Endocrine Abstracts

Primary hyperparathyroidism (PHP) is a common endocrine disorder. It is due to a single parathyroid adenoma in 80% of cases, most of the remainder due to hyperplasia of all four parathyroid glands. The only curative procedure is parathyroidectomy, but preoperative localization can be difficult. Isotope scanning with sestaMIBI is considered to be useful in localizing any parathyroid adenoma to help guided surgery. The aim of this study is demonstrated the influence of biochemical parameters, gland size and thyroid disease in accuracy of MIBI scintigraphy in the localization of parathyroid adenomas.

A series of 196 patients with PHP who underwent parathyroidectomy from 1995 to 2012 was included and divided into two groups: positive MIBI and negative MIBI. Positive value was defined when the pathologic gland was correctly localized and negative value when discordant result or no gland was localized.

Except one case of parathyroid carcinoma all were adenomas in MIBI+ group, however in MIBI− group, there were five hyperplastic glands and three cases of double adenoma, rest (86.1%) were adenomas. Serum calcium, phosphate, urinary calcium, PTH and 25OH-vitamine D values were similar and there was no statistically difference between size and weight of the pathologic gland in both groups.

Conclusion: This retrospective study shows there is no influence of biochemical parameters, gland size or tumoral weight in the accuracy of MIBI scintigraphy. We also demonstrate the negative effect of simultaneous thyroid disease in this diagnostic thecnique. More studies are needed to evaluate the influence of other parameters, like cell type, in accuracy of MIBI scan in parathyroid adenomas.