Body Surface Area (BSA)

Abstract

The body surface area (BSA) is a mathematical relationship, expressed in m 2 , with the result obtained from the height and weight of the patient. This measure is used in order to obtain a more comprehensive parameter of the patient's weight, to define more appropriate dosage. The BSA is widely used in oncology, and the majority of protocols specify the dose in m 2. The DuBois formula is probably the most used in oncology. The nomogram is a more precise way to calculate the body surface area in pediatrics. A nomogram is needed for body calculation of neonates. The formula by Meban (BSA cm 2 = 6.4954 × weight (g) 0.562 × crown-heel length (cm) 0.320) is possibly the best to estimate the body surface of newborns, followed by the Mosteller (√[(height in cm × weight in kg)/3600]) formula; however, the Boyd and Dubois formulas are not recommended for surface estimation of newborns for treatment , due to either overestimation or underestimation. A study compared Meban, Mosteller, Boyd, and Dubois formulas with a BSA-Mean (an arithmetic mean of these four formulas). The Meban formula is most similar to the BSA-Mean formula, with a mathematically perfect correlation and the least dissimilarity using Euclidean distance, followed by the Mosteller formula. The estimations by both Boyd and Dubois show about a 5% deviation above and below the BSA-Mean formula, respectively, with a consistent dissimilarity using Euclidean distance regardless of the same goodness of fit. The degree of deviation increases with weight and decreases with height [2, 3] (Fig. 15.1). DuBois Formula: BSA (m 2) = Height (cm)× Weight (kg) 3,600 Fig. 15.1 Body surface area (BSA) according to Dubois formula [2]