Résumé : The randomized multicentric phase II Neo-CheckRay trial investigated preoperative immune-modulating stereotactic body radiation therapy (iSBRT) 8 Gy x 3 fractions in combination with chemotherapy with or without the anti PD-L1 durvalumab and the anti-CD73 oleclumab in early-stage, high-risk, luminal B breast cancer. iSBRT was solely delivered to the primary breast cancer leveraging on its immune modulating potential to sustain an anti-tumour response. To avoid immunosuppression induced by radiation therapy (RT), the tumour draining lymph nodes (TDLN) were spared. Here, we present the constraints used in the Neo-CheckRay trial and a dosimetric analysis of all delivered treatment plans with a special focus on the dose to the TDLN.