A study on the dosage of chemotherapies according to body surface area or lean mass 

In oncology, chemotherapies are normally dosed according to body surface area. However, there is no evidence that organ functions, the distribution volume of drugs or their degradation in the liver and kidneys are directly linked to body surface area. On the other hand, the relationship between body composition and tolerability of therapy in specific cancers is very well established. Body composition and its changes in the course of therapy play an essential role in the prediction of therapy tolerance and prognosis. However, body composition is not taken into account in the traditional dose calculation. Muscle mass, fat mass and bone mass are relevant parameters. The decrease in muscle mass, for example, provides good indications for a worse clinical outcome and a poorer quality of life. Accurate measurement of body composition and a strategy to maintain muscle mass could help reduce side effects of therapy and improve survival. DXA measurement is the current gold standard for measuring body composition. However, it is not practical in every clinic. In practice, the analysis of images from computer tomograms (CT), which are usually already available from the therapy, has become established. A method for dosing chemotherapy based on body composition (fat and muscle mass) derived from CT images is promising. A standardized procedure must be developed for this and tested in different patient groups (ethnicity, cancer type and stage, etc.). Furthermore, the dosage of chemotherapy based on body surface area versus body lean mass is being investigated with regard to therapy side effects.