European Journal of Biomedical and Pharmaceutical Sciences

THE VALUE OF TECHNETIUM (TC99M) THYROID SCANS IN THE ASSESSMENT OF THYROID NODULES

Louai Al-Qatawna MD*, Amany Aljaafreh MD, Ahmed Albtoush MD, Khaled Alkhawaldeh MD,
Omar Yaseen Al Shokibi, MD

ABSTRACT

The purpose of this retrospective study was to assess the value of Technetium Pertechnetate (99mTc) thyroid scan in the assessment of thyroid nodules. Methods: Two hundred patients were included in this retrospective study. All patients had thyroid nodules (single or multiple thyroid nodules MNG, solid, cystic or combined) discovered by ultrasound and underwent thyroid scan 15 minutes after intravenous injection of 99m Tc-pertechnetate according to body weight. In addition, all patients underwent thyroid function test (TFT) and fine needle aspiration (FNA) after thyroid scan. Results: Patients with hyperthyroidism and those with inadequate specimen after final needle were excluded. 20% of patients had a nodule less than 1 cm and 65% had single nodule. Histopathology after FNA showed that 22(11%) of nodules were malignant, and 178 (89%) were benign. Thyroid scan revealed cold nodule in 14 nodules and normal in 8 malignant nodules. Thyroid isotope scan showed an overall sensitivity of 64%. The sensitivity for nodules more than 1cm was 90% and for nodules less than 1cmwas 3%. Conclusions: Tc99m thyroid has limited value in characterization of thyroid nodules and assessment of risk of malignancy. This scan has limited sensitivity and positive predictive value and normal thyroid scan cannot exclude malignancy, particularly in small nodules.

Keywords: Tc99m, Thyroid Scan, Thyroid nodule.