Response assessment challenges in clinical trials of gliomas.

Accurate, reproducible criteria for determining tumor response and progression after therapy are critical for optimal patient care and effective evaluation of novel therapeutic agents. Currently, the most widely used criteria for determining treatment response in gliomas is based on two-dimensional tumor measurements using neuroimaging studies (Macdonald criteria). In recent years, the limitation of these criteria, which only address the contrast-enhancing component of the tumor, have become increasingly apparent. This review discusses challenges that have emerged in assessing response in patients with gliomas and approaches being introduced to address them.