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Objective: Gallium-68-DOTA-D-Phe1-Try3-Octreotide ( 68 Ga-DOTATOC) is a radiolabeled somatostatin receptor (SSTR) analog that is widely used in the imaging of neuroendocrine tumors (NET). Benign and malignant prostate tumors have been observed to express SSTR. Diffuse symmetric DOTATOC uptake in the prostate is a normal positron emission tomography (PET) finding. The aim of this study was to evaluate the frequency and clinical significance of incidental atypical prostatic uptake in men undergoing 68 Ga-DOTATOC PET/computed tomography(CT)., Subjects and Methods: A retrospective review of consecutive male patients who underwent 68 Ga-DOTATOC PET/CT studies at Aalborg University Hospital, Denmark, from November 2010 to April 2020 was performed. Positron emission tomography/CT reports were searched for text words or phrases indicating incidental atypical prostatic uptake. In the resulting cohort, PET/CT were re-evaluated, and DOTATOC uptake in the prostate gland was categorized as focal, diffuse or mixed. The intensity of the uptake was visually graded using the Krenning visual score. Follow-up was based on all available clinical, biochemical, imaging, and pathology follow-up., Results: A total of 178 male patients underwent 193 68 Ga-DOTATOC PET/CT scans. Incidental atypical uptake of 68 Ga-DOTATOC on PET/CT in the prostatic bed was observed in eight patients (4.5%) (mean age 67 years, range 58-85 years). Six patients (75%) had diffuse uptake; two (25%) patients had focal uptake. Four patients out of eight with incidental findings (50%) had uptake less than or equal to that of the liver (Krenning score 2); four patients (50%) had uptake greater than that of the liver (score 3). All patients had measurements of serum prostate-specific antigen and were referred for urological evaluation. Five patients (62%) underwent a transrectal ultrasound, and three required a biopsy of the prostate. No cases of prostate malignancy (including prostatic cancer) were diagnosed., Conclusion: During a 10-year period, we found that 4.5% of men exhibited prostate incidentalomas on 68 Ga-DOTATOC PET/CT. No malignancy was found in the prostate in this population. Our data indicate absent malignancy among incidental 68 Ga-DOTATOC findings in the prostate.

Objective: Gallium-68-prostate-specific membrane antigen positron emission tomography/computed tomography ( 68 Ga-PSMA PET/CT) has become a well-established imaging method for the evaluation of patients with prostate cancer. However, several cases have revealed PSMA uptake in a large variety of conditions other than prostate cancer. Prostate-specific membrane antigen uptake in thyroid cancer has also been reported. The aim of the present study was to systematically investigate the prevalence and clinical significance of thyroid incidental findings in patients undergoing 68 Ga-PSMA PET/CT., Materials and Methods: We retrospectively identified all patients referred for 68 Ga-PSMA PET/CT at the Department of Nuclear Medicine, Aalborg University Hospital, Denmark between May 2015 and May 2019. Patients with increased PSMA uptake in the thyroid gland were included in the analysis. Follow-up included imaging, biochemical, and/or histopathological collected over six months., Results: A total of 341 patients were included. Increased 68 Ga-PSMA uptake in the thyroid gland was observed in 13 patients (4%). Focal uptake was observed in seven patients, diffuse uptake in five patients and mixed focal and diffuse uptake in one patient. Malignancy was verified in two patients (2/13 patients, 15%), both patients with focal PSMA uptake., Conclusion: Gallium-68-PSMA thyroid incidental findings are rare in prostate cancer patients. However, cases of focal PSMA uptake in the thyroid gland should be further investigated, as these findings may represent metastatic or primary malignancy of the thyroid gland.