title: Efficacy of in-vivo counting in parathyroid radioguided surgery and usefulness of its association with scintigraphy and intraoperative PTHi.
abstract: OBJECTIVE
  To evaluate the efficacy of the γ probe, alone and in combination with other techniques, in primary hyperparathyroidism surgery, as well as its ability to distinguish between single-gland and multiple-gland diseases.
  
  
  METHODS
  Sixty-three patients with primary hyperparathyroidism submitted to radioguided parathyroidectomy, with a minimum follow-up of 1 year, were included. A preoperatory scintigraphy with technetium-99m methoxyisobutylisonitrile was performed in all cases and the excised specimens were histopathologically examined. Intraoperative intact parathyroid hormone (ioPTHi) data were available for 59 patients.
  
  
  RESULTS
  Sixty-three patients underwent radioguided parathyroidectomy: 30 minimally invasive radioguided parathyroidectomy, 18 unilateral, and 15 bilateral surgeries. A receiver operating characteristic curve analysis was carried out to distinguish between normal and pathological glands. Using a cut-off value of 1.15 for the γ-probe in-vivo index, we obtained 87% sensitivity, 95% specificity, and 97% positive predictive value (PPV). There were statistically significant differences among in-vivo indexes sorted by type of gland histology (Kruskall-Wallis; P=0.001). A receiver operating characteristic curve was again used to discriminate between single-gland and several-gland pathologies. For a cut-off of 1.51, we achieved 67% sensitivity, 87% specificity, and 95% PPV.
  
  
  CONCLUSIONS
  Pathological glands can be detected by the γ probe (in-vivo index>1.15) with a PPV of 97%. Although an in-vivo index greater than 1.51 is suggestive of a solitary adenoma (PPV=95%), there are a significant number of cases (27%) with lower indexes, these would erroneously lead to an extended surgery in search of a multiglandulary disease. For this reason, the combined determination of the intraoperative intact parathyroid hormone is recommended to identify multiglandulary disease.
authors.affiliation: Department of aNuclear Medicine, University Hospital of Salamanca, Spain. palomagtalavera@gmail.com
authors.forename: Paloma
authors.initials: P
authors.lastname: García-Talavera
authors.forename: José-Ramón
authors.initials: JR
authors.lastname: García-Talavera
authors.forename: Carmen
authors.initials: C
authors.lastname: González
authors.forename: Esther
authors.initials: E
authors.lastname: Martín
authors.forename: Mariano
authors.initials: M
authors.lastname: Martín
authors.forename: Alberto
authors.initials: A
authors.lastname: Gómez
mesh_terms: D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000378:metabolism*; D016105:Parathyroidectomy / Q000379:methods*; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D012588:Scintillation Counting / Q000379:methods*; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology / Q000601:surgery*
chemical_list: D010281:Parathyroid Hormone