The Value of 99mTc-MIBI SPECT/CT in the Postoperative Assessment of Patients with Differentiated Thyroid Carcinoma

Abstract

Background: The therapeutic approaches of differentiated thyroid carcinoma (DTC) are surgery, ablation therapy with the postoperative use of radioiodine-131 (I-131), and thyroid-stimulating hormone (TSH) suppression therapy. After the surgical therapy, the patient should be assessed for remnants/metastases. Objective: The purpose of this research was to investigate the role of technetium-(99m)-methoxyisobutylisonitrile (Tc-99m-MIBI) single photon emission computed tomography/computed tomography (SPECT/CT) in the postoperative management of patients with DTC. Methods: The study comprised 22 DTC patients (13 women, 9 men; mean age 46.55 +/- 13.27 y) who underwent a total thyroidectomy previously. All patients were investigated for thyroid remnants/metastases by Tc-99m-MIBI SPECT/CT, posttherapy I-131 whole-body scan (WBS) and ultrasound (US). Serum TSH, thyroglobulin and anti-Tg antibody levels were measured. Results of imaging modalities and laboratory measurements were compared with each other. Results: Tc-99m-MIBI SPECT/CT, I-131 WBS and US respectively demonstrated thyroid remnants in 15 (68.18%), 22 (100%) and 14 (63.63%) of all patients and metastatic lymph nodes in 8 (100%), 6 (75%) and 6 (75%) of the 8 patients with lymph node metastases. Tc-99m-MIBI SPECT/CT also demonstrated lung metastases in 2 patients (9.09% of all patients). The same result was obtained with I-131 WBS. Conclusion: The findings of this study show that Tc-99m-MIBI SPECT/CT can be effective for detecting metastases in patients with DTC who underwent surgery prior to I-131 therapy.