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At least 19 records

Historical Changes in Histological Diagnosis of Lung Cancer

Background: Histological classification of lung cancer is essential for investigations of carcinogenesis and treatment selection. We examined the temporal changes of lung cancer histological subtypes. Methods: Lung cancer cases diagnosed in the Life Span Study cohort between 1958 and 1999 were collected from tumor registries (TR), mainly consisting of population-based cancer registries. A total of 1,025 cases were histologically reviewed according to the World Health Organization 2004 Classification by a panel of pathologists (PP). Sensitivity and specificity of diagnoses in TR were calculated, assuming that the diagnosis by PP was the gold standard. Results: Sensitivity and specificity were 0.91 and 0.92 for adenocarcinoma (AD), respectively, and 0.92 and 0.94, respectively, for squamous cell carcinoma (SQ). They were similar for AD and SQ throughout the observation period. For small cell carcinoma (SM), sensitivity was low until about 1980 (0.47 in 1958–1969, and 0.61 in 1970–1979) and then became higher thereafter (0.98 in 1980–1989, and 0.95 in 1990–1999), whereas specificity was high during the whole period (range 0.99 to 1.00). Among 45 cases that were not reported as SM in TR but diagnosed as SM by PP, 16 cases were recorded as undifferentiated carcinoma in TR. Conclusion: Diagnosis of AD and SQ of lung cancer were generally consistent between TR records and PP review, but SMs tended to be coded as other histological types until the 1970s.

60 APPLIED LIFE SCIENCES↗

Liver metastases of neuroendocrine tumors: is it possible to diagnose different histologic subtypes depending on multiphasic CT features?

Purpose: To assess and compare the multiphasic computed tomography (CT) features of neuroendocrine tumor (NET) liver metastases and to investigate the possibility to predict the histologic subtype of the primary tumor. Materials and methods: Between January 2013 and December 2017 patients with biopsy proven NET with at least one liver metastasis who underwent multiphasic CT were enrolled in this study. All cases were acquired using a standardized multiphasic liver CT protocol, arterial, portal, and hepatic venous phases were obtained. Images were retrospectively analyzed in consensus by two abdominal radiologists blinded to clinical data and histologic subtype. The size, number, and location of lesions were noted. Enhancement patterns of each lesion on arterial, portal, and hepatic venous phases were assessed. For quantitative analysis, CT attenuation of tumors, liver parenchyma, and aorta were measured using a circular region of interest (ROI) on arterial, portal, and hepatic venous phases for reflecting the blood supply of the tumor. Tumor-to-aorta and tumor-to-liver ratio were calculated in all three phases. Differences between subtypes of NET liver metastases were studied using ROC analysis of clustered data. Results: A total of 255 neuroendocrine tumor liver metastases divided into 101 (39.6%) pancreatic, 60 (23.5%) gastroenteric and 94 (36.8%) lung NET liver metastases were analyzed. Contrast enhancement of lesions was homogeneous in 78% of patients (n = 199), which was significantly more frequent in patients with pancreatic group than in those with gastroenteric origin (n = 90, 89.1% vs. n = 28, 46.7%; p < 0.001). Gastroenteric NET metastases frequently showed heterogeneous enhancement, which was significantly higher than in the other two groups (50% vs. 3% and 2%). With respect to the location of the primary tumor, the difference in enhancement patterns of the liver lesions was statistically significant (p < 0.001). Pancreatic NET metastases were mostly hyperdense on arterial images and isodense on portal and hepatic venous phase images (79.2%, n = 80). Gastroenteric NET metastases were mostly hyperdense on arterial phase images and hypodense on portal and hepatic venous phase images (n = 28, 46.7%). The most frequent pattern for lung NET metastases was hypoattenuation on all three phase images (n = 44, 46.8%). ROC analysis of clustered data revealed statistically significant differences between pancreatic NET liver metastases, gastroenteric NET liver metastases, and lung NET liver metastases in terms of tumor-to-aorta (T–A) ratio and tumor-to-liver (T–L) ratio (p < 0.001). Conclusion: We observed statistically significant differences in multiphasic CT features (enhancement pattern, T–A ratio, and T–L ratio) between histologic subtypes of NET liver metastases. As the difference in histological subtypes of NET liver metastases results in a different prognosis and different management strategy, these CT features might help to identify the primary tumor when it is not known to ensure accurate tumor staging and to provide optimal treatment.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Texture analysis of small renal cell carcinomas at MDCT for predicting relevant histologic and protein biomarkers

