Journal
INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS
Volume 67, Issue 3, Pages 660-669Publisher
ELSEVIER SCIENCE INC
DOI: 10.1016/j.ijrobp.2006.09.021
Keywords
head and neck cancer; intensity-modulated radiation therapy; parotid salivary glands; radiation dose; Bayesian analysis
Funding
- NCI NIH HHS [R01 CA095096, P50 CA097248] Funding Source: Medline
Ask authors/readers for more resources
Purpose: A common side effect experienced by head and neck cancer patients after radiation therapy (RT) is impairment of the parotid glands' ability to produce saliva. Our purpose is to investigate the relationship between radiation dose and saliva changes in the 2 years after treatment. Methods and Materials: The study population includes 142 patients treated with conformal or intensity-modulated radiotherapy. Saliva flow rates from 266 parotid glands are measured before and 1, 3, 6, 12, 18, and 24 months after treatment. Measurements are collected separately from each gland under both stimulated and unstimulated conditions. Bayesian nonlinear hierarchical models were developed and fit to the data. Results: Parotids receiving higher radiation produce less saliva. The largest reduction is at 1-3 months after RT followed by gradual recovery. When mean doses are lower (e.g., < 25 Gy), the model-predicted average stimulated saliva recovers to pretreatment levels at 12 months and exceeds it at 18 and 24 months. For higher doses (e.g., > 30 Gy), the stimulated saliva does not return to original levels after 2 years. Without stimulation, at 24 months, the predicted saliva is 86% of pretreatment levels for 25 Gy and < 31% for > 40 Gy. We do not find evidence to support that the overproduction of stimulated saliva at 18 and 24 months after low dose in 1 parotid gland is the result of low saliva production from the other parotid gland. Conclusions: Saliva production is affected significantly by radiation, but with doses < 25-30 Gy, recovery is substantial and returns to pretreatment levels 2 years after RT. (c) 2007 Elsevier Inc.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available