Bone Scan "Hot Spot" at the Superior Lateral Orbital Margin Fronto-zygomatic Suture Uptake Characterized with Tc-99m MDP SPECT/CT.

Findings of a solitary "hot spot" at the superior lateral orbital margin on bone scan scintigraphy is not uncommonly seen, and is often dismissed as a benign lesion. However, the exact etiology is indeterminate. We present two cases in which hybrid single photon emission computed tomography/computed tomography imaging was able to characterize and localize this uptake, demonstrating correlation to the right fronto-zygomatic suture.

Differentiating osteoradionecrosis from nasopharyngeal carcinoma tumour recurrence using 99Tcm-sestamibi SPECT/CT.

Osteoradionecrosis (ORN) of the base of skull is a known complication of external beam radiotherapy in the treatment of nasopharyngeal carcinoma, and is widely believed to be sequelae of radiation-induced endarteritis, leading to cellular death and fibrosis. Differentiating ORN from tumour recurrence is challenging and has direct clinical implications. We present a case where (99)Tc(m)-sestamibi SPECT/CT was used to differentiate ORN from tumour recurrence and in which prior imaging using bone scintigraphy and fluorodeoxyglucose PET/CT were equivocal.