Dr. Mary Lei is a consultant clinical oncologist specializing in the treatment of head, neck, and thyroid tumors. She undertook her undergraduate medical training at King's College London and completed specialist training at Imperial College Healthcare and Guy's and St Thomas' Foundation Trusts. Dr. Lei spent two years as a research fellow at the Royal Surrey County and the University of Surrey, focusing on image-guided intensity-modulated radiotherapy (IMRT) in head and neck cancer, earning a Medical Doctorate (MD). She is the lead for the clinical oncology radiotherapy research and development group and leads research and development for the network thyroid cancer team. Her expertise includes radiotherapy, head and neck cancer, thyroid cancer, and neuroendocrine tumors.