FUKUSHIMA Lives on the Line

148The Results of Thyroid Examinations, Our Goals, and Future ProspectsTable 1. Thyroid Screening Participation Rates in 2011 (as of March 31, 2012)Target areaTarget population (person) ANumber of participants (person) BParticipation rate (%) B/AResults by age groupNumber of the residents outside Fukushima Prefecture in B (person) CParticipation rate (%) C/B0–5 years6–10 years11–15 years16–18 yearsTamura City7,0806,18087.31,477 people1,774 people1,947 people982 people270.485.9%98.0%93.8%66.5%Minami-soma City12,5299,63676.92,757 people2,691 people2,679 people1,509 people2,60127.0 75.1%78.8%81.3%70.4%Date City11,35710,27490.52,389 people2,930 people3,256 people1,699 people1491.587.1%96.8%96.4%76.8%Kawamata Town2,4032,18891.1536 people609 people686 people357 people321.591.5%96.4%95.3%76.8%Hirono Town1,07769164.2167 people167 people244 people113 people11416.565.5%66.8%70.1%50.4%Naraha Town1,42993965.7219 people269 people283 people168 people14115.0 63.3%74.3%68.4%54.7%Tomioka Town2,9401,69657.7433 people455 people531 people277 people40523.956.4%62.0%59.9%50.3%KawauchiVillage35723064.457 people76 people59 people38 people4117.863.3%76.8%66.3%48.1%Okuma Town2,3861,54264.6478 people432 people446 people186 people26217.0 61.4%68.0%72.1%52.5%Futaba Town1,20471659.5217 people181 people207 people111 people35749.959.1%61.1%61.8%53.9%Namie Town3,6452,92280.2814 people769 people822 people517 people98433.780.5%83.5%79.7%75.9%KatsuraoVillage23314763.140 people43 people41 people23 people128.271.4%69.4%61.2%47.9%Iitate Village1,09091784.1242 people259 people255 people161 people566.187.0%86.0%84.2%77.4%Others*3636100.0 people7 people10 people19 people25.6%100.0%100.0%100.0%Total47,76638,11479.89,826 people10,662 people11,466 people6,160 people5,18313.677.5%84.9%84.5%68.7%*“Others” indicates participants outside the evacuation zone designated by the government, who undertook the thyroid screening mainly at schools.■The examination was performed in 2011 for residents in the evacuation zone designated by the government.■From October 2011 to March 2014, 79.8% of the target population (38,114 people) have participated in the examinationstudy were first examined and confirmed by the medical image screening committee made up of multiple specialists. The results were categorized into three classes, A, B, and C, where classes B and C were required to have a secondary examination. Class A was further categorized into subclasses A1 with no nodule or cyst, and A2 with nodules of ≤5 mm or cysts of ≤20 mm. Those who were classified as A1 or A2 were encouraged to undergo re-examination after 2.5 years, then every 2 years until age 20, and every 5 years after that. We included the mixed cysts that contained some solid parts in the category of nodule; thus, those classified as cysts in our context were considered benign. However, when they reach the size of ≥20.1 mm, mass effect may result. That was why those with cysts >20.1 mm were also encouraged to participate in the secondary study in case those cysts needed to be aspirated. Many nodules <5 mm are often difficult to distinguish from cysts, and are considered benign during ultrasound screening. All images of the A2 nodules were re-examined along with the B and C classes. If the routine re-examination in 2.5 years appeared to be too long a wait, these A2 cases were classified as class B and encouraged to participate in the secondary examination. In the routine clinical setting, the class A2 examination result is unremarkable and may not even be brought up. Re-examination in 2.5 years is usually considered sufficient for early detection. However, given that one of the aims of this survey is to promote the community’s understanding of their thyroid status over the long term, we considered it important to inform residents of our results and observations so that they could be aware of their individual conditions. We hope this reporting will help decrease concerns among residents who may consider seeking second opinions. We would also like to emphasize that the results of the primary examinations were assessed by various specialists who gathered from across the country from the outset, followed by the re-examinations performed by the committee that similarly consisted of specialists in the field. Those in classes B and C will undergo a secondary examination. Those in class C have an urgent need for further examination. Those in class B still require a secondary examination in <2.5 years, although it is not as urgent. For both B and C classes, a detailed secondary ultrasound examination is performed along with blood