Radiation-Related Dysphagia: From Pathophysiology to Clinical Aspects

In Western countries, head and neck cancers (HNCs) account for about 5% of all tumors. Due to tumor locations at the aero-digestive crossroad, patients frequently suffer from swallowing dysfunction caused both by primary cancer (baseline dysphagia) and cancer therapies (treatment-related dysphagia). In this regard, radiation-induced dysphagia represents a real “Achille’s heel” which historically occurs in more than 50% of patients and can lead to a malnutritional status and an increased risk of aspiration pneumonia. In fact radiotherapy, by restricting the driving pressure of the bolus through the pharynx and/or limiting the opening of the cricopharyngeal muscle, leads to a post-swallowing pharyngeal residue that may spill into the airway causing ab inges-tis pneumonia. On the contrary, an organ preservation strategy should provide both the highest tumor control probability (TCP) and the minimum function impairment with the subsequent maximum therapeutic index gain. In this regard, intensity-modulated RT (IMRT) might reduce the probability of postradiation dysphagia by producing concave dose distributions with better avoidance of several critical structures, such as swallowing organs at risk (SWOARs), which might result in better functional outcomes. Similarly, a prompt swallowing rehabilitation provided before, during, and soon after radiotherapy plays an important role in improving oncologic swallowing outcomes.