Whole saliva physico-biochemical changes and quality of life in head and neck cancer patients following conventional radiation therapy: A prospective longitudinal study

Background: We investigated the physico-biochemical changes in saliva and its relation to quality of life (QOL) in head and neck cancer patients following conventional radiation therapy (RT). Materials and Methods: 53 consecutive head and neck cancer patients underwent conventional RT using telecobalt photons. We analyzed objective sialometry and sialochemical parameters of salivary gland function and a physician reported Oral Assessment Protocol to assess the patients' QOL during (baseline, 3 and 6 weeks) and post RT (3 and 6 months). Statistical analysis was done using SPSS software (version 15.0; SPSS, Inc., Chicago, IL, USA). Results: Stimulated salivary flow rates had shown a consistent decline during and in post-RT analysis (P < 0.001). A significant correlation was seen between mean salivary flow rates at 6 months post-RT and mean salivary electrolytes and amylase levels during the same period (P < 0.001). Mean global QOL scores had significantly worsened during RT and were still significantly poorer at 6 months than initial pre-RT levels (P < 0.001). Further, significant correlation was established between salivary pH values with global QOL scores at 6 months (P = 0.05). Conclusions: Radiation-induced hyposalivation invariably persists and correlates with poor global QOL scores seen during and following conventional RT. Post RT, there is a trend for biochemical reversal toward pre-irradiation levels suggesting a subsiding inflammation or a probable functional recovery