This article corrects:

    In ref. 1, the following text was included on page 31:

    Because of new progression in 2008, she received PVC (procarbazine, CCNU, vinkristine) (Fig. 1C), and later cyclic TMZ, when MRI showed diffuse changes in the brainstem Cyclic TMZ was administered until June 2009.

    The correct wording for this text is as follows:

    Because of new progression in 2008, she received PVC (procarbazine, CCNU, vincristine) (Fig. 1C). Later, when MRI showed diffuse changes in her brainstem, cyclic TMZ was administered until June 2009.

    Also, a table should have been cited on page 36 in the ‘Clinical recommendations section’, in the following position:

    Clinical recommendations

    Most patients with pseudoprogression have modest or no new symptoms that correlate with the MRI changes, and the need of steroids is often stable or decreasing. Continuation of planned treatment and new imaging in 2–3 months is recommended, or sooner, if the patient deteriorates. MRI series should include axial, coronal and sagittal T1-weighted imaging, axial T2, and coronal FLAIR. Surgical exploration in a patient with suspected pseudoprogression should be avoided unless immediate diagnostic certainty is adamant. PIPG is a differential diagnosis in patients with repeated or severe epileptic seizures (Table 1).

    The missing table 1 is shown below:

    Table 1. Important aspects in the differential diagnosis of pseudoprogression, tumor recurrence, radiation necrosis, and peri-ictal pseudoprogression in patients with high-grade gliomas
     PseudoprogressionTumor recurrenceRadiation necrosisPeri-ictal pseudoprogression
    Temporal occurrenceWithin 3 (–6) months after therapy (radiotherapy, combined therapy)At any time3–12 months after therapy, but sometimes after several yearsRelated to clinical seizure activity
    Clinical correlates

    2/3 no new symptoms, steroid need often stable

    1/3 increased symptoms

    Gradual clinical worsening and steroid needClinical worsening

    Frequent and/or severe seizures

    More frequent in irradiated patients

    MRI findingsIncreased contrast enhancement and/or edema in the tumor area, resolves with timeIncreased contrast enhancement and increased edema in or outside the irradiated areasIncreased enhancement in irradiated area only, stabilizes with timeFocal cortical and/or leptomeningeal enhancing lesions, resolves with seizure control
    Histologic verification (biopsy)Usually not required, but sometimes of relevanceRequired in some casesRarely required, unless diagnostic uncertaintyShould be avoided
    RecommendationsContinue treatment, repeat MRI, consider increase in steroid doses if symptomaticDiscontinue current therapy, consider other options; palliative careIncrease steroid doses, repeat MRIOptimalize antiepileptic treatment, repeat MRI

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