A method of embolizing an area of treatment includes providing a composition that includes a radiopaque, non-biodegradable, water-insoluble iodinated benzyl ether of poly(vinyl alcohol) consisting of a poly(vinyl alcohol) (PVA) having covalently grafted thereon iodinated benzyl groups comprising from 1 to 4 iodine atoms per benzyl group as the only substituents wherein a grafted repeating unit has formula (I)wherein n is from 1 to 4: and introducing the composition into the area of treatment.