en A New Endpoint for Intraoperative PTH Measurement: Normal Basic Science Basic Science Original Original <sec> <div>Background</div> <p>We hypothesized that Io-PTH levels would decline to normal or near normal after successful parathyroidectomy.</p> </sec> <sec> <div>Objectives</div> <p>Evaluate efficacy and predictive factor of parathyroid hormone measurement during parathyroid resection.</p> </sec> <sec> <div>Materials and Methods</div> <p>Every Io-PTH level from 2001-10 at a single institution was evaluated. Charts were reviewed for preoperative diagnosis, final Io-PTH level, unilateral or bilateral exploration, calcium and parathyroid hormone levels.</p> </sec> <sec> <div>Results</div> <p>225 patients underwent 594 Io-PTH measurements. 16 patients were excluded. Final Io-PTH levels were normal (&amp;lt; 65 pg/mL) in 189 patients and elevated in 20 patients. 12 of 20 patients with elevated final Io-PTH levels had &amp;gt; 80% decrease, so that 201 patients had Io-PTH levels that were normal or dropped by &amp;gt; 80%. 8 patients had Io-PTH levels that dropped by &amp;lt; 80%, 4 of whom had &amp;lt; 50% decline. Normal or near-normal Io-PTH level after resection of a parathyroid adenoma allowed unilateral exploration in 146 patients. Persistent elevation of Io-PTH levels led to bilateral exploration in 22 patients.</p> </sec> <sec> <div>Conclusions</div> <p>Io-PTH levels should become normal or to drop by at least 80% during successful parathyroidectomy. Persistent elevations of Io-PTH after resection of an abnormal gland dictate the need for bilateral exploration.</p> </sec> Parathyroid Hormone , Parathyroid Neoplasms , Parathyroidectomy , Hypercalcemia 100 110 http://annbsurg.iums.ac.ir/browse.php?a_code=A-10-31-134&slc_lang=en&sid=1 Masoud Rezvani 1003194753284600201 1003194753284600201 Yes Department of Surgery, Abington Memorial Hospital, Pennsylvania, USA Ashwin Kurian 1003194753284600202 1003194753284600202 No Department of Surgery, Abington Memorial Hospital, Pennsylvania, USA Roya Azadarmaki 1003194753284600203 1003194753284600203 No Department of Surgery, Abington Memorial Hospital, Pennsylvania, USA Christopher Pezzi 1003194753284600204 1003194753284600204 No Department of Surgery, Abington Memorial Hospital, Pennsylvania, USA