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.

A Tick Cysteine Protease Inhibitor RHcyst-1 Exhibits Antitumor Potential

“…After four days, purified RHcyst-1 protein (50 μg/mouse) was administered by intratumoral injection and the control group were received a vehicle of PBS buffer, once a week for three weeks. The length and width of the tumors were measured each day with a caliper, and the volume of the tumors was calculated using the formula: Tumor volume = (Width 2 × Length)/2 [33]. For animal ethics reasons, mice bearing tumors of 2 cm3 in size were sacrificed and recorded as dead.…”

Mast Cells in Mammary Carcinogenesis: Host or Tumor Supporters?

“…Food and water consumption and animal body weight were measured weekly using a top-loading scale (METTLER ® PM 4000; LabWrench, Midland, Canada). At the end of the experiment, body weight gain and mortality index were calculated (21,22).…”

Implementation of Human Endpoints in a Urinary Bladder Carcinogenesis Study in Rats

“…Mean water consumption for each animal was calculated as the difference between the weight of the water bottle at the beginning of the week and the weight of the water bottle at the end of the week, divided by the number of animals in the cage times the number of days (23). The following formula was used to calculate the body weight gain (%): (Final body weight-Initial body weight)/Final body weight×100 (21). Animals were daily observed and the data was weekly filled in the scoring sheet.…”

“…A major obstacle to implement humane endpoints is a general lack of biomarkers that can be used as specific indicators of disease progression (20). Although sometimes tumor burden and disease progression can be directly measured using calipers, such as in assays of mammary carcinogenesis or in assays using xenograft models were the tumor cell lines are subcutaneously implanted (21,22), many other tumors are not externally visible and consequently their growth cannot be monitored, as in the case of urinary bladder tumors.…”