Differential diagnosis of metastases in bone scans: Chemotherapy induced bone necrosis

Aim: Influenced by the incorrect diagnosis of a bone metastasis caused by b one necrosis we evaluated reasons and frequency of bone necrosis in patient s referred for bone scanning in follow-up of tumors. Methods: Bone scans pe rformed within two years on patients with primary bone tumors or tumors met astatic to bone were reviewed in respect to the final diagnosis bone necros is. Results: We found the cases of three young patients who presented the a ppearance of hot spots on bone scintigrams which were finally diagnosed as bone necrosis. In two cases the diagnosis was based on histological finding s, in one case the diagnosis was made evident by follow-up. All the three p atients had been treated by chemotherapy and presented no other reason for the development of bone necrosis. Enhanced tracer uptake in all sites decre ased within eight weeks up to two years without therapy. Conclusion: Single and multiple hot spots after chemotherapy may be originated by bone necros is but mimikry metastases.