Current status and future challenges in cerebral blood flow mapping in intracranial tumors

CBF studies have been applied in patients with cranial tumors using XenonCT in order to evaluate the blood flow of both the tumor and the peritumoral brain tissue. The histology included mostly meningiomas or gliomas, less frequently neurinomas or metastases. Blood flow was determined in tumor tissue (TBF), peritumoral areas (PTBF) and cerebral hemispheres (hCBF). The CBF was compared to normative CBF values. In supratentorial tumors characteristical blood flow patterns were found according to the histology. PTBF was usually lower in edematous tissue than in normal brain tissue. TBF in malignant gliomas revealed a heterogeneous pattern with a central core of low flow and a peripheral zone with high flow. Global CBF values in patients with malignant gliomas were lower than in controls. Meningiomas showed significantly higher blood flow compared to gliomas or neurinomas. In some cases with large cerebellopontine angle tumors a reduction in brain stem blood flow was detected. In cavernous sinus tumors with carotid artery compression CBF and cerebrovascular reserve capacity was not impaired. These findings indicate that tumor induced alterations in cerebral circulation can be detected by CBF mapping. This diagnostic tool offers a further insight into perfusion related tumor pathophysiology and may thereby optimize individual neurooncological treatment strategies.