Abstract:

Objective

To investigate the value of 18F-fluorodeoxyglucose(FDG)PET/CT i maging in diagnosis of breast cancer and axillary ly mph node metastases.

Methods

According to the pathological diagnostic results 34 breast cancer patients were recruited for the study.Their ¹⁸F-FDG PET/CT i maging data were analyzed qualitatively by visual assess ment and semi-quantitatively by calculating maxi mu m standardized uptake values(SUVmax).The sensitivity,specificity and accuracy of the t wo methods were measured,Kappa test was used for the consistency of each of the t wo PET/CT diagnostic methods with pathological diagnosis,and the mean of SUVmax bet ween groups was compared using t wo independent samples t test.

Results

The comparison of the mean SUVmax bet ween the 2 groups showed the ¹⁸ F-FDGuptake was greater in the malignant breast lesion group than in the control group,with statistical significant difference bet ween the three groups(P=0.00).One case of pathological apocrine intraductal carcino ma,cancer in situ,was negatively uptaken by PET/CT.The qualitative analysis showed zero grade and semiquantitative analysis showed SUVmax as 1.5,because the lesion size was so s mall,＜5-8 c m,which was beyond the uptake range of PET/CT.In diagnosing breast malignancy,the diagnostic accuracy,sensitivity and specificity of ¹⁸ F-FDG PET/CT qualitative analysis was 97.9%,97.7%and 100.0%,respectively;for the semi-quantitative analysis,when the cut-off point of SUVmax was set at 2.0,the sensitivity,specificity,and accuracy was 93.2%,100.0% and 93.6%,respectively.The kappa value was 0.85 for qualitative analysis,with excellent agreement,and 0.64 for semi-quantitatively.In detecting axillary ly mph node metastases,the sensitivity,specificity,and accuracy of qualitative analysis were 55.9%,96.1%and 90.1%,respectively;for semi-quantitative analysis,the cut-off point of SUVmax was set at 1.8 (referenced to literature),the sensitivity,specificity,and accuracy were 45.8%,97.0%and 89.3%,respectively;the kappa value was 0.57 for the qualitative analysis and 0.51 for semi-quantitative analysis.

Conclusion

For detecting malignant breast lesions with ¹⁸ F-FDGPET/CT,when the cut-off point of SUVmax was set at 2.0,semi-quantitative analysis is opti mal.For detecting axillary ly mph node metastases,both qualitative analysis(Kappa value=0.57)and semi-quantitative analysis(Kappa value=0.51)have median agreement with pathological diagnosis.

Key words: Breast neoplas ms, Axillary ly mph node, ¹⁸ F-fluorodeoxyglucose, Positron emission Tomography, Tomography, X-ray computed