Effects of irradiation with conventional and multiple daily fractionation on serum amylase activity

The behaviour of serum alpha-amylase activity was determined in patients with head and neck cancer treated by radiation therapy. The levels of serum alpha-amylase activity during conventional and multiple daily fractionation were compared. Starting from the second day of treatment an increase of serum alpha-amylase activity was observed. The increase and its duration depended on the total daily dose: after the first day of treatment a linear correlation between serum levels and total daily dose could be observed. The size of the amylase increase correlated to the proportion of salivary gland tissue included in the irradiated volume.