Effect of radioactive iodine therapy on parotid gland function

In 37 males and females with thyroid carcinoma, treated with radio-iodine, parotid gland function was investigated before and one week after therapy. 34 subjects remained free of complaints and showed no effect of 131I-therapy on parotid flow rate. Following therapy, all of them showed alterations in the composition of parotid secretion, especially enhanced values for alpha-amylase activity, protein concentration and sodium concentration. Three subjects developed acute parotitis of the obstructive sialadenitis type. In these patients, flow rate was severely reduced. The values for PHI, sodium, alpha-amylase and protein in parotid saliva were markedly elevated. Just as in chronic recurrent parotitis, increased activity of salivary glandular kallikrein in radio-iodine sialadenitis was measured.