Intra-operative parathyroid hormone measurements - experience of a non-academic hospital

Background. Surgery is the treatment of choice for symptomatic primary hyperparathyroidism. The majority of research concerning intra-operative parathyroid hormone (ioPTH) measurements is conducted in university hospitals. Whether ioPTH measurements are feasible and useful in predicting the presence of remaining hyperfunctioning parathyroid tissue in a non-academic hospital remains uncertain. Methods. Data were collected on all patients with biochemically proven and surgically treated primary hyperparathyroidism treated at the Reinier de Graaf Hospital from August 2002 to December 2007. Results. Sixty-five patients were included. The mean pre-operative serum calcium level was 2.78 mmol/l (range 2.28 - 3.80 mmol/l, normal range 2.20 - 2.65 mmol/l) and the mean serum parathyroid hormone level 17.0 pmol/l (range 4.0 - 90.3 pmol/l, normal range 1.0 - 5.5 pmol/l). All patients were operated on for primary hyperparathyroidism, using ioPTH measurements during their first operation. Sensitivity and specificity rates of ioPTH measurements were 98% and 89%, respectively. The ioPTH test accurately indicated incomplete removal of all hyperfunctioning parathyroid tissue in 8 patients (12%). Five patients (8%) were re-explored immediately, of whom 4 were successfully treated in this single operative session. One patient was operated on successfully the next day. Two patients were operated on with a successful result during a second admission. In all the ioPTH measurements there was 1 false-positive result (1.5%) and 1 false-negative result (1.5%). The mean postoperative calcium value for the successfully treated patients was 2.34 mmol/l (range 2.14 - 2.71 mmol/l, normal range 2.20 - 2.65 mmol/l). The mean postoperative PTH level for the successfully treated patients was 3.76 pmol/l (range 0.40 - 7.1 pmol/l). Conclusion. Our data suggest that ioPTH measurements are feasible and useful in a non-academic hospital.