Hypothesis: The underlying mechanism of irradiation-induced injury to the salivary glands was an enigma for French radiobiologist Jean Bergonie,1 who first described the phenomenon in 1911. Bergonie was also the scientist who characterized as "radiosensitive" tissues that, like hematological stem cells, are composed of primitive, undifferentiated cells with a high mitotic rate; and yet he was aware that salivary cells, which are highly differentiated (especially serous acinar cells), and have a low mitotic rate, are particularly radiosensitive. The enigma has not been solved and xerostomia still causes much discomfort. Annually, irradiation-induced xerostomia affects between 30 000 and 50 000 individuals treated for head and neck cancer in the United States alone.
Nagler RM, Baum BJ. Prophylactic Treatment Reduces the Severity of Xerostomia Following Radiation Therapy for Oral Cavity Cancer. Arch Otolaryngol Head Neck Surg. 2003;129(2):247-250. doi:10.1001/archotol.129.2.247