Radiation Therapy for Post Parotidectomy Fistula

摘要

The incidence of parotid fistula following the surgery has been reported to be about 14%. The parotid fistula can be a very troublesome problem for the patient as it compromises the quality of life. It may result in wound dehiscence, and infection. Though several treatment modalities have been described in the literature but there is no consensus. The various management options include complete parotidectomy, tympanic neurectomy, radiation therapy, pressure dressings, anticholenergics and, of late, local injection of botulinum toxin. Radiation therapy had been in use as early as in 1936, but the number of cases is too scanty to make this as established modality. We describe a case of postparotidectomy fistula successfully treated by external beam radiation therapy. Case Report A 24 year old male patient presented to the Oto-Rhino-Laryngology department of our hospital in June 2001 with the complaint of a discharge from the right ear. Past history revealed that the patient had undergone surgery in a private hospital 5 months ago for a parotid abscess. He was subsequently diagnosed to have a fistulous connection between the right parotid gland and the external auditory canal and was taken to the oprating room for a partial parotidectomy along with fistulectomy. He was free of symptoms until December 2003 when he noticed a persistent ear discharge more so during swallowing of food and liquids. Contrast enhanced CT scans demonstrated a salivary fistula in the deeper part of ear canal with a sialo-pneumocele in the parapharyngeal region. A catheter was inserted in the sialo-pneumocele to drain the discharge, but he continued to have the persistent ear discharge. Surgery was not contemplated in view of the risk of injury to the facial nerve and therefore planning was made for ipsilateral parotid irradiation. Planning CT scan was done in supine position with the head turned to left side and immobilized with a cast. Both parotids were marked along with the other important adjoining structures like eyeball, spinal cord etc. The target volume consisted of the right parotid and a further 5mm surrounding margin. A dose of 30 Gy in 15 fractions over 3 weeks was delivered by the Linear Accelerator (Clinac 2300 CD) with mixed Photon and Electron beam (Fig. 1). He had complete relief of ear discharge at the end of the course of radiation.