Monitoring early response of experimental brain tumors to therapy using diffusion magnetic resonance imaging.

摘要: Quantitative magnetic resonance imaging was performed to evaluate water diffusion and relaxation times, T1 T2, as potential therapeutic response indicators for brain tumors using the intracranial 9L tumor model. Measurements were localized a column that intersected contralateral repeated at 2-day intervals before following single injection of 1,3-bis(2-chloroethyl)-1-nitrosourea (13.3 mg/kg). Tumor growth measured T2-weighted determine volumetric doubling time (Td) (Td = 64 +/- 13 h, mean SD, n 16) after 75 9 4) treatment during exponential regrowth. Apparent coefficient untreated independent volume or time, whereas times increased early growth. Diffusion displayed strongest effect regression by 55% 6-8 days treatment. Changes in also significant with increases 16% 27% T2. returned pretreatment levels 12 Histological examination supports model observed increase reflects an extracellular space Furthermore, subsequent apparent decrease is result viable cells repopulate this rate dependent on surviving cell fraction recurrent time. Serial measurements allowed determination log kill 1.0 0.3 (n 4). These results suggest are sensitive therapy-induced changes cellular structure may provide noninvasive indicator efficacy.