American Association of Endocrine Surgeons- Annual Meeting Abstract Papers

ARE FROZEN SECTIONS USEFUL AND COST-EFFECTIVE IN THE ERA OF INTRAOPERATIVE QPTH ASSAYS?
Maurizio Iacobone, Franco Lumachi, Gennaro Favia.
University of Padua, ITALY

Background: Frozen Sections (FS) have been widely used during parathyroid exploration, but, since intraoperative quick PTH (IOqPTH) assays are available, this role has become questionable. This prospective study was aimed to compare the cost-effectiveness and usefulness of FS and IOqPTH to correctly guide the surgical exploration and predict the postoperative cure in case of primary hyperparathyroidism (HPT).
Methods: Since January 2000, 102 patients underwent 44 bilateral neck explorations (BNE) and 68 minimally invasive or focused parathyroidectomies because of HPT. FS and a central laboratory IOqPTH assay were performed in all patients. Surgical exploration was considered complete when both an IOqPTH decline >50% and a FS diagnosis of parathyroid adenoma was done, and (in case of BNE) when at least 4 glands were identified.
Results: At a mean follow-up of 30 months, no persistent or recurrent HPT occurred. The final diagnosis revealed a single adenoma in 88 patients; potential pitfalls for successful neck exploration were represented by 2 cases of double adenoma, 12 cases of multiple hyperplastic glands and 4 cases of non-parathyroid removed tissue. FS correctly predicted the definitive histological diagnosis (potentially predicting a postoperative normocalcemia) only in 85 patients. FS failures potentially misguided the surgical exploration in 10 cases: 3 unrecognized multiglandular involvement, 2 misdiagnosed thyroid nodules (insufficient surgery) and 5 unrecognized single adenoma (unnecessarily prolonged exploration). In case of BNE, FS was never indispensable to correctly guide the surgical exploration; on the contrary, its failures unnecessarily prolonged surgery in 1 case. IOqPTH assay correctly guided the surgical strategy, predicting a postoperative normocalcemia, in 100% of cases. IOqPTH identified all cases of potential pitfalls, suggesting for the necessity of further exploration. In case of BNE, IOqPTH was not indispensable for adequate exploration, but the turnaround-time and costs were lower than FS (p<0.01).
Conclusions: The role of FS remains questionable, since it can misguide surgery. IOqPTH is indispensable for focused approach; in case of BNE, although unnecessary, it is most useful and cost-effective than FS.