Clinically relevant postoperative pancreatic fistula (CR-POPF) can significantly affect the treatment course and outcome in pancreatic cancer patients. Preoperative prediction of CR-POPF can aid the surgical decision-making process and lead to better perioperative management of patients. In this retrospective study of 108 pancreatic head resection patients, we present risk models for the prediction of CR-POPF that use combinations of preoperative computed tomography (CT)-based radiomic features, mesh-based volumes of annotated intra- and peripancreatic structures and preoperative clinical data. The risk signatures were evaluated and analysed in detail by visualising feature expression maps and by comparing significant features to the established CR-POPF risk measures. Out of the risk models that were developed in this study, the combined radiomic and clinical signature performed best with an average area under receiver operating characteristic curve (AUC) of 0.86 and a balanced accuracy score of 0.76 on validation data. The following pre-operative features showed significant correlation with outcome in this signature ( $$p < 0.05$$p<0.05 ) - texture and morphology of the healthy pancreatic segment, intensity volume histogram-based feature of the pancreatic duct segment, morphology of the combined segment, and BMI. The predictions of this pre-operative signature showed strong correlation (Spearman correlation co-efficient, $$\rho = 0.7$$ρ=0.7 ) with the intraoperative updated alternative fistula risk score (ua-FRS), which is the clinical gold standard for intraoperative CR-POPF risk stratification. These results indicate that the proposed combined radiomic and clinical signature developed solely based on preoperatively available clinical and routine imaging data can perform on par with the current state-of-the-art intraoperative models for CR-POPF risk stratification.

The statistical description of the face varies drastically with changes in pose. These variations make Face Recognition (FR) even more challenging. In this paper, four novel techniques are proposed, viz., Discrete Orthonormal Stockwell Transform (DOST), Entropy based image resizing, Denoising and Enhanced Training and Testing methodology, to improve the performance of an FR system. DOST is used for efficient Feature Extraction and Entropy based image resizing calculates the Optimum Resizing Factor (ORF) to be used. Denoising is done through a combination of Deghosting, Intensity Mapped Unsharp Masking and Anisotropic Diffusion. Pose neutralization is achieved through the enhanced Training and Testing methodology. Thus, a complete FR system for enhanced recognition performance is presented. Experimental results on four benchmark face databases, namely, CAS-PEAL R1, Color FERET, FEI and HP, illustrate the promising performance of the proposed techniques for face recognition

Robot-assisted minimally invasive esophagectomy (RAMIE) is a complex procedure that may benefit from workflow analysis for context-aware assistance and surgical data science. This study aimed to model the RAMIE workflow, validate the applicability of the obtained workflow model in the operating room (OR) and retrospectively assess its generalizability across three academic centers using video data and automated workflow analysis with machine learning (ML). A RAMIE workflow model was developed based on currently available literature, participatory OR observation, and expert interviews. This model was formalized to be included into a checklist tool to document the workflow live in the OR. To investigate generalizability of the workflow model, the surgical phases of 36 RAMIE videos from three different academic hospitals were retrospectively annotated. Based on this data set, a ML model was trained and tested within a six-fold cross validation. Ten surgical phases with 60 underlying steps were identified for RAMIE. The applicability of the workflow model was validated with live documentation in the OR. Multicenter video annotations revealed significant inter-institutional differences in the duration of all ten RAMIE phases. The ML model for automatic phase recognition showed an accuracy of 0.872 ± 0.091 and an f1-score of 0.872 ± 0.082 over all videos. The center with the best performing videos achieved a mean accuracy of 0.919 ± 0.036. The RAMIE workflow was successfully modeled and validated in a retrospective multicenter setting. Despite high variability in phase duration between surgical centers, ML-based phase recognition achieved highly promising results.

Background: The risk of postoperative pancreatic fistula (POPF), one of the most dreaded complications after pancreatic surgery, can be predicted from preoperative imaging and tabular clinical routine data. However, existing studies suffer from limited clinical applicability due to a need for manual data annotation and a lack of external validation. We propose AutoFRS (automated fistula risk score software), an externally validated end-to-end prediction tool for POPF risk stratification based on multimodal preoperative data. Materials and methods: We trained AutoFRS on preoperative contrast-enhanced computed tomography imaging and clinical data from 108 patients undergoing pancreatic head resection and validated it on an external cohort of 61 patients. Prediction performance was assessed using the area under the receiver operating characteristic curve (AUC) and balanced accuracy. In addition, model performance was compared to the updated alternative fistula risk score (ua-FRS), the current clinical gold standard method for intraoperative POPF risk stratification. Results: AutoFRS achieved an AUC of 0.81 and a balanced accuracy of 0.72 in internal validation and an AUC of 0.79 and a balanced accuracy of 0.70 in external validation. In a patient subset with documented intraoperative POPF risk factors, AutoFRS (AUC: 0.84 ± 0.05) performed on par with the uaFRS (AUC: 0.85 ± 0.06). The AutoFRS web application facilitates annotation-free prediction of POPF from preoperative imaging and clinical data based on the AutoFRS prediction model. Conclusion: POPF can be predicted from multimodal clinical routine data without human data annotation, automating the risk prediction process. We provide additional evidence of the clinical feasibility of preoperative POPF risk stratification and introduce a software pipeline for future prospective evaluation. Export

Graph neural networks (GNNs) are becoming increasingly popular in the medical domain for the tasks of disease classification and outcome prediction. Since patient data is not readily available as a graph, most existing methods either manually define a patient graph, or learn a latent graph based on pairwise similarities between the patients. There are also hypergraph neural network (HGNN)-based methods that were introduced recently to exploit potential higher order associations between the patients by representing them as a hypergraph. In this work, we propose a patient hypergraph network (PHGN), which has been investigated in an inductive learning setup for binary outcome prediction in oropharyngeal cancer (OPC) patients using computed tomography (CT)-based radiomic features for the first time. Additionally, the proposed model was extended to perform time-to-event analyses, and compared with GNN and baseline linear models.