880 Otolaryngology (ENT) Surgeons’ Understanding of Radiation Doses to the Eyes

Aim

Computed tomography (CT) scanning is an invaluable asset in ENT diagnostics. This snapshot study aimed to assess the knowledge ENT surgeons have regarding dose equivalence and dose accumulation of commonly requested.

Method

A sample of 302 dose length products (DLPs) for CT neck with and without contrast, CT sinuses and CT temporal bones were taken from anonymous data in Swansea University Health Board. ENT surgeons were asked to rank the mean doses, state a numerical dose and maximum scan number for each.

Results

From highest to lowest dose, the CT scans rank as follows: 1. Neck with contrast, 2. Neck, 3. Temporal bones, 4. Sinuses. CT neck with contrast was correctly ranked by 62.5% of surgeons, CT neck by 50%, CT sinuses by 12.5%, and CT temporal bones by 37.5%. Seniority of the surgeon did not affect the accuracy of their rankings.

While there is no maximum dose for patients, the maximum doses for bystanders were used to calculate dose equivalence to assess the impact of the scans. The maximum dose would be reached after having 3 CT temporal bones, 2 CT neck, 1.7 CT neck with contrast, and 7 CT sinuses. 84.3% overestimated the maximum number of scans, 12.5% underestimated the maximum, and 3.1% correctly estimated the maximum.

Conclusions

Radiation doses to the lens are poorly understood by ENT surgeons of all levels and while patients can receive as many scans as necessary to provide diagnostic value, it is important to understand the relative risk patients face by undergoing these scans.