A Prospective Comparative Study of Parathyroid Dual-Phase Scintigraphy, Dual-Isotope Subtraction Scintigraphy, 4D-CT, and Ultrasonography in Primary Hyperparathyroidism

Clin Nucl Med. 2016 Feb;41(2):93-100. doi: 10.1097/RLU.0000000000000988.

Abstract

Purpose: Preoperative localization of the diseased parathyroid gland(s) in primary hyperparathyroidism allows for minimally invasive surgery. This study was designed to establish the optimal first-line preoperative imaging modality.

Patients and methods: Ninety-one patients were studied consecutively in a prospective head-to-head comparison of dual isotope (Tc-MIBI vs I) subtraction parathyroid scintigraphy (PS), dual-phase PS, 4-dimensional (4D) CT, and ultrasonography (US). Surgery, histological confirmation, and postoperative normalization of Ca and parathyroid hormone were the reference standard.

Results: Ninety-seven hyperfunctioning parathyroid glands (HPGs) were identified by the reference standard. Sensitivity and specificity for subtraction PS, dual-phase PS, 4D-CT, and US were 93%, 65%, 58%, and 57% as well as 99%, 99.6%, 86%, and 95%, respectively. Interrater agreement was excellent for subtraction PS (κ = 0.96) while only fair for 4D-CT (κ = 0.34). Pinhole imaging and subtraction of delayed images (the latter especially in case of a nodular thyroid gland) increased the sensitivity of subtraction PS. SPECT/low-dose CT did not increase sensitivity but aided in the exact localization of the HPGs. Of 7 negative subtraction PS studies, 4D-CT and US were able to locate 3 and 1 additional HPGs, respectively.

Conclusions: Dual isotope pinhole subtraction PS has higher diagnostic accuracy compared with dual-phase PS, 4D-CT, and US as a first-line imaging study in primary hyperparathyroidism. In case of a negative scintigraphy or suspicion of multiglandular disease, 4D-CT and/or US is recommended as a second-line modality. However, diagnostic algorithms should be adapted in accordance with local availability and expertise.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Humans
  • Hyperparathyroidism, Primary / diagnostic imaging*
  • Male
  • Middle Aged
  • Radiopharmaceuticals*
  • Sensitivity and Specificity
  • Technetium Tc 99m Sestamibi*
  • Tomography, Emission-Computed, Single-Photon*
  • Tomography, X-Ray Computed*
  • Ultrasonography

Substances

  • Radiopharmaceuticals
  • Technetium Tc 99m Sestamibi