Research Article

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

Figure 2

A 55-year-old woman who underwent pelvic radiotherapy for cervical cancer developed hip pain at 12 months after radiotherapy. Diffuse, mild, linear FDG uptake (left SUVmax, 3.2; right SUVmax, 3.0) 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 3 months after diagnosis of SIF. The fused image showed a slight increase in metabolism (left SUVmax, 3.3; right SUVmax, 3.5), and the low-dose CT image showed an increased bone density and high-density range. After 9 months of follow-up, the range of high density and hypermetabolism decreased; the metabolic intensity decreased (left SUVmax, 2.3; right SUVmax, 2.2), but the bone density increased.