[Optimal posology in the neoplastic treatment (author's transl)]

It is known that a single very large dose of cytotoxic agent administered at once does not result in the same biological consequences as those exerted in the cases where the same dose of the same treatment is distributed with uniformity along a wide interval of time. Moreover its is also clear that at least in some cases, at least with some forms of therapy, at least for some ephemeral time, a beneficial effect may be achieved actually, to some extent at least. In order to achieve reliable indications concerning the optimal time distribution of the antineoplastic treatment however a mathematical model is needed where a realistic balance is drawn for the benefits and harmful outcomes of any form of cancer management. For this purpose a formal representation is introduced in the present paper, that provides a summary description of all processes taking place within the "system" consisting of a population of neoplastic cells and of its natural host under any form of cytotoxic treatment applied with any time-dependent intensity phi (t). The behaviour of the system is depicted in a deterministic way by four linear ordinary differential equations containing ten scalar parameters of 1: demographic, 2: cytokinetic, 3: toxicologic, and 4: clinical meaning.