Purpose: To assess CT texture features of small renal cell carcinomas (≤ 4cm) for association with key pathologic features including protein biomarkers. Methods: Quantitative CT texture analysis (CTTA) of small renal cancers (≤ 4cm) was performed on non-contrast and portal venous phase abdominal MDCT scans with an ROI drawn at the largest cross-sectional diameter of the tumor using commercially available software. Texture parameters including mean pixel attenuation, the standard deviation (SD) of the pixel distribution histogram, entropy, the mean of positive pixels, the skewness (i.e., asymmetry) of the pixel histogram, kurtosis (i.e., peakness) of the pixel histogram, and the percentage of positive pixels were correlated with pathologic data from surgical resection, including histology and nuclear grade, as well as microarray analysis in a subset (n = 40) including Ki67 index, CRP, and neovascularization (CD105/CD31). Results: Portal venous phase images were available in 249 patients (105 women, 144 men; mean age, 56.7 years) with tumors ≤ 4cm (mean, median, range, ± SD; 2.66, 2.60, 0.3–4.0 ± 0.85 cm). CT texture features of standard deviation, mean of the positive pixels, and entropy of the pixel histogram were significantly associated with histologic cell type (clear vs. non-clear; p < 0.001). Entropy and mean of the positive pixels also showed an association with nuclear grade, although not statistically significant. In the microarray analysis subset, kurtosis of the pixel histogram was associated with CD105/CD31 (p = 0.05). SD also showed some association with CD 105 positivity (p = 0.02) and CAIX expression (p = 0.01). Non-contrast CT images were available in 174 patients (72 women, 102 men; mean age, 57.5 years). Although the association with histology was not as strong as on the portal venous phase, in the subset of patients with microarray data, SD was found to correlate with CRP (p = 0.08), kurtosis with CRP (p = 0.004), CD105/CD31 (p = 0.002), and with Ki 67 index (p < 0.001). Conclusion: CT texture features were significantly associated with important histopathologic features in small renal cancers. These non-invasive measures can be performed retrospectively and may provide useful information when determining follow-up and treatment of small renal cancers.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Computational 3D histological phenotyping of whole zebrafish by X-ray histotomography

Organismal phenotypes frequently involve multiple organ systems. Histology is a powerful way to detect cellular and tissue phenotypes, but is largely descriptive and subjective. To determine how synchrotron-based X-ray micro-tomography (micro-CT) can yield 3-dimensional whole-organism images suitable for quantitative histological phenotyping, we scanned whole zebrafish, a small vertebrate model with diverse tissues, at ~1 micron voxel resolutions. Micro-CT optimized for cellular characterization (histotomography) allows brain nuclei to be computationally segmented and assigned to brain regions, and cell shapes and volumes to be computed for motor neurons and red blood cells. Striking individual phenotypic variation was apparent from color maps of computed densities of brain nuclei. Unlike histology, the histotomography also allows the study of 3-dimensional structures of millimeter scale that cross multiple tissue planes. We expect the computational and visual insights into 3D cell and tissue architecture provided by histotomography to be useful for reference atlases, hypothesis generation, comprehensive organismal screens, and diagnostics.

59 BASIC BIOLOGICAL SCIENCES↗

Data augmentation and multimodal learning for predicting drug response in patient-derived xenografts from gene expressions and histology images

Patient-derived xenografts (PDXs) are an appealing platform for preclinical drug studies. A primary challenge in modeling drug response prediction (DRP) with PDXs and neural networks (NNs) is the limited number of drug response samples. We investigate multimodal neural network (MM-Net) and data augmentation for DRP in PDXs. The MM-Net learns to predict response using drug descriptors, gene expressions (GE), and histology whole-slide images (WSIs). We explore whether combining WSIs with GE improves predictions as compared with models that use GE alone. We propose two data augmentation methods which allow us training multimodal and unimodal NNs without changing architectures with a single larger dataset: 1) combine single-drug and drug-pair treatments by homogenizing drug representations, and 2) augment drug-pairs which doubles the sample size of all drug-pair samples. Unimodal NNs which use GE are compared to assess the contribution of data augmentation. The NN that uses the original and the augmented drug-pair treatments as well as single-drug treatments outperforms NNs that ignore either the augmented drug-pairs or the single-drug treatments. In assessing the multimodal learning based on the MCC metric, MM-Net outperforms all the baselines. Our results show that data augmentation and integration of histology images with GE can improve prediction performance of drug response in PDXs.

