Value of Dedicated Head and Neck 18F-FDG PET/CT Protocol in Detecting Recurrent and Metastatic Lesions in Post-surgical Differentiated Thyroid Carcinoma Patients with High Serum Thyroglobulin Level and Negative 131I Whole-body Scan

Document Type: Original Article


Department of Nuclear Medicine, Tran Hung Dao Hospital, Hanoi, Vietnam


Objective(s): In clinical practice, approximately 10-25% of post-surgical differentiated thyroid carcinoma (DTC) patients with high serum thyroglobulin (Tg) and negative 131I whole-body scan (WBS) have poor prognosis due to recurrent or metastatic lesions after radioactive iodine treatment. The purpose of this study was to evaluate the value of 18F-FDG PET/CT scan in DTC patients with high serum Tg level and negative 131I WBS.
Methods: 69 post-surgical DTC patients with high serum Tg level and negative post ablation 131I WBS were enrolled in this study. All DTC patients underwent head and neck ultrasound, CT scan and whole-body 18F-FDG PET/CT, based on the dedicated head and neck protocol.
Results: Overall, 92 lesions were detected in 43 (62.3%) out of 69 patients with positive 18F-FDG PET/CT scan, compared to only 39 lesions detected on CT scan in 26 (37.7%) out of 69 patients. The sensitivity, accuracy and negative predictive value of 18F-FDG PET/CT were 88%,87% and 76%, respectively, which were significantly higher than those of CT scan (67.2%, 54.3% and 48.8%, respectively) (P<0.01). Specificity and positive predictive value of 18F-FDG PET/CT (90.5% and 95.2%, respectively) were similar to those of CT scan (95.2 % and 96.2 %, respectively) (P>0.05). The maximum standardized uptake value (SUVmax) threshold was 4.5 with a good diagnostic value (sensitivity of 92.3 % and specificity of 100 %). The dedicated head and neck 18F-FDG PET/CT protocol altered the treatment plan in 33 (47.8%) out of 69 DTC patients with high serum Tg level and negative 131I WBS.
Conclusion: Dedicated head and neck 18F-FDG PET/CT protocol showed a higher diagnostic value, compared to CT scan and played an important role in detecting recurrent or metastatic lesions in post-surgical DTC patients with high serum Tg level and negative 131I WBS.


Main Subjects

1. Bảo PTM, Hà LN. Experiences of I(131) therapy in differentiated thyroid carcinoma. Clin Med Oncol. 2006;2(1):30-7.

2. Mazzaferri EL, Jhiang SM. Long-term impact of initial surgical and medical therapy on pap­illary and follicular thyroid cancer. Am J Med. 1994;97(5):418-28.

3. Ha LN, Nhung NT, Son MH, Bieu BQ. Clinical characteristics and preliminary evaluation of empirical 131 I therapy in differentiated thyroid carcinoma patients with negative 131 I whole? Body scan and elevated serum thyroglobulin. J Clin Med Pharma. 2014;9(Special):92-9.

4. Cooper DS, Doherty GM, Haugen BR, Kloos RT, Lee SL, Mandel SJ, et al. Revised American Thyroid As­sociation management guidelines for patients with thyroid nodules and differentiated thyroid cancer. Thyroid. 2009;19(11):1167-214.

5. Townsend DW, Cherry SR. Combining anatomy and function: the path to true image fusion. Eur Radiol. 2001;11(10):1968-74.

6. Blodgett TM, Ryan A, Akbarpouranbadr A, McCook BM. PET/CT protocols and artifacts in the head and neck. PET Clin. 2007;2(4):433-43.

7. Boellaard R, O’Doherty MJ, Weber WA, Mottaghy FM, Lonsdale MN, Stroobants SG, et al. FDG PET and PET/CT: EANM procedure guidelines for tu­mour PET imaging: version 1.0. Eur J Nucl Med Mol Imaging. 2010;37(1):181-200.

8. Wong TZ. Fras IM. PET/CT protocols and practical issues for the evaluation of patients with head and neck cancer. PET Clin. 2007;2(4):413–21.

