Pre-operative localisation of parathyroid adenomas

An audit of the accuracy of imaging localisation of parathyroid adenomas prior to minimally invasive surgery, using ultrasound and sestamibi imaging.

Primary hyperparathyroidism is a common endocrine disorder that is caused in the majority of cases by a solitary parathyroid adenoma. Surgical removal of the parathyroid adenoma is curative, but traditionally involves bilateral neck exploration, with relatively long operative and recovery times, complications such as neck fibrosis, and the risks of GA. More recently, trends have been towards minimally invasive unilateral techniques under local anaesthesia, with the benefit of shorter operative and recovery times, better cosmetic results and the avoidance of GA. However, the success of minimally invasive surgery depends on accurate pre-operative localisation of parathyroid adenomas. It is therefore important to demonstrate that high levels of accuracy in pre-operative imaging are being achieved.

The standard: 

Reported sensitivity for imaging localisation of parathyroid adenomas varies in the published literature. Ultrasound is reported to have a sensitivity of 65-85% and sestamibi scintigraphy of 71-92%. The use of both techniques in combination increases sensitivity further to >90%.

Target: 

Suggested targets:

- Sensitivity of ultrasound 75%

- Sensitivity of sestamibi scintigraphy 80%

- Sensitivity of ultrasound and sestamibi scintigraphy combined 90%

Indicators: 

- Sensitivities of pre-operative ultrasound and sestamibi scintigraphy in the detection of parathyroid adenoma

- Separately and in combination, using surgical and histological findings as the reference standard

Data items to be collected: 

- Consecutive patients undergoing surgery for suspected parathyroid adenoma following pre-operative imaging localisation to be identified

- Imaging reports to be obtained in each case, specifically noting whether a parathyroid adenoma was identified and in which location

- Histological reports and/or operative notes to be obtained in each case, noting whether a parathyroid adenoma was identified and in which location

Suggested number: 

30 consecutive cases or all relevant patients over a one-year period

• Present the audit to all involved radiologists, radiographers and surgeons

• Arrange for parathyroid ultrasound to be performed and in nuclear medicine - Imaging to be reported by suitably trained operators

• Consider external training and review

• Use cases identified during the audit for teaching and training purposes of involved staff

• Establish a system to review imaging in cases where surgical and imaging findings are discordant

• Assistance may be required in retrieval of case notes, though in many cases histological reports are available electronically and may contain the relevant operative findings in the clinical details of the report

• Radiologist’s time involved in data collection (6 hours)

• Radiologist’s time involved in calculation of sensitivities and collation of data (2 hours)

1. Ahuja AT, Wong KT, Ching AS, Fung MK, Lau JY, Yuen EH, King AD. Imaging for primary hyperparathyroidism - what beginners should know. Clin Radiol 2004;59:967-76.

2. O'Doherty MJ, Kettle AG. Parathyroid imaging: preoperative localization. Nucl Med Commun 2003;24:125-31.

3. Nathan A. Johnson1, Mitchell E. Tublin1 and Jennifer B. Ogilvie2Parathyroid Imaging: Technique and Role in the Preoperative Evaluation of Primary Hyperparathyroidism  AJR June 2007, Volume 188, Number 6

Dr M Bydder.