Semi-automatic segmentation and surface reconstruction of computed tomography images by using rotoscoping and warping techniques

Background: Quick and large-scale segmentation along with three-dimensional (3D) reconstruction is necessary to make precise 3D musculoskeletal models for surface anatomy education, palpation training, medical communication, morphology research, and virtual surgery simulation. However, automatic segmentation of the skin and muscles remain undeveloped. Materials and methods: Therefore, in this study, we developed workflows for semi-automatic segmentation and surface reconstruction, using rotoscoping and warping techniques. Results: The techniques were applied to multi detector computed tomography images, which were optimised to quickly generate surface models of the skin and the anatomical structures underlying the fat tissue. Conclusions: The workflows developed in this study are expected to enable researchers to create segmented images and optimised surface models from any set of serially sectioned images quickly and conveniently. Moreover, these optimised surface models can easily be modified for further application or educational use

Segmentación de hueso, músculo y grasa en volúmenes TAC mediante relajación convexa

La segmentación de tejido óseo, graso y muscular en volúmenes TAC es de interés especial para cirujanos y radiólogos en el diagnóstico de algunas enfermedades y en planificación quirúrgica. Estos tejidos son muy difíciles de delinear debido a la presencia de múltiples y diferentes estructuras y a la similitud de valores de Hounsfield con los órganos circundantes. En este artículo se muestra un algoritmo automático para implementar la segmentación de hueso, músculo y tejido adiposo. La segmentación se lleva a cabo minimizando una función de energía mediante relajación convexa. En trabajos previos con esta técnica solo se habían considerado dos etiquetas (hueso y músculo) y los métodos tenían grandes problemas para segmentar con precisión el músculo esquelético debido a la presencia de órganos internos con valores Hounsfield muy similares a los del tejido muscular. En este trabajo se ha incluído el conocimiento previo sobre la distribución del músculo esquelético en los volúmenes de TAC abdominal, torácico y pelvis mediante la inclusión de una transformación de distancia binaria en el cálculo de los términos de coste. Para evaluar el rendimiento del algoritmo se ha utilizado una base de datos pública y se han obtenido diferentes métricas, como DICE, Jaccard, sensibilidad y exactitud para evaluar el rendimiento del algoritmo. La técnica se ha comparado con una implementación anterior de dos etiquetas, con técnicas de level-sets y con umbralización. El algoritmo propuesto superó a los otros métodos en todas las métricas consideradas.Ministerio de Economía y Competitividad DPI2016- 81103-

Skeletal muscle measures and physical function in older adults with cancer: sarcopenia or myopenia?

BACKGROUND: Skeletal muscle loss, commonly known as sarcopenia, is highly prevalent in older adults and linked with adverse outcomes in cancer, yet the definition and role of sarcopenia remains uncertain. The aim of this study was to examine the association of Computerized Tomography (CT) assessed skeletal muscle measures with physical function in older adults with cancer. RESULTS: CTs for 185 patients were available. Median age 73 (IQR 68-76) and 56.5% female. After controlling for sex and BMI, we found no evidence that SMI was associated with physical function impairments. Both SMD and SMG were associated physical function impairments and higher values were associated with decreased limitations in instrumental activities of daily living (RR 0.84 [CI 0.73-0.96] and 0.94 [CI 0.89-0.99], respectively), climbing stairs (RR 0.84 [CI 0.76-0.94] and 0.91 [CI 0.87-0.96]), walking 1 block (RR 0.77 [CI 0.67-0.90] and 0.91 [CI 0.85-0.97]), and prolonged Timed Up and Go (RR 0.83 [CI 0.75-0.92] and 0.92 [CI 0.88-0.96]). MATERIALS AND METHODS: Using the Carolina Senior Registry, we identified patients with CT imaging performed within 60 days +/- of baseline geriatric assessment (GA). Skeletal muscle area and density (SMD) were analyzed from L3 lumbar segments. Muscle area and height (m2) were used to calculate skeletal muscle index (SMI). Skeletal Muscle Gauge (SMG) was created by multiplying SMI x SMD. CONCLUSIONS: Skeletal muscle mass as assessed from CT imaging was not associated with physical function impairments. Skeletal muscle radiodensity was more associated with physical function and may aid in identifying older adults at risk for functional impairments

