title: Radioguided surgery of primary hyperparathyroidism using the low-dose 99mTc-sestamibi protocol: multiinstitutional experience from the Italian Study Group on Radioguided Surgery and Immunoscintigraphy (GISCRIS).
abstract: This study evaluated the accuracy of (99m)Tc-sestamibi scintigraphy and neck ultrasonography in patients with primary hyperparathyroidism (PHPT) and the role of intraoperative hand-held gamma-probes in minimally invasive radioguided surgery (MIRS) of patients with a high likelihood of a solitary parathyroid adenoma (PA). The study was undertaken under the aegis of the Italian Study Group on Radioguided Surgery and Immunoscintigraphy (GISCRIS).
  
  
  METHODS
  Clinical records were reviewed for 384 consecutive PHPT patients undergoing radioguided surgery using a low dose of (99m)Tc-sestamibi. Selection of patients for MIRS instead of traditional bilateral neck exploration was based on preoperative imaging indicating a solitary PA. (99m)Tc-Sestamibi (37-110 MBq, or 1-3 mCi) was injected in the operating theater 10-30 min before the start of the intervention. Either 11-mm collimated (309 patients) or 14-mm collimated (75 patients) gamma-probes were used. Intraoperative quick parathyroid hormone (IQPTH) assay was used on 308 patients (80.2%).
  
  
  RESULTS
  MIRS was successfully performed on 268 (96.8%) of 277 patients. Conversion to bilateral neck exploration was necessary in 9 patients (3.3%) because of either persistently high IQPTH levels after removal of the preoperatively visualized PA (4 patients), intraoperative frozen-section diagnosis of parathyroid carcinoma (2 patients), or hard-to-remove PA (3 patients). MIRS, which was performed under locoregional anesthesia in 72 patients, required a mean operating time of 37 min and a mean hospital stay of 1.2 d. MIRS was successfully performed also on 32 (78.0%) of 41 patients who had previously undergone thyroid or parathyroid surgery. No major surgical complications were observed in the MIRS group, and there were only 24 cases (11%) of transient postoperative hypocalcemia. The probe was of little help in patients with concomitant (99m)Tc-sestamibi-avid thyroid nodules and not helpful at all in patients with negative scan findings preoperatively. IQPTH measurement helped to disclose some cases of multigland parathyroid disease.
  
  
  CONCLUSIONS
  (99m)Tc-Sestamibi scintigraphy, especially if combined with neck ultrasonography, is highly accurate in selecting PHPT candidates for MIRS. The low-dose (99m)Tc-sestamibi protocol (which entails a low-to-negligible radiation exposure to the surgical team) is safe and effective for MIRS. MIRS plays a limited role in patients with concomitant (99m)Tc-sestamibi-avid thyroid nodules and should be discouraged in patients with negative (99m)Tc-sestamibi finding preoperatively. IQPTH can be recommended during MIRS to facilitate intraoperative identification of previously undiagnosed multigland parathyroid disease.
authors.affiliation: Nuclear Medicine Service, S. Maria della Misericordia Hospital, Rovigo, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Rubello
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Pelizzo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Boni
authors.forename: Riccardo
authors.initials: R
authors.lastname: Schiavo
authors.forename: Luca
authors.initials: L
authors.lastname: Vaggelli
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Villa
authors.forename: Sergio
authors.initials: S
authors.lastname: Sandrucci
authors.forename: Andrea
authors.initials: A
authors.lastname: Piotto
authors.forename: Gianpiero
authors.initials: G
authors.lastname: Manca
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Marini
authors.forename: Giuliano
authors.initials: G
authors.lastname: Mariani
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015984:Causality; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000601:surgery*; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D016105:Parathyroidectomy / Q000379:methods* / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000175:diagnosis / Q000453:epidemiology; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D025321:Surgery, Computer-Assisted / Q000379:methods* / Q000706:statistics & numerical data; D017256:Technetium Tc 99m Sestamibi; D016896:Treatment Outcome
chemical_list: D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi