[18F]FDG PET-MRI provides survival biomarkers in primary central nervous system lymphoma in the elderly: an ancillary study from the BLOCAGE trial of the LOC network

Laura Rozenblum; Damien Galanaud; Caroline Houillier; Carole Soussain; Amandine Baptiste; Lisa Belin; Véronique Edeline; Philippe Naggara; Marine Soret; Valérie Causse-Lemercier; Lise Willems; Sylvain Choquet; Renata Ursu; Khê Hoang-Xuan; Aurélie Kas

doi:10.1007/s00259-023-06334-w

[18F]FDG PET-MRI provides survival biomarkers in primary central nervous system lymphoma in the elderly: an ancillary study from the BLOCAGE trial of the LOC network

Eur J Nucl Med Mol Imaging. 2023 Oct;50(12):3684-3696. doi: 10.1007/s00259-023-06334-w. Epub 2023 Jul 18.

Authors

Laura Rozenblum^{1

2}, Damien Galanaud^{3

4}, Caroline Houillier⁵, Carole Soussain⁶, Amandine Baptiste⁷, Lisa Belin⁷, Véronique Edeline⁸, Philippe Naggara⁹, Marine Soret^{9

3}, Valérie Causse-Lemercier⁹, Lise Willems¹⁰, Sylvain Choquet¹¹, Renata Ursu¹², Khê Hoang-Xuan^#⁵, Aurélie Kas^#^{9

3}

Affiliations

¹ Department of Nuclear Medicine, Groupe Hospitalier Pitié-Salpêtrière, APHP, Sorbonne Université, Paris, France. Laura.rozenblum@gmail.com.
² Sorbonne Université, INSERM, CNRS, Laboratoire d'Imagerie Biomédicale, LIB, Paris, France. Laura.rozenblum@gmail.com.
³ Sorbonne Université, INSERM, CNRS, Laboratoire d'Imagerie Biomédicale, LIB, Paris, France.
⁴ Department of Neuroradiology, Groupe Hospitalier Pitié-Salpêtrière, APHP, Sorbonne Université, Paris, France.
⁵ Deparrment of Neurology 2 Mazarin, APHP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau, ICM, Paris, France.
⁶ Department of Hematology, Institut Curie, Site Saint-Cloud and INSERM U932 Institut Curie, Université PSL, 75005, Paris, France.
⁷ Department of Public Health, Sorbonne Université, INSERM, Institut Pierre Louis d'Epidémiologie Et de Santé Publique, AP-HP, Hôpitaux Universitaires Pitié-Salpêtrière - Charles Foix, Paris, France.
⁸ Department of Nuclear Medicine, Institut Curie, St-Cloud, France.
⁹ Department of Nuclear Medicine, Groupe Hospitalier Pitié-Salpêtrière, APHP, Sorbonne Université, Paris, France.
¹⁰ Department of Hematology, Cochin Hospital, APHP, Paris, France.
¹¹ Department of Hematology, Groupe Hospitalier Pitié-Salpêtrière, APHP, Sorbonne Université, Paris, France.
¹² Assistance Publique-Hôpitaux de Paris (AP-HP), Hôpital Saint-Louis, Service de Neurologie, Paris, France.

^# Contributed equally.

PMID: 37462774
DOI: 10.1007/s00259-023-06334-w

Abstract

Purpose: Primary central nervous system lymphoma (PCNSL) incidence is rising among elderly patients, presenting challenges due to poor prognosis and treatment-related toxicity risks. This study explores the potential of combining [18F]fluorodeoxyglucose ([18F]FDG) PET scans and multimodal MRI for improving management in elderly patients with de novo PCNSL.

Methods: Immunocompetent patients over 60 years with de novo PCNSL were prospectively enrolled in a multicentric study between January 2016 and April 2021. Patients underwent brain [18F]FDG PET-MRI before receiving high-dose methotrexate-based chemotherapy. Relationships between extracted PET (metabolic tumor volume (MTV), sum of MTV for up to five lesions (sumMTV), metabolic imaging lymphoma aggressiveness score (MILAS)) and MRI parameters (tumor contrast-enhancement size, cerebral blood volume (CBV), cerebral blood flow (CBF), apparent diffusion coefficient (ADC)) and treatment response and outcomes were analyzed.

Results: Of 54 newly diagnosed diffuse large B-cell PCNSL patients, 52 had positive PET and MRI with highly [18F]FDG-avid and contrast-enhanced disease (SUVmax: 27.7 [22.8-36]). High [18F]FDG uptake and metabolic volume were significantly associated with low ADCmean values and high CBF at baseline. Among patients, 69% achieved an objective response at the end of induction therapy, while 17 were progressive. Higher cerebellar SUVmean and lower sumMTV at diagnosis were significant predictors of complete response: 6.4 [5.7-7.7] vs 5.4 [4.5-6.6] (p = 0.04) and 5.5 [2.1-13.3] vs 15.9 [4.2-19.5] (p = 0.01), respectively. Two-year overall survival (OS) was 71%, with a median progression-free survival (PFS) of 29.6 months and a median follow-up of 37 months. Larger tumor volumes on PET or enhanced T1-weighted MRI were significant predictors of poorer OS, while a high MILAS score at diagnosis was associated with early death (< 1 year).

Conclusion: Baseline cerebellar metabolism and sumMTV may predict response to end of chemotherapy in PCNSL. Tumor volume and MILAS at baseline are strong prognostic factors.

Keywords: Outcome analysis; PET/MRI; Primary central nervous system lymphoma; [18F]FDG.