Xerostomia occurs after what dosage of cGy?

Xerostomia, or dry mouth, often occurs as a side effect of radiation therapy, particularly when the salivary glands are exposed to radiation. Research and clinical observations indicate that the onset of xerostomia can begin at doses around 1,000 cGy (or 10 Gy). This threshold is significant because it aligns with the amount of radiation that starts to damage the salivary glands enough to reduce saliva production, leading to the symptoms associated with xerostomia.

At lower doses, such as 500 cGy or 750 cGy, the risk of developing xerostomia is considerably lower, as these doses typically do not result in substantial damage to the function of the salivary glands. It is primarily at the 1,000 cGy level where the cumulative effects of radiation can lead to observable dry mouth symptoms due to the impairment of glandular function.

Thus, identifying 1,000 cGy as the threshold for when xerostomia is likely to occur is grounded in both clinical evidence and research findings regarding the tolerance of salivary glands to radiation.