A new round (#4) of IROCA is being prepared, for which we plan to evaluate radiotherapy charts and patient records of patients treated in the years 2023-2024 (100 patients per institution and per tumour site). We invite radiotherapy departments wishing to participate in the IROCA project to apply. A letter of interest should be emailed to Prof. Ferran Guedea (fguedea@iconcologia.net) and Prof. Julian Malicki (julian.malicki@wco.pl).