The Clinical Changes of Oral Cavity in Acute Phase in Head and Neck Cancer Patients Treated with Volumetric Modulated Arc Therapy

Abstract

Objectives: To investigate the incidence of acute radiation-induced toxicities including mucositis, xerostomia, dysgeusia, pulp vitality, weight loss, and quality of life (QOL) in patients with head and neck cancer (HNC) treated with volumetric modulated arc therapy (VMAT). In addition, this study aims to investigate the relationships between patient-related factors, treatment modalities, and intraoral changes during and post-treatment.

Materials and Methods: This prospective study was conducted in HNC patients receiving VMAT during January 2, 2024, to April 30, 2024. Data was collected through interviews and clinical examinations during radiotherapy and follow-ups in the first three months after treatment. Toxicity grading was assessed according to RTOG and CTCAE criteria while QOL assessment was performed using University of Washington Quality of Life Questionnaire (Version 4). The statistical analysis was done using descriptive statistics, Kaplan-Meier survival curves, log-rank tests, and Cox proportional hazard models with a significance level of p < 0.05.

Results: The patients included in this study were 31 cases totally. All experienced mucositis, xerostomia, and taste alterations during radiotherapy which occurred after a median of 10 fractions (95% confidence interval (CI): 8.66–11.34 for mucositis, 8.94–11.06 for xerostomia, 8.98–11.02 for taste alterations). The maximal grades of toxicities were grade 3 mucositis (RTOG criteria), grade 2 xerostomia (RTOG criteria), and grade 2 dysgeusia (CTCAE criteria). Tumor location in the oropharynx/oral cavity had significantly higher risk of mucositis and dysgeusia (adjusted hazard ratio (HR) 3.15 [95% CI: 1.03–9.65] and 3.34 [95% CI: 1.11–11.04], respectively). Concurrent or neoadjuvant chemotherapy increased the risk of mucositis and xerostomia (adjusted HRs for mucositis: 7.17 [95% CI: 1.17–44.16] and 11.98 [95% CI: 1.11–129.18]; for xerostomia: 4.51 [95% CI: 1.08–18.89] and 6.54 [95% CI: 1.15–37.30]). Salty and bitter taste impairments were more prevalent than sweet and sour impairments. Non-vital pulps were observed in 2.86% (3/105 teeth) during and one month after radiotherapy, with no statistically significant differences in electric pulp test across time points. At the final session of treatment, 73% of patients experienced weight loss with an average of 4.24 kg. VMAT affected body weight by 28.2%, after adjusting for feeding route differences (p < 0.001, Partial η² = 0.282). Significant changes in QOL were observed in taste alteration which started from the 11^th fraction, whereas pain, appearance, daily activity, recreation, swallowing, and salivation had significant changes from the 22^nd fraction and changes in speech occurred by the final session. There were no significant differences in chewing, shoulder function, mood, or anxiety. At three months post-treatment, persistent changes in xerostomia, salty/bitter taste alterations, and weight loss remained significant compared to pre-treatment levels.

Conclusion: Acute radiation-induced oral toxicities were observed in all patients undergoing VMAT. Most common toxicities were mucositis, xerostomia, and dysgeusia with severity of toxicity correlated with cumulative radiation dose. There were no the worst toxicity grade of mucositis and xerostomia in our study. At three months post-treatment, most toxicities showed substantial recovery to pre-treatment levels. However, xerostomia, salty/bitter taste alterations, and weight loss persisted and remained significantly different from baseline.