Objective and subjective assessment of xerostomia in patients of locally advanced head-and-neck cancers treated by intensity-modulated radiotherapy

Abstract

Background: Parotid-sparing intensity-modulated radiotherapy (IMRT) effectively reduces xerostomia in head-and-neck cancer (HNC). Changes in the salivary output at 1 year were studied and correlation with quality of life (QOL) changes in patients of locally advanced HNC (LAHNC) was drawn.

Materials and methods: Between October 2009 and October 2011, 20 patients of LAHNC were treated with IMRT using simultaneous integrated boost technique. High-risk clinical target volume (CTV) was given a dose of 66 Gy/30 fr, intermediate-risk CTV 60 Gy/30 fr, and low-risk CTV 54 Gy/30 fr. The saliva flow rate was estimated for 5 min at rest (unstimulated) and after using lemon drops (stimulated) for the next 5 min, at baseline (pretreatment), and 3, 6, and 12 months following treatment. Evaluation of patients' perception of dry mouth was done using EORTC-QLQ-C30 and HN35 questionnaires at the same time points.

Results: Baseline unstimulated and stimulated salivary flow rates were 0.659 ml/min and 1.69 ml/min, respectively. At 3 months, a significant reduction in unstimulated (0.346 ml/min) and stimulated (0.80 ml/min) flow rate was observed. Unstimulated flow rate continued to decrease further till 6 months (0.295 ml/min), but slight improvement was seen in stimulated flow rate (0.91 ml/min). At 12 months, minimal recovery was observed in both unstimulated (0.362 ml/min) and stimulated flow rates (1.09 ml/min). EORTC-QOL questionnaire mean scores for dryness and stickiness of saliva were 10 and 15 at baseline and increased to 36 and 25, respectively, at 3 months. At 6 months, symptom score for dryness further increased to 45 and then decreased to 33 at 12 months. Stickiness score remained static from 3 to 12 months. Salivary flow rate correlated well with dry mouth (P < 0.05) but not with the perception of sticky saliva (P = 0.82) at 6 months and beyond.

Conclusions: Both salivary flow rate and xerostomia-related questions worsened at 3 months even with IMRT and showed a similar pattern of recovery.

Keywords: Head-and-neck cancer; intensity-modulated radiotherapy; xerostomia.