A general approach to optimizing tumor treating fields therapy.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e14668-e14668
Author(s):  
Zeev Bomzon ◽  
Noa Urman ◽  
Hadas Sara Hershkovich ◽  
Eilon David Kirson ◽  
Ariel Naveh ◽  
...  
Keyword(s):  
Field Distribution ◽  
Electric Fields ◽  
Computational Models ◽  
Array Size ◽  
Patient Comfort ◽  
Improve Patient Survival ◽  
Tumor Bed ◽  
Tumor Treating Fields ◽  
Alternating Electric Fields ◽  
Improve Patient

e14668 Background: Tumor Treating Fields (TTFields) are alternating electric fields used to non-invasively treat cancer. TTFields are delivered via transducer arrays placed on the skin close to the tumor. Post-hoc analysis [1] has shown that delivering higher field power to the tumor and increasing usage (percent of time patient is actively treated) improve patient survival. Thus, optimizing the position of arrays to maximize TTFields power at the tumor could improve survival. At the same time, minimizing the array area to maximize patient comfort and consequently maximizing usage is also likely to improve survival. However, optimizing TTFields delivery is non-trivial since the field distribution is influenced by array positioning and geometry, the anatomy of the patient and the heterogeneous electric properties of different tissues. Here we present a general approach to optimizing Tumor Treating Fields using numerical simulations. Methods: Delivery of TTFields to the brains, lungs and abdomens of realistic computational models was investigated. The effect of the transducer array size and position on the field distribution within the phantoms was analyzed, and an approach for optimizing TTFields delivery developed. Results: Field power is generally highest in the region between the arrays, with larger arrays generally delivering higher field power. Anatomical features such as bones, the spine or a resection cavity significantly influence the field within this region. A general approach to optimizing TTFields delivery is: Maximize field power by using the largest arrays possible. To maximize patient comfort, array size are chose so that significant portions of the skin in the region of disease are not covered by the arrays. Place virtual arrays on a realistic computational model of the patient such that the tumor is located between them and simulate TTFields delivery to the patient. Apply an iterative algorithm to shift the arrays around their initial positions until field power in the tumor bed is maximized. Conclusions: We have developed a general approach to optimizing delivery of TTFields to the tumor. Effective TTFields treatment planning is expected to improve patient outcome. [1] Ballo et. al., submitted to RED Journal 2018.

Analysis of the EF-14 phase III trial reveals that tumor treating fields alter progression patterns in glioblastoma.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 2055-2055
Author(s):  
Suriya A. Jeyapalan ◽  
Steven A Toms ◽  
Andreas Felix Hottinger ◽  
Lawrence Kleinberg ◽  
Erqi Pollom ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Electric Fields ◽  
Growth Patterns ◽  
T Test ◽  
Phase Iii ◽  
Tumor Bed ◽  
Tumor Treating Fields ◽  
Alternating Electric Fields ◽  
Trial Testing ◽  
Chi Squared

2055 Background: The EF-14 [NCT00916409] trial showed that addition of alternating electric fields (Tumor Treating Fields, TTFields) to Temozolomide (TMZ) resulted in improved survival in newly diagnosed Glioblastoma (GBM) patients with supratentorial tumors treated compared to TMZ alone. TTFields delivery is planned to optimize dose at the tumor bed, leading to the hypothesis that TTFields treated patients are more likely to exhibit distal progressions, including progression to the infratentorial brain where TTFields dose is minimal when targeting the supratentorium. Here we present analysis of the EF-14 trial testing this hypothesis. Methods: Patients on treatment for more than two months who had an MRI that exhibited progression were included in the study (treatment: N=280/466, control: N=122/229). Regions of enhancing tumor, necrosis and resection were contoured on T1 contrast MRIs acquired at baseline and at the date of first progression. New lesions at progression were classified as distal if they appeared outside of a Proximal Boundary Zone (PBZ) of 20 mm surrounding the lesions identified in the baseline MRI. The rate of occurrence of distal progressions in the TTFields-treated arm was compared to the rate observed in the control arm. Patients with (distal) infratentorial progression were identified. Results: Distal progressions were more common in the treatment arm (49/280 (18%) vs. 10/122 (8%) P<0.02; chi-squared). Infratentorial progression were observed in 4% (10 patients) of the treatment arm vs. 0 patients in the control (P<0.002 t-test). Distal lesions at progression were more distant from the original lesion in the TTFields treated arm (58.57 + 28.12 mm vs 46.61 + 20.48 mm, P<0.02; Wilcoxon rank sum test. The relative tumor growth rates in TTFields treated patients were significantly slower than those observed in the control arm (0.036+ 0.126 ml/day vs. 0.036+ 0.183 ml/day P<0.03; t-test). Conclusions: This analysis indicates that adding TTFields to TMZ could impact GBM growth patterns. The results suggest that TTFields increases local control of tumor growth, emphasizing the need for adaptive treatment after progression to control progressing disease. Clinical trial information: NCT00916409.

