Technetium-99m Sestamibi Scintigraphy Pattern in Patients with Secondary Hyperparathyroidism

Abstract

Introduction: Metabolic bone disease is one of the major complications of end stage renal disease (ESRD). We aimed in this investigation to explore the role of Technetium99m sestamibi ( 99m Tc MIBI) scintigraphy in the preoperative assessment of refractory hyperparathyroidism in hemodialysis (HD) patients. Methods: Dual-phase 99mTc MIBI parathyroid scintigraphy was performed for 23 patients with ESRD who have persistent intact parathyroid hormone (iPTH) levels exceeding 300 pg/ml. Based on scintigraphy results, 13 patients underwent neck exploration during which only glands with positive scintigraphy findings were removed. Results:Among the six patients who had iPTH levels < 800 pg/ml, only one patient had positive scintigraphy findings (16.7%). Among the 17 patients who had iPTH levels ≥ 800 pg/ml, 16 patients had positive scintigraphy findings (94.1%). 99mTc MIBI scan detected 23 positive sites of focal trace uptake in those 17 patients. Partial parathyroidectomy was performed for 13 patients, removing in total 19 glands, while four patients declined surgery. On histological examination, 12 glands showed diffuse hyperplasia, four glands showed nodular hyperplasia and three glands revealed parathyroid adenoma. The three glands with parathyroid adenoma were correctly identified prior to surgery by 99m Tc MIBI scintigraphy. The long-term outcomes of these patients are now being monitored. Conclusion:ESRD patients with iPTH level ≥ 800 pg/ ml are more likely to have positive sites of focal tracer uptake on MIBI scan than patients with lower iPTH levels. Tc MIBI scintigraphy has the ability to correctly identify parathyroid adenoma prior to surgical exploration in these patients.

Absent 99mTc-MIBI Uptake in the Thyroid Gland during Early Phase of Parathyroid Scintigraphy in Patients with Primary and Secondary Hyperparathyroidism

“…However, not all studies in the literature report diminished thyroid MIBI uptake during the early phase of the parathyroid scintigraphy. Kandeel et al report normal thyroid uptake in the early scan and appropriate wash out in their series of patients with the end-stage renal disease, although the number of patients was small and the thyroid uptake during parathyroid scintigraphy was not the aim of their research [ 14 ]. Our study found normal thyroid MIBI distribution during parathyroid scintigraphy in 88.6% of patients with chronic renal failure.…”