Table 1 Criteria used for the definition of RN in our cohort
From: Stereotactic radiotherapy for brain metastases: predictive factors of radionecrosis
Criteria | Description of RN |
|---|---|
Radiological criteria | The suspected lesions must develop within the radiation fields of a high dose hypofractionated SRT At standard MRI, typical findings include central hypo-signal and peripheral enhancement (contrast-enhancing necrotic lesions) on T1-weighted post-contrast sequence and hypersignal (edema) on T2-weighted sequences An increase of the volume of the tumor followed by shrinkage on serial imaging without anticancer treatment is in favor of RN. RN can also be stable during the follow-up |
Pathological criteria | Typical patterns include hypocellular zones of necrosis and fibrinous exudates with degenerative or dystrophic changes in the vasculature, with telangiectasia, hyaline thickening of vessels, fibrinoid necrosis including intravascular thrombosis responsible for an increase of vascular permeability. Dystrophic calcifications can be associated |