A new grid electrode for electrochemotherapy treatment of large skin tumors

Abstract

Electrochemotherapy (ECT) is a local anticancer treatment for superficial tumors which involves the administration of a chemotherapeutic drug followed by short, high-voltage pulses. Incipient clinical experience with breast cancer patients are encouraging, with a local complete response rate ranging from 50 to 90%. However, since many patients present with multiple or widespread metastases, ECT, despite its high local antitumor efficacy, need to be applied several times in order to complete treatment delivery or maintain tumor control during the follow-up. In this paper, we propose the prototype of a new grid electrode aimed at the improvement of ECT application. The device is suitable for treating large, tumor-infiltrated skin surfaces as in breast cancer patients with chest wall metastases after mastectomy. According to our tests in different in vitro models, the new device allows to apply the voltage pulses more quickly and homogeneously when compared with standard pulse applicators. This technical advancement holds promise for improving ECT outcome and, hopefully, for sparing a number of patients from the need of multiple treatments

Controlled inactivation of Trichophyton rubrum using shaped electrical pulse bursts: Parametric analysis

“…Taking into account the experimental data that was acquired in our work, the PEF treatment methodology also could be a potent alternative method for treatment of the fungal infections in vivo. Currently, various microneedle and grid electrode arrays for skin electroporation, gene vaccination and tissue ablation are already available . Also non‐invasive electrode configurations are being proposed .…”

“…Currently, various microneedle and grid electrode arrays for skin electroporation, gene vaccination and tissue ablation are already available. [27][28][29] Also non-invasive electrode configurations are being proposed. 30 However, irreversible electroporation may result in thermal effects dependent on the pulse parameters and the total energy of the pulse procedure.…”

Electric field distribution study in inhomogeneous biological tissues

“…Eight, unipolar square voltage pulses, generated using BTX ECM 830 electroporator (Genetronics Inc, San Diego, California), were applied at the needles, at a frequency of 1 Hz, and at a pulse length 100 microseconds were applied to all the potato samples, both homogeneous and inhomogeneous. The pulse parameters are chosen as in Castiello et al 15 and Ongaro et al 35 The F I G U R E 1 A, Samples prepared. B, Set-up for electrical conductivity measurements 34 voltage pulses were applied by means of an electrode formed by a pair of needles, 1-cm long with a diameter of 0.5 mm, similar to the model in Figure 2, where the cylinder with a diameter of 9 mm was casted with one of the gels in Table 1.…”

“…Hence, this type of electrodes is able to cover a small surface (few cm 2 ), and they require multiple applications for treating larger areas, thus extended time of operation and theater and sedation of the patient . To alleviate this, a large grid electrode has been designed and developed . However, since a larger area is covered by the grid electrode, there is tissue inhomogeneity to be taken into account for the application of electrochemotherapy on large areas, like chest wall carcinoma after mastectomy .…”

“…14 To alleviate this, a large grid electrode has been designed and developed. [14][15][16] However, since a larger area is covered by the grid electrode, there is tissue inhomogeneity to be taken into account for the application of electrochemotherapy on large areas, like chest wall carcinoma after mastectomy. 2,3 Because of scars and variable amounts of extraneous tissues, including blood vessels and their contents, connective tissues, necrotic and dead cells, fat, and other inhomogeneities in the solid tumors, including irregular vascularization, pH variations, and heterogeneous oxygen concentration, 17 the remaining surface could have tissue inhomogeneity, since different tissues show different resistivity value at nonelectroporated condition.…”