Iron Maiden says singer Bruce Dickinson has been treated for cancer of the tongue, but hopes to be back to full fitness soon.

A statement posted Thursday on the band’s official website says a cancerous tumor was discovered during a check-up in December, and Dickinson has completed a seven-week course of chemotherapy and radiotherapy.

It says the prognosis is “extremely good,” and doctors expect Dickinson to make a full recovery, “with the all-clear envisaged by late May.”

Dickinson, who is 56, joined the British metal megastars in the early 1980s, and is also a commercial airline pilot. Iron Maiden’s hits include “Run to the Hills” and “The Number of the Beast.”