The Study On Efficacy Of Low-dose CT Perfusion In Early Evaluation Of Anti-angiogenic Therapy In Non-small Cell Lung Cancer

Background and purposeLung cancer is a malignant tumor with the highest morbidity and mortality in the world.Emerging anti-angiogenic therapy brings new hope to patients with advanced non-small cell lung cancer（NSCLC）.CT perfusion imaging（CTPI）is one of the most accurate non-invasive examinations of microcirculation in the living body,and has been increasingly used.The purpose of this study was to compare the change of CT perfusion parameters（CTPP）before and after treatment,the relationship between the maximum diameter of tumor and the rate of change of CTPP,analyze the diagnostic efficacy of each CTPP rate of change in efficacy evaluation,and observe the short-term efficacy of Anlotinib Hydrochloride.Material and methodsFrom August 2015 to May 2017,38 cases of stage IV（TNM8 staging）NSCLC patients who participated in the"Anlotinib Hydrochloride double-blind trial"at the Henan Cancer Hospital were enrolled in the study.CT examination and low-dose CTPI examination（80KV,150mA）were performed at baseline,after the first cycle of treatment and the second cycle of treatment,respectively.Differences in perfusion parameters,including perfusion,peak enhancement（PEI）,time to peak（TTP）,and blood volume（BV）were compared between experimental and placebo-treated groups who were at baseline and after the first cycle of treatment respectively.According to the curative effect after 2 cycles,the patients in the experimental group were divided into the disease control（DC）group and the disease progression（PD）group.The perfusion,PEI,TTP and BV difference between the DC group and the PD group at baseline and after the first cycle of treatment were compared.Compared with the baseline,the maximum diameter change rate（D2%）after 2cycles and the CTPP change rate（CTPP1%）after treatment for 1 cycles were analyzed,and the correlation between them was analyzed.According to the standard criteria 1.1 for the response evaluation criteria in solid tumor（RECIST）,the efficacy of 38 patients after 1 cycle and 2 cycles of treatment was evaluated The diagnostic performance of each CTPP1%for the evaluation of efficacy（DC and PD）was evaluated using the receiver operating characteristic curve（ROC）,and the area under the ROC curve（AUC）for different CTPPs was compared.Result25 patients in the experimental group of Anlotinib Hydrochloride and 13 cases in the control group were all classified stable disease（SD）after the first cycle of treatment.After the second cycle of treatment,2 patients in the experimental group were classified partial response（PR）,20 cases were classified as SD and 3 cases were classified as PD,objective response rate（ORR）was 8%（2/25）,and disease control rate（DCR）was 88%（22/25）respectively.In the control group,1 patient was classified SD and 12 patients as PD,ORR was 0%,and DCR was 8%（1/13）.At baseline,there was no significant difference in perfusion,PEI,TTP,BV,age,and location of tumor between the experimental group and the control group.After one cycle of treatment,the average perfusion values of the experimental group and the control group were（24.05±16.87）ml/min/100ml and（37.52±8.27）ml/min/100ml,the PEI were（26.08±13.61）HU and（35.55±7.75）HU respectively.Compared with the control group,the perfusion value and PEI in the experimental group were significantly decreased（p<0.05）.The experimental group was further divided into PD group including 3 cases,DC group including 22 cases.There was no significant difference in CTPP between the two groups at baseline.After one cycle of treatment,the average perfusion values of the DC group and the PD group were（21.03±15.30）ml/min/100ml and（46.17±11.14）ml/min/100ml,the PEI were（23.96±12.19）HU and（41.59±15.94）HU.,and the median BV were 4.24 ml/100g and 18.18 ml/100 g respectively.The DC group had lower perfusion,PEI,and BV than the PD group（p<0.05）.Each CTPP₁%was positively correlated with D₂%,and the rate of perfusion change was the highest,the correlation coefficient is 0.72..The ROC curve showed that when perfusion was reduced by 3.45%from baseline and the maximum AUC was obtained,the sensitivity and specificity were 91.70%and 100%,respectively;when the BV was reduced by 3.78%from the baseline,the maximum AUC was obtained with a sensitivity and specificity of 83.30%and 85.70%;When the PEI was reduced by 7.60%from baseline,the maximum AUC was obtained with sensitivity and specificity of 58.30%and 78.60%,respectively;the rate of perfusion change has the highest diagnostic accuracy for efficacy evaluation,higher than PEI（0.979 vs0.640 p=0.00）and BV（0.979 vs 0.856 p=0.02）.All low-dose CTPI images were in accordance with the diagnostic requirements.The median effective radiation dose of the final test was 13.3mSv.Conclusion1.CTPI can reflect the efficacy of anti-angiogenic therapy and the microcirculation changes of NSCLC in the early stage.2.CTPP rate of change is earlier than RECIST standard in evaluating the efficacy of anti-angiogenic therapy,the change rate of CTPP is proportional to the change rate of tumor size.3.in all CTPP,the rate of perfusion change was most effective in evaluating efficacy.4.Low-dose CTPI can meet clinical diagnosis.5.The efficacy of Anlotinib Hydrochloride as a third-line after-treatment is certain.