Does hyperbaric oxygen treatment have the potential to increase salivary flow rate and reduce xerostomia in previously irradiated head and neck cancer patients? A pilot study.

Irradiated head and neck cancer survivors treated in the Hyperbaric Oxygen (HBO) Unit, Copenhagen University Hospital, spontaneously reported improvement of radiation-induced dry mouth feeling. The aim of this pilot study was to evaluate salivary flow rate and xerostomia before and after HBO in irradiated head and neck cancer patients. Eighty patients eligible for HBO treatment on the indication of prevention/treatment of osteoradionecrosis or soft tissue radiation injury were consecutively sampled, of whom 45 had hyposalivation (i.e. unstimulated whole saliva (UWS) flow rate <0.1ml/min), and 69 complained of xerostomia. UWS and stimulated whole saliva (SWS) were collected prior to and after 30 sessions of hyperbaric oxygen treatment over 6weeks. Xerostomia was assessed using the visual analogue scale (VAS). Each HBO session involved compression to 243kPa (2.4 ATA) for 90min while breathing 100% oxygen from a facemask or hood. There was a significant decrease in xerostomia (p<0.001) and slight increase in UWS (p<0.001) and SWS (p<0.001) flow rate, from before HBO as compared to after. Twenty-five of 45 patients with hyposalivation achieved an increased UWS flow rate after HBO. In 12 of these, the flow rates increased to levels not associated with hyposalivation. Patient-assessed improvement of xerostomia and slightly increased UWS and SWS secretion after HBO treatment suggest that HBO may have a beneficial effect on radiation-induced salivary gland damage.