The corresponding surgical data has been given with tumor volume and postoperative outcome.

<p>Tumor volume was measured in cm³. Functional tumor localization (abbreviated as fg) was determined by preoperative MRI and classified according to Sawaya <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044885#pone.0044885-Sawaya1" target="_blank">[20]</a>. Surgery was primarily carried out according to the 5-ALA signal, with corresponding iMRI resection controls carried out following disappearances of this signal. The residual tumor volume following each iMRI scan has been indicated in parentheses. The green color code has been used to depict complete resection according to both modalities during the first iMRI scan itself. Yellow has been used to depict complete resection requiring several iMRI scans. Red has been used to depict intentional, incomplete tumor resection.