Importance: The majority of the patients with head and neck cancer (HNC) experience taste dysfunction (TD) during or after radiotherapy (RT). However, prospectively collected data for taste dysfunction have been limited, especially in the era of intensity-modulated RT (IMRT).
Objective: To evaluate the taste function in patients with HNC receiving IMRT by investigating the association between time course and recovery of TD in both acute and late phases.
Design, setting, and participants: From August 2017 to November 2020, patients treated at the Chang Gung Memorial Hospital with curative or postoperative IMRT for HNC were enrolled in this prospective cohort study. The data analysis was performed from March 2021 to January 2022.
Exposures: IMRT with and without concurrent chemotherapy.
Main outcomes and measures: Taste function was measured using the whole-mouth solution method for 4 tastes (salt, sweet, sour, and bitter). Subjective evaluations (National Cancer Institute Common Terminology Criteria for Adverse Events [version 4.03] and Subjective Total Taste Acuity scale) were used. Patient self-reported quality of life was evaluated using European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Head and Neck Module (EORTC QLQ-H&N35).
Results: A total of 87 patients (78 [90%] men and 9 [10%] women; mean [range] age, 58 [31-80] years) were enrolled. Overall TD rates were 79 of 86 (91.9%), 63 of 83 (75.9%), 27 of 81 (33.3%), 5 of 56 (8.9%), and 2 of 30 (6.7%) during RT, and 1 week, 3 months, 6 months, and 1 year after RT, respectively. Positive correlation occurred between objectively measured taste loss for the 4 taste qualities and subjective perception of taste loss. Only oral cavity mean dose 4000 cGy or greater predicted TD 3 months after RT. The mean oral cavity doses to the predicted 15% (D15), 25% (D25), and 50% (D50) probabilities were 25, 38, and 60 Gy at 3 months and 57, 60, and 64 Gy at 6 months, respectively.
Conclusions and relevance: In this cohort study, most patients still experienced TD during and at 3 months after RT. Only a few patients experienced long-term TD. A high oral cavity dose was associated with TD in patients with HNC receiving IMRT. Reducing oral cavity dose may promote early recovery of taste function after IMRT.