Devices and methods can be used to deliver thermal therapy to treat tissue. For example, this document provides devices and methods for treating varices, varicosity, other bleeding vessels, polyps, and cancer using microwave-delivered thermal therapy in a minimally invasive fashion. In some embodiment's provided herein, a multidirectional thermal therapy that does not injure surface tissues but causes endothelial injury and coagulation is described. In some implementations, varices are suctioned into a cup that is configured to deliver thermal therapy to the varices, resulting in coagulation.