Distribution of Radiola beIed l-(4-Amino-2-methyl-5-pyrimidinyl)methyl-3-(2- chloroethyl)-3-nitrosourea Hydrochloride in Rat Brain Tumor: Intraarterial versus Intravenous Administration1

To assess the rationale of ¡ntraarterial (i.a.) l-(4-amino-2-methyl-5pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea chemotherapy, dis tribution of 14C-labeled l-(4-amino-2-methyl-5-pyrirnidinyl)methyl-3(2-chloroethyl)-3-nitrosourea in rat glioma was studied after i.a. or i.v. infusion. Immediately after infusion, the tumor located in the hemisphere of intracarotid infusion received 4.6-fold higher radioactivity than the tumor located contralaterally to intracarotid infusion and 2.8-fold higher radio activity than i.v. infusion. The difference was kept up to 30 min after i.a. infusion. Autoradiographic observation indicated rather uniform distri bution of the tracer in the central portion of i.a. infusion. However, in the periphery of i.a. infusion, distribution of the tracer was nonhomogenous. The results indicate that i.a. l-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea chemotherapy is useful when the tumor has high blood flow and is located in the center of an infused area.