ESTRO 2024 - Abstract Book

S2189

Clinical - Upper GI

ESTRO 2024

the G3+ and G4+ MACEs. The use of volumetric modulated arctherapy significantly reduced V15LA compared with 3D conformal RT.

Conclusion:

In a cohort of ESOC patients treated with exclusive RT, incidence of MACEs was associated with V15LA, underlining the importance of CSS. These high CV risk patients should benefit from standard CV assessment and strict control of their risk factors.

Keywords: heart, esophageal cancer, radiotherapy

1185

Digital Poster

Treatment regimen is an independent predictor for severe lymphopenia in esophageal cancer patients

Christina T Muijs 1 , Sabine Visser 1 , Jannet C Beukema 1 , Jacco De Haan 2 , Boudewijn Van Etten 3 , Erik Korevaar 1 , Ewoud Schuit 4 , Johannes A Langendijk 1 1 University Medical Centre Groningen / University of Groningen, Radiation Oncology, Groningen, Netherlands. 2 University Medical Centre Groningen / University of Groningen, Medical Oncology, Groningen, Netherlands. 3 University Medical Centre Groningen / University of Groningen, Surgical Oncology, Groningen, Netherlands. 4 JUniversity Medical Center Utrecht, Utrecht University, Julius Center for Health Sciences and Primary Care, Utrecht, Netherlands

Purpose/Objective:

Lymphocytes play a role in the immune response to chemoradiotherapy. There is growing clinical data showing that radiation-induced lymphopenia (RIL) negatively affects tumor response and overall survival in several tumor sites. In a recent meta-analysis. 1, severe RIL was associated with worse pathologic response, progression free survival (PFS) and overall survival (OS). The risk of developing RIL greatly depends on radiotherapy parameters, such as dose to lymphocyte-rich organs and planned target volume (PTV)2. The number of fractions seems to reflect the opportunities to kill circulating lymphocytes, and might also be an important predictor. Therefore, the aim of this study was to evaluate whether treatment regimen (23 vs 28 fractions) is an independent predictor for severe RIL.

Material/Methods:

At our centre, all curatively treated oesophageal cancer patients are included in a prospective data registry (SFP OES), in which patient, tumour, treatment, toxicity and outcome data are collected. For the current analysis, we selected all patients who were treated with nCRT (CROSS; 23x1.8Gy, 5 courses carboplatin/paclitaxel) between April 2020 and August 2023, or with dCRT (extended CROSS; 28x1.8Gy, 6 courses carboplatin/paclitaxel) between July