Time course and significance of acute hyperamylasemia in patients receiving fractionated therapeutic radiation to the parotid gland region.

To improve our understanding of hyperamylasemia secondary to parotid gland irradiation, serial serum amylase levels were measured from 12 consecutive patients who received incidental parotid irradiation during radiotherapy of their head and neck tumors. Rapid transient increases in enzyme activity, limited to the first days of radiotherapy, were consistently found. Awareness of the frequency and nature of this response may avoid unnecessary investigation and concern for abdominal pathology in this clinical setting.