The safety profile of Tumor Treating Fields (TTFields) therapy in glioblastoma patients with ventriculoperitoneal shunts

Our plain-English summary of The safety profile of Tumor Treating Fields (TTFields) therapy in glioblastoma patients with ventriculoperitoneal shunts, by N.A. Oberheim-Bush, W. Shi, M.W. McDermott, et al (Journal of Neuro-oncology, 2022).

The study

• Authors: N.A. Oberheim-Bush, W. Shi, M.W. McDermott, A. Grote, J. Stindl, L. Lustgarten
• Journal: Journal of Neuro-oncology
• Published: 2022;158(3):453-461
• Cited by: 10 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Introduction: Tumor Treating Fields (TTFields, 200 kHz) therapy is a noninvasive, locoregional cancer treatment approved for use in newly diagnosed glioblastoma (GBM), recurrent GBM, and malignant pleural mesothelioma. GBM patients with hydrocephalus may require implantation of a ventriculoperitoneal (VP) shunt, however, the current TTFields therapy label does not include the use of VP shunts in GBM patients due to insufficient safety data. This analysis evaluates the safety of TTFields therapy use in this population.

Methods: Unsolicited post-marketing global surveillance data from patients with GBM and a VP shunt (programmable/non-programmable) who received TTFields therapy between November 2012-April 2021 were retrospectively analyzed. Adverse events (AEs) were assessed using the Medical Dictionary for Regulatory Activities version 24.0.

Results: Overall, 156 patients with VP shunts were identified and included in this analysis. In total, 77% reported ≥ 1 AE; the most common TTFields therapy-related AEs were non-serious and localized, beneath-array skin AEs (43%). The incidence and categories of AEs were comparable between patients with or without VP shunts. Six patients with VP shunts experienced seven serious TTFields therapy-related AEs: skin erosion at the shunt site (n = 3); wound dehiscence at the shunt site (n = 2) and at the resection scar (n = 2). No shunt malfunctions were deemed related to TTFields therapy.

Conclusions: In the real-world setting, TTFields therapy in GBM patients with VP shunts demonstrated good tolerability and a favorable safety profile. There was no evidence that TTFields therapy disrupted VP shunt effectiveness. These results suggest TTFields therapy may be safely used in patients with VP shunts.

© 2022. The Author(s).

In plain English

This article is not about asbestos exposure. It concerns a brain-tumor treatment and mentions malignant pleural mesothelioma only as another approved use of the device. The authors retrospectively analyzed unsolicited post-marketing safety reports on Tumor Treating Fields (TTFields, 200 kHz) therapy from the US, Europe, the Middle East and Africa, and Japan, collected between November 2012 and April 2021. They identified 156 adults with glioblastoma who used TTFields while having a ventriculoperitoneal (VP) shunt, an implanted device used to relieve hydrocephalus. Of these shunt patients, 77% reported at least one adverse event, compared with 70% of the non-shunt population. Scalp skin reactions were the most common (43% of shunt patients). Serious adverse events were reported by 46% of shunt patients and 20% of patients without shunts. Six shunt patients had seven serious events judged potentially related to TTFields, five of them at the shunt site. Shunt malfunction was considered unrelated to TTFields. The authors concluded the therapy appeared feasible and well tolerated and did not seem to interfere with shunt function. They noted the analysis was retrospective and not statistically powered.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Retrospective analysis of unsolicited post-marketing safety surveillance data
• Who was studied: 156 adult patients with glioblastoma (92 newly diagnosed, 64 recurrent) who received TTFields therapy while having a VP shunt. They were identified from safety reports from the US, Europe, the Middle East and Africa, and Japan between November 2012 and April 2021. They were compared with a non-shunt glioblastoma population of 18,471 patients.
• Exposure: Tumor Treating Fields (200 kHz) therapy used in the presence of a VP shunt: 47 programmable shunts, 12 non-programmable shunts and 97 unspecified. No asbestos exposure was studied.
• Main results:
  • 77% of patients with a VP shunt reported at least one adverse event (83% newly diagnosed, 69% recurrent), compared with 70% in the non-shunt population.
  • Non-serious local skin reactions on the scalp were the most common adverse events, reported by 43% of the shunt population.
  • Serious adverse events were reported in 46% of patients with shunts and 20% of patients without shunts.
  • The most common serious adverse event in the shunt population was hydrocephalus (19 patients, 12%). Of these patients, 15 did not yet have a shunt in place when it occurred.
  • After correction for multiple comparisons, the differences between the shunt and non-shunt populations were statistically significant for hydrocephalus, hypertension, fatigue, nausea/vomiting and urinary tract disorder.
  • Shunt malfunction was reported in 3% of shunt patients and was considered unrelated to TTFields therapy.
  • Six of the 156 shunt patients (5 newly diagnosed, 1 recurrent) had seven serious adverse events judged potentially related to TTFields therapy. Five of these were at the shunt site.
  • Shunt removal was required in three of the serious TTFields-related cases, and one case had an unknown outcome.
• The authors' conclusion: The authors concluded that TTFields therapy in patients with glioblastoma and a VP shunt was feasible and well tolerated, and did not seem to interfere with the normal function or effectiveness of the shunt.
• Limitations the authors state:
  • The study was retrospective and could not be statistically powered, so the authors say comparisons should be regarded as observational only.
  • Full medical histories and adverse-event details were not available for all patients.
  • Information on prior and concomitant treatments, such as steroids or bevacizumab, was not included.
  • Adverse events were not graded for severity.
  • Patients could not be followed up for later safety outcomes.

Topics

Medical terms in this study, explained in our Lexicon: Tumor Treating Fields (TTFields), Pleural Mesothelioma.

Related studies

• Tumour treating fields therapy for glioblastoma: current advances and future directions — O. Rominiyi, A. Vanderlinden, et al. (2021)
• Tumor Treating Fields dually activate STING and AIM2 inflammasomes to induce adjuvant immunity in glioblastoma — D. Chen, S.B. Le, et al. (2022)
• A review of tumor treating fields (TTFields): advancements in clinical applications and mechanistic insights — X. Li, K. Liu, et al. (2023)
• Tumor Treating Fields (TTFields) Therapy in Unresectable Pleural Mesothelioma: Overview of Efficacy, Safety, and Future Outlook — G.L. Ceresoli, L. Gianoncelli (2025)
• Expert guidance on prophylaxis and treatment of dermatologic adverse events with Tumor Treating Fields (TTFields) therapy in the thoracic region — M.J. Anadkat, M. Lacouture, et al. (2022)
• Tumor Treating Fields: An Innovative Therapy for Glioblastoma and Other Solid Tumors — J.N. Serventi, H.B. Newton (2025)

Browse return to medical research.