| Objective:Chosing the different background,to estimate the value of double-phase99mTc-MIBI SPECT predicting the effect of chemotherapy in nasopharyngeal carcinoma.Methods:Thirty patients of nasopharyngeal carcinoma which proven by pathology participated in this prospective study. All patients are done the double-phase99mTc-MIBI SPECT and MR before chemotherapy,after two cycles they do a MR to estimate the effect. The result of MR is consider to the standard whether multidrug resistance (MDR) or not. A GE UM670SPECT machine is used to this study, equipped the low-energy,high-resolution collimator. Everyone is injected370MBq by the vein, do the early and delay perform at the5min and120min. Head,neck a upper chest are all involved in the vision filed. The matrix size is128x128and zoom is1.0. SPECT projections are reconstructed with filtered backprojection technique. Images are displayed incoronal, sagital and transverse slices.The images are checked by two salted nuclear doctors, combined to the CT,SPECT and fusion images. Chosing different background to Semi-quantity analysis:ROI drawn in transverse slice which the lesion is most obviously is copied to cerebrum, trapezius and lung. Then the tnmor-to-background(T/B)ratios are obtained as T/C,T/M and T/L. The retention index are calculated according to different T/B. The relationships between efficacy of neoadjuvant chemotherapy and the early uptake ratio, late uptake ratio and washout rate of99mTc-MIBI are evaluated. Receiver operating characteristic curve (ROC curve)is drawn to determine the cutoff value of the diagnostic test. All data are analyzed with SPSS13.0software. Results:We evaluate the clinical curative effects evaluation according to the MRI.There are twenty-four focus contain into our study in nasopharynx, seven achieved complete remission (CR), thirteen had partial response (PR), four experienced stable disease, none of patients had progressive disease (PD).So twenty lesions were sensitive to chemotherapy and four insensitive.In neck metastatic cervical lymph nodes, there are twenty-three focus in our sample,two achieved complete remission (CR), fifteen had partial response (PR), six experienced stable disease, none of patients had progressive disease (PD).So seventeen lesions were sensitive to chemotherapy and six insensitive.The difference of the response rate between nasopharyngeal lesions and lymph nodes lesions was not statistically significant(F=0.1869p=0.6655).(1)Such T/B ratios as T/C,T/M and T/L were obtained when cerebrum, muscle and lung were as background respectively. We obtained the early uptake,the late uptake and the washout rate.We find that the sensitive was higher than the insensitive,the difference was statistically significant in early and late uptake,but the washout rate.(2)ROC curve analysis:the AUC for early uptake of99mTc-MIBI was best when we chose the cerebrum as the background,the AUC was0.943(SE=0.042;95%CI=0.860-1.026;P=0.002).The sensitivity, specificity were91.4%,80%.The late uptake results was the same as the early,when chose the cerebrum as the background,the AUC was0.929(SE=0.050;95%CI=0.831-1.027;P=0.02).The sensitivity, specificity were85.7%,77.3%.Conlusions:(1) The uptake of99mTc-MIBI in both early phase and late phase could to some extent predict the efficacy of neoadjuvant chemotherapy.(2) Through the Semi-quantity analysis,when chosing the cerebrum as background,the efficiency was perfect in predicting the efficacy of chemotherapy. |
PDF Full Text Request