Presented at the Meeting of the Middle Section of the American Laryngological, Rhinological and Otological Society, Inc., Minneapolis, Minnesota, January 25, 1998.
Radiation Dose to Otologic Structures During Head and Neck Cancer Radiation Therapy†
Article first published online: 2 JAN 2009
Copyright © 2000 The Triological Society
Volume 110, Issue 2, page 217, February 2000
How to Cite
Ondrey, F. G., Greig, J. R. and Herscher, L. (2000), Radiation Dose to Otologic Structures During Head and Neck Cancer Radiation Therapy. The Laryngoscope, 110: 217. doi: 10.1097/00005537-200002010-00006
- Issue published online: 2 JAN 2009
- Article first published online: 2 JAN 2009
- Manuscript Accepted: 26 DEC 1999
Background: Otologic structures are often contained within head and neck cancer radiation treatment ports. The dosimetry to otologic structures has not been routinely analyzed and radiation treatment planning does not currently attempt to specifically avoid the inner ear structures when dosimetry is calculated. Recent studies demonstrate that up to 30% of patients experience sensorineural hearing loss on multimodality therapy with cisplatin and radiation.
Methods: In the current case series, radiation dosimetry to otologic structures was calculated from computed tomogram treatment plans on patients. Fifteen nasopharyngeal, oral cavity, oropharyngeal, and hypopharyngeal cancer patients were analyzed.
Results: Between 8% and 102% of the total dose is delivered to the petrous bone/cochlea, with 4 of 15 patients getting more than 50% of the dose to at least one cochlea. The mastoid air cells received between 3% and 75% of the total dose, with higher doses being delivered to patients with bulky high neck metastases or nasopharyngeal tumors. The eustachian tubes received between 2% and 102% of the total dose, with 10 of 15 patients receiving more than 50% of the dose to this anatomic site.
Conclusion: We conclude that the cochlea and eustachian tubes receive significant radiation during treatment, particularly in nasopharyngeal cancer patients. Careful design of radiation treatment ports may allow for the reduction of radiation to hearing structures.