Dr. Shemen completed his residency training in General Surgery at the University of Toronto and Cedars-Sinai Medical Center in Los Angeles before pursuing specialized training in Otolaryngology–Head and Neck Surgery at the University of Toronto. Following his residency, he served as Chief Fellow in Head and Neck Surgery at Memorial Sloan Kettering Cancer Center, one of the world's leading cancer treatment institutions.

With over 40 years of clinical and surgical experience, Dr. Shemen remains committed to helping patients achieve the highest quality of life through expert diagnosis, innovative treatment, and compassionate care.
Dr. Shemen became a Fellow of the Royal College of Surgeons (Canada) in 1983 and was a Diplomate at the American College of Surgeons in 1984. He was appointed Program Director at Manhattan Eye, Ear, and Throat Hospital and has served as Chief of the Head and Neck Service at New York Hospital Queens for the past 15 years.

He is a Fellow of the American Academy of Otolaryngology – Head and Neck Surgery, and a member of the American Society for Head and Neck Surgery, the Society of Head and Neck Surgeons, and the New York Society of Head and Neck Surgeons.

Dr. Shemen is an Associate Clinical Professor of Otorhinolaryngology at the Weill Medical School, Cornell University and serves as a senior attending surgeon at New York Hospital Queens, Lenox Hill Hospital, and Manhattan Eye Ear Throat Hospital.

He has 80+ peer-reviewed articles and chapters focusing on thyroid and head and neck tumors, including papillary and follicular thyroid cancer. Dr. Shemen has chaired conferences and presented papers regionally, nationally, and internationally on topics including thyroid cancer symptoms and surgery, anaplastic thyroid cancer, oral cancer, and laryngeal cancer.