Learning Objectives: To assess the utility of DWI imaging in the assessment of recurrence of extensive petrous bone cholesteatomas.

Methods: A prospectively updated database of patients who had undergone surgery for extensive petrous bone cholesteatoma was interrogated. All patients had undergone annual DWI imaging. Data was collated including extent of disease, surgical approach and recurrence based on clinical assessment and DWI imaging. Analysis of factors associated with recurrence was undertaken.

Results: 63 patients were included. Age range was 10 to 83 years. 60% presented with good facial function (House-Brackmann grade I or II) and 33% presented with useable hearing. The most common location of disease was supralabyrinthine 33%) although 28 (44%) had apical disease. Complications were limited with one patient developing a CSF leak, one patient an abdominal wall haematoma, and one patient an infection in the wound. 11% had residual hearing following surgery. 63% had good facial function at 1 year post operatively. 5% had clinically apparent residual/recurrent cholesteatoma but 30% had residual/recurrent disease on DWI imaging. 70% of recurrence was initially managed conservatively but 60% eventually required repeat surgery.

Conclusions: DWI MRI is a useful technique for confirming the diagnosis and assessing extent of petrous bone choleseatoma. It has also become the gold standard for identification of recurrent disease and has much better sensitivity and specificity than clinical assessment. Its extensive use has demonstrated that recurrence rates of petrous bone cholesteatoma are much higher than historic papers based on clinical assessment would suggest. Not all recurrence requires treatment, however.