Influence of intensity-modulated radiation therapy technique on xerostomia and related quality of life in patients treated with intensity-modulated radiation therapy for nasopharyngeal cancer

Abstract

Background: The purpose of this study was to compare 5-field and 7-field intensity-modulated radiation therapy (IMRT) techniques in terms of xerostomia and related quality of life in patients with nasopharyngeal cancer.

Methods: Eight and 23 patients were treated with 5-field (group I) and 7-field (group II) techniques, respectively. The xerostomia was evaluated using the Radiation Therapy Oncology Group (RTOG) scale, stimulated and unstimulated salivary flow (SSF/USF), and xerostomia-related questionnaires (XQs). The assessments were done before and at 3, 6, 12, 18, and 24 months after radiotherapy.

Results: The mean parotid dose was 45.7 Gy and 29.9 Gy and the ≥G3 toxicity at 24 months was 25% and 19% in group I and II, respectively. Sixty-three percent and 93% of patients recovered at least 25% of SSF pretherapy values. The XQ scores of both groups improved over time but more so in group II.

Conclusion: The 7-field technique decreases the mean parotid dose, reducing xerostomia assessed by the RTOG/XQ score.