monitoring systems for radiation during combined disasters like earthquakes and nuclear incidents.
Article Synopsis
- The Great Eastern Japan Earthquake on March 11, 2011, triggered an accident at the Fukushima Daiichi Nuclear Power Plant, leading to extensive contamination screening for residents.
- Screening teams assessed contamination levels from March 11 to February 10, 2012, measuring 72,660 individuals and identifying 1,011 cases of varying contamination levels.
- While most workers were quickly screened and no harmful levels of external contamination were found, the peak contamination occurred shortly after the earthquake, suggesting iodine tablets would not have been effective during that time.
[Assessment, diagnosis and treatment of internal or body surface contamination].
Nihon Rinsho
March 2012
Article Synopsis
- - Radioactive contamination is divided into surface contamination, which can be measured using devices like G-M counters, and internal contamination, which requires methods like direct measurement and bioassay for assessment.
- - For surface contamination, cleaning methods like washing or wiping are effective, while internal contamination requires estimating the committed effective dose based on radioactive material in the body.
- - To treat internal contamination, options include reducing absorption with laxatives and using drugs like stable iodine, Prussian Blue, and DTPA for protection or treatment.
Article Synopsis
- This study investigates the effectiveness of accelerated fractionation radiotherapy for treating head and neck squamous-cell carcinoma (HNSCC) in areas with limited resources, following promising results from prior Western studies.
- Conducted from January 1999 to March 2004, the trial involved nearly 1,000 patients from various regions, comparing an accelerated treatment regimen of six sessions per week against a conventional five sessions per week.
- Results showed that both treatment groups received similar total radiation doses, with median treatment times differing, but the locoregional control rate after five years was noted to be 42% for patients receiving accelerated therapy.
Article Synopsis
- AK-2123, a hypoxic cell sensitizer, was evaluated in a randomized trial for its effectiveness when combined with radiotherapy in treating stage IIIA and IIIB uterine cervical cancer.
- A total of 333 patients participated in the study, receiving either standard radiotherapy alone or radiotherapy plus AK-2123, with promising doses administered over several weeks.
- Results showed that combining AK-2123 with radiotherapy significantly improved local tumor control and survival rates without increasing major side effects.
Regional hyperthermia combined with radiotherapy for locally advanced non-small cell lung cancers: a multi-institutional prospective randomized trial of the International Atomic Energy Agency.
Int J Clin Oncol
June 2007
Background: An International Atomic Energy Agency (IAEA)-sponsored, multi-institutional prospective randomized trial was conducted to clarify whether the combination of hyperthermia and radiotherapy improves the local response rate of locally advanced non-small cell lung cancer (NSCLC) compared with that obtained by radiotherapy alone.
Methods: Between October 1998 and April 2002, 80 patients with locally advanced NSCLC were randomized to receive either standard radiation therapy alone (RT) or radiation therapy combined with hyperthermia (RT + HT). The primary endpoint was the local response rate.
Article Synopsis
- AK-2123, a drug that enhances the effects of radiation therapy, was evaluated in a trial for its effectiveness in treating stage III and IV uterine cervical cancer alongside standard radiotherapy.
- The study included 333 patients, with half receiving only radiation therapy and the other half receiving both radiation and AK-2123 over a treatment period of around 4-5.5 weeks.
- Results showed that the combination therapy led to better local tumor control (61% vs 46%) and higher 60-month survival rates (57% vs 41%) without significantly increasing side effects.
Article Synopsis
- Hyperthermia may improve radiation therapy effects, particularly for challenging cases of locally advanced uterine cervical cancer, leading to a multi-center clinical trial to assess its combined efficacy.
- In the study, 110 patients were randomly assigned to receive either radiotherapy alone or radiotherapy plus hyperthermia, with careful monitoring and quality assurance of treatment methods.
- Results indicated a balanced comparison between the two groups, showing a notable 3-year overall survival rate of 73.2% for the patients involved in the trial.
Purpose: To investigate long-term changes in the cornea after ionizing irradiation in rabbits.
Methods: Mature albino rabbits (n = 4) were unilaterally irradiated with 20 Gy of x-rays. The contralateral eye served as a control.
Article Synopsis
- AK-2123 is a nitrotriazole compound that may enhance the effectiveness of radiation therapy on tumors in hypoxic conditions, particularly advanced cervical cancer.
- In a multicentric trial involving 98 patients who received external radiation, those treated with AK-2123 had a significantly higher complete response rate and overall survival compared to the control group.
- While the drug caused some transient neuropathy as a side effect, the results indicate that AK-2123 has strong potential as a radiation sensitizer in cancer treatment.
Article Synopsis
- A multicenter trial was conducted by the International Atomic Energy Agency (IAEA) to evaluate the effectiveness of mitomycin C (MMC) combined with radiotherapy in treating advanced head and neck cancer, compared to radiotherapy alone.
- The study included 478 patients with stage III or IV squamous cell carcinoma, and the outcomes showed that MMC had minimal side effects and did not significantly worsen any radiation-related complications.
- Overall survival rates showed that MMC did not improve locoregional control or survival for the majority of patients, except in a specific subgroup of N0 patients who benefited from the treatment.
Article Synopsis
- The text discusses recommendations for implementing high dose rate (HDR) 192Ir brachytherapy technology in developing countries, based on insights from an International Atomic Energy Agency (IAEA) meeting.
- Key recommendations include acquiring a complete HDR treatment system, upgrading infrastructure, ensuring budget support for maintenance and source replacement, and providing ongoing specialized training for medical personnel involved.
- The choice of HDR technology should consider its versatility in treating various conditions, economic feasibility in high patient volume scenarios, and additional benefits like safety for staff and patients.
Article Synopsis
- The study examines how countries in transition acquire radiotherapy technology, linking it to their economic capabilities and gross national income (GNI) per capita.
- It analyzes data from 72 countries, focusing on the availability of linear accelerators and other radiotherapy machines, to understand how income influences healthcare provision.
- Findings reveal a strong correlation between GNI/cap and the number of radiotherapy machines, indicating that smaller, lower-income nations are less equipped than larger populations in the same income bracket.