scholarly journals Tumor treating fields in the management of Glioblastoma: opportunities for advanced imaging

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Vikram S. Soni ◽  
Ted K. Yanagihara
Keyword(s):  
Clinical Trials ◽  
Cancer Therapy ◽  
Electric Fields ◽  
Randomized Clinical Trials ◽  
Phase Iii ◽  
Imaging Biomarkers ◽  
Tumor Treating Fields ◽  
Alternating Electric Fields ◽  
Promising Line

AbstractAlternating electric fields have been successfully applied to cancer cells in-vitro to disrupt malignant progression and this antimitotic therapy has now been proven to be efficacious in Phase II and Phase III randomized clinical trials of patients with glioblastoma. With additional clinical trials ongoing in a number of other malignancies, there is a crucial need for a better understanding of the radiographic predictors of response and standardization of surveillance imaging interpretation. However, many radiologists have yet to become familiarized with this emerging cancer therapy and there is little active investigation to develop prognostic or predictive imaging biomarkers. This article provides an overview of the pre-clinical data that elucidate the biologic mechanisms of alternating electric fields as a cancer therapy. Results from clinical trials in patients with glioblastoma are then reviewed while elaborating on the several limitations to adoption of this promising line of treatment. Finally, a proposal for the development of imaging markers as a means of overcoming some of these limitations is made, which may improve treatment utilization by augmenting patient selection not only in glioblastoma, but also other malignant conditions for which this therapy is currently being evaluated.

scholarly journals EXTH-37. A NOVEL TRANSDUCER ARRAY LAYOUT FOR DELIVERING TUMOR TREATING FIELDS TO THE SPINE

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi90-vi90
Author(s):  
Ariel Naveh ◽  
Ofir Yesharim ◽  
Ze’ev Bomzon
Keyword(s):  
Spinal Cord ◽  
Electric Fields ◽  
Computational Models ◽  
Leptomeningeal Disease ◽  
Computational Simulations ◽  
Transducer Array ◽  
Tumor Treating Fields ◽  
Transducer Arrays ◽  
Perpendicular Field ◽  
Computational Platform

Abstract Tumor Treating Fields (TTFields) are an antimitotic technology utilising electric fields to disrupt mitosis in cancer cells. TTFields are currently approved by the FDA for the treatment of Glioblastoma Multiforme (GBM) and Malignant Pleural Mesothelioma (MPM). TTFields are delivered through 2 pairs of transducer arrays placed on the patient’s skin. Each pair delivers TTFields in a single direction, and the pairs are placed to provide perpendicular field. Preclinical studies show that 1V/cm is the clinical threshold for the treatment to be effective. Some types of cancers send metastases to the spinal cord and CSF, i.e. leptomeningeal disease. The purpose of this study was to find transducer array layouts that deliver TTFields to the spine at therapeutic intensities of above 1 V/cm. Computational simulations testing the delivery of TTFields to the spine were performed using the Sim4Life 4.0 (ZMT Zurich) computational platform, and the Duke 3.1 and Ella 3.0 (ITI’S, Zurich) realistic computational models of a male and female respectively. “Standard” layouts in which a pair of arrays are placed on the front and back of the patient and second pair on the lateral aspects of the patient failed to deliver TTFields at therapeutic intensities to the spinal cord. This is probably because the spinal cord is surrounded by the CSF and spine, which shunt the electric fields from reaching the spinal cord. However, field intensities above 1 V/cm were observed when delivering TTFields when both arrays were placed on the patients back, with a first array placed close to the neck, and second array placed towards the thighs. In this case, the spinal cord and surrounding CSF act as a conductive cable, directing the electric field along the spine. This novel layout opens the possibility for treating cancerous disease along the spine.

