Building a New Model of Care for Rapid Breast Radiotherapy Treatment Planning: Evaluation of the Advanced Practice Radiation Therapist in Cavity Delineation.

•Examination of a new model-of-care in breast radiotherapy treatment planning.•Breast cavity contouring education and training provided by radiation oncologists.•Prospective contouring of 30 cavities by the advanced practice radiation therapist.•Physician acceptance of cavity contours was high for well-visualised cavities.•Low visibility cavity and complex delineation cases require review with physicians.