Type:
Educational Exhibit
Keywords:
Performed at one institution, Diagnostic or prognostic study, Prospective, Metastases, Cancer, Diagnostic procedure, Comparative studies, PET-CT, Thyroid / Parathyroids, Hybrid Imaging, Hybrid, Molecular and Translational Imaging
Authors:
A. A. M. M. S. khalifa1, S. M. I. Y. Shalaby2, M. Ali1, A. Mostafa1, A. Ibrahim1, A. Yassin3; 1Cairo/EG, 2Cairo, Ca/EG, 3cairo, cairo/EG
DOI:
10.26044/ecr2020/C-07318
Conclusion
Discussion
- The differentiated thyroid cancer cells after total thyroidectomy & radioiodine ablation may undergo a process of transformation thus losing some or all their ability to take up & retain iodine, but they still retain the ability to absorb FDG(6).
- The role of FDG PET/CT in differentiated thyroid cancer is well established, particularly in patients presenting with elevated Thyroglobulin levels and negative radioactive iodine whole body scan. The uptake of FDG is related to tumor size, thyroid capsule invasion and histological variants with poor prognosis (7).
- The sensitivity of using FDG PET/CT in detection of cancer thyroid is very high and more accurate than the other imaging modalities as it is capable of differentiating among tumors, scars, fibrosis and necrosis(8).
- Also PET/CT images from survey of the body could reveal abnormal areas of uptake indicating the spread of the thyroid cancer to lymph nodes, lungs, bones or central nervous system(9).
Recommendations
We recommend careful & short term estimation of serum thyroglobulin with thyroglobulin antibodies during the follow up period of patients with differentiated cancer thyroid to pick up early and even slight elevation in its values. In the latter situation when I (131) whole body scan is negative 18F-FDG PET/CT is recommended in localization of the possible sites of local recurrence or distant metastases and to guide further management for patients in such patient's group.
Conclusion
- 18F-FDG PET/CT has a role in patient with differentiated thyroid cancer, specifically those presented by elevated serum thyroglobulin level and negative I (131) whole body scanning.
- Co-registered FDG PET/CT provides precise anatomical localization of recurrent and/or metastatic thyroid carcinoma, leading to improved diagnostic accuracy.
- Co-registered FDG PET/CT has a higher sensitivity and accuracy than those of CT or PET alone, regarding the loco-regional cervical nodal metastases as well as the distant metastases.
- FDG PET/CT may alter the patient management, via either detection of additional lesions not demonstrated by the usual radiologic procedure with verification of their nature; subsequently this may help in guiding to the suitable therapeutic intervention.