Physiological F18- PSMA 1007 Uptakes in Different Sympathetic Ganglia. A Single Institution Observation.

1253 Introduction: The physiological uptake noted in different sympathetic ganglia (cervical’ Stellate”, celiac and sacral) observed in prior publications regarding Ga-68 labelled PSMA radiopharmaceutical is well known and described as a potential “pitfall” in interpretation for malignant lesions on PET/CT studies [1-9]. The physiological uptake in sympathetic ganglia are scarce the literature with regard to F-18- PSMA ligands [10]. We report the first single institution experience in observing the uptakes in different sympathetic ganglia with descriptions on the different morphological variations observed using F18-PSMA 1007 as a main radiopharmaceutical for patient assessment with prostate cancer. Material & Methods: All patient who were referred to perform F-18 PSMA 1007 with prostate cancer diagnosis were included in the study. A retrospective analysis of these cases included studies done over almost one-year period at Jaber Alahmad Center for Molecular Imaging (JACMI).135 patients with a diagnosis of prostate Cancer were included in the study group. Patients were imaged from Nov 2018 till end Dec 2019. Patient were injected with a dose formula of 0.06 mCi/Kg (ranges of injected dose were from 3.13 mCi - 8.6 mCi). The uptake period was ranging from 53 min till 158 minutes post radiotracer injection. All our studied populations were imaged using GE Discovery MI. a low dose CT was used for image attenuation correction and anatomical localization. The CT protocol was done using 120 kV with Auto mA that ranged from minimum 10 mA- max 150 mA with a noise index 30 and slice thickness 3.75 mm. Subsequently, PET images wed acquired for 2 min / bed using a time of flight (TOF) and Shrap IR with filter cutoff 6 mm, 2 iteration and 8 subsets using 256 matrix size.PET/CT studies were reported by experienced nuclear medicine physician. The pattern of the sympathetic ganglia was reviewed from the previous published literature and the uptakes noted at cervical” stellate”, celiac and sacral sympathetic ganglia region were identified. The morphology “shape” of the identified sympathetic ganglia is noted and unilateral or bilateral observation was assigned with the help of experience radiologist. Results: After reviewing 135 patient scans, the commonest sympathetic ganglia were the celiac (125 patients ‘92.5%’) followed by the cervical “stellate “ganglia (108 patients ‘80%’) and to significant degree sacral ganglia (71 patients ‘52.6’). Bilateral identification was common finding in the different locations (Figure 1 and 2). The commonest morphological type is the band like pattern. Representative images of the different pattern of uptakes are shown (Figure 3). Conclusions: Using F18-PSMA 1007 PET/CT in studying patients with prostate cancer will encounter physiological uptakes in sympathetic ganglia. The uptake pattern and the location should be well appreciated and awareness of such pattern should not lead false positive interpretations. The findings are very common in certain degrees in specific sympathetic ganglion anatomical locations. The findings encountered in this work support similar observations seen with other PSMA labelled with Ga-68 and F-18 published in the literature.