Commissioning a Narrowband (TL-01) Ultraviolet B Phototherapy Cabinet (Without getting your Fingers ... or Anything Else Burnt!)

Abstract

The recent introduction of narrowband UVB (TL01) phototherapy into the Dermatology Department of a general hospital is described. The initial treatment regime was modelled on that of an established centre. It is important to establish an appropriate starting dose for each patient to avoid either overdosage (resulting in painful erythema) or underdosage (slower patient throughput). Measurement of the minimum erythemal dose (MED) within the cabinet proved problematic and a separate testing device was built. The Waldmann cabinet was factory calibrated and did not appear to match a UK traceable standard (60% difference). This made it difficult to transfer dose levels between centres and between the treatment unit and the MED testing device. The treatment regime adopted has erred on the side of caution. Although this approach has been prudent it could have been improved by having UK standard treatment regimes, and consensus over dosimetry standards.