Nuclear Medicine and Molecular Imaging in Nodal Staging and Surveillance of Ocular Melanoma: Case Reports and Review of the Literature

Whole-body ¹⁸F-FDG PET/MRI study in surveillance of UM (case 1). Whole-body maximal-intensity-projection (MIP) images exhibit tracer-avid left eye lesion and numerous tracer-avid lesions in liver. Axial ¹⁸F-FDG PET/MRI of left eye demonstrates high T1-signal lesion in left globe with increased tracer uptake, with SUV_max of 8.3 (top line on MIP image; top row of images). On representative layer of liver (bottom line on MIP image; bottom 2 rows of images), multiple liver lesions with variable low and high T1 signals show increased uptake, with SUV_max of 4.0–11.7. In addition, diffusion-weighted imaging (DWI) shows more small metastases with restricted diffusion (arrows) than does contrast-enhanced T1-weighted MRI (T1C+) or PET. T1C− = non–contrast-enhanced T1-weighted MRI; T2 = T2-weighted MRI. Color version of this figure is available as supplemental file at http://tech.snmjournals.org.

^99mTc-filtered sulfur colloid SPECT/CT (case 2). (A) Coronal PET/MR image demonstrating successful radiotracer injection to right-eye subconjunctival region by ophthalmologist. (B) Axial PET/MR image. (C) Axial low-dose CT image. Tiny sentinel lymph node (arrows) was identified in right fossa of parotid gland. Node was negative for metastasis on biopsy. Color version of this figure is available as supplemental file at http://tech.snmjournals.org.

Whole-body maximum-intensity-projection ¹⁸F-FDG PET/CT and ¹⁸F-FDG PET/MRI in surveillance of CM (case 2). Consecutive anterior and right lateral views do not demonstrate hypermetabolic metastasis or recurrence at baseline or at the first (12 mo) or second (16 mo) follow-up (F/u-1 and F/u-2, respectively).