I think you may be referring to Ling-Zhi, the mushroom commonly used by the Chinese for its medicinal properties.
When I was undergoing 35 days radiation, I consumed on a daily basis double boiled bird's nest and half a tea spoon of Ling Zhi cracked spores. It has to be cracked spores to be useful. Either I was lucky or my immune system was good or the combination helped cause I had very little side effect from the radiation.
It is therefore worth a try although it is costly.