## 7 Advanced Human Body Measurement Techniques  
Recently, new measures of human body shape have been investigated that can provide additional information regarding morphological variations between individuals that cannot be obtained using traditional measures [80]. These measures of body shape have been shown to improve predictions of both the amount and distribution of fat within the human torso [81]. Derived indices--such as \(BMI\) and the waist-hip ratio (WHR)--are the primary method used to conduct clinical and population-level diagnostics of disease risk [82; 83], estimate body composition [84; 85; 86] and prescribe drug dosages, as in the case of BSA. These derived indices provide simple proxies of fat distribution and body shape, which can be easily obtained and interpreted by practitioners and patients. However, they are also considered a relatively unsophisticated approach to assessing body composition and health risk, reducing the complexity of human form down to a single one-dimensional value. Contemporary studies instead use more direct imaging approaches, such as magnetic resonance imaging (MRI) or computed tomography (CT) scanning to assess fat distribution [87; 88]. Despite their high accuracy, MRI and CT are not ideal for routine practice due to their high cost and harmful radiation exposure, making anthropometry the most practical solution.  
More sophisticated measures of body shape could surpass the use of body girths in obesity assessment and health monitoring, providing finer morphological distinctions in body characteristics [80; 52; 77]. The reason for this being that shape measures can identify scale-invariant variations in external human form [89] and complement existing anthropometrics when estimating body composition [81; 90]. Modern three-dimensional (3D) imaging systems have been used increasingly to investigate new measures of body shape [77; 90; 91; 92], and novel body shape indices, such as the surface-based body shape index (SBSI) [93]. Recently, researchers have used 3D imaging devices to assess the validity of existing BSA estimation formulae, as well as suggest improvements to parameters within these formulae [16; 46; 51; 94]. These studies reported the excellent reliability of 3D-imaging-derived BSA measurements and demonstrated the inaccuracies of existing BSA estimation formulae. However, none of these previous studies investigated the use of 3D imagingtechnology to calculate BSA and subsequent chemotherapy dosages in practice compared to existing BSA estimation formulae. Therefore, future studies that investigate how alterations in dosage relate to error in BSA measurement to inform the future development of improved dose calculation methods are needed. Previously, instrumented booth 3D imaging devices have been too large and expensive to be feasibly used in practice, typically costing more than USD 100,000 and measuring approximately 2.0 m in width and 3.0 m in height. However, recent developments in low-cost, smartphone-based systems that can acquire 3D imaging data have led to increased accessibility of this technology [95]. For example, Size Stream LLC has developed a smartphone-based application, which enables 3D imaging data to be collected anywhere, with no hardware installation requirements or additional costs above that of the price of a standard smartphone [96]. Further research investigating the use of advanced body measures within chemotherapy dosing must ensure that any measurement device is quick and easy-to-use, compact and low-cost to enable all practitioners to acquire this information without relying on expensive, non-portable 3D imaging devices. Advanced body measurement techniques using modern digital technology, such as smartphone-based 3D imaging devices, enables the surface area of the entire body, or of individual body segments to be measured from a single image, offering a potentially viable alternative method of calculating chemotherapy dosing.