Methodological aspect of epidemiological inquiries in clinical radiobiology
determination of the dose effectively delivered to all or part of an organism, especially when there is a radioactive link (localisation and percentage of each isotope, fraction of the dose over a period of time);
the delay between application of the product and its long-term effects;
interaction with the spontaneous course and various treatments;
the relative rareness of complications, the patients are treated from an average age of at least 40 years, after verification of the inefficacy of other treatments.