ABSTRACT
PURPOSE: The purpose of our study is to validate the robustness and accuracy of consensus contour in 2-deoxy-2-[ 18 F]fluoro-D-glucose ( 18 F-FDG) PET radiomic features. METHODS: 225 nasopharyngeal carcinoma (NPC) and 13 extended cardio-torso (XCAT) simulated data were enrolled. All segmentation were performed with four segmentation methods under two different initial masks, respectively. Consensus contour (ConSeg) was then developed using the majority vote rule. 107 radiomic features were extracted by Pyradiomics based on segmentation and the intraclass correlation coefficient (ICC) was calculated for each feature between masks or among segmentation, respectively. In XCAT ICC between segmentation and simulated ground truth were also calculated to access the accuracy. RESULTS: ICC varied with the dataset, segmentation method, initial mask and feature type. ConSeg presented higher ICC for radiomic features in robustness tests and similar ICC in accuracy tests, compared with the average of four segmentation results. Higher ICC were also generally observed in irregular initial masks compared with rectangular masks in both robustness and accuracy tests. Furthermore, 19 features (17.76%) had ICC ≥ 0.75 in both robustness and accuracy tests for any of the segmentation methods or initial masks. The dataset was observed to have a large impact on the correlation relationships between radiomic features, but not the segmentation method or initial mask. CONCLUSIONS: The consensus contour combined with irregular initial mask could improve the robustness and accuracy in radiomic analysis to some extent. The correlation relationships between radiomic features and feature clusters largely depended on the dataset, but not segmentation method or initial mask.
ABSTRACT
PURPOSE: The aim of this study is to explore the robustness and accuracy of consensus contours with 225 nasopharyngeal carcinoma (NPC) clinical cases and 13 extended cardio-torso simulated lung tumors (XCAT) based on 2-deoxy-2-[[Formula: see text]F]fluoro-D-glucose ([Formula: see text]F-FDG) PET imaging. METHODS: Primary tumor segmentation was performed with two different initial masks on 225 NPC [Formula: see text]F-FDG PET datasets and 13 XCAT simulations using methods of automatic segmentation with active contour, affinity propagation (AP), contrast-oriented thresholding (ST), and 41% maximum tumor value (41MAX), respectively. Consensus contours (ConSeg) were subsequently generated based on the majority vote rule. The metabolically active tumor volume (MATV), relative volume error (RE), Dice similarity coefficient (DSC) and their respective test-retest (TRT) metrics between different masks were adopted to analyze the results quantitatively. The nonparametric Friedman and post hoc Wilcoxon tests with Bonferroni adjustment for multiple comparisons were performed with [Formula: see text] 0.05 considered to be significant. RESULTS: AP presented the highest variability for MATV in different masks, and ConSeg presented much better TRT performances in MATV compared with AP, and slightly poorer TRT in MATV compared with ST or 41MAXin most cases. Similar trends were also found in RE and DSC with the simulated data. The average of four segmentation results (AveSeg) showed better or comparable results in accuracy for most cases with respect to ConSeg. AP, AveSeg and ConSeg presented better RE and DSC in irregular masks as compared with rectangle masks. Additionally, all methods underestimated the tumour boundaries in relation to the ground truth for XCAT including respiratory motion. CONCLUSIONS: The consensus method could be a robust approach to alleviate segmentation variabilities, but did not seem to improve the accuracy of segmentation results on average. Irregular initial masks might be at least in some cases attributable to mitigate the segmentation variability as well.
ABSTRACT
We aimed to investigate the safety and efficacy of XINSORB bioresorbable sirolimus-eluting scaffold in porcine model. XINSORB scaffolds and metallic Firebird2™ stents were randomly implanted into minipigs' coronary arteries. Angiography, optical coherent tomography (OCT) and histopathological analyses were performed at post-procedure and 14-, 28-, 90-, 180-day follow-up. Thirty-two minipigs were enrolled. Eight XINSORB scaffolds and 8 Firebird2 stents were examined at each time point. Quantitative coronary angiography showed that in-scaffold late luminal loss (LLL) of XINSORB scaffold was 0.26 ± 0.13, 0.50 ± 0.16, 0.88 ± 0.29 and 0.43 ± 0.24 mm at 14-, 28, 90-, and 180-day follow-up respectively, and the corresponding diameter stenosis (DS) was 7.3 ± 4.7, 12.0 ± 9.5, 22.1 ± 8.0, and 16.0 ± 9.5%. Neither in-scaffold LLL nor DS of XINSORB scaffold was significantly different in comparison with Firebird2 stent. No difference of luminal area, device area, neointimal hyperplasia, and area stenosis was detected between two devices under OCT. Scaffold area of XINSORB remained steady through the observation. Histopathology revealed the similar findings. The greatest late recoil of XINSORB scaffold was about 4.12% at 90-day follow-up, which was comparable to Firebird2 stent. Both devices showed low injury or inflammation of vessel wall. XINSORB scaffold showed early neointimal coverage on struts within 28 days under scanning electron microscopy. XINSORB scaffold suppressed neointimal hyperplasia as effectively as Firebird2 did without obvious late device recoil during the 180 days follow-up. It is feasible to carry out clinical trial to investigate the safety and efficacy of XINSORB scaffold for patients with coronary artery diseases.