Intraoperative Magnetic Resonance Imaging for Resection of Intra-Axial Brain Lesions: A Decade of Experience Using Low-Field Magnetic Resonance Imaging, Polestar N-10, 20, 30 Systems

Abstract BACKGROUND: Typically, neurosurgery is performed several weeks after diagnostic imaging. In the majority of cases, histopathology confirms the diagnosis of neoplasia. In a small number of cases, a different diagnosis is established or histopathology is nondiagnostic. The frequency with which these outcomes occur has not been established. OBJECTIVE: To determine the frequency and outcome of disappearing brain lesions within a group of patients undergoing surgery for suspected brain tumor. METHODS: Over the past decade, 982 patients were managed in the intraoperative magnetic resonance imaging unit at the University of Calgary, Calgary, Alberta, Canada. These patients have been prospectively evaluated. RESULTS: In 652 patients, a brain tumor was suspected. In 6 of the 652 patients, histopathology indicated a nontumor diagnosis. In 5 patients, intraoperative images, acquired after induction of anesthesia, showed complete or nearly complete resolution of the suspected tumor identified on diagnostic magnetic resonance imaging acquired 6 ± 4 (mean ± SD) weeks previously. Anesthesia was reversed, and the surgical procedure aborted. The lesions have not progressed with 6 ± 2 years of follow-up. CONCLUSION: Intraoperative magnetic resonance imaging prevented surgery on 5 patients with disappearing lesions.

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Combining 5-Aminolevulinic Acid Fluorescence and Intraoperative Magnetic Resonance Imaging in Glioblastoma Surgery

Neurosurgery ◽

10.1227/neu.0000000000001035 ◽

2015 ◽

Vol 78 (4) ◽

pp. 475-483 ◽

Cited By ~ 35

Author(s):

Sonja B. Hauser ◽

Ralf A. Kockro ◽

Bertrand Actor ◽

Johannes Sarnthein ◽

René-Ludwig Bernays

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Aminolevulinic Acid ◽

Complete Resection ◽

Normal Brain ◽

Resonance Imaging ◽

Tissue Samples ◽

Intraoperative Magnetic Resonance Imaging ◽

Low Field ◽

Tumor Remnant

Abstract BACKGROUND: Glioblastoma resection guided by 5-aminolevulinic acid (5-ALA) fluorescence and intraoperative magnetic resonance imaging (iMRI) may improve surgical results and prolong survival. OBJECTIVE: To evaluate 5-ALA fluorescence combined with subsequent low-field iMRI for resection control in glioblastoma surgery. METHODS: Fourteen patients with suspected glioblastoma suitable for complete resection of contrast-enhancing portions were enrolled. The surgery was carried out using 5-ALA–induced fluorescence and frameless navigation. Areas suspicious for tumor underwent biopsy. After complete resection of fluorescent tissue, low-field iMRI was performed. Areas suspicious for tumor remnant underwent biopsy under navigation guidance and were resected. The histological analysis was blinded. RESULTS: In 13 of 14 cases, the diagnosis was glioblastoma multiforme. One lymphoma and 1 case without fluorescence were excluded. In 11 of 12 operations, residual contrast enhancement on iMRI was found after complete resection of 5-ALA fluorescent tissue. In 1 case, the iMRI enhancement was in an eloquent area and did not undergo a biopsy. The 28 biopsies of areas suspicious for tumor on iMRI in the remaining 10 cases showed tumor in 39.3%, infiltration zone in 25%, reactive central nervous system tissue in 32.1%, and normal brain in 3.6%. Ninety-three fluorescent and 24 non-fluorescent tissue samples collected before iMRI contained tumor in 95.7% and 87.5%, respectively. CONCLUSION: 5-ALA fluorescence–guided resection may leave some glioblastoma tissue undetected. MRI might detect areas suspicious for tumor even after complete resection of all fluorescent tissue; however, due to the limited accuracy of iMRI in predicting tumor remnant (64.3%), resection of this tissue has to be considered with caution in eloquent regions.

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