More than 50% of cancer patients have radiotherapy (RT) as part of their care pathway. Scientific and technological advances leads to an increase in demand. The development of hypofractionation is also increasing the capacity to treat more patients. These transformations raise questions from an organizational point of view, the quality of care and the response to patient needs.

Several publications highlight that evaluating patient's experience, satisfaction, and collecting their ideas are excellent foundations for delivering patient-centered care (3,4). To assess the patient experience in RT, Olausson et al. developed and validated a questionnaire in English. To this day , this questionnaire has not been validated in French.

The main objective is to validate the psychometric property of reliability of the Radiotherapy Experience Questionnaire (RTEQ) after its adaptation into French. This project also includes an assessment of patient satisfaction regarding their RT care pathway.

This study is part of a broader initiative aimed at redesigning the patient journey in radiotherapy, and innovating in the tools and in the overall care approach.

There will be 4 steps in this study.

• Phase 1: the RTEQ has been adapted into French by a working group. Phase alreaday completed.
• Phase 2: this is the RTEQ pre-test translated into French. Currently in progress. Comprehension of the questionnaire will be assessed in 50 patients at the Centre Leon Berard (CLB) to obtain the final French version. Patients will complete the RTEQ and a debriefing questionnaire at a time. Patients undergoing hypofractionated RT (between 2 and 10 sessions) as well as patients with more than 11 sessions will be included. Patients undergoing hypofractionated RT will complete the questionnaire at the penultimate session. Patients with at least 11 sessions will be included and will complete the questionnaire during the last week of treatment. The debriefing questionnaire has been developed to determine whether the questionnaire is too long, whether each questions are clear and comprehensive or not.
• Phase 3: pre-test analysis. A descriptive analysis of the responses to each item, as well as the debriefing questionnaire, will be carried out. A meeting with the working group will decide on the necessary modifications for a final version.
• Phase 4: Paucicentric study + validation of the psychometric properties of the RTEQ in French.

Patients will complete the RTEQ and the EORTC PATSAT-C33 questionnaire.

• Group 1: For patients undergoing hypofractionated RT: one measurement period, between Days 2 and 7 (Time n°1).
• Group 2: For patients with at least 11 sessions, two measurement periods: during the first week between Days 2 and 7 (Time n°1) and then during the last week (Time n°2).

Inclusion Criteria:

• Age >= 18 years
• Patient requiring curative external radiotherapy (at least 2 sessions)
• Patient covered by a medical insurance
• Patient informed and not opposing to the study

Exclusion Criteria:

• Patient who don't understand or can't read French
• Any congitive impairment or condition likely to limit the use of scales and questionnaires
• Patient requiring tutorship or curatorship or patient deprived of liberty