Usefulness of 99m Tc-SESTAMIBI Scintigraphy in Persistent Hyperparathyroidism after Kidney Transplant

Purpose 99mTc-labeled sestamibi scintigraphy combined with single-photon emission computed tomography (SPECT) has ahigh positive predictive value for localizing hyperfunctioning parathyroid lesions in primary hyperparathyroidism (pHPT) butrelatively low sensitivity and specificity in secondary hyperparathyroidism (sHPT) and tertiary hyperparathyroidism (tHPT). The purpose of this study is to investigate the usefulness of 99mTc-sestamibi scintigraphy in persistent hyperparathyroidismafter kidney transplant (KT). Methods Retrospectively evaluated 50 patients who received parathyroidectomy after KT at a single medical center. Theparathyroid lesion with the highest sestamibi uptake intensity of a patient was graded from 0 to 3. Uptake intensity wasanalyzed in correlation with parathyroid hormone (PTH), calcium, ionized calcium, phosphorus, and vitamin D. Results Per-patient analysis, 43 patients had hyperplasia, 6 patients had adenomas, and 1 patient had a carcinoma. Only 3patients with hyperplasia did not demonstrate any sestamibi uptake in the parathyroid scans. Out of the 148 pathologicallyconfirmed parathyroid lesions, SPECT/CT images were able to identify 89 lesions (60%) and planar images of 71 lesions(48%). The average of sestamibi uptake intensity was mild at grade 1.6. Uptake intensity showed a positive correlation withparathyroid hormone (PTH) level but not with phosphorus, calcium, ionized calcium, or vitamin D levels. The largest lesionshowed a high positive predictive value, especially in lesions with a diameter over 1.0 cm. Conclusions Regardless of relatively low and less discrete uptake in KT patients, it well depicts the largest and the mosthyperfunctioning lesion.