ESTRO 2021 Abstract Book

S944

ESTRO 2021

Conclusion Several hypotheses have been advanced to explain the pathological pathways leading to possible break of immune tolerance during RT, but the mechanism is still poorly understood and the decision to offer radiotherapy in this setting continues to be challenging. In our experience, quiescent-phase ARDs seemed not to affect radiotherapy toxicity, and all the reported adverse events were low grades. Nowadays, literature experiences in irradiating patients with ARDs are in the form of exiguous retrospective studies and case reports, and we have no data to assess the best-tolerated dose and fractionation schedules in this subset.