5,000 parathyroid operations without frozen section or PTH assays: measuring individual parathyroid gland hormone production in real time.

BACKGROUND: Determining the physiologic activity (hormone production) of individual parathyroid glands can provide tremendous guidance during parathyroidectomy.
METHODS: A 6.5-year prospective study of 5,000 patients with sporadic, non-multiple endocrime neoplasia (MEN) primary hyperparathyroidism who underwent surgery without frozen section or parathyroid hormone (PTH) assays was conducted. Patients who had a frozen section were not included; the removal of parathyroid glands was determined solely by the physiologic activity of each gland as determined by contained radioactivity. All operations were within 2.25 hours of sestamibi scanning. Ex vivo measurements of parathyroid glands, thyroid nodules, lymph nodes, thymus, and fat were obtained from all patients, constituting >32,000 specimens. All patients had at least two parathyroid glands evaluated; 59% had four glands evaluated. Ratios were compared with histology and preoperative/postoperative labs.
RESULTS: Parathyroid glands occur in three distinct groups according to their hormone production, indicating the type of pathology present. Adenomas (n=5,120) contained 57+/-38% of background radioactivity; hyperplastic glands (n=640) contained 16+/-4%; and normal glands (n=9,400) contained 4+/-0.1% (all p<0.00001). Fat and lymph nodes were always less than normal glands (p<0.005). There was no overlap between different tissue types in any individual (p<0.001). Contained radioactivity was a better predictor of cure than histology (p<0.0001). The average operative time was 19.4 minutes with (99.9%) discharged within 5 hours. The initial cure rate was 99.23% with missed contralateral second adenomas causing all failures (subsequently cured).
CONCLUSIONS: Measures of sequestered radioactivity is an extremely accurate estimate of individual parathyroid gland hormone production allowing near 100% distinction between normal, hyperplasic, and adenomatous glands as well as distinguishing parathyroids from other neck tissues (fat, lymph nodes, thyroid). This instantaneous measurement is sufficient to determine which glands should be removed and which should remain in situ, while eliminating frozen sections and PTH assays in nearly all patients undergoing parathyroid surgery. This insight allows the operation to progress very rapidly.