[The importance of fractioning in radiotherapy for Hodgkin's disease (author' transl)].

The dose considered necessary to adequately treat Hodgkin's disease lesions is 4,000 rads in four weeks. The different possibilities of fractioning this dose may have a direct effect upon late tolerance to this type of irradiation. On the one hand, the authors determined the single equivalent doses for each type of fractioning according to ELLIS, COHEN and J. DUTREIX, and secondly calculated the number of sessions necessary in order to come as close as possible to the dose equivalent to 5 times 200 rads. For example, it emerges that 15 sessions of 250 rads, i.e. 3,750 rads, and 10 sessions of 330 rads, i.e. 3300 rads are equivalent to 20 times 200 rads, i.e. 4,000 rads in 26 days for healthy tissue. The authors finally established for each reference system a graph making it possible to determine according to the type of fractioning and for a spread of 26 days the total dose necessary to obtain the same effects as 4,000 rads delivered in 20 sessions of 200 rads.