Effects of dose and scheduling on growth delay of the Lewis lung carcinoma produced by the perfluorochemical emulsion, Fluosol-DA.

The perfluorochemical emulsion, Fluosol-DA, combined with breathing a 95% oxygen/5% carbon dioxide atmosphere enhances the response of several rodent tumors. B6D2F1/J mice bearing Lewis lung tumors, measuring 50-100 mm3 were treated with 4, 8 and 12 ml/kg of Fluosol-DA intravenously each morning. Three Gy fractions twice per day were employed and carbogen breathing was maintained 1 hr prior to and during each X ray treatment. The dose modifying factors were 1.42 +/- 0.16 at 4 ml/kg, 1.85 +/- 0.23 at 8 ml/kg, and 2.17 +/- 0.34 at 12 ml/kg. In a second experiment, a single dose of Fluosol-DA (12 ml/kg) was administered on day 1 to B6D2F1/J male mice, bearing established subcutaneous Lewis lung tumors, as described above. X rays were delivered in 2, 3, or 4 Gy fractions once per day for five days. The dose modifying effect was 2.60 +/- 0.54. The effect of this treatment program was the same as that seen with single dose radiation. These experiments demonstrate that Fluosol-DA need not be administered with every fraction to produce an improved treatment outcome with fractionated X rays.