Increased Uptake of 18F-PSMA-1007 in Corpus Luteum Demonstrated by PET/CT.

ABSTRACT: Two women were referred for an 18F-PSMA-1007 PET/CT in follow-up of an adenoid cystic tumor of the subglottic region and the bronchus, respectively. Only limited tracer uptake was seen in the region of local recurrence and in the region of known metastases. Unexpectedly, an incidental finding consisting of a high tracer uptake at a corpus luteum in the ovary was found in both women.

Influence of medication and PTH levels on detection of parathyroid adenomas with dual isotope parathyroid scintigraphy.

Localization of parathyroid adenomas is a crucial step to facilitate minimally invasive parathyroidectomy. In this study, we investigated sensitivity and positivity rate of SPECT-based dual isotope parathyroid scintigraphy in detecting parathyroid adenomas, and the effect of medication and parathyroid hormone (PTH)-level on detection of adenomas. Two hundred and thirty-seven patients with primary hyperparathyroidism undergoing dual isotope parathyroid scintigraphy with SPECT-CT in our centre between January 1st 2013 and December 31st 2017 were included in this retrospective study. Sensitivity and positivity rate for accurate location of parathyroid adenomas, based on histopathological findings after surgery and follow-up PTH and calcium, were calculated. The impact of pre-operative medication (thyroxin, calcium-antagonists, antacids, vitamin D, bisphosphonates and calcium) and PTH-levels between positive and negative scans was evaluated by using univariate and multivariate analysis, and a ROC analysis respectively. Overall patient-based sensitivity of scintigraphy for finding parathyroid adenomas was 72% for scintigraphy, with a positivity rate of 60%. No significant effect of investigated medication on positivity rate was found. PTH-level was significantly higher in patients with positive scintigraphy (median 96.3 ng/L vs 75.2 ng/L, P < 0.01). Optimum cut-off for detection of adenomas for PTH was 79.4 ng/L with a sensitivity of 67% and a specificity of 63%. In this retrospective cohort, sensitivity and positivity rate of dual-isotope SPECT-CT for parathyroid adenomas were in line with previous studies. No statistically significant influence of medication on positivity of scintigraphy was found, suggesting these medication types should not be stopped prior to scintigraphy. PTH level was no useful parameter to predict positivity of scintigraphic imaging.

Detection of Unexpected Brown Tumors Due to Hyperparathyroidism Diagnosed by 18F-FDG PET/CT.

A 27-year-old man was called to receive a kidney transplant. The preoperative CT of the chest showed multiple osteolytic lesions, as well as a hypodense structure posterior in the right thyroid lobe. Blood analysis showed elevated parathyroid hormone, phosphorus, and alkaline phosphatase levels, with normal calcium and 25-OH-vitamin D. F-FDG PET/CT demonstrated generalized elevated FDG uptake in the bone (due to hyperparathyroidism), as well as multiple hypermetabolic focal lesions spread throughout the bone (fitting brown tumors). The nodule posterior of the right thyroid lobe showed an intense FDG uptake as well, suggestive of a parathyroid adenoma/hyperplasia. Histopathology confirmed the diagnosis.