***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Purpose To study the feasibility and clinical value of dynamic contrast-enhanced ( DCE ) computed tomography ( CT ) for early evaluation of targeted therapy efficacy in non-small cell lung cancer ( NSCLC ) . Methods We measured tumor diameter , peak height ( PH ) , time to peak ( TP ) , tumor mass – aortic peak height ratio ( M/A ) , and blood perfusion ( BP ) in 20 patients with advanced NSCLC using DCE-CT before and 7 days after treatment . Therapy efficacy was assessed with conventional CT 4–6 weeks post-treatment . Results Patients were grouped into those with partial response ( PR ) , stable disease ( SD ) , and progressive disease ( PD ) according to the therapy efficacy assessment at 4–6 weeks post-treatment . The PR group primary tumor diameter ( P = 0.0007 ) and BP ( P = 0.0225 ) were reduced at 7 days post-treatment ; the SD group DCE-CT value changes were not significant . The PD group M/A ( P = 0.0443 ) and BP ( P = 0.0268 ) were increased 7 days post-treatment . The BP decrease group had significantly longer progression-free survival than the BP increase group ( median , 54 vs. 6 weeks ) . Conclusion DCE-CT can evaluate targeted therapy efficacy at 7 days post-treatment . Decreased primary tumor diameter and BP indicate tumor sensitivity to therapy ; increased BP with unchanged tumor diameter suggests the tumor is not sensitive to therapy . Reduced BP suggests treatment effectiveness OBJECTIVE The purpose s of this study were to determine the reproducibility of quantitative colorectal cancer perfusion measurements using dynamic contrast-enhanced MDCT , and to compare this with measurements from skeletal muscle . SUBJECTS AND METHODS Ten patients ( mean age , 67 years ; six men , four women ) with histologically proven colorectal cancer were examined prospect ively using 4-MDCT . Perfusion studies ( cine mode ; 4 x 5 mm collimation ; 1 acquisition/s ; 65 seconds total ) were performed through the tumor epicenter after IV bolus contrast administration ( iopamidol 340 , 100 mL ; 5 mL/s ) and repeated within 48 hours . Quantitative values for blood volume , blood flow , mean transit time , and permeability were determined using commercial software . Two regions of interest were studied on the axial image : one within the tumor and another within the left gluteal muscle . Measurement reproducibility was assessed using Bl and -Altman statistics . RESULTS For the tumor , the mean difference ( 95 % limits of agreement ) was -0.04 mL/100 g tissue ( -2.50 , 2.42 ) ; 8.80 ( -50.5 , 68.0 ) mL/100 g tissue/min ; -0.99 ( -8.19 , 6.20 ) seconds ; and 1.20 ( -5.42 , 7.83 ) mL/100 g tissue/min for blood volume , blood flow , mean transit time , and permeability , respectively . For muscle , the mean difference ( 95 % limits of agreement ) was 0.02 ( -1.40 , 1.43 ) , 6.60 ( -11.2 , 24.3 ) , -3.76 ( -16.87 , 9.35 ) , and 1.30 ( -4.68 , 7.28 ) , respectively . CONCLUSION Quantitative perfusion measurements are reproducible . Measurements from tumor are less variable than from skeletal muscle PURPOSE Effective systemic therapy for advanced carcinoid is lacking . The combination of bevacizumab ( BEV ) and pegylated ( PEG ) interferon alpha-2b was evaluated among patients with metastatic or unresectable carcinoid tumors . PATIENTS AND METHODS Forty-four patients on stable doses of octreotide  were r and omly assigned to 18 weeks of treatment with bevacizumab or PEG interferon alpha-2b . At disease progression ( PD ) or at the end of 18 weeks ( whichever occurred earlier ) , patients received bevacizumab plus PEG interferon until progression . Functional computer tomography ( CT ) scans were performed to measure effect on tumor blood flow . RESULTS In the bevacizumab arm , four patients ( 18 % ) achieved confirmed partial response ( PR ) , 17 patients ( 77 % ) had stable disease ( SD ) , and one patient ( 5 % ) had PD . In the PEG interferon arm , 15 patients ( 68 % ) had SD and six patients ( 27 % ) had PD . Progression-free survival ( PFS ) rates after 18 weeks of monotherapy were 95 % in bevacizumab versus 68 % on the PEG interferon arm . The overall median PFS for all 44 patients is 63 weeks . Compared with paired baseline measurements on functional CT scans , we observed a 49 % ( P < .01 ) and 28 % ( P < .01 ) decrease in tumor blood flow at day 2 and week 18 among patients treated with bevacizumab . No significant changes in tumor blood flow were observed following PEG interferon . PEG interferon alpha-2b treatment was associated with decrease in plasma basic fibroblast growth factor ( bFGF ; P = .04 ) and increase in plasma interleukin-18 ( IL-18 ; P < .01 ) . No significant changes in bFGF or IL-18 following treatment with bevacizumab were observed . CONCLUSION Bevacizumab therapy result ed in objective responses , reduction of tumor blood flow , and longer PFS in patients with carcinoid than PEG interferon treatment With the emergence of novel targeted therapies , imaging techniques that assess tumor vascular support have gained credence for response assessment alongside st and ard response criteria . Computed tomography ( CT ) perfusion techniques that quantify regional tumor blood flow , blood volume , flow- extraction product , and permeability-surface area product through st and ard kinetic models are attractive , but the level of evidence for CT perfusion to be a truly mature biomarker remains insufficient . Studies to date have not been powered to assess this . Future studies that include good quality prospect i ve validation correlating perfusion CT to outcome end points in the trial setting are needed to take CT perfusion forward as a biomarker in oncology The current criteria for evaluating antiangiogenic efficacy is insufficient as tumor shrinkage occurs after blood perfusion decreases . Tumor blood volume ( BV ) in computed tomography perfusion imaging and circulating endothelial cells ( CEC ) might predict the status of angiogenesis . The present study aim ed to vali date their representation as feasible predictors in non‐small‐cell lung carcinoma ( NSCLC ) . A total of 74 patients was categorized r and omly into two arms undergoing regimens of vinorelbine and cisplatin ( Navelbine and platinum [ NP ] ) with rh‐endostatin or single NP .  The response rate , perfusion imaging indexes and activated CEC ( aCEC ) during treatment were recorded . Progression‐free survival ( PFS ) was determined through follow up . Correlations among the above indicators , response and PFS were analyzed : aCEC increased significantly in cases of progressive disease after single NP chemotherapy ( P = 0.024 ) . Tumor BV decreased significantly in cases with a clinical benefit in the combined arm ( P = 0.026 ) , whereas inverse correlations existed between ∆aCEC ( post‐therapeutic value minus the pre‐therapeutic value ) and PFS ( P = 0.005 ) and between ∆BV and PFS ( P = 0.044 ) ; a positive correlation existed between ∆aCEC and ∆BV . Therefore , both aCEC and tumor BV can serve as predictors , and detection of both indicators can help evaluate the chemo‐antiangiogenic efficacy in NSCLC more accurately Objective We investigated the feasibility of serial dynamic contrast-enhanced computed tomography ( DCE-CT ) in patients with advanced/metastatic non-small cell lung cancer ( NSCLC ) receiving anti-angiogenic ( sorafenib ) and anti-EGFR ( erlotinib ) treatment , and correlated tumour blood flow ( BF ) with treatment outcome . Methods DCE-CTs were performed at baseline and 3 and 6 weeks after starting treatment . Tumour BF , calculated with the maximum slope method , and percentage change were measured in 23 patients ( 14 male ; median age 59 years ) .  Tumour BF was compared at baseline and weeks 3 and 6 ; the relation with RECIST/Crabb response and progression-free survival ( PFS ) was assessed . Results Mean tumour perfusion decreased from 39.2 ml/100 g/min at baseline to 15.1 ml/100 g/min at week 3 ( p < 0.001 ) and 9.4 ml/100 g/min at week 6 ( p < 0.001 ) . Tumour perfusion was lower in RECIST and Crabb responders versus non-responders at week 3 ( 4.2 versus 17.7 ml/100 g/min , p = 0.03 ) and week 6 ( 0 versus 13.4 ml/100 g/min , p = 0.04 ) . Patients with a decrease larger than the median at week 6 tended to have a longer PFS ( 7.1 versus 5.7 months , p = 0.06 ) . ConclusionS erial DCE-CTs are feasible in patients with NSCLC and demonstrated a