The value of intraoperative parathyroid hormone monitoring in patients with primary hyperparathyroidism and varying baseline parathyroid hormone levels

Abstract

Background When applying intraoperative parathyroid hormone monitoring (IOPTH) to patients with primary hyperparathyroidism (PHPT), there are established criteria predicting biochemical cure in patients with basal parathyroid hormone (PTH) levels in the medium range (100–400 pg/ml); however, there is a challenge concerning patients with low (less than 100 pg/ml) or high (more than 400 pg/ml) basal PTH levels. The aim of this study was to investigate the value of the ‘Vienna criterion’ applied during IOPTH in patients with PHPT and various basal PTH concentrations. Methods Consecutive patients between 1999–2009 with a biochemical diagnosis of PHPT who underwent surgical parathyroidectomy were included. Based on preoperative PTH levels they were divided into three groups: group 1 (low) (<100 pg/ml), group 2 (medium) (100–400 pg/ml) and group 3 (high) (>400 pg/ml) basal PTH. PTH was measured at the start of the operation, when the gland was excised and then at 5, 10 and 15 min after. Calcium and PTH levels were measured at 7 days and 12 months postoperatively. Sensitivity, specificity, positive and negative predictive value, as well as accuracy of IOPTH were calculated for the different groups postoperatively. Results 675 patients with PHPT were analysed. Sensitivity and specificity were 83.7 per cent and 66.7 per cent in group 1 (n = 187), 90.7 per cent and 69.2 per cent in group 2 (n = 433), and 94.4 per cent and 100 per cent in group 3 (n = 55) to predict cure. Preoperative creatinine (p = 0.002) showed significant statistical difference between the groups but was not related to intraoperative PTH decline. At 12 months follow-up normocalcaemia was documented in 98.9 per cent in group 1, 99.0 per cent group 2, and 98.0 per cent of group 3 patients. Conclusion Normocalcaemia was predicted intraoperatively by applying the ‘Vienna criterion’ in 98 to 100 per cent and was confirmed after 12 months follow-up in up to 99.0 per cent of patients. Low specificity and a high false-negative rate in patients with low basal PTH show that other criteria might be better suited for this group.

Diagnostic utility of 11C‐methionine PET/CT in primary hyperparathyroidism in a UK cohort: A single‐centre experience and literature review

“…A recent meta‐analysis has reported that 18 F‐fluorocholine is more sensitive than 11 C‐methionine for detecting the affected gland in PHPT 44 . Finally, intraoperative PTH monitoring (IOPTH) is a sensitive and specific predictor of surgical cure, and can be a useful tool in cases where preoperative imaging results are equivocal 45–47 …”

“…44 Finally, intraoperative PTH monitoring (IOPTH) is a sensitive and specific predictor of surgical cure, and can be a useful tool in cases where preoperative imaging results are equivocal. [45][46][47] A limitation of our study is that patients did not all receive all imaging modalities as part of their diagnostic work-up for PHPT. A formal head-to-head comparison between all imaging modalities within our cohort was, therefore, not possible.…”

Diagnostic Value of Four-Dimensional Dynamic Computed Tomography for Primary Hyperparathyroidism in Patients with Low Baseline Parathyroid Hormone Levels

“…Second, several studies have shown that the preoperative localization rates of imaging modalities are lower in these patients, as the lesions tend to be smaller in size and weight [ 2 ]. Third, IOPTH assays may have a lower specificity and a higher false-negative rate in these patients, as the baseline PTH levels are already low [ 28 ]. It should be noted that the success rate of surgical resection depends not only on the accuracy of the preoperative imaging modality but also on the surgeon’s skill.…”