Fully-automated Body Composition Analysis in Routine CT Imaging Using 3D Semantic Segmentation Convolutional Neural Networks

Body tissue composition is a long-known biomarker with high diagnostic and prognostic value in cardiovascular, oncological and orthopaedic diseases, but also in rehabilitation medicine or drug dosage. In this study, the aim was to develop a fully automated, reproducible and quantitative 3D volumetry of body tissue composition from standard CT examinations of the abdomen in order to be able to offer such valuable biomarkers as part of routine clinical imaging. Therefore an in-house dataset of 40 CTs for training and 10 CTs for testing were fully annotated on every fifth axial slice with five different semantic body regions: abdominal cavity, bones, muscle, subcutaneous tissue, and thoracic cavity. Multi-resolution U-Net 3D neural networks were employed for segmenting these body regions, followed by subclassifying adipose tissue and muscle using known hounsfield unit limits. The S{\o}rensen Dice scores averaged over all semantic regions was 0.9553 and the intra-class correlation coefficients for subclassified tissues were above 0.99. Our results show that fully-automated body composition analysis on routine CT imaging can provide stable biomarkers across the whole abdomen and not just on L3 slices, which is historically the reference location for analysing body composition in the clinical routine

Body Composition as a Predictor of Toxicity in Patients Receiving Anthracycline and Taxane–Based Chemotherapy for Early-Stage Breast Cancer

Poor body composition metrics (BCM) are associated with inferior cancer outcomes; however, in early breast cancer (EBC) there is a paucity of evidence regarding BCM’s impact on toxicities. This study investigates associations between BCM and treatment-related toxicity in EBC patients receiving anthracyclines-taxane based chemotherapy

Skeletal Muscle Measures as Predictors of Toxicity, Hospitalization, and Survival in Patients with Metastatic Breast Cancer Receiving Taxane-Based Chemotherapy

Severe skeletal muscle (SM) loss (sarcopenia), is associated with poor cancer outcomes including reduced survival and increased toxicity. This study investigates SM measures in metastatic breast cancer (MBC) patients receiving first line taxane-based chemotherapy and evaluates associations with treatment toxicity and other outcomes

Impact of body composition on outcomes from anti-PD1 +/- anti-CTLA-4 treatment in melanoma.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have transformed treatment for melanoma, but identifying reliable biomarkers of response and effective modifiable lifestyle factors has been challenging. Obesity has been correlated with improved responses to ICI, although the association of body composition measures (muscle, fat, etc) with outcomes remains unknown. METHODS: We performed body composition analysis using Slice-o-matic software on pretreatment CT scans to quantify skeletal muscle index (SMI=skeletal muscle area/height2), skeletal muscle density (SMD), skeletal muscle gauge (SMG=SMI × SMD), and total adipose tissue index (TATI=subcutaneous adipose tissue area + visceral adipose tissue area/height2) of each patient at the third lumbar vertebrae. We then correlated these measures to response, progression-free survival (PFS), overall survival (OS), and toxicity. RESULTS: Among 287 patients treated with ICI, body mass index was not associated with clinical benefit or toxicity. In univariable analyses, patients with sarcopenic obesity had inferior PFS (HR 1.4, p=0.04). On multivariable analyses, high TATI was associated with inferior PFS (HR 1.7, p=0.04), which was particularly strong in women (HR 2.1, p=0.03). Patients with intermediate TATI and high SMG had the best outcomes, whereas those with low SMG/high TATI had inferior PFS and OS (p=0.02 for both PFS and OS). CONCLUSIONS: Body composition analysis identified several features that correlated with improved clinical outcomes, although the associations were modest. As with other studies, we identified sex-specific associations that warrant further study

Survivorship in immune therapy: Assessing toxicities, body composition and health-related quality of life among long-term survivors treated with antibodies to programmed death-1 receptor and its ligand.

