Figure 2

Serial MR imaging in Case 2. T1-weighted image after application of contrast agent. a) January 2004, before surgery. GBM located in the left frontal region. b) August 2004, post-operative radiotherapy and chemotherapy. Start of TTField treatment. An enhancing lesion suspected to be recurrent or residual tumor. c) March 2005, TTF treatment. The enhancing lesion became partly cystic. d) June 2005, regression of the cystic part. A subtle enhancing lesion still present. e) November 2011. A subtle enhancing lesion without progression. f) Proton MR spectroscopy of the enhancing lesion with dominant noise signal, suggesting gliosis rather than tumor. g) Neighboring spectrum is practically normal, demonstrating that MR spectroscopy provided reliable data from the selected slice. GBM, Glioblastoma multiforme; MR, magnetic resonance; TTField, tumor-treating fields.