title: Justified follow-up: a final intraoperative parathyroid hormone (ioPTH) Over 40 pg/mL is associated with an increased risk of persistence and recurrence in primary hyperparathyroidism.
abstract: BACKGROUND
  After parathyroidectomy for sporadic primary hyperparathyroidism (PHPT), overall rates of persistence/recurrence are extremely low. A marker of increased risk for persistence/recurrence is needed. We hypothesized that final intraoperative parathyroid hormone (FioPTH) ≥40 pg/mL is indicative of increased risk for disease persistence/recurrence, and can be used to selectively determine the degree of follow-up.
  
  
  METHODS
  A retrospective review of PHPT patients undergoing parathyroidectomy with ioPTH monitoring was performed. An ioPTH decline of 50 % was the only criteria for operation termination. Patients were grouped based on FioPTH of <40, 40-59, and >60 pg/mL.
  
  
  RESULTS
  Between 2001 and 2012, 1,371 patients were included. Mean age was 61 ± 0.4 years, and 78°% were female. Overall persistence rate was 1.4°%, with a 2.9°% recurrence rate. Overall, 976 (71°%) patients had FioPTH < 40, 228 (16.6°%) had FioPTH 40-59, and 167 (12.2°%) had FioPTH ≥60. Mean follow-up was 21 ± 0.6 months. Patients with FioPTH <40 were younger, with lower preoperative serum calcium, PTH, and creatinine (all p ≤ 0.001). Patients with FioPTH <40 had the lowest persistence rate (0.2 %) versus patients with FioPTH 40-59 (3.5 %) or FioPTH ≥60 (5.4 %; p < 0.001). Recurrence rate was also lowest in patients with FioPTH <40 (1.3 vs. 5.9 vs. 8.2 %, respectively; p < 0.001). Disease-free status was greatest in patients with FioPTH <40 at 2 years (98.5 vs. 96.8 vs. 90.5 %, respectively) and 5 years (95.7 vs. 72.3 vs. 74.8 %, respectively; p < 0.01).
  
  
  CONCLUSIONS
  Patients with FioPTH < 40 pg/mL had lower rates of persistence and recurrence, than patients with FioPTH 40-59, or ≥60. Differences became more apparent after 2 years of follow-up. Patients with FioPTH ≥40 pg/mL warrant close and prolonged follow-up.
authors.affiliation: Section of Endocrine Surgery, Department of Surgery, University of Wisconsin, Madison, WI, USA.
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Rajaei
authors.forename: Alex M
authors.initials: AM
authors.lastname: Bentz
authors.forename: David F
authors.initials: DF
authors.lastname: Schneider
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Sippel
authors.forename: Herbert
authors.initials: H
authors.lastname: Chen
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Oltmann
mesh_terms: D000236:Adenoma / Q000097:blood / Q000601:surgery; D000368:Aged; D015415:Biomarkers / Q000097:blood*; D005260:Female; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000097:blood* / Q000453:epidemiology* / Q000601:surgery; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D010282:Parathyroid Neoplasms / Q000097:blood / Q000601:surgery; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D010281:Parathyroid Hormone