Recent Clinical Article
Initial Experience Using Intraoperative Magnetic Resonance Imaging During a Trans-Sulcal Tubular Retractor Approach for the Resection of Deep-Seated Brain Tumors: A Case Series
Peter T. Sylvester, MD
Charles Kulwin, MD
Mitesh V. Shah, MD
Aravind Somasundaram, BS
Ashwin A. Kamath, MD
Thomas L. Beaumont, MD, PhD
Keith M. Rich, MD
Michael R. Chicoine, MD
BACKGROUND: Intraoperative magnetic resonance imaging (iMRI) is a powerful tool for guiding brain tumor resections, provided that it accurately discerns residual tumor.
OBJECTIVE: To use histopathology to assess how reliably iMRI may discern additional tumor for a variety of tumor types, independent of the indications for iMRI.
METHODS: A multicenter database was used to calculate the odds of additional resection during the same surgical session for grade I to IV gliomas and pituitary adenomas. The reliability of iMRI for identifying residual tumor was assessed using histopathology of tissue resected after iMRI.
RESULTS: Gliomas (904/1517 cases, 59.6%) were more likely than pituitary adenomas (176/515, 34.2%) to receive additional resection after iMRI (P < .001), but these tumors were equally likely to have additional tissue sent for histopathology (398/904, 44.4% vs 66/176, 37.5%; P = .11). Tissue samples were available for resections after iMRI for 464 cases, with 415 (89.4%) positive for tumor. Additional resections after iMRI for gliomas (361/398, 90.7%) were more likely to yield additional tumor compared to pituitary adenomas (54/66, 81.8%) (P = .03). There were no significant differences in resection after iMRI yielding histopatho- logically positive tumor between grade I (58/65 cases, 89.2%; referent), grade II (82/92, 89.1%) (P = .98), grade III (72/81, 88.9%) (P = .95), or grade IV gliomas (149/160, 93.1%) (P = .33). Additional resection for previously resected tumors (122/135 cases, 90.4%) was equally likely to yield histopathologically confirmed tumor compared to newly-diagnosed tumors (293/329, 89.0%) (P = .83).
CONCLUSION: Histopathological analysis of tissue resected after use of iMRI for grade I to IV gliomas and pituitary adenomas demonstrates that iMRI is highly reliable for identifying residual tumor.