BILATERAL TEMPORAL-LOBE NECROSIS AFTER RADIOTHERAPY - CONFOUNDING SPECT RESULTS

A patient with seizures and a contrast-enhancing temporal lesion after radiation therapy for a chondrosarcoma of the nasal septum is describ ed. To differentiate between radiation necrosis and recurrent tumor, t hallium-201 (Tl-201) SPECT was used. Tl-201 SPECT revealed high local accumulation suggesting tumor growth; however, pathologic examination demonstrated focal necrosis with reactive changes but without tumor. T he Tl-201 SPECT findings in this patient demonstrate a possible diagno stic pitfall in differentiating recurrent tumor from radiation necrosi s.