Endocrine Abstracts

Introduction: Primary hyperparathyroidism affects 0.3% of the general population¹. 90% are due to single parathyroid adenoma¹. Surgical treatment is the only definitive cure². Improvements in imaging permit radiologists to better identify parathyroid adenomas¹, enabling more targeted surgery¹, thus shortening general anaesthesia, as well as lowering post-operative complication rates. Neck ultrasound (US) and parathyroid scintigraphy (MIBI) are commonly used together for adenoma detection.^1,2 The aim of our quality improvement project was to evaluate the parathyroid service at the Royal Cornwall Hospital Trust (RCHT). We identified what imaging (US/MIBI/both) was performed, adenoma detection rate, surgical intervention and overall patient outcome.

Methods: We performed CRIS data search of patients undergoing MIBI from March 2013 to March 2021, assembling a log of all parathyroidectomies, relevant histopathological records and examining biochemistry records (PTH and calcium) pre- and post-surgery.

Results: 201 parathyroid surgeries were performed over 9 years. Of 201 patients, six underwent US only, 44 underwent MIBI only, and 151 benefitted from both US and MIBI. 82 patients undergoing both US and MIBI had a concordant imaging result whilst 5 had discordant results. The remainder demonstrated an adenoma on either US (19) or MIBI (40) only. Three patients were excluded as they only had planar SPECT imaging. A combination of USS and MIBI had the highest true positive rate (87%) vs MIBI only (76%), USS only (59%). Over nine years, 422 MIBI were performed for 201 surgeries. The success rate of patients undergoing surgery was 93%. Furthermore, 64 patients who were diagnosed with primary hyperparathyroidism were aged fifty or younger. 11 patients were screened for MEN1, two of whom with subsequently confirmed diagnosis.

Conclusion: Over 75% of patients undergo US and MIBI. Discordancy was low between US and MIBI (3.3%), although less than 50% of patients who had MIBI proceeded to surgery.