Taste Buds

Taste buds are primarily located on the circumvallate and fungiform papillae of the tongue, with smaller distributions on the tonsillar pillars, base of the tongue, soft palate, pharynx, and larynx. Hypogeusia, a reduced ability to taste, or ageusia, a complete loss of taste perception for sweet, sour, bitter, or salty substances, is an early and common complaint among patients undergoing head and neck radiotherapy. Histological changes in taste buds appear at 10 Gy, with higher doses leading to their complete obliteration.¹³

Taste acuity may decline by a factor of 1,000 to 10,000 due to direct radiation-induced damage to the taste buds or secondary effects such as impaired salivary function and mucositis. Perception of acidic and bitter tastes is affected early, while sweet and salty sensations diminish as treatment progresses. Although taste sensation generally recovers within 2–4 months following radiotherapy, some patients may experience permanent alterations or a lifelong loss of taste perception.¹³