Detection of (Sub)Clinical Toxicity in Irradiated vs. Non-irradiated Surgically Treated Esophageal Cancer Patients: a Pilot Study (CROSS SECT)

Rationale: Radiation-induced cardiac and pulmonary toxicity after treatment for intra-thoracic tumors is a clinically relevant problem, which may jeopardize the benefit of (neo-adjuvant) (chemo) radiotherapy. Although cure rates are rising since the introduction of neo-adjuvant chemoradiation (neo-CRT) as current standard treatment for esophageal cancer (EC), recent studies showed that there is a substantial risk of non-cancer treatment-related death in these patients. Furthermore, this risk is underestimated as the cause of death of many patients remains unknown, since the distinction between tumor related and non-cancer related death can be difficult. Cardiac and pulmonary toxicity and its interaction as seen in pre-clinical studies might explain for these unknown deaths as suggested in several clinical studies. Clinical imaging studies performed shortly after treatment showed changes in different cardiac function parameters, all related to radiation dose parameters. Systematic imaging studies analysing subclinical toxicities at longer follow up have never been performed, most probably because of poor survival rates. However, identification of the magnitude of (subclinical) cardiopulmonary toxicity, by performing several cardiopulmonary function tests, is essential in this patient group as this toxicity is most likely the cause of the increased mortality after thoracic radiotherapy. For future perspectives, these results can be used to select the best diagnostic methods for a prospective cohort study to develop prediction tools for cardiopulmonary toxicity.. Objective: The main objective of this study is to determine the most suitable diagnostic test to identify cardiopulmonary (dys)function in EC survivors treated with neo-CRT followed by surgical resection. Furthermore, we want to estimate the difference in cardiopulmonary (dys)function in EC survivors treated with neo-CRT followed by surgical resection compared to EC survivors who were treated with surgical r