System and methods for determining placement of a transducer array relative to a subject's head, which may be used in treating cancer in the subject, are provided. These techniques may include constructing, based on one or more images, a representation of the subject's head that includes information for a plurality of structures including one or more tumors positioned within the subject's brain. The representation of the subject's head may be used to calculate electric field propagation for one or more arrangements of a transducer array on a surface of the subject's head. These techniques may further include determining one or more rate of energy absorption distributions and/or one or more electric field distributions using the calculated electric field propagation for multiple arrangements of the transducer array. A rate of energy absorption distribution may indicate a rate of energy absorbed at the one or more tumors. An electric field distribution may indicate an amount of electric field at individual regions of the subject's brain that include the one or more tumors and span across the entirety of the subject's brain. Using the one or more rate of energy absorption distributions and/or the one or more electric field distributions, an indication of how to place the transducer array on the subject's head such that at least a portion of the one or more tumors are exposed to electric fields emitted by the transducer array may be generated.
