In an asymptomatic patient, would this be safe?

Is there any reason to withhold radiation such as in case of T1N0 breast cancer advising patient to not do breast conservation but instead get mastectomy?

I’ve only found two case reports- one in which this was very toxic https://www.redjournal.org/article/S0360-3016(17)33150-4/fulltext
And the other in which no mention of toxicity is made (http://www.jnccn.org/content/13/11/1310.full.pdf). Wondering if anyone knows of other series or has personal experience in terms of toxicity, tolerance and potential late effects.