Purpose

To prospectively investigate the changes of quantitative parameters in dynamic contrast-enhanced MRI (DCE-MRI) and the apparent diffusion coefficient (ADC) of diffusion weighted imaging (DWI) in cervical cancer patients before and after neoadjuvant chemotherapy (NACT).

Patients and Methods

Thirty-eight patients with locally advanced cervical cancer (in stageⅠB2、ⅡA2、ⅡB) under-went DCE-MRI and DWI one week before and 4 weeks after NACT. The patients were classified into two groups: significant reaction group (sCR include CR and PR) and non-sCR(include PD and SD) group according to the Response Evaluation Criteria in Solid Tumors (RECIST). The DCE-MRI pharmacokinetics parameters (mean K^trans, mean K_ep, mean V_e, mean V_p) and ADC value（mean ADC, Minimum ADC）were measured and compared between the sCR and non sCR groups. Receiver operating characteristic (ROC) curves were constructed to describe the diagnostic accuracy of the significant parameters and their decision thresholds.

Results

There were 22 and 16 patients in sCR and non sCR groups, respectively. Before NACT, the mean K^trans was higher but the mean V_e was lower in sCR (0.875 ± 0.329 min-1, 0.661 ± 0.184 min-1) group than those in non sCR group (0.549 ± 0.314 min-1, 0.791 ± 0.117 min-1), and these differences were statistically significant (z = -3.134，p < 0.05；z = -2.129, p < 0.05, respectively). After NACT, the mean K^trans (0.553 ± 0.347 min-1 versus 0.942 ± 0.508 min-1; z = -2.602, p < 0.05) and the changed value of K^trans (△K^trans = -0.322 ± 0.261 min-1 versus △K^trans = 0.393 ± 0.415 min-1; F = 4.776，p < 0.05) were significantly lower in the sCR group compared with those in the non-sCR group. However the meanADC (1048.239 ± 139.899 mm2/s versus 947.050 ± 153.515 mm2/s; z = -2.099，p <0.05) and the changed value of meanADC (△meanADC = 76.627 ± 169.323 e-3mm2/s versus △meanADC = 28.271 ± 102.935 e-3mm2/s; F = 4.757, p < 0.05) between the two groups were just higher in the sCR group compared with those in the non-sCR group. The remained parameters such as V_p and K_ep had no statistically difference between the two groups. When combined the parameters values before and aftertreatment by using ROC curves, the area under curve (AUC) of pre-mean K^trans, △K^trans and pre-mean K^trans combined with post meanADC were 0.801（P < 0.05），0.955（P < 0.001）and 0.878（P < 0.05）. The optimal cut off value for distinguishing sCR from non sCR were the pretreatment K^trans (0.7020 min-1) and △K^trans ( 0.0437 min-1), and their sensitivity and specificity were 77.3 ％, 81.2 ％, 95.5 ％ and 81.2 ％respectively.

Conclusion

Quantitative parameters of DCE-MRI and ADC provided a new noninvasive way to reflect the changes of hemodynamics and water molecular diffusion in cervical cancer patients with NACT. The quantitative parameters, such as pre-mean K^trans ,△K^trans and pre-mean K^trans combined with post meanADC, could predict the treatment efficacy more precisely. However, the quantitative DCE-MRI combined with DWI could not improve the prognostic efficacy significantly.

References

There is no relevant references in the abstract, which only appeared in the paper. So there is no specific reference to the literature.