@article{r2segtrainingfreeoodmedicaltumorsegmenta, title = {R$^{2}$Seg: Training-Free OOD Medical Tumor Segmentation via Anatomical Reasoning and Statistical Rejection}, author = {Shuaike Shen and Ke Liu and Jiaqing Xie and Shangde Gao and Chunhua Shen and Ge Liu and Mireia Crispin-Ortuzar and Shangqi Gao}, year = {2025}, eprint = {2511.12691}, archivePrefix = {arXiv}, url = {https://arxiv.org/abs/2511.12691}, }