Minimally invasive radio-guided parathyroidectomy on a group of 452 primary hyperparathyroid patients. Refinement of preoperative imaging and intraoperative procedure

The aim of this study was to investigate the efficacy of minimally invasive radio-guided parathyroidectomy (MIRP) in primary hyperparathyroid (PHPT) patients. Patients, methods: 452 consecutive PHPT patients were evaluated. Inclusion criteria for MIRP were (a) evidence at scintigraphy of a solitary parathyroid adenoma (PA); (b) a clear sestamibi uptake in the PA; (c) the absence of concomitant thyroid nodules; (d) no history of familial HPT or MEN; (e) no history of previous neck irradiation. Intra-operative protocol consisted of the injection of a low 37 MBq sestamibi dose in the operating suite 10 min before surgery. A hand held 11-mm collimated gamma probe was used. Quick PTH (QPTH) was routinely measured. Results: 344 out of the 452 patients met the inclusion criteria, and MIRP was successfully performed in 321 of them (93.3%). No major intra-operative complication was recorded. MIRP required a mean operative time of 32 min, and a mean hospital stay of 1.2 d. The parathyroid to background ratio (P/B) calculated by the probe was well correlated with the P/B calculated by sestamibi SPECT (r = 0.91; p <0.01), while no significant correlation was found between the probe-calculated P/B and the P/B calculated at planar sestamibi scan. Conclusions: In our experience: (a) an accurate preoperative localising imaging protocol based on planar and SPECT sestamibi scan, and neck US is effective in selecting PHPT patients for MIRP, (b) the P/B calculated by sestamibi SPECT seems able to predict the probe-calculated P/B more accurately than the P/B calculated at planar scan, (c) the low 37 MBq sestamibi dose protocol proved to be a safe and effective approach to perform MIRP. (orig.)