This study aimed to determine the risk of malignancy in FDG-avid thyroid nodules by stratifying nodules based on ultrasound features into suspicious and non-suspicious categories. 48 nodules in 47 patients underwent ultrasound examination, FDG PET/CT imaging, and FNAC. Nodules with one or more suspicious ultrasound features such as hypoechogenicity, irregular margins, microcalcifications, or increased vascularity had a higher risk of malignancy, with 5 of 24 nodules found to be malignant. Nodules without suspicious features had a lower risk, with only 2 of 24 found to be indeterminate and none malignant. While SUV max values did not help discriminate lesions, ultrasound features
2. AIM
To determine the malignancy risk in an FDG avid thyroid nodule and
to stratify according to the presence or absence of suspicious
ultrasound features and thereby identify the nodule which requires
further cytological assessment
3. MATERIALS
• Retrospective study
•Feb 2011-Dec 2013
•FDG avid thyroid nodule assessed with ultrasound and FNAC/Sx
were performed
•Inclusion criteria were
•All nodules had US guided FNAC regardless of USG features
4. USG FEATURES
Suspicious features
•Marked hypoechogenecity
•Irregular margins
•Microcalcifications
•Marked increase in vascularity
•Taller than wide
No suspicious features
purely cystic lesions
5. METHODS
IV 300MBq FDG <287-328MBq>
SIEMENS BIOGRAPHY TRUE V(Extended FOV) with 16 slice CTPET/CT Images
Uptake Time 58-111 <Avg-78minutes>
Two independent Physicians to assess the nodule
SUV max were estimated using decay corrected radioactivity concentration and patient weight
ROI at max lesion
USG
Dedicated sonographers on Logiq E9 GE
Linear 6-15 and 5-9 were used
6. USG findings were correlated with respective FDG-PET/CT images and FDG
avid nodule by Supervist radiologist and Nuclear physician/radiologist
FNAC was done irrespective of sonographic stratification
Sonographic characterization of the nodules were done prospectively
TWO CATEGORY
SUSPICIOUS
NON SUSCPICIOUS
STATISTICS
Fishers exact test and Wilcoxon rank sum test for benign and malignant
nodules
GRAPH using GRAPH pad Prism v.06 for Mac.OSX
7. RESULTS 48 nodules in 47 patient
24 no suspicious features Size avg 1.8cm
22-beningn
2- indeterminate
24-one or more suspicious features Size avg 1.9 cm
5 malignant
7 indeterminate
12 benign
11. DISCUSSION:
SUV max values were not useful in discrimination the lesion
Ultrasound features were promising in suspicious lesions
CRITIQUE
Sample size
Limited studies
FNAC
Lack of final HPE
Conclusion USG
