Mythbuster: No need to avoid creams before radiotherapy

Researchers say their findings should change clinical practice

Thin or moderate application of a topical agent before radiation therapy is unlikely to affect the skin dose, although a thick amount should be avoided, US researchers say.

Researcher Dr Brian Baumann, of Washington University in St Louis, Missouri, says the recommendation that patients avoid topical agents for several hours before daily radiotherapy because it might increase the radiation dose came into practice between the 1920s and 1950s.

That was in an era of orthovoltage radiation, which delivered a higher dose to the skin. Modern megavoltage radiation treatments now delivered a smaller dose to the skin, so this recommendation might no longer be relevant, he said.

To investigate, Dr Baumann and colleagues conducted an online survey of patients and physicians regarding topical therapy use from January 2015 to March 2017. 

They also evaluated the effect of topical agents on skin