title: Estimation of rat mammary tumor volume using caliper and ultrasonography measurements.
abstract: Mammary tumors similar to those observed in women can be induced in rats by intraperitoneal administration of N-methyl-N-nitrosourea. Determining tumor volume is a useful and quantitative way to monitor tumor progression. In this study, the authors measured dimensions of rat mammary tumors using a caliper and using real-time compound B-mode ultrasonography. They then used different formulas to calculate tumor volume from these tumor measurements and compared the calculated tumor volumes with the real tumor volume to identify the formulas that gave the most accurate volume calculations. They found that caliper and ultrasonography measurements were significantly correlated but that tumor volumes calculated using different formulas varied substantially. Mammary tumors seemed to take on an oblate spheroid geometry. The most accurate volume calculations were obtained using the formula V = (W(2) × L)/2 for caliper measurements and the formula V = (4/3) × π × (L/2) × (L/2) × (D/2) for ultrasonography measurements, where V is tumor volume, W is tumor width, L is tumor length and D is tumor depth.
authors.affiliation: Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Faustino-Rocha
authors.forename: Paula A
authors.initials: PA
authors.lastname: Oliveira
authors.forename: Jacinta
authors.initials: J
authors.lastname: Pinho-Oliveira
authors.forename: Catarina
authors.initials: C
authors.lastname: Teixeira-Guedes
authors.forename: Ruben
authors.initials: R
authors.lastname: Soares-Maia
authors.forename: Rui Gil
authors.initials: RG
authors.lastname: da Costa
authors.forename: Bruno
authors.initials: B
authors.lastname: Colaço
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Pires
authors.forename: Jorge
authors.initials: J
authors.lastname: Colaço
authors.forename: Rita
authors.initials: R
authors.lastname: Ferreira
authors.forename: Mário
authors.initials: M
authors.lastname: Ginja
mesh_terms: D000818:Animals; D005260:Female; D015674:Mammary Neoplasms, Animal / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000473:pathology*; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000473:pathology*; D008770:Methylnitrosourea / Q000633:toxicity; D010808:Physical Examination / Q000295:instrumentation / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D047368:Tumor Burden; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods*
chemical_list: D008770:Methylnitrosourea