Abstract Book

S53

ESTRO 37

Results A total of 135 patients with esophageal cancer were included in this study. 3DCRT, IMRT and VMAT were used for neoadjuvant radiation dose delivery in 41 (30.4%), 60 (44.4%) and 34 (25.2%) patients, respectively. The three groups were comparable regarding baseline characteristics, expect for ASA score (p=.008) (Table 1). Dose distribution to the lungs varied significantly between the three modalities (Table 2). A total of 41 patients (30.4%) developed pneumonia following esophagectomy. In multivariable logistic regression analysis (adjusted for age, ASA score and pulmonary comorbidity), the risk of postoperative pneumonia was significantly lower in the IMRT and VMAT group compared to the 3D-CRT group (corresponding OR’s and 95%-CI’s: 0.30 (0.11–0.82, p=0.018) and 0.31 (0.10–0.99, p=0.049), respectively).

Table 1 Baseline characteristics

Conclusion The proposed nomogram predicts 1-year PFS after TMT for esophageal cancer and may aid in individualized treatment decision-making before esophagectomy. External validation is warranted. PV-0099 Neoadjuvant radiation dose to the lungs and the risk of postoperative pneumonia in esophageal cancer A.S. Borggreve 1 , P.S.N. Van Rossum 2 , R. Van Hillegersberg 3 , J.P. Ruurda 3 , S. Mook 2 1 UMC Utrecht, Radiation Oncology and Surgical Oncology, Utrecht, The Netherlands 2 UMC Utrecht, Radiation Oncology, Utrecht, The Netherlands 3 UMC Utrecht, Surgical Oncology, Utrecht, The Netherland Purpose or Objective Neoadjuvant chemoradiation followed by surgical resection is the cornerstone of curative treatment for locally advanced, resectable esophageal cancer. The radiation dose distribution on the surrounding vital organs depends on clinical characteristics such as tumor location, tumor length, N-status, as well as on the radiation modality used (e.g. 3D-CRT, IMRT, VMAT). Neoadjuvant radiation dose has already been associated with several postoperative complications, such as anastomotic leakage, cardiac complications and wound infections. Another frequently observed complication is postoperative pneumonia (up to 39%). It was hypothesized that a larger volume of the lungs that receives radiation dose, potentially influences the risk of postoperative pneumonia in esophageal cancer patients. The aim of the current study was to investigate whether radiation dose delivery with 3D-CRT, IMRT or VMAT during neoadjuvant chemoradiotherapy in esophageal cancer patients affects the risk of postoperative pneumonia. Material and Methods Patients with esophageal cancer who underwent neoadjuvant chemoradiotherapy according to the CROSS regimen followed by a transthoracic esophagectomy in our tertiary referral center were included. Baseline variables such as age, sex, ASA score, comorbidity and histopathology, as well as the outcome postoperative pneumonia were prospectively acquired. Pneumonia was defined according to the Uniform Pneumonia Score (UPS). Three commonly used radiation modalities with varying dose distributions to the lungs were compared, namely 3D-CRT, IMRT or VMAT. Baseline characteristics, radiation technique and the risk of postoperative pneumonia were analyzed using uni- and multivariable logistic regression analysis.

Table 2: Radiation dose to the lungs for the three modalities

Conclusion The risk of postoperative pneumonia following esophagectomy is significantly lower when neoadjuvant radiation dose is delivered using IMRT or VMAT, compared to 3D-CRT. These results can contribute to future refinement of the dose constraints for the lungs. PV-0100 Impact of lung dose on postoperative complications after trimodality treatment in esophageal cancer M. Thomas 1,2 , G. Defraene 1 , M. Lambrecht 1,2 , J. Moons 3 , P. Nafteux 3 , K. Haustermans 1,2 1 KU Leuven – University of Leuven, Oncology - Experimental Radiation Oncology, Leuven, Belgium 2 University Hospitals Leuven, Radiation Oncology, Leuven, Belgium 3 University Hospitals Leuven, Thoracic Surgery, Leuven, Belgium Purpose or Objective Preoperative chemoradiotherapy (preCRT) followed by surgery is considered standard of care in the treatment of locally advanced esophageal cancer (EC). The aim of this study was to investigate the effect of radiation dose on the risk of postoperative pulmonary and cardiac complications among EC patients treated with a trimodality approach.