Comparison of131I-whole Body Scan and18F-FDG PET/CT on the Metastatic Management of Differentiated Thyroid Cancer After Operation / 中国医学影像学杂志

ABSTRACT

Purpose To explore the clinical value of131I-whole body scan (131I-WBS) and 18F-FDG PET/CT on the metastatic management of patients with differentiated thyroid cancer (DTC) after operation.Materials and Methods Serum thyroglobulin (Tg) of 27 patients after DTC surgery was measured one day before131I therapy, and the patients underwent131I-WBS on 3-5 days after131I therapy. According to the results of Tg and 131I-WBS, all the patients were divided into 4 types as follows type I Tg (+),131I-WBS (-); type II Tg (+),131I-WBS (+); type III Tg (-),131I-WBS (+); and type IV Tg (-), 131I-WBS (-). Then the patients received18F-FDG PET/CT scan within a week after 131I-WBS. The results of131I-WBS and18F-FDG PET/CT scan were analyzed according to histopathologic findings or clinical and imaging follow-up of at least 6 months as diagnosis standard.Results The examinations uncovered that metastasis occurred in 52 lesions of 22 cases out of the 27 cases.131I-WBS revealed 24 metastatic lesions (46.2%) in 8 cases (36.4%), and18F-FDG PET/CT showed 35 metastatic lesions (67.3%) in 15 cases (68.2%), the difference with statistic significance (χ2=4.46 and 4.74,P0.05). Based on that, therapeutic plans were modified for 13 patients with type I metastasis and 1 patient with type IV metastasis.Conclusion131I-WBS and18F-FDG PET/CT are complementary for detecting metastatic lesion and help to decide the following treatment of DTC patients after surgery. Moreover,18F-FDG PET/CT shows advantages in detecting metastatic lesion in Tg-positive and negative131I-WBS type of DTC patients after surgery, thus can provide an important clinical guidance for this type of patients.