60 APPLIED LIFE SCIENCES↗

Histological Findings in Wild Rodents of the Great Basin

In the western United States, significant environmental change is expected through the combined effects of climate change, tree mortality, drought, and invasive species. Wild animals can be used as indicators of threats to populations and even entire communities by looking for histopathological changes in their tissues. This method may identify threats to wild populations quickly and more accurately than waiting to observe population declines; however, baseline data are needed for comparisons. In this work, rodents are surveyed at 5 sites in the Great Basin to record histopathological changes. Additionally, one site is next to a copper mine that was in operation for nearly 100 years. This site is compared to the other more pristine sites. Liver, lung, heart, and kidney tissues of 143 rodents from 10 species were processed and examined using standard histological methods. Thirty percent of rodents had histopathological changes. The most common histopathological changes were extramedullary hematopoiesis (11.9%), hyperplastic BALT (6.3%), and pyelitis (4.9%). Two pathogens were found: the nematode Capillaria hepatica (0.7%) and the fungus Emmonsia crescens (2.8%). The most common rodent captured, Peromyscus maniculatus (n = 116), was used to determine whether sex and mass predict histopathological changes. Body mass, not sex, was the best predictor, suggesting that heavier, older individuals should be selectively sampled if the goal is to assess potential threats to rodent populations. Data such as these can be compared to future data to assess populations and communities for effects of environmental change.

59 BASIC BIOLOGICAL SCIENCES↗

Histologic Analysis with the Newly Designed Exoskeleton Seal{sup ®} Stent-Graft in the Porcine Abdominal Aorta

Purpose: To investigate the technical feasibility of a novel exoskeleton Seal{sup ®} stent-graft and analyze early histologic changes in the porcine abdominal aorta. Materials and Methods: Six pigs received an abdominal stent-graft (Group I), and six received an iliac branch stent-graft (Group II). Groups were subdivided as follows: Group Ia, which received three bifurcated main-body stent-grafts; Group Ib, which received three bifurcated main-body stent-grafts with both iliac graft-stents; Group IIa, which received three simple uni-iliac tapered stent-grafts; and Group IIb, which received three uni-iliac tapered tapered stent-grafts with right straight limb and left branched limb. Statistical analyses were performed with the Wilcoxon signed-rank test and mixed-model regression analysis. Results: The primary technical success rate (< 24 h) was 83% because of two acute thromboses in the lumen of the stented abdominal aorta immediately after stent-graft placement. At 4 weeks, late thrombosis occurred in two pigs. Higher mean neointimal hyperplasia areas (23.5% vs. 16.2%; P = .047), neointimal hyperplasia thicknesses (545.5 μm vs. 422.2 μm; P = .001), and degrees of collagen deposition (2.71 vs. 2.33; P = .002) were observed at the bare-metal stent-graft compared with the proximal exoskeleton portion of the stent-graft, with no significant differences between the patent and occluded groups or among the four types of stent-grafts. Conclusions: The exoskeleton stent-graft demonstrates 66% of patency rate during 1-month follow-up due to four cases of thromboses; however, the endothelialization on the junction of proximal graft showed no significant differences between the patent and occluded groups. Further studies should investigate long-term outcomes with prolonged neointimal hyperplasia.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Deep learning for Alzheimer's disease: Mapping large-scale histological tau protein for neuroimaging biomarker validation

Abnormal tau inclusions are hallmarks of Alzheimer's disease and predictors of clinical decline. Several tau PET tracers are available for neurodegenerative disease research, opening avenues for molecular diagnosis in vivo. However, few have been approved for clinical use. Understanding the neurobiological basis of PET signal validation remains problematic because it requires a large-scale, voxel-to-voxel correlation between PET and (immuno) histological signals. Large dimensionality of whole human brains, tissue deformation impacting co-registration, and computing requirements to process terabytes of information preclude proper validation. We developed a computational pipeline to identify and segment particles of interest in billion-pixel digital pathology images to generate quantitative, 3D density maps. The proposed convolutional neural network for immunohistochemistry samples, IHCNet, is at the pipeline's core. We have successfully processed and immunostained over 500 slides from two whole human brains with three phospho-tau antibodies (AT100, AT8, and MC1), spanning several terabytes of images. Our artificial neural network estimated tau inclusion from brain images, which performs with ROC AUC of 0.87, 0.85, and 0.91 for AT100, AT8, and MC1, respectively. Introspection studies further assessed the ability of our trained model to learn tau-related features. We present an end-to-end pipeline to create terabytes-large 3D tau inclusion density maps co-registered to MRI as a means to facilitate validation of PET tracers.

60 APPLIED LIFE SCIENCES↗

Can MRI be used to diagnose histologic grade in T1a (< 4 cm) clear cell renal cell carcinomas?

