BACKGROUND

TTFields are low intensity (e.g., 1-4 V/cm) alternating electric fields within the intermediate frequency range (e.g., 100-300 kHz), which may be used, for example, to treat tumors as described in U.S. Pat. No. 7,565,205, which is incorporated herein by reference in its entirety. TTFields therapy is an approved mono-treatment for recurrent glioblastoma (GBM), and an approved combination therapy with chemotherapy for newly diagnosed GBM patients. TTFields can also be used to treat tumors in other parts of a person's body (e.g. lungs, ovaries, pancreas). TTFields are induced non-invasively into the target region by transducer arrays (i.e., arrays of capacitively coupled electrode elements) placed directly on the patient's body (e.g., using the Novocure Optune™ system), and applying AC voltages between the transducer arrays.

FIGS. 1 and 2depict an example of a prior art layout for positioning the transducer arrays on a patient's body for treating a tumor in the patient's thorax and/or abdomen. In this layout, first and second transducer arrays are positioned on the front and back of the patient's thorax and/or abdomen, respectively (as seen inFIG. 1); and third and fourth transducer arrays are positioned on the right and left sides of the patient's thorax and/or abdomen, respectively (as seen inFIG. 2). An AC voltage generator applies an AC voltage (e.g., 150 kHz) between the front and back transducer arrays for a first interval of time (e.g., one second), which generates an electric field with field lines that generally run in a front/back direction. Then, the AC voltage generator applies an AC voltage at the same frequency between the right and left transducer arrays for a second interval of time (e.g., one second), which generates an electric field with field lines that generally run in a right/left direction. The system then repeats this two-step sequence for the duration of the treatment.

SUMMARY OF THE INVENTION

One aspect of the invention is directed to a first method of applying an alternating electric field to a target region in a person's spinal anatomy. The first method comprises affixing a first set of electrode elements having a first centroid to the person's back with the first centroid positioned adjacent to an upper portion of the person's spine; and affixing a second set of electrode elements having a second centroid to the person's back with the second centroid positioned adjacent to a lower portion of the person's spine. After affixing the first and second sets of electrode elements, an alternating voltage is applied between the first set of electrode elements and the second set of electrode elements.

In some instances of the first method, the electrode elements of the first and second sets are capacitively coupled. In some instances of the first method, the alternating voltage that is applied between the first set of electrode elements and the second set of electrode elements has a frequency between 100 kHz and 300 kHz. In some instances of the first method, the first set of electrode elements comprises a plurality of electrode elements wired in parallel, and the second set of electrode elements comprises a plurality of electrode elements wired in parallel.

In some instances of the first method, the first centroid is positioned at a height between the T8 and T9 vertebra, and the second centroid is positioned at a height between the L3 and L4 vertebra. In some instances of the first method, the first centroid is positioned at a height above the T1 vertebrae, and the second centroid is positioned at a height below the L3 vertebrae.

In some instances of the first method, the alternating electric field has a frequency and field strength that reduces viability of cancer cells in the target region. In some instances of the first method, the alternating electric field has a frequency and field strength that suppresses an autoimmune response in the target region.

Another aspect of the invention is directed to a second method of applying an alternating electric field to a target region in a person's spinal anatomy. The second method comprises affixing a first set of electrode elements having a first centroid to the person's head with the first centroid positioned on an upper surface of the person's head; and affixing a second set of electrode elements having a second centroid to the person's back with the second centroid positioned adjacent to the person's spine. After affixing the first and second sets of electrode elements, an alternating voltage is applied between the first set of electrode elements and the second set of electrode elements.

In some instances of the second method, the electrode elements of the first and second sets are capacitively coupled. In some instances of the second method, the alternating voltage that is applied between the first set of electrode elements and the second set of electrode elements has a frequency between 100 kHz and 300 kHz. In some instances of the second method, the first set of electrode elements comprises a plurality of electrode elements wired in parallel, and the second set of electrode elements comprises a plurality of electrode elements wired in parallel. In some instances of the second method, the first centroid is positioned on the vertex of the head. In some instances of the second method, the second centroid is positioned at a height below the L3 vertebrae.

In some instances of the second method, the alternating electric field has a frequency and field strength that reduces viability of cancer cells in the target region. In some instances of the second method, the alternating electric field has a frequency and field strength that suppresses an autoimmune response in the target region.

Another aspect of the invention is directed to a third method of determining where to position a first set of electrode elements having a first centroid and a second set of electrode elements having a second centroid on a person's body before the first and second sets of electrode elements are used to apply an alternating electric field to a target region in the person's spinal anatomy. The third method comprises identifying a location of a tumor in the person's spinal anatomy; and outputting, based on the identified location, a recommendation for positioning the first and second sets of electrode elements. The recommendation is either (a) to affix the first set of electrode elements to the person's back with the first centroid positioned adjacent to an upper portion of the person's spine, and to affix the second set of electrode elements with the second centroid positioned adjacent to a lower portion of the person's spine or (b) to affix the first set of electrode elements to the person's head with the first centroid positioned on an upper surface of the person's head, and to affix the second set of electrode elements to the person's back with the second centroid positioned adjacent to the person's spine.

In some instances of the third method, the recommendation for positioning the first and second sets of electrode elements is made by (a) simulating affixation of a first set of electrode elements to the person's back at each of a first plurality of positions with the first centroid positioned adjacent to an upper portion of the person's spine, (b) simulating affixation of a second set of electrode elements to the person's back at each of a second plurality of positions with the second centroid positioned adjacent to a lower portion of the person's spine, (c) simulating application of an alternating voltage between the first set of electrode elements and the second set of electrode elements at each of the first plurality of positions and at each of the second plurality of positions, respectively, and (d) determining, based on step (c), which of the first plurality of positions and which of the second plurality of positions results in an optimized alternating electric field in the target region. In some of these instances, step (d) comprises determining which of the first plurality of positions and which of the second plurality of positions (i) maximizes a portion of the target region that has a field strength of at least 1 V/cm, (ii) maximizes uniformity of the field in the target region, or (iii) maximizes the intensity of the field in the target region.

In some instances of the third method, the recommendation for positioning the first and second sets of electrode elements is made by (a) simulating affixation of a first set of electrode elements to the person's head at each of a first plurality of positions with the first centroid positioned on an upper surface of the person's head, (b) simulating affixation of a second set of electrode elements to the person's back at each of a second plurality of positions with the second centroid positioned adjacent to the person's spine, (c) simulating application of an alternating voltage between the first set of electrode elements and the second set of electrode elements at each of the first plurality of positions and at each of the second plurality of positions, respectively, and (d) determining, based on step (c), which of the first plurality of positions and which of the second plurality of positions results in an optimized alternating electric field in the target region. In some of these instances, step (d) comprises determining which of the first plurality of positions and which of the second plurality of positions (i) maximizes a portion of the target region that has a field strength of at least 1 V/cm, (ii) maximizes uniformity of the field in the target region, or (iii) maximizes the intensity of the field in the target region.