AIM: Antibodies to programmed death-1 receptor and its ligand (anti-PD-1/PD-L1) produce durable responses in many cancers. However, the long-term effects of anti-PD-1/PD-L1 blockade are not well defined. We identified the toxicities, health outcomes and health-related quality of life (HRQoL) amongst long-term survivors treated with anti-PD-1/PD-L1. METHODS: We assessed 217 patients who received anti-PD-1/PD-L1 for melanoma, renal cell carcinoma or non-small-cell lung carcinoma between 2009 and 2017, with survival greater than two years after treatment. Patient and tumour characteristics, immune-related adverse events (irAEs), cardiometabolic parameters (glucose, blood pressure, body mass index [BMI]), body composition (using automated body composition analyser, computed tomography and Slice-o-matic software) and HRQoL outcomes were tracked. RESULTS: Among the included patients, most were men (70.3%) and at anti-PD-1/PD-L1 initiation had an average age of 61.0 years and median BMI of 28.5. Median overall survival was not reached; 33 (15.2%) died during the follow-up primarily from progressive cancer (n = 28). At the last follow-up, most patients Eastern Cooperative Oncology Group performance status was 0 (38%) or 1 (41%). There was no difference in blood pressure, glucose or BMI from baseline to two years after treatment initiation. Body composition showed increased adiposity (p = 0.05), skeletal muscle mass (p = 0.03) and skeletal muscle gauge (p = 0.04). We observed chronic irAEs at the last follow-up including hypothyroidism (10.6%), arthritis (3.2%), adrenal insufficiency (3.2%) and neuropathy (2.8%). New diagnoses of type 2 diabetes (6.5%) and hypertension (6.0%) were observed, with uncertain relationship to anti-PD-1/PD-L1. Patient-reported outcomes compared favourably with cancer and general populations, although younger age (p = 0.003) and need for subsequent therapy (p = 0.03) were associated with worse HRQoL outcomes. CONCLUSION: Durable responses to anti-PD-1/PD-L1 therapy and favourable HRQoL outcomes are encouraging. Chronic events may be more common than previously thought although no clear chronic adverse cardiometabolic effects were observed

The impact of low skeletal muscle mass in abdominal surgery

Although perioperative outcome in transplant and surgical oncology patients has greatly improved during the last decades, preoperative risk assessment remains of utmost importance to further improve outcomes and adapt patient-tailored treatment strategies. Low skeletal muscle mass is associated with increased age and disease, such as cancer and liver disease. Considering the increasing age of the population, the increasing incidence of cancer, the remaining shortage of donor livers, and the increased surgical and medical treatment options, skeletal muscle mass could be an important addition used for risk assessment. Moreover, it may be a therapeutic target to improve treatment outcomes. Therefore, the aim of this thesis was to investigate the applicability of skeletal muscle mass measurements and to define the relevance of decreased skeletal muscle mass in surgical oncology and liver transplant patients

A series of studies to identify the aetiology of aberrant body composition status in cancer and possible methods of body composition manipulation

Host body composition (BC) is associated with outcomes in colorectal cancer (CRC). Muscle and fat appear to be crucial in both disease causation and response. The aim of this thesis is to identify and understand the aetiology of deleterious changes in BC; explore the underlying immune dysfunction of the disease and ascertain whether we can arrest the process of muscle dysfunction in CRC. In Chapters 2-5, using our population data, we identify relationships between tumour, environment and host. Visceral obesity (VO) is independently associated with prognostically favourable tumour characteristics whilst myosteatosis is independently associated with an aggressive tumour phenotype and is a strong a predictor of future distant recurrence. The environment and genetic background are implicated; deprivation appears a determinant of sarcopenia and BMI whilst ethnicity determines BC status and inflammatory state. In Chapters 7-9 we identified that dendritic cell (DC) lipid status is dependent on anatomical location and is associated with BC status. Increased intracellular lipid within circulating DC is significantly associated with myosteatosis. Whilst, in response to microbial stimulation, oxidised fat content is significantly increased in DC in healthy controls compared to the CRC population. Fat scavenger receptor CD36 expression is significantly increased in the CRC DC population suggesting DC in CRC fail to respond appropriately to commensal antigens. Finally, to ascertain if we could modulate this response through intervention, we undertook a review of the literature which informed the construction of a randomised trial to identify whether using neuromuscular muscular electrical stimulation (NMES) pre- and post-operatively in rectal cancer patients could alter BC, reduce inflammation and improve outcome. Host BC and the immune response to CRC is influenced by both the tumour and host’s environment. Cellular targets exist which may moderate the immune response. Manipulating host BC by interventions such as NMES may prompt an anti-inflammatory response.Open Acces