Radiation-associated malignancies of the ear canal and temporal bone

Abstract

Objectives/hypothesis: To examine our experience with surgically treated radiation-associated malignancy (RAM) of the temporal bone.

Study design: Retrospective chart review.

Methods: Thirteen patients treated surgically for temporal-bone RAM during 1999 to 2012 were identified. Demographics, symptoms at presentation with RAM, interval between initial radiotherapy and diagnosis of RAM, pathologic features of RAM, treatment, and recurrence and survival were obtained from medical records.

Results: Ten patients had squamous cell carcinoma; three had sarcoma. The mean period between completion of radiotherapy and diagnosis of RAM was 13.38 years (range, 4.5-33.3 years). Three-year overall and disease-free survival rates were 59.8% and 42.3%, respectively. Seven patients (54%) had RAM limited to the external auditory canal (LEAC); six had RAM extending beyond it (EEAC). The mean age was 66.5 years for LEAC patients versus 41.1 years for EEAC patients (P = .0161). Compared to patients with EEAC disease, patients with LEAC disease were more likely to have negative margins (100% vs. 33%; P = .021) and less likely to have postoperative adjuvant therapy (0% vs. 67%; P = .0209). The 3-year disease-specific survival was significantly better for patients with LEAC disease versus EEAC (log rank P = .023).

Conclusions: To our knowledge, this is the largest reported series of surgically treated RAM of the ear canal or temporal bone. This study highlights the need for vigilance for RAM in patients treated with head and neck radiation.

Level of evidence: 4. Laryngoscope, 125:1198-1204, 2015.

Keywords: Radiation complications; radiation-associated tumors; sarcoma; squamous cell carcinoma; temporal bone tumors.