Abstract
A quantitative dose-response curve for salivary gland function in patients during radiotherapy is presented. Salivary-function data used in this study were observed from 4 previous published reports. All patients were treated with 60C teletherapy to the head and neck using conventional treatment techniques. Salivary dysfunction was determined at specific dose levels by comparing salivary flow rates before therapy with flow rates at specific dose intervals during radiotherapy up to a total dose of 6000 cGy [Gray]. Fifty percent salivary dysfunction occurred after 1000 cGy and 80% dysfunction was observed by the end of the therapy course (6000 cGy). The salivary-function curve was also compared to the previously published dose-response curve for taste function. Comparisons of the 2 curves indicate that salivary dysfunction precedes taste loss and that the shapes of the dose-response curves are different. A new term, tissue tolerance ratio, defined as the ratio of responses of 2 tissues given the same radiation dose, was used to make the comparison between gustatory and salivary gland tissue effects. Measurements of salivary gland function and analysis of dose-response curves may be useful in evaluating chemical modifiers of radiation response.