Is a prospective trial necessary to suggest a clinical relevance?

摘要

We would like to thank Dr Chamberlain for his comments on our article and take this opportunity to respond to the issues he has raised. Radiological measurement of low-grade glioma (LGG) growth is a hot topic and clarification is required. Firstly, we wish to emphasize that although not validated by a prospective trial, our calculation method (velocity of diametric expansion [VDE]) has been successfully reproduced in other institutions. Four other studies (107, 64, 21, and 21 patients in each, independent databases) demonstrated similar ranges of VDE (median 3.5-5.5 mm/y) using the ellipsoid approximation used in our study.