Imaging definitions
| Variable | Score | Score Description |
|---|---|---|
| Necrosis | 0 no, 1 yes | Necrosis is defined as a region within the tumor that does not enhance or shows markedly diminished enhancement, is high on T2W and proton density images, is low on T1W images, and has an irregular border |
| Enhancement | 0 no, 1 yes | Contrast enhancement is defined as having all or portions of the tumor that demonstrate significantly higher signal on the postcontrast T1W images compared to precontrast T1W images |
| Enhancing rim | 0 none, 1 thin, 2 thick, N/A | If most of the enhancing rim is thin, regular, and has homogenous enhancement, the tumor receives a score of 1. If most of the rim demonstrates nodular and/or thick enhancement, the score is 2. If there is only solid enhancement and no rim, the score is 0. The scoring is not applicable if there is no contrast enhancement |
| Enhancing margin | 0 well defined, 1 poorly defined, N/A | If most of the outside margin of the enhancement is well defined, the tumor is scored 1 The scoring is not applicable if there is no contrast enhancement |
| NEM (grade III) | 0 smooth, 1 irregular | If most of the outside nonenhancing margin of the tumor is well defined and smooth (geographic), the tumor is scored 0. If the margin is ill defined, the tumor is scored 1 |
| Solid enhancement | 0 none, 1 part, 2 all, N/A | If the enhancing portion of the tumor enhances solidly, without cystic or necrotic components, the tumor is scored 2. If there are both regions of solid enhancement as well as necrosis or central irregular nonenhancement or cyst formation, the tumor is scored 1. If the tumor demonstrates only peripheral or ring enhancement without significant portions, the tumor is scored 0. If there is no enhancement, this variable is not applicable |
| nCET | 0 no, 1 yes | Nonenhancing tumor is defined as regions of T2W hyperintensity (less than the intensity of cerebrospinal fluid, with corresponding T1W hypointensity) that are associated with mass effect and architectural distortion, including blurring of the gray-white interface |
| Edema | 0 none, 1 mild, 2 moderate/severe | If no convincing edema, as demonstrated by regions of very bright T2W signal, then a score of 0 is given. If there is clearly visible, bright T2W signal not associated with mass effect and architectural distortion (see nonenhancing tumor) and not extending more than 1 cm beyond the tumor margin, the score is 1. If there is more extensive, very bright T2W signal intensity, often following white-matter tracts and extending significantly beyond (>1 cm) the margins of the tumor, the edema is scored a 2 |
| Cyst(s) | 0 no, 1 yes | Cysts are well defined, rounded, often eccentric regions of very bright T2W signal and low T1W signal essentially matching CSF signal intensity, with very thin, regular, smooth, nonenhancing or regularly enhancing walls, possibly with thin, regular, internal septations |
| Multifocal | 0 no, 1 yes | Multifocal is defined as having at least one region of tumor, either enhancing or nonenhancing, which is not contiguous with the dominant lesion and is outside the region of signal abnormality (edema) surrounding the dominant mass |
| Satellites | 0 no, 1 yes | A satellite lesion is within the region of signal abnormality surrounding the dominant lesion but not contiguous in any part with the major tumor mass |
| Extent of resection | <20%, 20%–89%, 90%–99%, 100% | The first postoperative scan (contrast-enhanced MR imaging) was assessed for tumor residual. Presence of both enhancing and nonenhancing tumor was determined. Scans were scored 100% resection if no tumor residual was visible. Trace tumor residual <10% of the total corresponded to the 90%–99% category. If the tumor was debulked, but substantial tumor remained, a score of 20%–89% was used. If the tumor was biopsied only, then 0%–19% was used. |
| TCM | 0 no, 1 yes | |
| ECM | 0 no, 1 yes, N/A | |
| Location | Frontal, parietal, temporal, occipital, corpus callosum, thalamus | |
| Size | Unidimensional, largest diameter in millimeters | |
| Side | Left, right |
Note.—NEM indicates nonenhancing margin; nCET, noncontrast-enhancing tumor; TCM, tumor crosses midline; ECM, edema crosses midline.