Differential kinetics of parotid and submandibular gland function as demonstrated by scintigraphic means and its possible implications.

Is the differential kinetics of secretion of saliva between the parotid and submandibular glands responsible for the relative difference in radiosensitivity? Radiation-induced dysfunction is more often noted in the parotid glands than the submandibular glands. This difference in susceptibility is often attributed to the difference in the cellular composition of these glands. During our studies using 99Tcm-pertechnetate to quantitate salivary gland function in patients treated with radioiodine, we noted frequent unstimulated discharge of saliva from the submandibular glands compared with parotid secretion. We hypothesize that the relative resistance of the submandibular glands could be due to the differential kinetics of the parotid and submandibular glands, as evidenced by using 99Tcm-pertechnetate to study their function.