9. Fleming ID, Cooper JS, Henson DE, Hutter VP, Ken­nedy BJ, Murphy GP, et al. American joint commit­tee on cancer. AJCC Cancer Staging Manual. New York: Springer; 2010.

10. Som PM. Detection of metastasis in cervical lymph nodes: CT and MR criteria and differential diagno­sis. AJR Am J Roentgenol. 1992;158(5):961-9.

11. Bannas P, Derlin T, Groth M, Apostolova I, Adam G, Mester J, et al. Can (18)F-FDG-PET/CT be generally recommended in patients with differentiated thy­roid carcinoma and elevated thyroglobulin levels but negative I-131 whole body scan? Ann Nucl Med. 2012;26(1):77-85.

12. Shammas A, Degirmenci B, Mountz JM, McCook BM, Branstetter B, Bencherif B, et al. 18F-FDG PET/CT in patients with suspected recurrent or metastat­ic well-differentiated thyroid cancer. J Nucl Med. 2007;48(2):221-6.

13. Marcus C, Whitworth PW, Surasi DS, Pai SI, Subra­maniam RM. PET/CT in the management of thyroid cancers. AJR Am J Roentgenol. 2014;202(6):1316- 29.

14. Feine U, Lietzenmayer R, Hanke JP, Wohrle H, Muller-Schauenburg W. [18FDG whole-body PET in differentiated thyroid carcinoma. Flipflop in up­take patterns of 18FDG and 131I]. Nuklearmedizin. 1995;34(4):127-34.

15. Yamamoto Y, Wong TZ, Turkington TG, Hawk TC, Coleman RE. Head and neck cancer: dedicated FDG PET/CT protocol for detection--phantom and initial clinical studies. Radiology. 2007;244(1):263-72.

16. Beyer T, Antoch G, Muller S, Egelhof T, Freudenberg LS, Debatin J, et al. Acquisition protocol consider­ations for combined PET/CT imaging. J Nucl Med. 2004;45 (Suppl 1):25S-35S.

17. Schluter B, Bohuslavizki KH, Beyer W, Plotkin M, Buchert R, Clausen M. Impact of FDG PET on pa­tients with differentiated thyroid cancer who pres­ent with elevated thyroglobulin and negative 131I scan. J Nucl Med. 2001;42(1):71-6.

18. Na SJ, Yoo IeR, O JH, Lin C, Lin Q, Kim SH, et al. Diag­nostic accuracy of (18)F-fluorodeoxyglucose pos­itron emission tomography/computed tomogra­phy in differentiated thyroid cancer patients with elevated thyroglobulin and negative (131)I whole body scan: evaluation by thyroglobulin level. Ann Nucl Med. 2012;26(1):26-34.

19. Townsend DW. Dual-modality imaging: combining anatomy and function. J Nucl Med. 2008;49(6):938- 55.

20. van den Brekel MW, Stel HV, Castelijns JA, Nauta JJ, van der Waal I, Valk J, et al. Cervical lymph node metastasis: assessment of radiologic criteria. Ra­diology. 1990;177(2):379-84.

21. Bertagna F, Bosio G, Biasiotto G, Rodella C, Puta E, Gabanelli S, et al. F-18 FDG-PET/CT evaluation of patients with differentiated thyroid cancer with negative I-131 total body scan and high thyroglob­ulin level. Clin Nucl Med. 2009;34(11):756-61.

22. Rosario PW, de Faria S, Bicalho L, Alves MF, Borges MA, Purisch S, et al. Ultrasonographic differentia­tion between metastatic and benign lymph nodes in patients with papillary thyroid carcinoma. J Ul­trasound Med. 2005;24(10):1385-9.

23. Nahas Z, Goldenberg D, Fakhry C, Ewertz M, Zeiger M, Ladenson PW, et al. The role of positron emis­sion tomography/computed tomography in the management of recurrent papillary thyroid carci­noma. Laryngoscope. 2005;115(2):237-43.

24. Ma C, Xie J, Kuang A. Is empiric 131I therapy jus­tified for patients with positive thyroglobulin and negative 131I whole-body scanning results? J Nucl Med. 2005;46(7):1164-70.