Does retrospective clinical empiricism face the challenge of evidence-based trials in radiotherapy?

In the present paper author makes an attempt to answer to the question whether this house believes in that the retrospective radiotherapy have had a major impact on the progress in radiotherapy or rather randomized clinical trials (RCTs). Among many retrospective studies there are deliberately selected those which have provided significant and paramount progress in radiotherapy, and they are discussed in details. On the other hand, analyses of the RCTs are focused not only on their clinical benefits, but also on some uncertainties and pitfalls. An average local tumor control (LTC) estimates may often lead to misleading conclusions, because despite precise randomization, large genetic and molecular heterogeneities often impacted the results. Therefore, the author discusses advantages of the hierarchical clustering taxonomy, which allows to select specific genetic and molecular patterns, which significantly correlate with optimal LTC benefit, instead of an average end points. Finally, the author concludes that this house should believe in both, retrospective and randomized trials, but of the highest quality and clinical implications.