Highly efficient DNA incorporation of intratumourally injected [125I]iododeoxyuridine under thymidine synthesis blocking in human glioblastoma xenografts.

Intratumoural (i.t.) injection of radio-iododeoxyuridine (IdUrd), a thymidine (dThd) analogue, is envisaged for targeted Auger electron- or beta-radiation therapy of glioblastoma.

Preclinical Auger and gamma radiation dosimetry for fluorodeoxyuridine-enhanced tumour proliferation scintigraphy with [123I]iododeoxyuridine.

Animal experiments have shown that short blocking of thymidine (dThd) synthesis with fluorodeoxyuridine (FdUrd) results in significantly increased DNA incorporation of [(125)I]iododeoxyuridine ([(125)I]IdUrd) in tumour and rapidly cycling tissues. Based on these results, we give an Auger and gamma radiation dosimetry estimate for a scintigraphy study in glioblastoma patients using [(123)I]IdUrd. The Auger radiation dosimetry calculated for patients is based on measurement of DNA-incorporated [(125)I]IdUrd in rapidly dividing tissues in nude mice xenografted with human glioblastoma.