Tumor Treating Fields for Glioblastoma Treatment: Patient Satisfaction and Compliance With the Second-Generation Optune® System

Background:

Tumor treating fields (TTFields) are a non-invasive antimitotic therapy that delivers alternating electric fields via the Optune^® system. The Phase III EF-14 trial in newly diagnosed glioblastoma multiforme (GBM) showed significantly improved progression-free, overall and long-term survival when Optune was used together with maintenance temozolomide (TMZ) compared with TMZ alone. Compliance (average monthly use) was associated with better clinical outcome. The first-generation Optune system weighed approximately 6 pounds (~2.7 kg). The second-generation redesigned Optune system weighs 2.7 pounds (~1.2 kg). We tested and compared GBM patient experience with the second-generation system versus the first-generation system.

Methods:

Ten newly diagnosed and recurrent GBM patients in Germany (median age: 52.9 years [31-79]) were prospectively monitored over the first month of transitioning from the first-generation to the second-generation Optune system. Questionnaires using a numerical analog scale assessed feedback at baseline (first generation) and after 1 month of second-generation use.

Results:

After transitioning to the second-generation system, compliance improved by more than 10% in four patients, was maintained in five patients and decreased by more than 10% in one patient. Following transition, eight out of nine patients reported a reduction in the triggering of malfunction alarms. Self-reported patient feedback showed improved handling and portability (weight, mobility) of the second- versus the first-generation Optune system.

Conclusions:

This patient user survey suggests that patient satisfaction with the second-generation Optune system is improved versus the first-generation system. Improved features of the new system help patients achieve and maintain a higher rate of treatment compliance.

NovoTTF™-100A System (Tumor Treating Fields) transducer array layout planning for glioblastoma: a NovoTAL™ system user study

Background

Optune™, previously known as the NovoTTF-100A System™, generates Tumor Treating Fields (TTFields), an effective anti-mitotic therapy for glioblastoma. The system delivers intermediate frequency, alternating electric fields to the supratentorial brain. Patient therapy is personalized by configuring transducer array layout placement on the scalp to the tumor site using MRI measurements and the NovoTAL System. Transducer array layout mapping optimizes therapy by maximizing electric field intensity to the tumor site. This study evaluated physician performance in conducting transducer array layout mapping using the NovoTAL System compared with mapping performed by the Novocure in-house clinical team.

Methods

Fourteen physicians (7 neuro-oncologists, 4 medical oncologists, and 3 neurosurgeons) evaluated five blinded cases of recurrent glioblastoma and performed head size and tumor location measurements using a standard Digital Imaging and Communications in Medicine reader. Concordance with Novocure measurement and intra- and inter-rater reliability were assessed using relevant correlation coefficients. The study criterion for success was a concordance correlation coefficient (CCC) >0.80.

Results

CCC for each physician versus Novocure on 20 MRI measurements was 0.96 (standard deviation, SD ± 0.03, range 0.90–1.00), indicating very high agreement between the two groups. Intra- and inter-rater reliability correlation coefficients were similarly high: 0.83 (SD ±0.15, range 0.54–1.00) and 0.80 (SD ±0.18, range 0.48–1.00), respectively.

Conclusions

This user study demonstrated an excellent level of concordance between prescribing physicians and Novocure in-house clinical teams in performing transducer array layout planning. Intra-rater reliability was very high, indicating reproducible performance. Physicians prescribing TTFields, when trained on the NovoTAL System, can independently perform transducer array layout mapping required for the initiation and maintenance of patients on TTFields therapy.