Peng Hou

Quantification of metabolic tumor activity and burden in patients with non-small-cell lung cancer: Is manual adjustment of semiautomatic gradient-based measurements necessary?

PURPOSE Metabolic tumor burden (MTB) measurements including metabolic tumor volume and total lesion glycolysis have been shown to have prognostic value in non-small-cell lung cancer (NSCLC). The calculation of MTB typically utilizes software to semiautomatically draw volumes of interest around the tumor, which are subsequently manually adjusted by the radiologist to include the entire tumor. The manual adjustment step can be time-consuming and observer-dependent. We compared the agreement of MTB values obtained using the semiautomatic method with and without manual adjustment in NSCLC patients. METHODS This IRB-approved prospective study included 134 patients with histologically proven NSCLC who underwent fluorine-18 fluorodeoxyglucose PET/computed tomography. The MTB of the primary tumor was measured with a semiautomatic gradient-based method without manual adjustment (the semiautomatic gradient method) and with manual adjustment (the manually adjusted semiautomatic gradient method) by two radiologists using the MIM PETedge tool. The paired t-test, Wilcoxon signed-rank test, and concordance correlation coefficient (CCC) were calculated to evaluate the agreement between MTB measures obtained with these two methods, as well as agreement between the two radiologists for each method. RESULTS Maximum standardized uptake value was identical between the two methods. No statistically significant difference was present for peak standardized uptake value, metabolic tumor volume, and total lesion glycolysis values between the two methods (P=0.23, 0.45, and 0.37, respectively). Excellent agreement between the two methods was found in terms of CCC (CCC>0.98 for all measures). Interobserver reliability was excellent for all measures (CCC>0.90). CONCLUSION The semiautomatic gradient-based tumor-segmentation method can be used without the additional manual adjustment step for MTB quantification of primary NSCLC tumors.

Consistency of metabolic tumor volume of non-small-cell lung cancer primary tumor measured using 18F-FDG PET/CT at two different tracer uptake times.

ObjectivesThe objective of this study was to test the hypothesis that the metabolic tumor volume (MTV) of primary non-small-cell lung cancer is not sensitive to differences in 18F-fluorodeoxyglucose (18F-FDG) uptake time, and to compare this consistency of MTV measurements with that of standardized uptake value (SUV) and total lesion glycolysis (TLG). MethodsUnder Institutional Review Board approval, 134 consecutive patients with histologically proven non-small-cell lung cancer underwent 18F-FDG PET/computed tomography scanning at about 1 h (early) and 2 h (delayed) after intravenous injection of 18F-FDG. MTV, SUV, and TLG of the primary tumor were all measured. Student’s t-test and Wilcoxon’s signed-rank test for paired data were used to compare MTV, SUV, and TLG between the two scans. The intraclass correlation coefficient (ICC) was used to assess agreement in PET parameters between the two scans and between the measurements made by two observers. ResultsMTV was not significantly different (P=0.17) between the two scans. However, SUVmax, SUVmean, SUVpeak, and TLG increased significantly from the early to the delayed scans (P<0.0001 for all). The median percentage change between the two scans in MTV (1.65%) was smaller than in SUVmax (11.76%), SUVmean(10.57%), SUVpeak(13.51%), and TLG (14.34%); the ICC of MTV (0.996) was greater than that of SUVmax (0.933), SUVmean (0.952), SUVpeak (0.928), and TLG (0.982). Interobserver agreement between the two radiologists was excellent for MTV, SUV, and TLG on both scans (ICC: 0.934–0.999). ConclusionMTV is not sensitive to common clinical variations in 18F-FDG uptake time, its consistency is greater than that of SUVmax, SUVmean, SUVpeak, and TLG, and it has excellent interobserver agreement.

Silent aspiration in patients with exacerbation of COPD

Patients with chronic obstructive pulmonary disease (COPD) are susceptible to aspiration, probably due to discoordination between breathing and swallowing, cricopharyngeal muscle dysfunction, and changes in lung volume [1, 2]. Terada et al. [3] found a significantly higher prevalence of an abnormal swallowing reflex in patients with COPD than in healthy controls. Shaker et al. [4] found that patients with acute exacerbation of COPD (AECOPD) have a higher risk of aspiration. In this cross-sectional study, using the technetium-99m–sulfur colloid (99mTc-SC) salivary scintigraphy method that is believed to be more sensitive than techniques using in previous studies, the prevalence and risk factors of silent aspiration in hospitalised AECOPD patients was studied. Radionuclide imaging of silent aspiration http://ow.ly/s3pz300hiSN