RANO criteria (response assessment)

What it is

RANO (Response Assessment in Neuro-Oncology) criteria are standardized guidelines for assessing how a glioma responds to treatment based on imaging and clinical factors. They define categories such as progression, response, and stable disease consistently and account for treatment-related effects like pseudoprogression and pseudoresponse.

Understanding RANO criteria (response assessment)

Assessing whether a glioma is responding, stable, or progressing is essential but can be complicated by treatment effects that distort imaging. RANO criteria provide a consistent framework for making these judgments — considering changes in the enhancing and non-enhancing tumor, the use of steroids, and the person's clinical status — so that response is assessed reliably and comparably. Importantly, RANO incorporates the recognition that early apparent growth may be pseudoprogression and that improvement on anti-angiogenic drugs may be pseudoresponse, helping avoid misinterpretation. Standardized criteria are especially important in clinical trials (to measure whether treatments work) and also guide everyday clinical decisions. There are versions tailored to different situations (such as low-grade gliomas). Understanding RANO criteria in gliomas clarifies how treatment response is assessed in a standardized, reliable way.

Why it matters

Understanding RANO criteria helps patients and families see how treatment response is assessed consistently — using standardized guidelines that account for tricky treatment effects, ensuring reliable evaluation in care and trials.