Advantages

Indirect method Safe Practical and objective tool Reliable Portable Easy-to-use Non-invasive Reproducible Time and cost effective technique Relatively inexpensive, when compared to more sophisticated methods like DXA, CT or MRI Requires little training to use the equipment BIA appears to show good correlations when compared with gold standard methods Validated method to assess body composition in patients with cancer Good application consistency in cancer patients Usefulness as a tool for assessing the nutritional status of patients with cancer BIA measures may serve as early indicators for improvement in nutritional and health status BIA measures can useful to evaluate and predict outcomes, such as post-operative complications BIA-derived PhA does not depend on regression equations to be calculated and as prognostic factor of patient survival BIA-derived measures (FFM, FM, body weight, BMI) are correlated with the risk of developing colon cancer and potentially other cancers BIA-derived PhA and BIVA are considered to reflect both nutritional and hydration status

Disadvantages

Does not measure the entire body, gives incomplete information Not routinely available outside the research setting More expensive than using anthropometric measures Generally considered less accurate than radiological assessment methods Evaluations should be done under the same circumstances and taking into consideration an adequate fluid balance and food intake Possible sources of error: nutrition status, physical activity, phase of the menstrual cycle, placement of electrodes, limb length, blood chemistry, altered fluid balance, edema, endocrine diseases, treatment with growth hormone, acute illness, intensive care treatment, organ transplantation, position of the body and movements during the measure, type of electrodes, use of oral contraceptives Loses accuracy when patients are in the extremes of BMI ranges (≤16 kg/m2 or ≥35 kg/m2) Regarding the hydration status, dehydration or over hydration may underestimate or overestimate LBM or FBM As a consequence of the fluid accumulation, BIA may imprecisely measure FFM or FM in persons diagnosed with BC and gynaecological cancer BIA has provided inconsistent findings, with poorer accuracy and precision in obese/oedematous individuals It has limited use in advanced cancer and BC because of the large fluid shifts that occur in these cancer cohorts and cannot distinguish tumor or lymphedema in the lean and fat tissue depots Underestimates FFM in patients with advanced cancer, compared with DXA Relies on a large number of prediction equations using linear regression to estimate body composition based on a variety of predetermined variables that may differ between different populations and were derived from healthy individuals