Optimization of SPECT/CT scan schemes in localizing preoperative parathyroid lesions

Abstract

Objective To compare the diagnostic efficiencies of different scanning schemes of dual-phase 99Tcm-methoxyisobutylisonitrile (MIBI) planar imaging with or without SPECT/CT in the preoperative localization of parathyroid lesions. Methods Forty-two patients (20 males, 22 females; average age (53.1±14.8) years) with primary or secondary hyperparathyroidism who underwent parathyroidectomy from June 2011 to June 2016 were analyzed retrospectively. All patients underwent dual-phase 99Tcm-MIBI planar scan and dual-phase SPECT/CT scan. The images were collected according to the following 4 procedures: dual-phase planar imaging (S1), dual-phase planar imaging+ early-phase SPECT/CT (S2), dual-phase planar imaging+ delayed-phase SPECT/CT (S3), dual-phase planar imaging+ dual-phase SPECT/CT (S4). Pathological results were considered as the gold standard. A total of 168 parathyroid glands in 42 patients were evaluated by the 4 imaging procedures respectively.The diagnostic efficiencies were calculated and compared by χ2 test. Results Seventy-eight abnormal parathyroid lesions were found. The diagnostic sensitivities of S1, S2, S3, S4 were 66.7% (52/78), 89.7%(70/78), 69.2%(54/78), 89.7%(70/78), and the accuracies were 78.6%(132/168), 94.0%(158/168), 85.1%(143/168), 94.0%(158/168), respectively. The diagnostic accuracies of S2 and S4 were significantly higher than those of S1 and S3 (χ2 values: 17.027 and 7.176, both P<0.01). Conclusions The dual-phase planar imaging together with early-phase and dual-phase SPECT/CT imaging have high diagnostic efficiencies in the preoperative localization of parathyroid lesions. Considering reducing radiation dose and examine time, the dual-phase planar imaging together with early-phase SPECT/CT is a better choice. Key words: Hyperparathyroidism; Diagnosis; Tomography, emission-computed, single-photon; Tomography, X-ray computed; Technetium 99m sestamibi