significant decrease in tumour BF  following sorafenib/erlotinib therapy . Early changes in tumour BF correlated with objective response and showed a trend towards longer PFS BACKGROUND AND PURPOSE : Perfusion CT ( PCT ) provides a rapid , reliable , and non-invasive technique for assessing tumor vascularity . The purpose of this study was to assess whether pretreatment dynamic perfusion CT ( PCT ) may predict response to induction chemotherapy and midterm progression-free survival ( PFS ) in advanced oropharynx squamous cell carcinoma ( SCCA ) and to compare the results with those derived by tumor volume measurements . MATERIAL S AND METHODS : Nineteen patients underwent routine contrast-enhanced CT ( CECT ) , pretreatment PCT , and conventional endoscopy .  Tumor response was determined according to radiologic ( RECIST ) criteria . The  PCT parameters , tumor volume , radiologic response , and PFS were analyzed with use of Cox-proportional hazards model , receiver operating characteristic ( ROC ) , and Kaplan-Meier analysis . RESULTS : The baseline blood flow ( BF ) , blood volume ( BV ) , and permeability surface area product ( PS ) were significantly higher , whereas mean transit time ( MTT ) was significantly lower in the responders than in the nonresponders ( P ≤ .002 ) . BV showed 100 % sensitivity , MTT and PS had the highest specificity ( 100 % ) , and BF showed 84.2 % sensitivity and 66.7 % specificity for prediction of tumor response after induction chemotherapy . The pretreatment tumor volume correlated with PFS in the pooled patients group ( r = 0.4 ; P < .0001 ) , whereas postinduction tumor volume correlated significantly with PFS in the responders and nonresponders ( r = 0.22–0.64 ; P ≤ .006 ) . Pretreatment tumor volume ( P = .0001 ) and BF ( P = .001 ) were significant predictors for PFS . CONCLUSIONS : Pretreatment PCT parameters may predict response after induction chemotherapy . Tumor volume and BF values may predict PFS in patients with advanced oropharyngeal SCCA Objective To observe the dynamic changes of blood perfusion and hypoxic status with CT perfusion imaging and hypoxia imaging in patients of non-small-cell lung cancer ( NSCLC ) who were treated with recombinant human endostatin ( RHES ) .  Methods Fifteen previously untreated patients with histologically or cytologically confirmed NSCLC were enrolled . They were r and omly divided into research group ( n=10 ) and negative control group ( n=5 ) . The patients of the research group continuously used RHES for ten days , and simultaneously had CT perfusion imaging and hypoxia imaging performed on days 1 , 5 and 10 , respectively . The remaining 5(control ) only had CT perfusion imaging and hypoxia imaging , without using RHES , on days 1 , 5 and 10 , respectively . According to the above results , we could obtain a “ time window ” during which RHES improves blood perfusion and hypoxia of lung cancer . Results In the research group , after using RHES , capillary permeability surface ( PS ) and tumour to normal tissue ( T/N ) decreased at first , and then increased . Their lowest points occurred on about the fifth day with statistical significance compared with the first day ( T/N , p=0.00 ; PS , p<0.01 ) . Blood flow ( BF ) was first increased and then decreased . Its highest point occurred on about the fifth day with statistical significance compared with the first and tenth day ( all p<0.01 ) . The PS , BF and T/N peaked on the fifth day in the research group with statistical significance compared with the negative control group as well ( all p<0.01 ) . The above results suggested that RHES ’s “ time window ” was within about one week after administration . Conclusion RHES ’s “ time window ” is within about one week after administration , which provides an important experimental basis for combining RHES with radiotherapy in human tumours This paper is an overview of the new response evaluation criteria in solid tumours :  revised RECIST guid 
    Output:
    
DCE-CT may be a useful tool in assessing treatment response in patients with lung cancer .
It seems that particularly permeability and blood flow are important perfusion values for predicting treatment outcome .