AB181. SOH24AB_035. Systematic review of the literature concerning imaging techniques of the thyroid and parathyroid glands

Background: Primary hyperparathyroidism due to parathyroid adenomas is the most common cause of hypercalcemia in otherwise healthy adults. Up until recent advances in preoperative imagining, excision of these adenomas required bilateral exploration of the neck. With the advent of preoperative imaging, and intraoperative parathyroid assay, a minimally invasive approach is now used. Dual-isotope simultaneous subtraction imaging, while not yet in widespread use, is a novel technique with promising results. This study aims to determine the increase in accuracy in identifying the location of parathyroid adenomas with the dual-tracer simultaneous-acquisition method compared with the single-tracer, dual-phase protocol that is currently predominant.

Methods: Existing peer-reviewed journals were searched to identify trials and studies that evaluated and compared dual-isotope scanning with scintigraphy. Online research databases PubMed, SCOPUS, and Cochrane were analysed and selected based on their relevance based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The search scanned for studies with patients who had undergone dual-radioisotope imaging preoperatively. The abstracts were inspected according to established criteria and the texts were then examined to extract the clinical data.

Results: The primary outcome was the success rate of dual radioisotope imagining, defined as sensitivity and specificity. Results after systematic evaluation of potentially relevant articles, 12 studies were downloaded and 7 studies, consisting of 3,701 patients, met the study criteria. Sensitivity and specificity for dual isotope imagining were 93% and 99%, respectively. This confirms a statistically significant higher diagnostic accuracy than dual-phase computed tomography (CT), 4D-CT and ultrasound as first-line imagining

Conclusions: In preoperative assessment of primary hyperparathyroidism and to guide surgery, dual-isotope subtraction imagining is currently the most accurate technique, yet its use is not widespread. This review highlights the scope for further, more widespread research in this area.

Keywords: Thyroid; parathyroid; dual-isotope; systematic review; Ireland