Lean tissue imaging: a new era for nutritional assessment and intervention.

Body composition refers to the amount of fat and lean tissues in our body; it is a science that looks beyond a unit of body weight, accounting for the proportion of different tissues and its relationship to health. Although body weight and body mass index are well-known indexes of health status, most researchers agree that they are rather inaccurate measures, especially for elderly individuals and those patients with specific clinical conditions. The emerging use of imaging techniques such as dual energy x-ray absorptiometry, computerized tomography, magnetic resonance imaging, and ultrasound imaging in the clinical setting have highlighted the importance of lean soft tissue (LST) as an independent predictor of morbidity and mortality. It is clear from emerging studies that body composition health will be vital in treatment decisions, prognostic outcomes, and quality of life in several nonclinical and clinical states. This review explores the methodologies and the emerging value of imaging techniques in the assessment of body composition, focusing on the value of LST to predict nutrition status.

Assessment of nutritional status in cancer--the relationship between body composition and pharmacokinetics.

Several nutritional assessment tools have been used in oncology settings to monitor nutritional status and its associated prognostic significance. Body composition is fundamental for the assessment of nutritional status. Recently, the use of accurate and precise body composition tools has significantly added to the value of nutritional assessment in this clinical setting. Computerized tomography (CT) is an example of a technique which provides state-of-the-art assessment of body composition. With use of CT images, a great variability in body composition of cancer patients has been identified even in people with identical body weight or body mass index. Severe muscle depletion (sarcopenia) has emerged as a prevalent body composition phenotype which is predictive of poor functional status, shorter time to tumor progression, shorter survival, and higher incidence of dose-limiting toxicity. Variability in body composition of cancer patients may be a source of disparities in the metabolism of cytotoxic agents. Future clinical trials investigating dose reductions in patients with sarcopenia and dose-escalating studies based on pre-treatment body composition assessment have the potential to alter cancer treatment paradigms.

Nutritional status, cachexia and survival in patients with advanced colorectal carcinoma. Different assessment criteria for nutritional status provide unequal results.

BACKGROUND & AIMS: Different nutrition assessment tools and definitions are proposed for cancer-associated malnutrition and wasting (cachexia). We studied the associations between these assessments and overall survival in stage IV colorectal carcinoma patients. METHODS: Anthropometric measures, energy intake, biochemical variables, nutritional risk screening, assessment of malnutrition, cachexia and body composition from computed tomography images were analysed, in 77 patients from Norway and Canada. Results were dichotomized into presence or absence of nutritional risk, malnutrition, cachexia and sarcopenia (low muscle mass) and associated with survival. RESULTS: Overall, 22% up to 55% of the patients had cachexia according to different cachexia criteria: 34% were malnourished, 42% were at nutritional risk, and 39% were sarcopenic. Forty-four percent of the patients did not meet criteria for any of these conditions. Patients with cachexia defined by Cancer Cachexia Study Group (CCSG) had shorter survival in an unadjusted analysis, [Hazard ratio (HR) = 2.43; 95% confidence interval (CI) 1.32-4.47; P = 0.005]. After adjusting for nation, age and gender, cachexia (HR = 2.26; CI 1.18-4.32; P = 0.014) and malnutrition (HR = 1.83; CI 1.06-3.13; P = 0.029) remained significant predictors of survival. CONCLUSIONS: Nutritional depletion in up to 55% of the patients was found. The lack of concordance between the results obtained by different assessment criteria was obvious. CCSG's cachexia score was the best prognostic factor for overall survival.