ESTRO 2021 Abstract Book

S1371

ESTRO 2021

Results FD and UIH could provide similar geometric performance in parotids, temporal lobes, lens, and eyes (DICE, p > 0.05). OAR_FD had better geometric performance in the optic nerves, oral cavity, larynx, and femoral heads (DICE, p < 0.05). OAR_UIH had better geometric performance in the bladder (DICE, p < 0.05). In dosimetric analysis, both Plan_FD and Plan_UIH had nonsignificant dosimetric differences compared to Plan_Manual for most PTV and OARs dose-volume indices. The only significant dosimetric difference was the maximum dose of the left temporal lobe for Plan_FD vs. Plan_Manual ( p = 0.05). Only one significant correlation was found between the mean dose of the femoral head and its HD index (R = 0.4, p = 0.01).

Conclusion Deep learning-based OARs auto-segmentation for NPC and rectal cancer has a nonsignificant impact on most PTV and OARs dose-volume indices. Correlations between the auto-segmentation geometric metric and dosimetric difference were not observed for most OARs. PO-1652 Clinical evaluation of deep learning for auto-segmentation of CT images in RT for lung cancer N. Johnston 1,2 , J. De Rycke 3 , Y. Lievens 1,2 , B. Vanderstraeten 1,2 1 Ghent University Hospital, Department of Radiotherapy-Oncology, Ghent, Belgium; 2 Ghent University, Department of Human Structure and Repair, Ghent, Belgium; 3 Ghent University, Physics master graduate, Ghent, Belgium

Purpose or Objective Accurate target and organ at risk (OAR) delineation is a crucial step in radiotherapy treatment planning. The