PRE-OPERATIVE IMAGING FOR PARATHYROIDECTOMY, WHAT IS THE MOST EFFICIENT STRATEGY?

AUTHORS:
B. Al-Kendi (Dublin, Ireland) , V. Nikhil (Dublin, Ireland) , M. Kerin (Galway, Ireland) , l. Spoehr (Galway, Ireland) , Y.X. Lee (Galway, Ireland) , H. Glazier (Galway, Ireland) , O. Young (Galway, Ireland) , J. Bruzzi (Galway, Ireland) , A. Lowery (Galway, Ireland)
Background:
Accurate preoperative imaging is essential in informing the optimal approach to surgery for patients with primary hyperparathyroidism. Dual-phase scintigraphy combined with SPECT-CT offers anatomic precision and functional information. However, current guidelines continue to recommend dual imaging prior to planning minimally-invasive parathyroidectomy (MIP) versus 4-gland exploration(4-GE).
Methods:
Retrospective observational study including all patients undergoing first-time surgery for primary Hyperparathyroidism in UHG from January 2018 to December 2022. Multiple data points were collected to include pre-operative investigations, operation type and outcomes.
Results:
235 patients were included. 64.3% underwent MIP. 80% of all histopathology revealed adenomas. 96% of all patients received dual imaging preoperatively with SPECT/CT and US performed on the same day. 26.8% of patients had adenoma localised on SPECT/CT only (sensitivity: 58.1%, specificity: 71%, PPV: 85.7%). 9.8% had adenoma localised on US only (sensitivity: 15.6%, specificity: 73.3%, PPV: 65.2%). 45.1% were dual localised on both SPECT/CT and US (sensitivity: 75.6%, specificity: 46.6%, PPV: 84.9%). 18.3% were dual unlocalized. Cure rate was 91.5% amongst the dual localised group, 86% in the dual unlocalised group and 96.5% when localised with SPECT/CT alone.
Conclusions:
A dual-imaging modality with SPECT/CT and US should remain the first-line imaging strategy. This approach has higher sensitivity rates and poses no inherent patient or surgical related risks. Patients with disease unilocalised on SPECT/CT alone had a positive predictive value, specificity, and likelihood ratio for adenoma detection comparable to dual localised patients. Therefore, SPECT/CT alone is sufficient for directing MIP in the presence of a negative ultrasound.