Use of the Response Assessment in Neuro-Oncology (RANO) criteria in clinical trials and clinical practice

The RANO-HGG criteria attempts to address this issue by including increase in nonenhancing disease in the definition of progression (Table 2) (3). Because of the difficulties in quantifying nonenhancing disease progression, the RANO-HGG criteria suggests that any qualitative increase in nonenhancing disease constitutes progression. [...]this component of the RANO-HGG criteria is often omitted from immunotherapy trials. The exceptions are patients who develop new areas of enhancement outside of the radiation field (beyond the high-dose region or 80% iso-dose line) or if there is unequivocal evidence of viable tumor on histopathologic sampling. Because of the difficulty in differentiating pseudoprogression from true progression there is the suggestion that the first postradiation MRI, rather than the postoperative MRI, should be used as the baseline scan (18). Since BM are generally spherical, 1D measurement was used.