Dynamic susceptibility contrast perfusion MRI helps in differentiating double-expressor from non-double-expressor...

In the 2016 WHO Classification of Lymphoid Tissue Neoplasms, co-expression of MYC and BCL2 is newly designated as double expressor lymphoma. Patients with primary central nervous system lymphoma with double expressor (DE-PCNSL) have been reported to have a higher risk of recurrence and a worse prognosis than those with PCNSL without double expressor (non-DE-PCNSL). The aim of this study was to determine whether DE-PCNSL has characteristic clinical and MR imaging features compared to non-DE-PCNSL.

This study included 36 immunocompetent patients with PCNSL, including 16 with double expressor and 20 without double expressor. The enhancement pattern and the values of apparent diffusion coefficient (ADC), relative cerebral blood volume (rCBV), leakage-corrected rCBV, and K2 at enhancing lesions were compared between the DE-PCNSL and non-DE-PCNSL groups. The mean and minimum values from the ROI on ADC maps were designated as ADC_mean and ADC_min, respectively. The data of rCBV, leakage-corrected rCBV and K2 were obtained from dynamic susceptibility contrast (DSC) perfusion MRI. The Kaplan-Meier method was used to estimate progression-free survival (PFS) differences.

DE-PCNSL was significantly more common in women (12 of 16 patients, 75%) compared to non-DE-PCNSL (7 of 20 patients, 35%; P =.02). The rCBV ratio and leakage-corrected rCBV ratio were significantly lower in DE-PCNSL compared to non-DE-PCNSL (P =.02 and P =.03, respectively). There was no significant difference in the enhancement pattern and ADC_mean, ADC_min and K2 values between the two groups. DE-PCNSL tended to have a shorter PFS than non-DE-PCNSL, although the difference was not significant.

rCBV and leakage-corrected rCBV may help differentiate double-expressor from non-double-expressor subtypes in PCNSL.