Osteoradionecrosis of the temporal bone. Bony necrosis and exposure of petrous temporal bone having history of radiation therapy and not healing over a period of 03 months.
Cause: The main cause is high-dose radiotherapy or high local doses of brachytherapy, given around the petrous temporal bone for malignancies of the
- Parotid gland
- External auditory canal
- Middle ear
- Maxilla
- Nasopharynx
- Pituitary.
Pathogenesis.
Due of its density (compact bone), petrous bone absorbs more radiation than soft tissues. There is also poor blood supply of the tympanic ring, which increases its susceptibility. Radiation inhibits mitosis, tissue repair, leading to vasculitis of blood vessels and avascular necrosis. It is more commonly seen in microvascular diseases (atherosclerotic and diabetic patients), or following trauma such as dental extraction.
Clinical features. It is of two types.
- Localized. Seen when petrous bone was in the periphery of the radiation field. There is mild otalgia and otorrhoea, with small areas of exposed bone in the external auditory canal. It generally occurs when the. Computed tomography (CT) shows small areas of sequestration.
- Diffuse or extensive form. Seen when radiation is directed at the petrous temporal bone. There is more severe symptoms of pain and otorrhoea. There may be erosion of the facial canal, inner ear involvement, as well as intracranial complications, brain abscesses, meningitis and death. CT shows widespread bony destruction.
Management.
Prevention. Plan radiotherapy carefully. Scheduling any surgical intervention prior to radiotherapy, and wait for full wound healing before irradiation.
Treatment.
First exclude recurrence of malignancy.
- Localized. Managed conservatively. Ear toilet with careful removal of sequestra, local antibiotics and analgesics. Healing usually takes up to 1-4 years.
- Diffuse or extensive form. Radical surgical debridement and repair is often necessary to prevent complications and effect healing. Use of hyperbaric oxygen in radiation-injured tissue and osteoradionecrosis is given but results are controversial.
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Learning resources.
- Scott-Brown, Textbook of Otorhinolaryngology Head and Neck Surgery.
- Glasscock-Shambaugh, Textbook of Surgery of the Ear.
- Logan Turner, Textbook of Diseases of The Nose, Throat and Ear Head And Neck Surgery.
- Rob and smith, Textbook of Operative surgery.
- P L Dhingra, Textbook of Diseases of Ear, Nose and Throat.
- Hazarika P, Textbook of Ear Nose Throat And Head Neck Surgery Clinical Practical.
- Mohan Bansal, Textbook of Diseases of Ear, Nose and Throat Head and Neck surgery.
- Anirban Biswas, Textbook of Clinical Audio-vestibulometry.
- W. Arnold, U. Ganzer, Textbook of Otorhinolaryngology, Head and Neck Surgery.
- Salah Mansour, Textbook of Comprehensive and Clinical Anatomy of the Middle Ear.
- Susan Standring, Gray’s Anatomy.
- Ganong’s Review of Medical Physiology.
Author:
Dr. Rahul Kumar Bagla
MS & Fellow Rhinoplasty & Facial Plastic Surgery.
Associate Professor & Head
GIMS, Greater Noida, India
msrahulbagla@gmail.com
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