Table 2:
New criteria for response assessment of high-grade gliomasa
| Standardization of Imaging Definitions |
| Measurable and nonmeasurable disease for contrast-enhancing lesions |
| Measurable disease: 2D contrast-enhancing lesions with clearly defined margins, with 2 perpendicular diameters of at least 10 mm, visible on ≥2 axial sections that are preferably, at most, 5 mm apart |
| Nonmeasurable disease: either unidimensionally measurable lesions, masses with margins not clearly defined, or lesions with maximal perpendicular diameters <10 mm |
| Multiple lesions |
| A minimum of 2 (maximum of 5) largest lesions should be measured on the basis of the sum of products of perpendicular diameters |
| Enhancing lesions are considered target lesions for evaluation of response |
| Definition of progression |
| ≥25% increase in sum of products of perpendicular diameters of enhancing lesions compared with smallest tumor measurement at reference scan (if no decrease) or best response after initiation of therapy |
| Significant increase in T2/FLAIR nonenhancing lesion compared with reference scan or best response |
| Clear progression of nonmeasurable disease |
| Clear clinical deterioration |
| Reference MR imaging |
| Criteria for determining progression are dependent on the time from initial chemotherapy |
| If obtaining the reference MR image immediately postoperative, MR imaging in the first 12 weeks may represent |
| pseudoprogression and pseudoresponse |
| If obtaining the reference scan after that initial 12-week period, then it reduces the likelihood of confusion with pseudoprogression |
| Take note of enhancement outside radiation field; it may indicate progression (Fig 6) |
| A reference MR image should ideally be obtained within 24–48 hours after surgery and no later than 72 hours after surgery, to avoid interpretation of postoperative changes as residual enhancing disease |
a
Based on Wen et al 2010.67