Is it safe to irradiate a patient with Cowden syndrome?

I irradiated 1 patient with breast cancer and Cowden syndrome about 25-30 years ago and she tolerated it well without any unusual early or late toxicity

I irradiated a patient with Cowden Syndrome last year and she developed profound fatigue from radiation, so much so that we had to stop treatment.

I have never done it for limited data and concern for toxicities.