Resumen de Evaluation of a ferret-specific formula for determining body surface area to improve chemotherapeutic dosing
Krista L. Jones, L. Abbigail, Michael T. Kearney, Anderson F. da Cunha, Daniel C. Cutler, Meredith E. Shapiro, Thomas N. Tully, Keijiro Shiomitsu
Evaluation of a ferret-specific formula for determining body surface area to improve chemotherapeutic dosing Krista L. Jones DVM, MS; L. Abbigail Granger DVM; Michael T. Kearney MS; Anderson F. da Cunha DVM, MS; Daniel C. Cutler DVM; Meredith E. Shapiro MAp Stat; Thomas N. Tully DVM, MS; Keijiro Shiomitsu BVSc Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803. (Jones, Granger, Kearney, da Cunha, Cutler, Shapiro, Tully, Shiomitsu) Dr. Jones’ present address is School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6150, Australia.
Dr. Cutler's present address is Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506.
Ms. Shapiro's present address is Covance Laboratories, 124 Owen Rd, Monona, WI 53716.
Address correspondence to Dr. Jones (kljones@ucdavis.edu).
OBJECTIVE To use CT-derived measurements to create a ferret-specific formula for body surface area (BSA) to improve chemotherapeutic dosing.
ANIMALS 25 adult ferrets (19 live and 6 cadavers).
PROCEDURES Live subjects were weighed, and body measurements were obtained by each of 3 observers while ferrets were awake and anesthetized. Computed tomography was performed, and a 3-D surface model was constructed with open-source imaging software, from which BSA was estimated. The CT-derived values were compared with BSA calculated on the basis of the traditional tape method for 6 cadavers. To further validate CT analysis software, 11 geometric shapes were scanned and their CT-derived values compared with those calculated directly via geometric formulas. Agreement between methods of surface area estimation was assessed with linear regression. Ferret-specific formulas for BSA were determined with nonlinear regression models.
RESULTS Repeatability among the 3 observers was good for all measurements, but some measurements differed significantly between awake and anesthetized ferrets. Excellent agreement was found between measured versus CT-derived surface area of shapes, traditional tape– versus CT-derived BSA of ferret cadavers, and CT-derived BSA of cadavers with and without monitoring equipment. All surface area formulas performed relatively similarly.
CONCLUSIONS AND CLINICAL RELEVANCE CT-derived BSA measurements of ferrets obtained via open-source imaging software were reliable. On the basis of study results, the recommended formula for BSA in ferrets would be 9.94 × (body weight)2/3; however, this represented a relatively minor difference from the feline-derived formula currently used by most practitioners and would result in little practical change in drug doses.
