Tumor treating fields combined with concurrent chemoradiotherapy for glioblastoma: A multi-institutional analysis

The clinical benefit of extending tumor treating fields (TTFields) beyond concurrent chemoradiotherapy (CRT) for newly diagnosed glioblastoma (ndGBM) is unclear. This multi-institutional retrospective study compared patients who continued TTFields into adjuvant temozolomide (CRT-TT, n = 68) versus those who discontinued after CRT (CRT-T, n = 32). With a median follow-up of 36.9 months, median progression-free survival (mPFS) did not significantly differ between the groups (12.8 vs. 12.5 months; hazard ratio [HR] 0.95, 95% confidence interval [CI] 0.57–1.59; p = 0.853) nor did median overall survival (mOS) (20.6 vs. 16.6 months; HR 0.73, 95% CI 0.43–1.27; p = 0.267). Additionally, continuing TTFields into the adjuvant phase did not increase scalp toxicity. Although a numerically longer OS was seen in the CRT-TT group, the lack of statistical significance may reflect limited power and non-randomized allocation. These findings underscore the need for further investigation.