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

Abstract

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