ABSTRACT
OBJECTIVES: The aim of this study is to analyse the diagnostic value of positron emission tomography (PET) in patients with giant cell arteritis (GCA) despite glucocorticoid (GC) therapy before PET acquisition. METHODS: Consecutive patients with strongly suspected GCA according to 2022 EULAR/ACR criteria were included. The physician diagnosis of GCA after 6 months of follow-up was the gold standard. PET was performed at baseline and 6 months later. In patients with negative results at 60 min, delayed imaging was performed at 180 min. RESULTS: Twenty-six patients were included with a median (IQR) age of 70.5 (57-88) years. Baseline PET was positive in all but one: 18 patients at 60 min and 7 patients after delayed imaging at 180 min. The median (IQR) GC dose at the time of baseline PET was 45 mg/d (26.2-45) of prednisone equivalent with a median exposure of 14 days (7-76.2). At 6 months of follow-up, PET was performed in 22 patients, with positive results in 16. Delayed imaging was performed in 6 patients due to negative PET at 60 min, with positive results in all cases, despite treatment with GC and/or biological therapy. CONCLUSIONS: In patients on GC therapy, delayed imaging protocols applying procedural recommendations for vascular quantification could improve diagnostic accuracy. Therefore, we suggest performing imaging only at 180 min in patients who have been on GCs for more than 3 days as well as in those with highly suspected GCA but negative findings in baseline PET at 60 min.
ABSTRACT
ABSTRACT: A 63-year-old man was remitted for a 68 Ga-PSMA-11 PET/CT scan due to biochemical recurrence with a PSA of 0.32 ng/mL 1 year after radical prostatectomy of locally advanced Gleason 6 (3 + 3) ISUP 2 pT3a pN0 prostate cancer. 68 Ga-PSMA-11 PET/CT showed multiple cutaneous and subcutaneous uptake foci in the upper body. Physical examination revealed numerous dome-shaped, ruby-red papules. These were consistent with a previous diagnosis of cutaneous hemangiomas. Cherry hemangiomas (also known as Campbell de Morgan spots) are the most common type of benign vascular proliferation of the skin. Due to the nonspecific 68 Ga-PSMA-11 uptake of vascular lesions, careful interpretation should be considered in order to avoid a potential pitfall in nonmalignant conditions.
