Selective localization of radioiodinated alkylphosphocholine derivatives in tumors.

We have designed and synthesized two radioiodinated analogs of hexadecylphosphocholine in order to evaluate their tumor imaging potential. 12-(m[125I]iodophenyl)dodecyl phosphocholine (NM-324) and hexadecyl-2-[N,N-dimethyl-N-(m[125I]iodobenzyl)-ammonium] ethyl phosphate (NM-326) demonstrated the ability of such compounds to localize in and thereby visualize the Walker 256 tumor in rats. However, the tumor avidity of NM-324 was far superior to NM-326. In addition, NM-324 showed excellent tumor localization in athymic mice bearing subcutaneous human tumors.