New MR perfusion features in primary central nervous system lymphomas: pattern and prognostic impact.

Abstract

Some MR perfusion features predict overall survival (OS) and progression-free survival (PFS) in glioblastomas. Prognostic value of MR perfusion in primary CNS lymphomas (PCNSL) remains unexplored being the aim of this investigation. We retrospectively analyzed 3Tesla dynamic susceptibility contrast MR perfusion in 37 pre-surgical PCNSL for normalized regional cerebral blood volume rCBVmean and rCBVmax and for a PCNSL-typical shoulder-like increase of the time-signal intensity curve ("TSIC-shoulder"), indicating moderate vessel permeability. These MR perfusion features, tumor and edema size, number of lesions and patient characteristics were correlated with OS and PFS. Only patient's age was prognostic for OS (p=0.0037) and PFS (p=0.0088). 23 PCNSL had the TSIC-shoulder, a middle-sized diameter (39.5±10.8mm), volume (15.7±11.3ml), peritumoral edema (23±8.7mm) and moderately increased rCBVmean and rCBVmax (1.7±0.5; 3.9±1.2). Seven PCSNL with the TSIC-shoulder presented a sun-like pattern ("rCBV-sun") with a rim of marginally high rCBV. These unifocal PCNSL were larger (43±11.2mm; 25.62±19.2ml), with more peritumoral edema (32.8±7.6mm) and lower CBVmean (0.8±0.3) and rCBVmax (2.2±0.7), compared to the remaining six multifocal PCNSL without the TSIC-shoulder (26.3±8.3mm; 4.7±4ml; 16.3±6.4mm; 2.4±1.6; 4.4±2.3). Only patient age was predictive for OS and PFS of PCNSL; MR perfusion parameters and features were not. Most PCNSL revealed the TSIC-shoulder, moderate size, peritumoral edema and rCBV increase. However, larger, solitary PCNSL additionally had a rCBV-sun pattern and more edema, maybe due to a centrifugal vessel proliferation, whereas smaller, multifocal PCNSL contain apparently more concentrated and less permeable blood vessels represented by higher rCBV, no TSIC-shoulder and less edema.