Comments on the review article «Cerebral radiation necrosis: Diagnostic challenge and clinical management»

Dear Editor:

I read with great interest the review article by Eisele and Dietrich¹ on the exciting, little-understood subject of cerebral radiation necrosis secondary to surgical treatment for brain tumours.

The mechanisms involved in the physiopathogenesis of the condition are largely unknown; they may even vary with respect to the factors cited by authors as determinants: type of radiation, dose, treatment volume, and fractionation schedule. I would also like to add the type of supplementary treatment administered, which is normally chemotherapy, as mentioned in the review article.

The adjuvant chemotherapy used was different in each of the various studies establishing neuroradiological criteria over the past 3 decades.^2–4 It is therefore admirable that other authors⁵ have attempted to compare the degree of correlation or concordance according to these criteria, in order to assess the type of progression, and suggest adding hyperintensity to FLAIR sequences to make contrast-enhanced sequences even more useful for assessing subsequent clinical worsening. We should also highlight that they compare treatments with the same adjuvant chemotherapy, in this case bevacizumab + irinotecan, which confers validity to the study and its results. Their main contribution was the inclusion of FLAIR sequence to the RECIST criteria (RECIST-F).

Based on the recruitment of a large number of patients from the AVAglio trial and after failing to demonstrate the usefulness of antiangiogenic therapy as a first line treatment after surgery in patients with glioblastoma, other authors also establish criteria to assess the response to this therapy and for this to be done uniformly.⁶

Our understanding of neuroradiology is expanding in parallel to the different surgical treatments and chemotherapies for patients with brain tumours. Although our gold standard continues to be anatomical pathology complemented by genetic/molecular techniques, advanced magnetic resonance imaging makes categorisation of tumours quicker and more reliable, which provides clarity in decision-making regarding these patients.