Implementation of durvalumab maintenance treatment after concurrent chemoradiotherapy in inoperable stage III non-small cell lung cancer (NSCLC)-a German radiation oncology survey

Background: Durvalumab as maintenance treatment after platinum-based concurrent chemoradiotherapy (cCRT) has become the standard of care in inoperable stage III non-small cell lung cancer (NSCLC). In this nationwide survey, we solicited members of the German Radiation Oncology Society to review the current distribution and clinical settings of durvalumab treatment after cCRT, observed side effects and summarize follow-up management. Methods: We surveyed radiation oncology institutions in Germany via an anonymous online questionnaire sent by e-mail to all members of the German Radiation Oncology Society which agreed their willingness to participate. Results: We received a total of 255 responses (response rate: 18%). Of which 203 (80%) were completed and returned and thus eligible for further evaluation. The respondents work in 87 different cities and 44% in a private medical practice, 29% in university and 22% in a general hospital. Durvalumab was implemented in clinical routine by 70% of respondents. Major reasons for failed implementation in clinical practice reported by the respondents were patient's ineligibility (42%), lack of required PD-L1 status (25%), decision of medical oncologists (7%) or absence of updated German guidelines (7%). Thirty-six percent of all respondents report low (<= 30%) PD-L1 testing before cCRT based on IHC assay. No respondent had applied durvalumab in less than 14 days after the completion of CRT. Severe side effects requiring hospital admission in more than 10% of all patients were reported by 12% of all respondents. Conclusions: Durvalumab maintenance is already implemented in the radiation oncology community and administered by the absolute majority of respondents. Low testing rates of PD-L1 at initial diagnosis were observed and should be considered a major barrier to universal adoption and integration in the clinical work-flow in countries with durvalumab approval restricted to PD-L1 positive patients. No respondent applies durvalumab in less than 14 days after cCRT.