Acta Neurochir (2017) 159:2405–2408
Differentiating radionecrosis from tumour recurrence is a major issue in neuro-oncology. Conventional imaging is far from being validated as an alternative to histologicalassessment.
We report the case of a patient operated on for suspected recurrence of brain metastasis 9 months after cyberknife radiosurgery. While magnetic resonance imaging showed strong enhancement of the lesion, intraoperative contrast-enhanced ultrasonography (CEUS) surprisingly did
not—different from what is expected for brain metastases.
Histopathological examination documented radionecrosis. For the first time, we describe radionecrosis with CEUS; further investigation is needed; however, the lack of enhancement could represent an important hallmark in differential diagnosis with neoplastic tissue.