Standardised prevalence ratio and the most likely cluster of childhood and adolescent thyroid cancer cases derived from flexibly shaped spatial scan statistics in Fukushima Prefecture, Japan. The numbers near municipal town hall points show the municipal number of thyroid cancer cases. The most likely cluster, which is shown with the hatch diagonal stroke in the map, contains 8 municipalities. The numbers of observed and expected cases are 42 and 29.76. The relative risk is 1.411 and the statistical testing p-value against the null hypothesis of geographically homogeneous risk is 0.75. The map in this figure was created with ArcGIS version 10.5 (http://desktop.arcgis.com/).