title: Improving Tumor Treating Fields Treatment Efficacy in Patients With Glioblastoma Using Personalized Array Layouts.
abstract: OBJECTIVE
  To investigate tumors of different size, shape, and location and the effect of varying transducer layouts on Tumor Treating Fields (TTFields) distribution in an anisotropic model.
  
  
  METHODS
  A realistic human head model was generated from MR images of 1 healthy subject. Four different virtual tumors were placed at separate locations. The transducer arrays were modeled to mimic the TTFields-delivering commercial device. For each tumor location, varying array layouts were tested. The finite element method was used to calculate the electric field distribution, taking into account tissue heterogeneity and anisotropy.
  
  
  RESULTS
  In all tumors, the average electric field induced by either of the 2 perpendicular array layouts exceeded the 1-V/cm therapeutic threshold value for TTFields effectiveness. Field strength within a tumor did not correlate with its size and shape but was higher in more superficial tumors. Additionally, it always increased when the array was adapted to the tumor's location. Compared with a default layout, the largest increase in field strength was 184%, and the highest average field strength induced in a tumor was 2.21 V/cm.
  
  
  CONCLUSIONS
  These results suggest that adapting array layouts to specific tumor locations can significantly increase field strength within the tumor. Our findings support the idea of personalized treatment planning to increase TTFields efficacy for patients with GBM.
authors.affiliation: Institute of Biophysics and Biomedical Engineering, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal. Electronic address: cwenger@fc.ul.pt.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Wenger
authors.affiliation: Institute of Biophysics and Biomedical Engineering, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Salvador
authors.affiliation: Section on Tissue Biophysics and Biomimetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Basser
authors.affiliation: Institute of Biophysics and Biomedical Engineering, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal.
authors.forename: Pedro C
authors.initials: PC
authors.lastname: Miranda
mesh_terms: D016880:Anisotropy; D001932:Brain Neoplasms / Q000473:pathology* / Q000628:therapy*; D004599:Electric Stimulation Therapy / Q000295:instrumentation / Q000379:methods*; D004574:Electromagnetic Fields; D005909:Glioblastoma / Q000473:pathology* / Q000628:therapy*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008953:Models, Anatomic; D057285:Precision Medicine / Q000295:instrumentation / Q000379:methods*; D014159:Transducers; D016896:Treatment Outcome; D047368:Tumor Burden