scholarly journals CTNI-73. OVERALL SURVIVAL OF NEWLY DIAGNOSED GLIOBLASTOMA PATIENTS TREATED BY STANDARD THERAPY IN COMPARISON TO STANDARD THERAPY PLUS TUMOR TREATING FIELDS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii59-ii59
Author(s):  
Aaron Rulseh ◽  
Adam Derner ◽  
Jan Sroubek ◽  
Jan Klener ◽  
Josef Vymazal
Keyword(s):  
Overall Survival ◽  
Electric Fields ◽  
Standard Therapy ◽  
Intermediate Frequency ◽  
Microtubule Assembly ◽  
Control Group ◽  
Newly Diagnosed ◽  
Tumor Treating Fields ◽  
Alternating Electric Fields ◽  
Overall Survival Benefit

Abstract BACKGROUND Tumor treating fields (TTFields; 200 kHz) have shown significant prolonged survival in newly diagnosed (ndGBM). TTFields are anti-mitotic, low intensity, intermediate frequency alternating electric fields. The applied fields disrupt the mitotic spindle, microtubule assembly and the segregation of intracellular organelles during cell division, leading to apoptosis or mitotic arrest. We compared overall survival (OS) between patients recently treated with standard therapy and standard therapy plus TTFields at our institution. METHODS Subjects (N=25) with ndGBM treated with standard therapy plus TTFields (STDTh-TTF) at our institution were included. Standard therapy (STDTh) consisted of surgical resection, followed by combined radiotherapy and chemotherapy (Temozolomide). In 3 cases, biopsies were performed instead of resection. The date of resection or biopsy was considered the entry date and was used in calculating survival. The study took place from July 2015 to April 2019. A matching control group of 25 subjects with ndGBM were treated with STDTh alone at our institution and were assembled from our database based primarily on date of resection or biopsy, and secondarily by age (2 subjects underwent biopsy in place of resection). When assembling the control group, the investigators were blinded to survival outcome. RESULTS Significantly greater overall survival was observed for the group treated by TTFields in addition to standard therapy (p &lt; 0.001; Hazard ratio [HR] 0.21; 95% confidence interval [CI] 0.1–0.45; median survival time STDTh-TTF 31.7 months, STDTh 7.1 months). The groups were balanced with respect to sex, and no differences with respect to age (p = 0.13; STDTh-TTF mean 51.58 years, SD 8.8; STDTh mean 52.42 years, SD 8.7) or inclusion date (p = 0.22) by paired t-test were detected. CONCLUSIONS Our initial results appear promising with respect to overall survival benefit in patients undergoing TTFields treatment in addition to standard therapy.

scholarly journals CTNI-68. EFFICACY OF TTFIELDS IN ELDERLY PATIENTS WITH NEWLY DIAGNOSED GLIOBLASTOMA (GBM) – SUB-GROUP ANALYSIS OF THE EF-14 TRIAL

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii58-ii58
Author(s):  
Zvi Ram ◽  
Chae-Yong Kim ◽  
Jay-Jiguang Zhu
Keyword(s):  
Elderly Patients ◽  
Electric Fields ◽  
Group Analysis ◽  
Progression Free Survival ◽  
The Elderly ◽  
Underlying Disease ◽  
Newly Diagnosed ◽  
Serious Adverse Events ◽  
Tumor Treating Fields ◽  
Alternating Electric Fields

