133P - The influence of body composition on TTFields intensity in the lungs

Date 07 May 2017
Event ELCC 2017
Session Poster Display Session
Topics Lung and other Thoracic Tumours
Presenter Uri Weinberg
Citation Annals of Oncology (2017) 28 (suppl_2): ii28-ii51. 10.1093/annonc/mdx091
Authors U. Weinberg1, N. Urman2, H.S. Hershkovich2, Z. Bomzon2, E.D. Kirson2, Y. Palti2
  • 1Novocure GmbH, Park 6, 6039 Root D4 - Luzern/CH
  • 2Novocure Ltd, Haifa/IL

Abstract

Background

Tumor Treating Fields (TTFields) are low intensity, alternating electric fields in the intermediate frequency range that disrupt mitosis. The therapy is FDA approved for the treatment of glioblastoma, and a pivotal study testing the efficacy of TTFields in non-small cell lung cancer is planned. TTFields are delivered through two pairs of transducer arrays (TL) placed on the patient's skin. Since the efficacy of TTFields increases with intensity, it is important to identify factors that influence field intensity in the lungs. Therefore, it is important to understand how body shape and composition influence the field intensity. Here we present a computer-simulation-based study investigating the effect of body size, shape and composition on the field distribution in the lungs.

Methods

The study was performed using the Sim4Life software package and realistic computational phantoms of a female (ELLA), male (DUKE) and obese male (FATS). Various array layouts were placed on the models, and the distribution of TTFields within their lungs were calculated and compared.

Results

For all models, uniform field distributions within the lungs were obtained when the arrays were axially-aligned with the parenchyma as much as anatomically possible. The layouts that generated the highest average field intensities were those in which one pair of arrays delivered an electric field from the anterolateral to the posterior-contralateral aspect of the patient, with the second pair inducing the field from the antero-contralateral to the posterolateral aspect of the patient. In all models, these layouts led to average field intensities in the lungs of above the therapeutic threshold (>1 V/cm). The highest field intensities developed in DUKE's lungs and the lowest field intensities developed in FATS's lungs. Analysis suggests that field attenuation was caused primarily by layers of fat. Hence, the lower field intensities in the lungs of ELLA and FATS can be largely attributed to the thick layers of fat present in FATS and the fatty tissue in ELLA's breasts.

Conclusions

This study provides insights into how TTFields distribution in the lungs is influenced by body composition. These insights will help to optimize TL placement and design in the future.

Clinical trial identification

Legal entity responsible for the study

Novocure

Funding

Novocure

Disclosure

U. Weinberg, N. Urman, H.S. Hershkovich, E.D. Kirson: Employee of Novocure. Z. Bomzon: Paid employee of Novocure Ltd. Y. Palti: The author is a shareholder in Novocure.