Introduction: Thyroid lesions with indeterminate cytology represent about 15% of all thyroid biopsies with the risk of malignancy 1530%. So the identification of low-risk patients in this group is very important.
Few studies evaluated thyroid Tc-99m MIBI [MIBI] scan as a tool for work-up of indeterminate cytology thyroid lesions. The negative predictive value of this test in excluding malignancy appears to be high (95%). But it is not used routinely.
This study evaluated the role of MIBI scan in the assessment of these lesions.
Methods: Patients with indeterminate cytology and Tc-99m Pertechnetate thyroid scan-cold nodules were included in the study during the period of January 2009 to August 2012 retrospectively. MIBI scan was offered to the patients who initially did not accept surgery as a treatment option.
Results: Sixteen patients were included in the analysis (three men and 13 women, age: 52±15 years, lesion size 21±8 mm). All patients had suspicion for follicular lesion cytology (Bethesda 3). Three patients (18.7%) had cold lesions on MIBI scan and surveillance was offered. The follow-up of 1236 months showed no sonographic and clinical changes in these patients. Thirteen patients had hot lesions. Nine patients (69%) were operated and four (44%) of them had malignancy (two papillary carcinoma, one follicular variant of papillary carcinoma and one follicular carcinoma). Four patients with hot MIBI nodule refused operation and continued the follow-up during 612 months with stable sonographic characteristics.
Conclusions: In our small sample size experience, we were able to define a low risk of malignancy in 18.7% of the patients with MIBI scan assessment. This protocol helped to decrease unnecessary surgical intervention from 67 to 56%. Larger studies with longer follow-up are needed to validate the amount of cold lesions in this unique subgroup and mainly the long-term consequences of the patients with active surveillance policy.
27 Apr - 01 May 2013
European Society of Endocrinology