Primary hyperparathyroidism with surgical indication and negative or equivocal scintigraphy: safety and reliability of PTH washout. A systematic review and meta-analysis.

OBJECTIVE

Despite the improvements in ultrasound (US) and scintigraphy, 10-20% of patients with primary hyperparathyroidism (PHPT) still have discordant findings. We performed a systematic review and meta-analysis to assess the safety and the diagnostic performance of US-guided PTH washout (FNA-PTH) in patients with PHPT, a suspected parathyroid lesion on US but negative or equivocal scintigraphy.

METHODS

The review was registered on PROSPERO (CRD42019124249). PubMed, Scopus, CENTRAL and Web of Science were searched until February 2019. Original articles reporting complications and diagnostic performance of FNA-PTH in biochemically and histopathologically diagnosed PHPT were selected. The risk of bias of included studies was assessed through QUADAS-2. Summary operating points were estimated using a random-effects model.

RESULTS

Out of 2573 retrieved papers, nine cohort studies were included in the review. No major procedure-related complications were found. Pooled sensitivity was 95% (95% CI: 91-98; I 2: = 14%) and positive predictive value was 97% (95% CI: 93-100; I 2: = 39%). There were not enough data for specificity and negative predictive value to perform a meta-analysis. However, pooling results of all lesions, they were estimated to be 83 and 73%, respectively.

CONCLUSIONS

In patients with biochemically proven PHPT and discordant imaging, FNA-PTH was a safe and accurate procedure. In this specific setting of patients, FNA-PTH could be used as a rule-in test for minimally invasive parathyroidectomy.