Aria version 15

All patients treated with RT between 2011 and 2019 at our Department of Radiation Oncology were included into this analysis and were screened for treatment with multiple RT courses. A course of RT was defined as a prescribed treatment to one anatomical site under the umbrella of one medical indication at one particular point in time in the patient history. Regarding the time dimension, for a RT to count as a new course, a minimum of 30 days needed to elapse since the last RT. For example, a patient having undergone RT for an oropharynx primary and for two lung metastases 6 months later, was counted as having received two courses of RT. However, a patient with small cell lung cancer (SCLC), who received RT to the primary and to synchronous brain metastasis, was counted as having received one course of RT only. The total number of RT courses was assessed in the Record and Verify System (Aria® Version 15, Varian®). We used the term multiple repeat RT (MRRT) to characterize a unique cohort of patients, who were treated with minimum five radiotherapy courses during their disease history. A minimum of five RT courses was chosen for inclusion into this study because of the lack of safety and efficacy data in the literature about such patients.

All patients included in this study received at least five courses of RT at the Department of Radiation Oncology of the USZ within the last decade. This large number of RT courses was chosen to investigate the most complex cohort of patients with the most treatments and year-long follow-up, where continuity and coordination of care appear most important. A cut-off of two or three RT treatments seemed too low to adequately assess continuity and coordination of care over time, which is why a minimum of five RT courses was chosen. A RT course was defined as a prescribed RT regimen to one anatomical site for one medical indication. To identify this patient cohort, we screened all treatment records in the Record and Verify System (Aria® Version 15, Varian®) to long-list patients who received at least five RT courses between 2011 and 2019. We used the term multiple repeat RT (MRRT) to characterize the treatment of such patients. A short-list of patients was then obtained by selecting patients who were still alive at the time of study design and initiation in fall 2020.