Primary Hyperparathyroidism: Redefining Cure

Primary hyperparathyroidism is the most common cause of hypercalcemia. Follow-up can be resource-intensive and costly. The aim of this study was to determine if there is a subset of patients who can be defined cured earlier than six months. This was a retrospective study of patients who underwent parathyroidectomy between January 2012 and March 2014. Patients with a history of multiple endocrine neoplasia syndrome, and secondary or tertiary hyperparathyroidism were excluded. Patients with normal preoperative calcium and parathyroid hormone (PTH) and those without six months follow-up were excluded. Patients were divided into two groups: cured and not cured. Data analysis was performed between the two groups. A total of 509 patients were screened, and 214 met our inclusion criteria: 202 in the cured category and 12 in the not cured category (94% cure rate). There was no significant difference between age, gland weight, or pre-operative PTH. There was a statistically significant difference between final intraoperative PTH (IOPTH) (37 vs 55, P = 0.008) and per cent PTH decrease (69 vs 43%, P < 0.0001). There was a significant difference between intraoperative cure rate (P < 0.0006), imaging concordance (P = 0.0115), and solitary versus multiglandular disease (P = 0.0151). Subgroup analysis in patients with concordant imaging, solitary parathyroid adenoma, and IOPTH decrease by 50 per cent to normal or near-normal correlated with a six-month cure rate of 97 per cent. Patients with primary hyperparathyroidism with concordant imaging, single-adenoma pathology, and IOPTH decrease by 50 per cent to normal or near-normal levels (15–65 pg/mL) can be considered cured and may need less frequent follow-up.