High-frequency noise is present in several modalities of medical images. It originates from the acquisition process, scanner configurations, the scanned body, or to other external factors. This way, prospective filters are an important tool to improve image quality. In this paper, we propose a non-local weighted operational anisotropic diffusion filter and evaluate its effect on magnetic resonance images and on kV/CBCT radiotherapy images. We also provide a detailed analysis of non-local parameter settings. Results show that the new filter enhances previous local implementations and has potential application in radiotherapy treatments.