Lack of radiosensitization in Lewis lung carcinoma and a murine plasmacytoma by MTDQ and MTDQ-DA.

MTDQ, and its watersoluble derivative MTDQ-DA, have been tested in combination with radiation using the murine plasmacytoma X5563 and the Lewis lung carcinoma. Neither of the two compounds showed any effect on the single dose radiation response as measured by tumour growth delay. In addition no effect of MTDQ-DA on the response of the X5563 plasmacytoma to fractionated radiation was observed. As a control, studies with the established hypoxic cell sensitizer Misonidazole showed that both tumours could be sensitized to radiation by that drug, in the case of Lewis lung carcinoma the use of the excision cell survival assay showed that this was due to hypoxic cell sensitization.