Sacral Insufficiency Fracture after Radiotherapy for Cervical Cancer: Appearance and Dynamic Changes on 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

Figure 3

A 47-year-old woman who underwent pelvic radiotherapy for cervical cancer developed hip pain at 21 months after radiotherapy. Diffuse, mild, linear FDG uptake (left SUVmax, 3.0; right SUVmax, 2.6) parallel to the sacroiliac joint in the bilateral sacral ala (yellow arrow) was found in the fused axial image, while the low-dose CT image showed high density and a very small right anterior sacral fracture line (white arrow). Follow-up FDG PET/CT at 12 and 24 months after diagnosis of SIF. The bilateral sacral ala essentially returned to normal.