Abstract BACKGROUND Tumor Treating Fields (TTFields) are an anti-mitotic, regional treatment that utilizes low intensity alternating electric fields delivered non-invasively to the tumor using a portable medical device. In the EF-14 phase 3 study leading to FDA approval, TTFields significantly extended survival in newly diagnosed GBM when added to maintenance temozolomide (TMZ). Elderly GBM patients usually have worse prognosis and often receive only partial treatment for the disease. This sub-group analysis examined the effects of TTFields in the elderly population (≥65 years of age) enrolled in the EF-14 study. METHODS All 134 elderly patients (≥65 years of age) from the EF-14’s intent-to-treat population were included in the analysis, Overall survival (OS) and progression-free survival (PFS), as well as adverse event frequency and severity were compared between the TMZ/TTFields arm and the TMZ alone arm. RESULTS The median age was 69 (range: 65–83), median KPS was 90%, and 69% were male. Median PFS from randomization was 6.5 months versus 3.9 months in the TMZ/TTFields versus TMZ alone arms, respectively (hazard ratio [HR], 0.47 [95%CI 0.30, 0.74] P&lt; 0.0236). Median OS was 17.4 months versus 13.7 months in the TMZ/TTFields versus TMZ alone arm, respectively (HR 0.51 [CI 0.33, 0.77] P&lt; 0.020). Serious adverse events (SAEs) were reported in 39% of patients treated with TMZ/TTFields and in 33% of patients treated with TMZ alone. None of the SAEs were considered related to TTFields but attributed to TMZ or to the underlying disease. Grades 1–2 skin AEs related to TTFields were observed in 51% of patients. CONCLUSION Consistent with the overall outcome of the EF-14 study, elderly patients treated with TMZ/TTFields showed significantly better OS compared to patients on TMZ alone, and without increase in grade III or IV toxicity.

scholarly journals Tumor-Treating Fields at EMBC 2019: A Roadmap to Developing a Framework for TTFields Dosimetry and Treatment Planning

2020 ◽  
pp. 3-17
Author(s):  
Ze’ev Bomzon ◽  
Cornelia Wenger ◽  
Martin Proescholdt ◽  
Suyash Mohan
Keyword(s):  
Patient Outcome ◽  
Treatment Planning ◽  
Electric Fields ◽  
Dose Distribution ◽  
Pleural Mesothelioma ◽  
Adaptive Planning ◽  
Tumor Bed ◽  
Short Overview ◽  
Tumor Treating Fields ◽  
Rigorous Treatment

AbstractTumor Treating Fields (TTFields) are electric fields known to exert an anti-mitotic effect on cancerous tumors. TTFields have been approved for the treatment of glioblastoma and malignant pleural mesothelioma. Recent studies have shown a correlation between TTFields doses delivered to the tumor bed and patient survival. These findings suggest that patient outcome could be significantly improved with rigorous treatment planning, in which numerical simulations are used to plan treatment in order to optimize delivery of TTFields to the tumor bed.Performing such adaptive planning in a practical and meaningful manner requires a rigorous and scientifically proven framework defining TTFields dose and showing how dose distribution influences disease progression in different malignancies (TTFields dosimetry). At EMBC 2019, several talks discussing key components related to TTFields dosimetry and treatment planning were presented. Here we provide a short overview of this work and discuss how it sets the foundations for the emerging field of TTFields dosimetry and treatment planning.

scholarly journals IMMU-42. DUAL ACTIVATION OF THE cGAS-STING PATHWAY AND AIM2-INDUCED PYROPTOSIS BY TUMOR-TREATING FIELDS PRODUCES ANTI-TUMOR IMMUNITY IN GLIOBLASTOMA

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii113-ii114
Author(s):  
Dongjiang Chen ◽  
Mathew Sebastian ◽  
Tarun Hutchinson ◽  
Ashley Ghiaseddin ◽  
Sonisha Warren ◽  
...  
Keyword(s):  
Electric Fields ◽  
Tumor Immunity ◽  
Type I ◽  
Cervical Lymph Nodes ◽  
Tumor Treating Fields ◽  
Type I Ifns ◽  
Alternating Electric Fields ◽  
Dual Activation ◽  
Sting Pathway

