3. Somatostatin scintigraphy
Somatostatin scintigraphy is an appropriate test to assess for a site of ectopic cortisol production. 68Ga-PSMA-11 PET/CT is an agent used for the detection and staging of prostate carcinoma. 18FDG-PET scan could disclose a metabolically active lesion producing cortisol, a cortisol-producing neoplasm may not be metabolically active, and frequently carcinoid tumors, which could be the source of Cushing syndrome, not infrequently show little glucose utilization at 18FDG-PET. Lutetium Lu 177 vipivotide tetraxetan is an agent recently approved for use for adult patients with prostate-specific membrane antigen-positive metastatic castration-resistant prostate cancer previously treated with androgen receptor inhibition and taxane-based chemotherapy. 68Ga-DOTA-FAPI-04 PET/CT is a technique for malignancies expressing fibroblast activation protein (FAP), particularly lung malignancies, breast cancer, prostate cancer, various sarcomas, and head and neck cancers.
Abdominal CT assessing for a pancreatic source of ACTH production was performed (Figure 4) and showed fatty liver but bilaterally normal adrenal glands. Brain MRI was normal.
Figure 4. Axial enhanced coronal abdominal CT shows normal adrenal glands (arrows) and a somewhat hypointense liver (Liv) compared with the spleen (Spl), suggesting fatty infiltration.
A 2-day low-dose dexamethasone suppression test was performed and was abnormal, again indicating hypercortisolism and Cushing syndrome. Somatostatin (octreotide) SPECT-CT was performed (Figure 5).
Figure 5. Octreotide In111 SPECT-CT scintigraphy.
Which of the following represents an appropriate interpretation or this examination? (Click on the correct answer to be directed to the seventh of twelve pages)