PhD ceremony Ms. F.H. Jorna: Diagnostic tools and risk identification in management of hyperparathyroidism

PhD ceremony: Ms. F.H. Jorna, 16.15 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Diagnostic tools and risk identification in management of hyperparathyroidism

Promotor(s): prof. J.T.M Plukker, prof. C.A. Stegeman

Faculty: Medical Sciences

Hyperparathyroidism (HPT) is the overproduction of parathyroid hormone (PTH) by overactive parathyroid gland(s) which is treated by surgical removal of the gland(s). This thesis describes diagnostic tools that can be used before and parathyroidectomy. Various preoperative scintigraphy techniques were evaluated according to their possibilities for enabling a surgical plan. SPECT was valuable in addition to planar 99mTc-Sestamibi scintigraphy for primary HPT. Preoperative scintigraphy in case of secondary HPT was not meaningful. The value of the gammaprobe and intraoperative PTH monitoring were evaluated during an operation for secondary HPT. The probe had a limited role in guiding the resection, but was useful in confirming the resection of overactive glands. Intraoperative PTH monitoring had a high positive predictive value, but low negative predictive value. Its potential benefit is low because of high pre-test probability of surgical cure after resection of four glands and difficult interpretation of PTH in secondary HPT. Another study showed that P-gp and MRP1 had no significant role in the retention of 99mTc-Sestamibi in the parathyroid gland.

This thesis also describes risk factors for severe secondary HPT and parathyroid carcinoma. Serum PTH, phosphate and alkaline phosphatase at 1 year after the start of dialysis were independently associated with increased risk for parathyroidectomy. A palpable neck mass, PTH >3 times the upper normal limits and significantly high serum calcium, in patients presenting with HPT may indicate the presence of parathyroid carcinoma.