Application Of Diffusion-weighted Imaging To Evaluate The Efficacy Of Neoadjuvant Chemotherapy In Locally Advanced Cervical Cancer

Objective:To investigate the application of diffusion-weighted magnetic resonance imaging (DWI) and apparent diffusion coefficient (ADC) to monitor the curative effect value of neoadjuvant chemotherapy (NACT) for locally advanced cervical cancer (LACC)Method:18squamous cell carcinoma patients (FIGO stage IB2, IIA and Ⅱb) had been chosen from May2010to May2012in the second Xiangya Hospital of Central South University and all patients’ clinical data had been collected.Every patient did3times of the conventional MRI and DWI before chemotherapy,14days after the first time of NACT and14days after the second time of NACT.All operations completed in Philips Intera Achieva3superconducting magnetic resonance scanner.DWI used a single shot-spin echo-echo planar and short T1inversion recovery sequence to collect datas(TR/TE=952ms/53ms, Flip angle90degrees,matrix is124×100,field range is36×36cm,lay-er thickness/layer spacing=5mm/1.5mm,diffusion weighted coefficient b value were0,300,600,900s/mm2). Every patient did the detection of tissue pathology before chemotherapy,14days after the first time of NACT and after radical operation.Using HE staining and immunohistochemical SP method to detect the density of humor cells,proliferating cell nuclear antigen and aquaporin1’s expression in cervical cancer tissue.According to the evaluation standard of curative effect in solid tumors,in a conventional magnetic resonance imaging T2W1to measure the tumor radial line as a prevail,and evaluat the curative effection of locally advanced cervical cancer after the second time of NACT,then divided into effective group(complete response and partial response) and ineffective group(progression of disease and stable of disease).Trough the MR Workspace Release2.6.3Workstations and worked with the DWI image.Observing the cervical cancer’s DWI image characteristics and the changes of ADC value at different bvalue,then choose the best bvalue;In the condition of the best bvalue imaging,detected the cervical cancer’s DWI image characteristics and the changes of ADC value at different time of chemotherapy,and the relationship between the change and the curative effect.In the different chemotherapy group,compared the change characteristics of cervical tissue’s microscopic pathological structure(the number of tumor cells,the expression of PCNA、 AQP1),and the relationship between the change characteristics and ADC value. Results:1、All18patients completed2times of NACT,13cases were effective chemotherapy(one of them was complete response,twelve of them were partial response),5cases were ineffective chemotherapy(one case was progression of disease and four cases were stable of disease),the rate of effective chemotherapy was72.2%.17cases did the radical surgery after chemotherapy,one case changed to radiotherapy.15cases did supplementary treatment after surgery(9cases did chemotherapy,7cases did radiotherapy,4cases did radiotherapy and chemotherapy).Postoperative follow-up was (19.39±7.253)months,18cases survived.2、The DWI image characteristic and ADC value of cervical cancer lesions at different bvalue.When b=0s/mm2,cervical lesions’ signal was not homogeneous slightly higher echo,and consistent with T2WI signal;when bvalue was300、600、900s/mm2,lesions showed a hyper echo.With the increase of the bvalue,the DWI degree of image distortion and artifacts were not obvious,but when b value was900s/mm2,the diseased tissue image’s contrastion was more clear than300and600s/mm2.The ADC value at different b value were (1.05±0.27)×10-3mm2/s、(0.96±0.21)×10-3mm2/s and (0.86±0.16)×10-3mm2/s.With the increase of the bvalue,ADC value significantly reduced (P=0.043).The study selected b=900s/mm2as the best bvalue. 3、The ADC value of cervical cancer lesions at different time and different efficacy of chemotherapy group. The ADC value of the cervical cancer lesions which was effective chemotherapy before the chemotherapy、after the first time of NACT and after the second time of NACT were (0.87±0.19)×10-3mm2/s、0.90±0.18)×10-3mm2/s and (0.97±0.17)×10-3mm2/s.The ADC value which was after the second time of NACT significantly higher than the first time of NACT and before the chemotherapy (p=0.001, p=0.000),after the first chemotherapy was no significant difference compared with that before chemotherapy (P=0.165).Cervical cancer lesions which was ineffective chemotherapy,the ADC value had no significant differences at three different time(p=0.681).4、The effect of chemotherapy on cervical cancer’s tumor cell density and the expression of PCNA、AQP1.In the cervical cancer which were effective chemotherapy,after the second time of NACT, the density of tumor cells and the expression of PCNA positive cells、AQP1significantly reduced than the first time of NACT (p=0.004, p=0.003, p=0.000); but in the cervical cancer which were ineffective chemotherapy,the density of tumor cells and the expression of PCNA positive cells、AQP1had no significant difference before and after chemotherapy (p=0.819, p=0.577, p=0.936).5、The correlation between the ADC value and the expression of PCNA、AQP1in the corresponding tissue of the cervical cancer lesions at different time of the chemotherapy.For the cervical cancer which were effective chemotherapy,ADC value’s change and the expression of PCNA’s change showed a significant negative correlation after the first time of NACTA (r=-0.640,P=0.018) and after the second time of NACT (r=-0.626,P=0.022)Conclusions:1、Satisfactory DWI images of cervical cancer can be obtained when b value is900s/mm2.2. ADC value can be used to monitor the effect of neoadjuvant chemotherapy in the locally advanced cervical cancer.3、The increased ADC values is associated with the decreased tumor cells’proliferation activity in locally advanced cervical cancer with chemotherapy sensitivity. Figure10,tables8,references49.