Objective To evaluate whether an early change in 18F-fluorodeoxyglucose (18F-FDG) uptake can predict tumor response to epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) and prognosis in patients with non-small cell lung cancer (NSCLC). Methods From August 2009 to April 2015, 22 patients with NSCLC who were eligible to EGFR-TKI treatment were enrolled. PET-CT scan was performed before (baseline) and 1 month after EGFR-TKI administration. Up to 5 hottest single tumor lesions (no more than 2 per organ) were considered to be target lesions. Maximum standardized uptake values (SUVmax) were measured, and post-treatment percentage changes in SUVmax (ΔSUV%) were calculated. PET responses were classified using PET response criteria in solid tumors (PERCIST). Then conventional CT scan was performed every 2 months for follow-up. Kappa statistic was used to compare agreement between the RERCIST recommendations-based therapeutic response evaluation and those based on RECIST1.1 criteria. Fisher exact test was used to compare the probability of disease progression in the early metabolic response and non-response groups. Predictive accuracy of ΔSUV% with respect to response or non-progression at CT scan was evaluated by ROC analysis. Progression-free survival (PFS) was determined by Kaplan-Meier survival analysis, and between-group comparison was performed by log-rank test. Results After 1 month of EGFR-TKI treatment, 12 patients (55%) showed partial metabolic response (PMR), 6 (27%) had stable metabolic disease (SMD), and 4 (18%) had progressive metabolic disease (PMD). There was a moderate agreement(Kappa=0.506,P<0.05) between PET response at 1 month based on PERCIST recommendations and CT response at 3 months according to RECIST 1.1. Non-progression was significantly more frequent in patients with an early PMR (χ2=11.941, P=0.005). Progression had been confirmed later during therapy in all patients with PMD . By using ROC analysis, the area under the curve for prediction of response was 0.906 (95% CI, 0.766—1.000; P=0.002), corresponding to a sensitivity of 88.9% and specificity of 84.6% at a cut-off of 40.36% in ΔSUV%. Using a cut-off value of 25.84% in ΔSUV%, highΔSUV% group (ΔSUV% ≥ 25.84%) had significantly longer PFS than low ΔSUV% group (ΔSUV%<25.84%). Conclusion Early assessment of PET-CT at 1 month of EGFR-TKI treatment could be useful to predict tumor response and clinical outcome in patients with NSCLC.

Objective This study focused on the low voltage and low concentration contrast agent technology in vascular imaging of stroke patients.Methods Totally144 patients of ischemic stroke confirmed from January 2022 to January 2023 were enrolled.They were divided into four groups according to different imaging methods:conventional group(tube voltage 120kV,iodine concentration 370mgI/ml),low voltage group(tube voltage 80kV,iodine concentration 370mgI/ml),low concentration group(tube voltage 120kV,iodine concentration 320mgI/ml)and dual-low group(tube voltage 80kV,iodine concentration 320mgI/ml),the post-processing technology adopted ASiR algorithm for 3D reconstruction.Then to compare contrast signal-to-noise ratio(CNR)and signal-to-noise ratio(SNR)of the reconstructed image,image quality score,CT values of internal carotid artery(ICA),anterior cerebral artery(AA)A1,middle cerebral artery(MA)M1,posterior cerebral artery(PA)P1,vertebral artery(VA)and basilar artery(BA),mean iodine intake and radiation dose parameters including volume CT dose index(CTDIvol)and dose length product(DLP).Results The CNR and SNR values in dual-low group were significantly less than the other three groups(P<0.05),while image quality score and CT value of each artery were no differences among the four groups(P>0.05).What's more,CTDIvol,DLP and iodine intake volume in dual-low group were significantly less than the others(P<0.05).Conclusion The dual-low technology scanning could obtain satisfactory head and neck CT angiography for stroke patients.