Active bone marrow segmentation based on computed tomography imaging in anal cancer patients: A machine-learning-based proof of concept.

PURPOSE: Different methods are available to identify haematopoietically active bone marrow (ActBM). However, their use can be challenging for radiotherapy routine treatments, since they require specific equipment and dedicated time. A machine learning (ML) approach, based on radiomic features as inputs to three different classifiers, was applied to computed tomography (CT) images to identify haematopoietically active bone marrow in anal cancer patients. METHODS: A total of 40 patients was assigned to the construction set (training set + test set). Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography (18FDG-PET) images were used to detect the active part of the pelvic bone marrow (ActPBM) and stored as ground-truth for three subregions: iliac, lower pelvis and lumbosacral bone marrow (ActIBM, ActLPBM, ActLSBM). Three parameters were used for the correspondence analyses between 18FDG-PET and ML classifiers: DICE index, Precision and Recall. RESULTS: For the 40-patient cohort, median values [min; max] of the Dice index were 0.69 [0.20; 0.84], 0.76 [0.25; 0.89], and 0.36 [0.15; 0.67] for ActIBM, ActLSBM, and ActLPBM, respectively. The Precision/Recall (P/R) ratio median value for the ActLPBM structure was 0.59 [0.20; 1.84] (over segmentation), while for the other two subregions the P/R ratio median has values of 1.249 [0.43; 4.15] for ActIBM and 1.093 [0.24; 1.91] for ActLSBM (under segmentation). CONCLUSION: A satisfactory degree of overlap compared to 18FDG-PET was found for 2 out of the 3 subregions within pelvic bones. Further optimization and generalization of the process is required before clinical implementation.

Analysis of surgical delay and its influence on morbimortality in patients with hip fracture. / Análisis de las causas de demora quirúrgica y su influencia en la morbimortalidad de los pacientes con fractura de cadera.

INTRODUCTION: Surgical delay for hip fractures (>48h) has been associated with greater adverse clinical events. However, the influence of the reasons for delay is unclear. The objective of this study was to analyse the causes of surgical delay and its influence on morbidity and mortality, in patients with hip fracture with indication for surgical treatment. MATERIAL AND METHOD: A cohort of 376 hip fractures operated at our centre between January 2012 and December 2016 was retrospectively reviewed. Patients younger than 65 years and pathological fractures were excluded. Of these, 280 patients were operated with a surgical delay>48h. The causes of the delay were: antiaggregation (AG), anticoagulation (AC), medical reasons (MM), preoperative cardiac tests or administrative/organizational reasons. Surgical wound complications, general complications and mortality were compared. RESULTS: There was a greater proportion of surgical wound complications in the AC group (P=.063). Patients in the AG, AC, and MM groups had higher rates of general associated complications (P=.3). Seven point fifty-one percent of the patients included died one year after surgery. The mortality rate at one year was highest in the MM group (P=.005). CONCLUSION: The mortality rate was statistically significantly higher in the MM group. When comparing results, patients in the AG, AC, and MM groups presented higher rates of general complications.