Retrospective examination of pseudoprogression in IDH mutant gliomas

Ethan A Wetzel; Matthew J Farrell; Blaine S C Eldred; Vicki Liu; Ishan Saha; Serendipity Zapanta Rinonos; Terry Prins; Tie Li; Minsong Cao; John Hegde; Tania Kaprealian; Negar Khanlou; Linda M Liau; Phioanh Leia Nghiemphu; Timothy Francis Cloughesy; Robert A Chong; Benjamin M Ellingson; Albert Lai

doi:10.1093/noajnl/vdad028

Retrospective examination of pseudoprogression in IDH mutant gliomas

Neurooncol Adv. 2023 Mar 18;5(1):vdad028. doi: 10.1093/noajnl/vdad028. eCollection 2023 Jan-Dec.

Authors

Ethan A Wetzel¹, Matthew J Farrell², Blaine S C Eldred¹, Vicki Liu¹, Ishan Saha¹, Serendipity Zapanta Rinonos¹, Terry Prins¹, Tie Li¹, Minsong Cao², John Hegde², Tania Kaprealian², Negar Khanlou³, Linda M Liau⁴, Phioanh Leia Nghiemphu¹, Timothy Francis Cloughesy¹, Robert A Chong¹, Benjamin M Ellingson^{4

5}, Albert Lai¹

Affiliations

¹ Department of Neurology, University of California, Los Angeles, Los Angeles, CA, USA.
² Department of Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, USA.
³ Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
⁴ Department of Neurosurgery, University of California, Los Angeles, Los Angeles, CA, USA.
⁵ Department of Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, USA.

Abstract

Background: Tumor surveillance of isocitrate dehydrogenase (IDH) mutant gliomas is accomplished via serial contrast MRI. When new contrast enhancement (CEnew) is detected during postsurgical surveillance, clinicians must assess whether CEnew indicates pseudoprogression (PsP) or tumor progression (TP). PsP has been better studied in IDH wild-type glioblastoma but has not been well characterized in IDH mutant gliomas. We conducted a retrospective study evaluating the incidence, predictors, natural history, and survival of PsP patients in a large cohort of IDH mutant glioma patients treated at a single institution.

Methods: We identified 587 IDH mutant glioma patients treated at UCLA. We directly inspected MRI images and radiology reports to identify CEnew and categorized CEnew into TP or PsP using MRI or histopathology.

Results: Fifty-six percent of patients developed CEnew (326/587); of these, 92/326 patients (28% of CEnew; 16% of all) developed PsP and 179/326 (55%) developed TP. All PsP patients had prior radiation, chemotherapy, or chemoradiotherapy. PsP was associated with longer overall survival (OS) versus TP patients and similar OS versus no CEnew. PsP differs from TP based on earlier time of onset (median 5.8 vs 17.4 months from treatment, P < .0001) and MRI features that include punctate enhancement and enhancement location.

Conclusion: PsP patients represented 28% of CEnew patients and 16% of all patients; PsP patients demonstrated superior outcomes to TP patients, and equivalent survival to patients without CEnew. PsP persists for <1 year, occurs after treatment, and differs from TP based on time of onset and radiographic features. Poor outcomes after CEnew are driven by TP.

Keywords: IDH1/2; contrast enhancement; glioma; pseudoprogression; radiation necrosis.

Abstract

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