Uptake in sympathetic ganglia on ⁶⁸ Ga-PSMA-HBED PET/CT: A potential pitfall in scan interpretation

The aim of this study was to assess the frequency of PSMA-HBED uptake in coeliac and stellate ganglia in patients presenting for PSMA-HBED PET/CT scan.

Prostate-specific membrane antigen-HBED PET/CT scans of 100 consecutive patients were analysed. Coeliac and stellate ganglia were identified by their anatomical location. PSMA-HBED uptake in these ganglia was recorded as either present or absent. If present, the SUV_max value for each ganglion was measured and compared to SUV_max of mediastinal blood pool.

Of the 100 patients, 45 had PSMA-HBED uptake in the right coeliac ganglion and 81 had PSMA-HBED uptake in the left coeliac ganglion. The mean SUV_max for the right coeliac ganglion was 2.6 (range 1.2-4.0) and for the left, 2.7 (range 1.2-6.5). An SUV_max 1.5 times greater than that of mediastinal blood pool activity was found in 25 of right and 47 of left coeliac ganglia. Stellate ganglion uptake of PSMA-HBED was identified in 54 of right and 74 of left stellate ganglia. The mean SUV_max for the right and left stellate ganglia were 2.2 (range 1.6-3.6) and 2.4 (range 1.4-4.2) respectively. An SUV_max 1.5 times greater than that of mediastinal blood pool activity was found in 12 of right and 32 of left coeliac ganglia.

Uptake in coeliac and stellate ganglia is a frequent finding on PSMA-HBED PET/CT imaging. Often this uptake can be sufficiently high to cause potential diagnostic confusion. It is important to be aware of this physiologic uptake to avoid incorrect diagnosis of metastatic prostate carcinoma.