Watching old Doctor Who stories that I haven't seen in decades, I noticed that the third story with Jon Pertwee's Third Doctor, "The Ambassadors of Death" (1970), includes aliens that need to be dosed with radiation to survive and thrive. That actually seemed very similar to a plot point from the First Doctor's second story, "The Daleks" (1963); the daleks were also revealed to need radiation exposure to stay alive.
As a practical matter, needing exposure to ionizing radiation is absurd (although certainly no more absurd that some other things feature on Doctor Who). However, it does seem like a natural thematic element for science fiction from the post-war Nuclear Age. However, I suspect that "The Daleks" probably wasn't the first work to feature the idea of aliens (or perhaps monsters of some other nature) that needed regular radiation exposure. So what was the first, and was this already a well-know science fiction trope by 1963?