Primary central nervous system lymphomas in immunocompromised patients require specific response criteria

Area of Science:

• Neuro-oncology
• Radiology
• Immunology

Background:

• Primary central nervous system lymphomas (PCNSL) are associated with immunosuppression.
• Immunocompromised patients with PCNSL exhibit distinct radiological features.
• Current MRI response criteria may not accurately assess PCNSL in this population.

Purpose of the Study:

• To describe the radiological evolution of treated PCNSL in immunocompromised patients.
• To propose adapted MRI response criteria for immunocompromised individuals with PCNSL.

Main Methods:

• Multicenter retrospective study.
• Inclusion of adult immunocompromised patients with newly diagnosed PCNSL.
• Evaluation of MRI data at baseline, intermediate, end-of-treatment, and follow-up.

Main Results:

• At baseline, most PCNSL lesions were necrotic and some hemorrhagic.
• Post-treatment, many patients showed persistent contrast enhancement and large necrotic lesions.
• These concerning radiological features were not associated with poorer outcomes and diminished over time.

Conclusions:

• End-of-treatment MRI in immunocompromised patients with PCNSL may show alarming features like persistent enhancement.
• These findings are often linked to lesion necrosis and hemorrhage, not necessarily a worse prognosis.
• Adapted MRI response criteria are proposed for this specific patient group.