Schwickert H C, Stiskal M, Roberts T P, van Dijke C F, Mann J, Mühler A, Shames D M, Demsar F, Disston A, Brasch R C
Department of Radiology, University of California, San Francisco 94143, USA.
Radiology. 1996 Mar;198(3):893-8. doi: 10.1148/radiology.198.3.8628889.
To assess the effect of x rays on tumor capillary permeability with macromolecular contrast medium (MMCM)-enhanced magnetic resonance (MR) imaging.
One of paired R3230 mammary adenocarcinomas implanted in the flanks of 48 Fischer rats was treated with a single 5- or 15-Gy dose of x rays. After 1 or 3 days, MR imaging in 30 rats was performed unenhanced and enhanced with albumin-(gadolinium diethylenetriaminepentaacetic acid)30 (0.02 mmol gadolinium per kilogram body weight). Signal intensity enhancement was analyzed to estimate fractional blood volume and permeability-surface area product (PS). In 18 irradiated rats, 2.5 mg/kg cisplatin was injected intravenously, and fractional tumor platinum concentrations were measured spectrometrically.
MR imaging showed highest capillary permeability 1 day after 15 Gy (PS 110% above control [P<.001]); PS was elevated 57% 1 day after 5 Gy and 63% 3 days after 15 Gy (P<.05). The largest mean tumor platinum fraction occurred 1 day after 15 Gy: 48% versus 20% (control)(P<.05).
Transient irradiation-induced increase in tumor capillary permeability to cisplatin can be quantified with MMCM-enhanced MR imaging.
