Parathyroid surgery: Correlation between pre-operative localization studies and surgical outcomes

Objective Pre-operative imaging techniques have enabled minimally invasive parathyroid surgery to supersede the traditional approach to hyperparathyroidism (HPT) surgery, which included cervical exploration. Cervical ultrasound (US) and sestamibi scan (MIBI) are commonly performed, but the results of these localization tests do not always match. This study correlated surgical outcomes with pre-operative localization findings, including matched positive US and MIBI studies, one positive study (US or MIBI), conflicting studies or negative results. Design Retrospective medical record review. Patients A hundred and sixty nine consecutive patients who underwent parathyroidectomy from January 2005 to December 2012. Measurements Correlation between surgical outcomes and pre-operative localization tests. Results All patients (134F/35M, 59·6 ± 13·5 years of age) had primary HPT. US and MIBI localization studies matched in 76%, whereas 10·7% had positive MIBI only and 8·3% US only. Studies were negative in 3·6% and contradictory in 1·8%. Minimally invasive parathyroidectomy was performed in 87% of the matched group and 89% of the MIBI-only group. Surgical success rate, defined as postoperative normalization of calcium and PTH levels, was similar in patients with a single positive study (MIBI or US) vs double-matched studies (MIBI and US). Patients were followed up for 6 weeks. Overall, pathology was consistent with adenoma in 95%. Discussion Parathyroidectomy success rate was similar in patients with primary HPT and MIBI-only or US-only positive localization studies compared to those with matched US/MIBI studies. The results support a clinical algorithm in which positive results from one imaging technique, either MIBI or US, are sufficient to refer a patient for parathyroid surgery.