[What technique for what tumor? Ethical and methodological issues: cervical cancer]

[Strategy for technical evaluation in radiation oncology: methodological and ethical aspects, the French society for radiation oncology's opinion]

Evidence-based medicine is a paradigm founded on a hierarchy of research design, accepted as a dogma. Applied to radiation oncology, and specifically to radiotherapy technical comparisons, evidence-based medicine implies methodological and ethical problems. The concept of "incremental" evolution and the dosimetric evidence are proposed as an acceptable alternative to comparative clinical trials if total dose, time, fractionation, and target volumes are not modified. For other situations, either randomized comparative trials or observational studies are needed. When randomized comparative trials are not possible, observational studies, whose validity can be enhanced by appropriate methodology, must be considered as a valid method.