FREQUENCY OF TUMOR-RELATED VASCULATURE IN PRIMARY CNS LYMPHOMA ON ROUTINE MRI

Abstract Primary central nervous system lymphoma (PCNSL) is known to express angiogenic factors and can have spontaneous or biopsy-related hemorrhage. Radiographically, PCNSL is characterized by homogenous enhancement and diffusion restriction, as well as T2/FLAIR abnormalities. A higher frequency of tumor-related vessels has been reported in gliomas compared to brain metastases, but this has not been assessed in PCNSL. We used a clinical database of patients with PCNSL treated at the University of Washington and reviewed pretreatment MRIs for 48 patients treated between 2014-2021 for whom susceptibility sequences were available. Median age at diagnosis was 64 years (range 35-90 years). Patients were 27.1% male and 72.9% female. Each lesion was scored by at least two independent reviewers for the presence of a prominent vessel located either centrally or eccentrically, and for the presence of hemorrhage. Lesions that were scored differently by the two reviewers (n=26) were then scored by a third independent reviewer. In several cases the findings were felt to be indeterminate. Lesions were considered measurable if they were greater than 5 mm in two perpendicular planes, and a total of 93 measurable lesions were categorized. Prominent vessels were seen in 56/93 (60.2%) lesions, with 26/56 (46.4%) being central and 30/56 (55.4%) being eccentric. An additional 7/93 (7.5%) lesions were indeterminate. Hemorrhage was seen in 11/93 (11.8%) lesions. We conclude that prominent vessels can be seen in a majority of PCNSL lesions on standard MRI.