by Katrina M. Jensen, Fort Worth, Texas, USA
Radiation fibrosis is documented to have a large impact on the overall strength of the muscles used in swallowing. This is true in all head and neck cancer patients where there has been a significant radiation dose to the structures of swallowing. In the laryngectomy population, this is an added consideration in how the swallow has been impacted. In the case of radiation fibrosis, there has been an alteration of the muscle fibers that are responsible for contracting and moving the food from the mouth through the throat and into the stomach. The effects of this fibrosis can vary greatly but typical changes include stiffness, where the muscle or structure (such as the tongue) is no longer a soft and flexible as it was prior to radiation treatment. In addition, radiation fibrosis within muscle tissue is also knows to have a significant impact on the muscle’s ability to fully contract , essentially accounting for a weakness within the swallowing muscles as they are no longer able to contract as strongly. In many cases, muscles impacted by radiation fibrosis are able to become stronger with targeted therapy, although the reports vary greatly as to how effective this is in light of the changes to the muscle fibers themselves [12,13].