The purpose of this study is to identify features of the cumulative dose-volume histogram (DVH) for patients treated with trimodality therapy in oesophageal cancer and correlate these with postoperative complications.

Intention to treat analysis in patients initially assigned to be treated with the trimodality protocol: neoadjuvant chemoradiotherapy followed by surgery.

The investigators will retrospectively evaluate several parameters of the treatment planning of patients treated with a preoperative regimen (CROSS regimen 41,4 Gy in 23 fractions or 50, 4 Gy in 28 fractions ):

• PTV volume1
• MLD, V30, V20, V15, V10, VS5 (Volume lung less dan 5 Gy)2 (lung toxicity)
• MHD, V20, V30, V403 (heart toxicity)
• Mean stomach dose, V50 stomach
• Mitochondrial DNA if available per patient Pre-existing cardiac,pulmonary comorbidity, smoking behavior, BMI, type of surgery and chemotherapy (especially taxanes) will be scored and take into account in a multivariate analysis. The investigators will collect these data and correlate the data with the presence of postoperative complications, time of onset of complications and duration of hospitalization. These latter data are already scored in a prospective manner at the Atrium Medical Center in Heerlen.

Inclusion Criteria:

• Oesophageal cancer patients
• initially treated with a preoperative dose of radiation in combination with chemotherapy and subsequently undergone surgical resection

Exclusion Criteria:

• Patients who were treated with definitive chemoradiation or palliative radiotherapy

Oesophageal cancer patients who were initially treated with a preoperative dose of radiation in combination with chemotherapy and who subsequently underwent surgical resection at the Atrium Hospital in Heerlen. All patients were included in a prospectively maintained database.