Differentiation of Peri-Ictal Pseudoprogression from Tumor

Recurrence in a Patient with Treated Glioma: Value of Diffusion Weighted

and Perfusion Imaging

Dr Nader Zakhari and Dr Thanh Nguyen

The Ottawa Hospital

EE-07

Disclosure

Dr Thanh Binh Nguyen has received an investigator-initiated research grant from Bayer Pharmaceutical

Purpose

Peri-ictal pseudoprogression “PIPG”

= Transient MR abnormalities in patients with brain tumor–related seizures that can incorrectly suggest tumor progression.

Purpose

To present the MR findings of PIPG including diffusion and perfusion imaging.

To differentiate PIPG from true tumor progression and avoid unnecessary interventions.

Case Report

Presentation: August 2013

36 year-old man

Several simple and complex partial seizures with and without generalization.

Case Report

History: February 2010 3 years earlier was diagnosed with left frontal anaplastic astrocytoma (III/IV)

Treatment (completed in 2010):

Surgery Adjuvant radiation (60 Gy in 6 weeks) Concomitant and adjuvant Temozolomide

Case Report

Management: August 2013

Admission MRI Treatment: phenytoin and levetiracetam No recurrence of seizures

Imaging findings

Baseline post-operative MR (Sept. 2012) before presentation:

Left frontal craniotomyPostoperative changesNo diffusion restriction

FLAIR DWI

Imaging findings

T1 post-contrast CBV

Postoperative changesNo concerning enhancementNo increased CBV

Baseline post-operative MR (Sept. 2012) before presentation:

Imaging findings

FLAIR

Left frontal cortical swelling and hyperintensity

MRI Aug. 2013 at presentation:

Imaging findings

Left frontal cortical diffusion restriction

DWI & ADC

MRI Aug. 2013 at presentation:

Imaging findings

T1 post-contrast

T1 pre-contrast

Enhancement

Left frontal cortical/leptomeningeal enhancement

MRI Aug. 2013 at presentation:

Imaging findings

Dynamic Susceptibility Contrast Perfusion

Cortical increased CBV in the left frontal region

MRI Aug. 2013 at presentation:

Imaging findings

FLAIR

Resolution of swelling and signal abnormality

MRI follow up Oct. 2013:

Imaging findings

DWI and ADC

MRI follow up Oct. 2013:

Resolution of diffusion restriction

Imaging findings

Enhancement

MRI follow up Oct. 2013:

T1 pre-contrast

T1 post-contrast

Resolution of leptomeningeal/cortical enhancement

Imaging findings

Dynamic Susceptibility Contrast Perfusion

Resolution of increased CBV in the left frontal region

MRI follow up Oct. 2013:

Summary

Peri-ictal pseudoprogression “PIPG”1

Seizure-associated MR abnormalities in the surgical bed mimicking tumor progression

Rare entity ( <1%) Survivors of glioma who have undergone radiotherapy

Average 10 years after treatment

Summary

Previously described seizure-associated MRI abnormalities: 2-4

Cortical swellingCortical T2/FLAIR hyperintensityCortical diffusion restriction Cortical and/or leptomeningeal enhancement Increased cerebral blood volume (rCBV)

Summary

Mechanism of seizure-associated MRI abnormalities: 2-5

metabolism of seizing neurons Compensatory blood flow: perfusion metabolism > blood flow:

Local tissue hypoxia diffusion restrictionAnaerobic metabolism: lactate & Pco2:

vascular dilatation & leakiness disruption of blood brain barrier and enhancement

Summary

PIPG TUMOR RECURRENCE

Distribution Predominantly cortical Predominantly subcortical

Reversibility Transient & reversible Progressive

Diffusion restriction

Cortical Not limited to the cortexNot a constant feature

Contrast enhancement

Cortical &/or focal leptomeningeal

Predominantly subcorticalLeptomeningeal enhancement

more common diffuse

Perfusion Increased Increased

References1. Rheims S, Ricard D, van den Bent M et al. Peri-ictal

pseudoprogression in patients with brain tumor. Neuro Oncol. Jul 2011; 13(7): 775–782

2. Rath JJG, Smits M, Ducray F, van den Bent M. J. Increased rCBV in status epilepticus. J Neurol 2012;259:1746–1748

3. Kim JA, Chung JI, Yoon PH et al. Transient MR Signal Changes in Patients with Generalized Tonicoclonic Seizure or Status Epilepticus: Periictal Diffusion-weighted Imaging. AJNR Am J Neuroradiol 2001; 22:1149–1160.

4. Szabo K, Poepel A, Pohlmann-Eden B et al. Diffusion-weighted and perfusion MRI demonstrates parenchymal changes in complex partial status epilepticus. Brain (2005), 128, 1369–1376.

5. Canasa N, Breiac P, Soares P et al. The electroclinical-imagiological spectrum and long-term outcome of transient periictal MRI abnormalities. Epilepsy Research 2010;91:240—252

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