Late, persistent, substantial, treatment-related symptoms after radiotherapy (LAPERS): A new method for longitudinal analysis of late morbidity - applied in the EMBRACE study.

These findings indicate limitations of incidence methods for reporting substantial patient-reported symptoms, since a considerable proportion of patients with symptoms do not experience them persistently over time, as they may fluctuate or get successfully treated. In contrast, the LAPERS method for longitudinal analysis identifies patients with clinically relevant, long-lasting symptoms.