Der Einfluß von 5-Fluoro-uracil auf die Länge der DNS-Synthesephase menschlicher Tumoren

Summary

In synchronization therapy the length of the S-period plays an important role because irradiation must be applied at the right time after inhibition of the DNA synthesis (with Fluoro-uracil). With different methods (mitotic index, cytophotometric studies and double labelling with ³H- and ¹⁴C-thymidine) we investigated the length of S-period in human tumors and the influence of FU-infusion on the duration of the DNA-synthesis phase.

The following results have been found: 1. The length of the S-phase spreads from 8–16 h. 2. An infusion with FU lasting 12 h, has no influence on the duration of the DNA-synthesis phase in the same tumor tissue.

At the moment we are considering whether any consequences to the synchronization therapy used up to this time, have to be drawn from these results.