Oral Presentation The Annual Scientific Meeting of the Endocrine Society of Australia and the Society for Reproductive Biology 2014

Accuracy of pre-operative localisation of parathyroid adenoma with ultrasound and sestamibi scintigraphy in primary hyperparathyroidism – review of single centre experience. (#51)

Christopher Rowe 1 , Shaun McGrath 1
  1. John Hunter Hospital, Newcastle, NSW, Australia

Introduction:  Accurate pre-operative localisation of parathyroid adenomas allows appropriate selection of patients for minimally invasive parathyroidectomy (MIP). 

Methods: Retrospective review of patients with confirmed biochemical primary hyperparathyroidism who underwent both localisation ultrasound (performed by a single operator) and sestamibi scintigraphy (majority performed at a single practice with 99mTc-pertechnetate subtraction) over the period 2010 to 2013. Adenoma localisation was confirmed at parathyroidectomy.   Conditions known to predispose to multigland hyperplasia were excluded.  Results were compared to a previous audit of period 2005–2009.  

Results: 139 patients were identified, with average age of 66 years.  78% were female.  62% had mild primary hyperparathyroidism (corrected calcium < 2.75mmol/), while 8% had severe disease (calcium >3mmol/L).   The sensitivity of ultrasound to detect any abnormality ‘possibly consistent’ with an enlarged parathyroid was 85%, with a positive predictive value (PPV) for adenoma at that location of 92%.  When ultrasound imaging was considered ‘highly likely’ to show an adenoma, sensitivity was 70%, with a PPV of 98%.  Sensitivity of scintigraphy to detect any abnormality ‘possibly consistent’ with parathyroid adenoma was 81%, with a positive predictive value of 97% at that site.  Limiting scintigraphy results to those ‘highly likely’ to show parathyroid adenoma gave a sensitivity of 58%, but PPV of 100%.  92 cases had a concordant abnormality on both ultrasound and scintigraphy (sensitivity 69%) with a PPV for adenoma at that site of 100%.  In this group, 69 patients underwent MIP  with 67 cured.  When compared to past audit data, sensitivity of both techniques improved from 67% to 85% for ultrasound and 74% to 81% for scintigraphy.

Conclusions: Parathyroid ultrasound and sestamibi scintigraphy are complementary techniques to localise parathyroid adenomas pre-operatively.  Concordant abnormalities on both modalities improves confidence with patient selection for MIP.  There was evidence of improvement in localisation technique over time.