Clinical Application Study For The Evaluation Value Of Iodine Maps Of Dual Source Dual Energy CT On Chemoradiotherapy Effect For Cervical Cancer

Objective:To investigate the preliminary value of iodine maps of dual source dual energy CT scanning on the evaluation of Chemoradiotherapy effect for Cervical cancer from the multi-parameter quantitative measurement such as iodine concentration,change of lesion size and change of iodine value.Method:The cervical cancer patients who were pathologically confirmed and intended to undergo concurrent chemoraodiotherapy were collected. In all patients before and after treatment,contrast enhanced CT scan by dual source dual energy CT would be taken. The contrast agent was Ioverol(320mgI/ml), the dose was 75 ml, and the flow rate was 3.5ml/s. Dual energy mode settings: tube A voltage 140 kvp with current 178 mA, tube B voltage 100 KVp with current 230 mA,scan slice thickness and interval was 5mm, with reconstruction slice thickness of 1mm. Dynamic and real-time exposure dose adjustment and automatic tube current modulation was open.Reconstruction data of dual energy image was transmitted to the Siemens MMWP workstation,using VNC software analysis processing, setting 50% iodine mixed fusion graph. Two experienced radiologist dis-blindly observed the images and measured the maximum tumor diameter, selecting region of interest from the substantial part from the tumor. The measurements were carried out in both arterial and venous phases, iodine concentration was normalized using the iodine concentration of the iliac artery in the same layer(iodine concentration of the lesion / internal iliac arterial iodine concentration). Randomly selected 20 female patients who underwent dual-phase contrast-enhanced pelvic scan from a general 64 row CT as control group for radiation dose comparison. SPSS 19.0 was employed for statistical analysis of standard iodine value of both phase before treatment and iodine value change rate after therapy.Results:A total of twenty-one patients completed the theraputic courses and performed the contrast-enhanced CT scanning were subsequently evaluated. In a comparison between tumor size<5cm(n=13)and tumor size≥5cm(n=8) before CRT, we controlled for age, preSAI(iodine uptake in arterial phase before CRT),preSVI( iodine uptake in venous-phase before CRT), and cell differentiated level and found no significant differences. According to the RECIST1.1, 15 cases were divided into R(responding,including CR 5 cases and PR 10 cases)group, the remaining 6 cases were classified into NR(non-responding,including SD 6 cases)group. A significant difference of preSAI was found between three groups, p=0.02. The iodine value decreased ratio in arterial phase of the PR group was higher than that of SD group(p<0.01),and there was no significance in venous phase(p>0.05). The iodine value in arterial phase of R group before treatment is significantly higher than that of NR group(p<0.01). When the standard iodine value in arterial phase before RCT is 0.345, the AUC for outcome prediction was 0.875.Conclusion:1.The change of SAI of dual source dual energy CT scanning can be an early assessment parameter for the chemoradiotherapy effect for cervical carcinoma 2.Pre-SAI is helpful for the effect prediction on chemoradiotherapy for cervical cancer; 3. Dual source CT dual energy scan provides more valuable functional information,and does not increase radiation dose,can be widely promoted to clinical application.