Interdisciplinary Neurosurgery · Published 2026-06-01 · DOI 10.1016/j.inat.2026.102290
Masashi Kinoshita, Sho Tamai, Akihiro Nishiyama, Hiroko Ikeda, Mitsutoshi Nakada
Background: Tumor treating fields (TTFields) are an established adjunctive therapy for newly diagnosed glioblastoma (GBM). However, detailed radiological response patterns during long-term treatment, particularly in patients with high-risk molecular features, remain incompletely described in routine clinical practice. Case Summary: We report a 40-year-old man with isocitrate dehydrogenase–wildtype GBM harboring a platelet-derived growth factor receptor alpha (PDGFRA) V658A mutation and an unmethylated O6-methylguanine-DNA methyltransferase promoter, both associated with poor prognosis. Following subtotal resection, the patient received standard radiotherapy with concomitant and adjuvant temozolomide combined with TTFields, which was maintained with high compliance (>75%). Durable radiological control of the supratentorial lesion was achieved. At 32 months postoperatively, a new non-enhancing lesion developed in the medulla oblongata while the primary lesion remained controlled. Temporary discontinuation of TTFields during additional radiotherapy for the brainstem lesion was followed by local recurrence near the original tumor site, which subsequently regressed after TTFields therapy was resumed. Conclusions: This case illustrates that TTFields may provide sustained, region-specific tumor control in molecularly high-risk GBM when applied with high compliance. The time-dependent radiological changes during treatment interruption and resumption highlight the importance of continuous TTFields use and emphasize practical considerations regarding anatomical limitations of in infratentorial regions.
Abstract from DOAJ. Public domain (CC0 1.0).
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Kinoshita, M., Tamai, S., Nishiyama, A., et al. (2026). Radiological response to tumor treating fields in glioblastoma harboring a PDGFRA mutation and an unmethylated MGMT promoter. Interdisciplinary Neurosurgery. https://doi.org/10.1016/j.inat.2026.102290