53 Retrospective analyses on toxicity in esophageal cancer patients the development of these models and make them more robust in different patient groups by not only selecting the best performing variables in that cohort of patients but including the most (clinically) relevant parameters [32]. Besides this, more knowledge in mechanisms will help in early detection and preventive measurements in these patient groups. We did not find a convincing explanation for the better survival of diabetic patients in this multivariable model. The difference in overall survival in these diabetic patients in univariate analysis became apparent after 20 months, suggesting it was not tumour related but might be patient or therapy related as the highest risk for tumour recurrence is within the first two years (figure 7, suppl. data). Diabetic patients had a significantly higher dose to the lungs and experienced radiation pneumonitis more frequently but, in these patients, it did not seem to influence overall survival as much as it did in the non-diabetic patients. A possible explanation might be a stricter follow up in these patients in which more preventive measurements might have been taken. A stricter patient selection for the curative treatment schedule might be another explanation. Summarizing, cardiac dose volume parameters predicted the risk of pericardial effusion and pulmonary dose volume parameters predicted the risk of radiation pneumonitis. However, in this patient cohort, pulmonary DVH parameters (V45) were more important for OS than cardiac DVH parameters. These results suggest that reducing the cardiac dose at the expense of the dose to the lungs might not always be a good strategy in oesophageal cancer patients. 4
RkJQdWJsaXNoZXIy MTk4NDMw