ABSTRACT
Objective To evaluate the role of 131I SPECT/CT in post-surgical re-staging and recurrence risk stratification in patients with DTC and its impact on subsequent treatment strategy.Methods 131I-WBS and 131I SPECT/CT were performed at the same time 5 to 7 d after 131I treatment in 118 patients (33 males,85 females,average age 45 years) with DTC.Difference in the localization and qualitative diagnosis of 131I uptake lesions between 131I-WBS and 131I SPECT/CT were compared.Value of 131I SPECT/CT in the diagnosis of TNM staging,risk stratification and impact on the treatment strategy was evaluated.Paired χ2 test was used for data analysis.Results A total of 509 foci with 131I uptake were detected.131I-WBS found 449 foci with 131I uptake,354 of which (78.84％) were correctly diagnosed.131I SPECT/CT found 509 foci with 131I uptake,and 504(99.02％) were correctly diagnosed.The difference was statistically significant (χ2=21.51,P<0.01).131I-WBS changed the clinical staging in 13 cases with diagnostic accuracy of 5/13.131I SPECT/CT changed the clinical staging in 19 cases and with diagnostic accuracy of 19/19 (χ2=74.41,P<0.01).131I-WBS changed the risk stratification of 13 patients after operation and the accuracy was 5/13,the corresponding data were 22 and 100％(22/22) for 131I SPECT/CT (χ2=74.41,P<0.01).The treatment strategy was changed in 50 patients with 131I SPECT/CT.Conclusions Compared with 131I-WBS,131I SPECT/CT could provide more accurate positioning and qualitative information for 131I treatment and is more accurate in re-staging and risk stratification.