The consistency of neuropathological diagnoses in patients undergoing surgery for suspected recurrence of glioblastoma.

PURPOSE: Clinical factors and neuro-imaging in patients with glioblastoma who appear to progress following standard chemoradiation are unable to reliably distinguish tumor progression from pseudo-progression. As a result, surgery is commonly recommended to establish a final diagnosis. However, studies evaluating the pathologists' agreement on pathologic diagnoses in this setting have not been previously evaluated. METHODS: A hypothetical clinical history coupled with images of histological sections from 13 patients with glioblastoma who underwent diagnostic surgery for suspected early recurrence were sent to 101 pathologists from 50 NCI-designated Cancer Centers. Pathologists were asked to provide a final diagnosis (active tumor, treatment effect, or unable to classify) and to report on percent active tumor, treatment effect, and degree of cellularity and degree of mitotic activity. RESULTS: Forty-eight pathologists (48%) from 30 centers responded. In three cases > 75% of pathologists diagnosed active tumor. In two cases > 75% diagnosed treatment effect. However, in the remaining eight cases the disparity in diagnoses was striking (maximum agreement on final diagnosis ranged from 36 to 68%). Overall, only marginal agreement was observed in the overall assessment of disease status [kappa score 0.228 (95% CI 0.22-0.24)]. CONCLUSIONS: Confidence in any clinical diagnostic assay requires that very similar results are obtained from identical specimens evaluated by sophisticated clinicians and institutions. The findings of this study illustrate that the diagnostic agreement between different cases of repeat resection for suspected recurrent glioblastoma can be variable. This raises concerns as pathological diagnoses are critical in directing standard and experimental care in this setting.

THE DESIGN AND USE OF A MINIMALLY-INVASIVE, EXPANDABLE RETRACTOR FOR DEEP-SEATED BRAIN LESIONS.

Access to deep-seated brain lesions (e.g., tumors, aneurysms, hematomas, and other malformations) is challenging due to the potential for retraction-induced injury. Traditionally, neurosurgeons use dissection and blade retractors to push apart tissue to visualize and operate on target lesions. These blades apply focal pressure onto the brain, resulting in ischemia, edema, and parenchymal trauma, leading to complications in up to 29% of cases. Tubular retractors were introduced to distribute forces radially and have led to improved safety and clinical outcomes. However, reports indicate that tubular retractors still led to complications in up to 9.1% of cases. Other concerns include significant pressure in the direction of insertion and the displacement of anatomic landmarks leading to inaccurate stereotaxis. We present a novel, minimally-invasive brain retractor that utilizes an expandable soft balloon to further reduce retraction-induced injury and increase stereotactic accuracy with a minimal port of entry. The device consists of a balloon catheter system, a clear sheath, and integration with neuronavigation stylets. This approach can reduce the rate of iatrogenic injury and improve clinical outcomes for brain lesion operations. Furthermore, we illustrate the efficacy of this device in use compared to those of conventional tubular and blade retractors in a pig cadaver.

Patterns of bevacizumab use in patients with glioblastoma: an online survey among experts in neuro-oncology.

BACKGROUND: Bevacizumab (BEV) received accelerated FDA approval in 2009 for the treatment of recurrent glioblastoma (rGBM). Unfortunately, prospective randomized controlled phase 3 studies (AVAglio and Radiation Therapy Oncology Group 0825 in newly diagnosed, European Organisation for Research and Treatment of Cancer 26101 in rGBM) failed to show an overall survival benefit with BEV added to standard therapy. In light of these data, we aimed to capture current utilization patterns and perceived value of BEV in the treatment of GBM among experts in the field. METHODS: An online questionnaire comprising 14 multiple choice questions was sent out in spring 2017 to 207 oncologists/neuro-oncologists treating patients with GBM at all National Cancer Institute-designated cancer centers in the United States. RESULTS: Sixty-two of 207 (30%) invitees responded (by training, 70% neuro-oncologists, 20% medical oncologists, 10% pediatric oncologists/neuro-oncologists). Participants reported use of BEV most frequently in rGBM for control of edema (85% of respondents) and/or when no other treatment options were available (68%). BEV is rarely used in newly diagnosed GBM (<5% of cases by 78% respondents and in 5% to 10% cases by 15% respondents). Sixty-six percent of participants indicated that they thought BEV improved symptoms, 30% that it improved symptoms and survival, 3% that it had no benefit in GBM patients. CONCLUSION: In this cross-sectional online survey we found that among neuro-oncology experts in the United States in 2017, BEV is predominantly utilized in select patients with rGBM, and is only rarely used in a small subgroup of patients with newly diagnosed GBM for control of edema. The low response rate may have introduced a nonresponse bias.

Widely metastatic IDH1-mutant glioblastoma with oligodendroglial features and atypical molecular findings: a case report and review of current challenges in molecular diagnostics.

BACKGROUND: Gliomas with 1p/19q-codeletion as well as mutation of isocitrate dehydrogenase (IDH) 1 are typically characterized as oligodendrogliomas with comparatively good response to treatment with radiation and chemotherapy. CASE PRESENTATION: We present the case of a 28-year-old man with an IDH1 and TP53 mutant high grade glioma with abnormalities in chromosomes 1 and 19 suggestive of anaplastic oligodendroglioma that rapidly progressed to widespread metastatic disease. Biopsy of a liver lesion confirmed metastasis of the patient's known brain primary and chemotherapy with temozolomide was initiated. The patient's rapidly growing tumor burden with fulminant liver failure and tumor lysis led to multisystem failure of which the patient died. Further molecular testing illustrated features more consistent with glioblastoma: multiple large chromosomal aberrations including loss of whole chromosome 1 and 2q; gain/amplification of MYCN, MET, and CDK4; loss of CDKN2A/B; and an ATRX mutation. CONCLUSION: This case illustrates the importance of higher level molecular diagnostic testing for patients with particularly aggressive disease progression that is not concordant with standard prognoses. Additional data on cases with atypical alterations of 1p and 19q are needed to better understand the distinct biology of these cancers so that appropriate therapies can be developed.