Abstract OBJECTIVES Tumor Treating Fields (TTFields) was approved in combination with adjuvant temozolomide chemotherapy for newly diagnosed Glioblastoma (GBM) patients and resulted in a significant improvement in overall survival. TTFields are low-intensity alternating electric fields that are thought to disturb mitotic macromolecules’ assembly. In many patients, a transient stage of increased peritumoral edema is often observed early during TTFields treatment, suggesting that a major component of therapeutic efficacy by TTFields may be an immune mediated process. We hypothesize that TTFields activate the immune system by triggering pyroptosis and type I Interferon (IFN) response. METHODS A panel of GBM cell lines were treated with TTFields at the clinically approved frequency of 200 kHz using an in vitro TTFields system. Cells were analyzed for the production of micronuclei and activation of both pyroptosis and STING pathways using immunostaining, quantitative PCR, ELISA and cytometry. Pre-treated mouse GBM cells were injected into mouse brain to monitor survive and immunophenotyping. GBM patients’ blood was collected, and PBMC were isolated and analyzed by single cell RNAseq. RESULTS TTFields resulted in a significantly higher rate of micronuclei structures released into the cytoplasm, which were co-localized with two upstream dsDNA sensors AIM2 and cGAS. TTFields-activated micronuclei-dsDNA sensor complexes led to i) induction of pyroptotic cell death, as measured by LDH release assay, and through AIM2-recruited caspase1 activation and cleavage of pyroptosis-specific Gasdermin D; and ii) activation of STING pathway leading to the increase of type I IFNs and pro-inflammatory cytokines. In mouse model, double knocking down of STING/AIM2 eliminated the tumor suppression effects caused by TTFields. TTFields pretreated wild type cells successfully elevated dendritic cell level in mouse cervical lymph nodes which can be reversed by double knocking down. CONCLUSIONS These results provide compelling evidence that TTFields induces effective anti-tumor immunity in GBM cells and patients.

scholarly journals ACTR-46. TUMOR TREATING FIELDS COMBINED WITH RADIOTHERAPY AND TEMOZOLOMIDE FOR THE TREATMENT OF NEWLY DIAGNOSED GLIOBLASTOMA: FINAL RESULTS FROM A PILOT STUDY

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi23-vi24 ◽  
Author(s):  
Rachel Grossman ◽  
Dror Limon ◽  
Felix Bokstein ◽  
Deborah Blumenthal ◽  
Camit Ben Harush ◽  
...  
Keyword(s):  
Pilot Study ◽  
Electric Fields ◽  
Randomized Study ◽  
Progression Free Survival ◽  
Skin Toxicity ◽  
Tumor Treating Fields ◽  
Alternating Electric Fields ◽  
Newly Diagnosed Glioblastoma ◽  
Secondary Endpoints ◽  
Sensitizing Effect

Abstract BACKGROUND Tumor Treating Fields (TTFields) are a non-invasive, loco-regional, anti-mitotic treatment comprising low intensity alternating electric fields approved for GBM. Preclinical data show that TTFields have a radio-sensitizing effect. This pilot study evaluated the safety and feasibility of TTFields/RT/TMZ in ndGBM patients. METHODS Patients with histologically confirmed ndGBM were treated with TTFields/RT/TMZ followed by maintenance TTFields and TMZ for up to 24 months. TTFields (200kHz) were delivered for >18 hours/day with removal of the transducer arrays during RT delivery. TMZ was administered at 75 mg/m2/daily for 6 weeks and RT at a total dose of 60 Gy. The primary endpoint was safety of the combined TTFields/RT/TMZ; secondary endpoints included progression-free survival (PFS), overall survival (OS) and toxicity. Adverse events (AEs) were graded per CTCAE V4.0. RESULTS Ten patients were enrolled at a single center in Israel between April and December 2017. All patients had recovered from maximal debulking surgery or biopsy. Five patients (50%) had undergone gross total resection; rest had biopsy only. Median age was 59 and median KPS was 80. Median dose of RT was 60 Gy. Six patients (60%) reported at least one AE. The most common AE was TTFields-related skin toxicity reported in 4 patients (40%), of Grade 1–2 in severity. Two patients reported serious AEs (seizures and general deterioration) considered unrelated to TTFields. Median PFS with RT/TMZ/TTFields was 10.5 months. Median OS has not been reached. CONCLUSIONS The proportion of patients with TTFields-related skin toxicity was similar to that reported in EF-14 phase 3 study (52%). No other TTFields-related toxicities were reported. There was no increase in RT- or TMZ-related toxicities with TTFields/RT/TMZ combination. A phase 2 randomized study has been initiated to investigate the efficacy of concomitant RT/TMZ/TTFields in 60 ndGBM patients.

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