OptimalTTF-1: Enhancing tumor treating fields therapy with skull remodeling surgery. A clinical phase I trial in adult recurrent glioblastoma

Anders Rosendal Korshoej, Slavka Lukacova, Yasmin Lassen-Ramshad, Christian Rahbek, Kåre Eg Severinsen, Trine Lignell Guldberg, Nikola Mikic, Mette Haldrup Jensen, Søren Ole Stigaard Cortnum, Gorm von Oettingen, Jens Christian Hedemann Sørensen

Research output: Contribution to journalJournal articleResearchpeer-review

21 Citations (Scopus)
64 Downloads (Pure)


Background: Preclinical studies suggest that skull remodeling surgery (SR-surgery) increases the dose of tumor treating fields (TTFields) in glioblastoma (GBM) and prevents wasteful current shunting through the skin. SR-surgery introduces minor skull defects to focus the cancer-inhibiting currents toward the tumor and increase the treatment dose. This study aimed to test the safety and feasibility of this concept in a phase I setting.

Methods: Fifteen adult patients with the first recurrence of GBM were treated with personalized SR-surgery, TTFields, and physician's choice oncological therapy. The primary endpoint was toxicity and secondary endpoints included standard efficacy outcomes.

Results: SR-surgery resulted in a mean skull defect area of 10.6 cm2 producing a median TTFields enhancement of 32% (range 25-59%). The median TTFields treatment duration was 6.8 months and the median compliance rate 90%. Patients received either bevacizumab, bevacizumab/irinotecan, or temozolomide rechallenge. We observed 71 adverse events (AEs) of grades 1 (52%), 2 (35%), and 3 (13%). There were no grade 4 or 5 AEs or intervention-related serious AEs. Six patients experienced minor TTFields-induced skin rash. The median progression-free survival (PFS) was 4.6 months and the PFS rate at 6 months was 36%. The median overall survival (OS) was 15.5 months and the OS rate at 12 months was 55%.

Conclusions: TTFields therapy combined with SR-surgery and medical oncological treatment is safe and nontoxic and holds the potential to improve the outcome for GBM patients through focal dose enhancement in the tumor.

Original languageEnglish
Article numbervdaa121
JournalNeuro-oncology advances
Issue number1
Number of pages11
Publication statusPublished - Dec 2020


Dive into the research topics of 'OptimalTTF-1: Enhancing tumor treating fields therapy with skull remodeling surgery. A clinical phase I trial in adult recurrent glioblastoma'. Together they form a unique fingerprint.

Cite this