The 1st International Symposium of the Radiation Medical Science Center for the Fukushima Health Management Survey
This symposium was held on Jan 14-15, 2019, in Fukushima City, Japan, and the chief members of the Fukushima Health Management Survey and related Japanese academic societies participated as speakers.
This symposium was held in Fukushima City on January 14-15, 2019. In this symposium, a wide range of issues concerning the Great East Japan Earthquake were dealt with. There were four presentations on thyroid ultrasound examination. Two are from Fukushima Medical University, and two were presented by overseas experts.
Dr. Hiroshi Shimura, the Director of the Thyroid Examination Department of Fukushima Medical University, explained the results from the first round to the third round thyroid ultrasound examination of the Fukushima Health Management Survey. He reported the participation rate, the number of subjects underwent the secondary test, and the number of cases with malignant or suspected malignancy by cytology. Many patients diagnosed with malignancy had already undergone surgery, and most reported papillary cancer. He said the effects of overdiagnosis was negligible since, 1) no further examination of nodules smaller than 5 mm was performed, 2) fine needle aspiration was performed only to limited subjects according to the recommendations by the Japan Association of Breast and Thyroid Sonology, and 3) active surveillance was recommended for patients with a small cancer which was considered low risk.
Dr. Zhanat Carr from WHO outlined how to justify a long-term medical follow-up program affected by nuclear accidents. She introduced the recommendations of IARC, an organization within WHO,
that population-based screening of thyroid cancer is not recommended; rather, individual-based monitoring program should be considered only when there was high dose exposure.
Dr. Sanae Midorikawa from the Department of Radiation Health Management, Fukushima Medical University, explained what she learned from the dialogue with the Fukushima residents. She said thyroid cancer screening itself was causing anxiety in various situations, and the increased number of detected thyroid cancer caused raising concern for radiation exposure. She also noted that most residents did not know the existence of harms regarding thyroid examination and felt that there were more advantages than harms. Therefore, the explanation, consent, and voluntariness, which are essential for decision making of residents, were not guaranteed in the present thyroid examination.
Dr. Yong-Sik Lee, a Korean head and neck surgeon, explained the situation of thyroid cancer overdiagnosis in South Korea. There was a strong opposition from the Korean thyroid surgery group when the idea that ultrasonic detection of thyroid nodules should be stopped to solve the overdiagnosis problem was presented. He summarized the following lessons from Korea. 1) Do not try to find thyroid cancer in asymptomatic people, 2) most of the palpable cancers can be cured by treatment, and 3) overcoming the anxiety of invisible threats can be achieved only when the residents really trust the medical staff.