One aspect of the present disclosure relates a method of diagnosis and/or treatment of a solid tumor. The method includes directly measuring neural activity within a solid tumor for a time and determining a state of the solid tumor based on the neural activity. The diagnosis and/or treatment can be determined based on the state of the solid tumor. In some instances, the neural activity can be used in a closed loop to detect the neural activity, determine the state, determine the risk, apply treatment, check again for neural activity, and cease treatment when the neural activity is gone.