Objective: To assess whether MRI can differentiate low-grade from high-grade T1a cc-RCC. Materials and methods: With IRB approval, 49 consecutive solid < 4 cm cc-RCC (low grade [Grade 1 or 2] N = 38, high grade [Grade 3] N = 11) with pre-operative MRI before nephrectomy were identified between 2013 and 2018. Tumor size, apparent diffusion coefficient (ADC) histogram analysis, enhancement wash-in and wash-out rates, and chemical shift signal intensity index (SI index) were assessed by a blinded radiologist. Subjectively, two blinded Radiologists also assessed for (1) microscopic fat, (2) homogeneity (5-point Likert scale), and (3) ADC signal (relative to renal cortex); discrepancies were resolved by consensus. Outcomes were studied using Chi square, multivariate analysis, logistic regression modeling, and ROC. Inter-observer agreement was assessed using Cohen’s kappa. Results: Tumor size was 24 ± 7 (13–39) mm with no association to grade (p = 0.45). Among quantitative features studied, corticomedullary phase wash-in index (p = 0.015), SI index (p = 0.137), and tenth-centile ADC (p = 0.049) were higher in low-grade tumors. 36.8% (14/38) low-grade tumors versus zero high-grade tumors demonstrated microscopic fat (p = 0.015; Kappa = 0.67). Microscopic fat was specific for low-grade disease (100.0% [71.5–100.0]) with low sensitivity (36.8% [21.8–54.6]). Other subjective features did not differ between groups (p > 0.05). A logistic regression model combining microscopic fat + wash-in index + tenth-centile-ADC yielded area under ROC curve 0.98 (Confidence Intervals 0.94–1.0) with sensitivity/specificity 87.5%/100%. Conclusion: The combination of microscopic fat, higher corticomedullary phase wash-in and higher tenth-centile ADC is highly accurate for diagnosis of low-grade disease among T1a clear cell RCC.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Insights into the histology of planarian flatworm Phagocata gracilis based on location specific, intact lipid information provided by GCIB-ToF-SIMS imaging

Planarian flatworms are known as the masters of regeneration, re-growing an entire organism from as little as 1/279th part of their body. While the proteomics of these processes has been studied extensively, the planarian lipodome remains relatively unknown. In this study we investigate the lipid profile of planarian tissue sections with imaging Time-of-Flight – Secondary-Ion-Mass-Spectrometry (ToF-SIMS). ToF-SIMS is a label-free technique capable of gathering intact, location specific lipid information on a cellular scale. Lipid identities are confirmed using LC-MS/MS. Our data shows that different organ structures within planarians have unique lipid profiles. The 22-carbon atom poly unsaturated fatty acids (PUFAs) which occur in unusually high amounts in planarians are found to be mainly located in the testes. Additionally, we observe that planarians contain various odd numbered fatty acid species that are usually found in bacteria, localized in the reproductive and ectodermal structures of the planarian. An abundance of poorly understood ether fatty acids and ether lipids were found in unique areas in planarians as well as a new, yet unidentified class of potential lipids in planarian intestines. Identifying the location of these lipids in the planarian body provides insights into their bodily functions and, in combination with knowledge about their diet and their genome, enables drawing conclusions about planarian fatty acid processing.

Angerer, Tina B.↗

Is Routine Splenectomy Justified for All Left-Sided Pancreatic Cancers? Histological Reappraisal of Splenic Hilar Lymphadenectomy

Background: Although splenectomy is recommended during resection for left-sided resectable pancreatic ductal adenocarcinoma (PDAC) to perform lymphadenectomy of station 10 (splenic hilum), no level I evidence justifies this procedure. This study aims to evaluate the rate of lymph node (LN) and contiguous involvement of the splenic hilum in resectable distal PDAC. Methods: We retrospectively reviewed all patients who underwent splenopancreatectomy for PDAC in the past 10 years. Station 10 LN were routinely isolated, and all corresponding microscopic slides were reinterpreted by a pathologist. The computed tomography (CT) results of patients with tumoral involvement of the spleen or splenic hilum by contiguity (TISOSH) and ≤ 10 mm between the tumor and spleen on pathology were blindly reviewed by two radiologists to evaluate CT for diagnosis of TISOSH. Results: We included 110 consecutive patients, including 104 with analyzable station 10 LN. The tumor was N+ in 58 (53%) patients. The median number of LN identified at station 10 was 2.0 ± 3.0. No station 10 LNs were detected in 42 (40%) patients. No patients had tumor-positive LN at station 10. TISOSH was found in nine (8%) patients, and was significantly associated with tail location (p = 0.001), tumor size (p = 0.005), and multivisceral involvement (p = 0.015). For diagnosis of TISOSH, the sensitivity and specificity of CT were respectively 89% and 95% for radiologist 1 and 89% and 100% for radiologist 2. Conclusions: Splenic preservation during resection of distal PDAC may be an option in selected patients with body tumors and no suspected splenic or splenic hilum involvement on preoperative CT.

62 RADIOLOGY AND NUCLEAR MEDICINE↗