[Radioprotective effects of hypoxyradiotherapy on saliva secretion]

In radiotherapy, use of an enormous radical dose may be necessary. However, it is sometimes limited by the poor tolerance of the surrounding normal tissues. Transient systemic hypoxia induced by breathing 10.5% oxygen gas during radiotherapy may protect the normal tissues. In treating non-Hodgkin's lymphoma (NHL) involving the Waldeyer's ring, radioprotective effects of hypoxia on radiation responses of the pharyngeal mucosa and saliva secretion were observed, giving a radioprotective factor (RPF) of 1.43 in saliva quantity and 1.31 in ptyalin secretion. Other responses were milder and occurred later.