Endocrine Abstracts

Introduction: Primary hyperparathyroidism is the most common cause of hypercalcemia in the ambulatory setting. Once the diagnosis has been confirmed, imaging of the parathyroid glands is performed locally with a combination of ultrasound scan (USS) and sestamibi/single-photon emission computed tomography (SPECT CT) to localise a parathyroid adenoma prior to surgery.

Method: Data was collected on patients undergoing parathyroid surgery between November 2012 and December 2014. We analysed the following:

1. Pre and post-operative calcium and parathyroid hormone (PTH) levels

2. USS report

3. Setstamibi/SPECT CT report

4. Location and histology of parathyroid gland(s) removed

5. Post-operative calcium and PTH levels.

Results: 21 patients underwent parathyroidectomy. In 19 patients the location of the removed parathyroid gland was documented. All patients had undergone both USS and sestamibi/SPECT CT imaging.

Mean age was 63.3 years and 80% were female. Mean pre-operative calcium was 2.75 mmol/l and mean PTH 16.9 pmol/L. Surgical findings included eight left sided parathyroid adenomas (42.1%), ten right sided (52.6%) and one in the mediastinum (5.3%). One patient (4.7%) had two parathyroid glands removed which were both on the right side. Histology indicated 19 parathyroid adenomas (90.4%), one parathyroid neoplasia (4.7%) and one (4.7%) thyroid tissue. 52.6% had ultrasound and operation findings that correlated. 66.8% had sestamibi and operation findings that correlated. Eight patients (42.1%) had both ultrasound and sestamibi results that matched surgical findings. 20/21 patients had a biochemical cure (normal calcium postoperatively; mean 2.40 mmol/l.) 16/17 patients also had a PTH measured within normal limits; mean value of 5.14 pmol/L.

Conclusions: Sestamibi/SPECT CT scan imaging was slightly more sensitive than USS. Imaging was useful for localising parathyroid glands pre-operatively in around two thirds of patients. 95.2% of patients had their primary hyperparathyroidism cured surgically. No surgical complications were reported.