Table 5. Ablation study of FCFE and MHARF on the BraTS 2020 dataset.

Methods	WT			TC			ET			Average
	DSC↑	HD95↓ (mm)		DSC↑	HD95↓ (mm)		DSC↑	HD95↓ (mm)		DSC↑	HD95↓ (mm)
Basic	0.915	1.866		0.847	3.018		0.783	2.800		0.848	2.561
Basic + FCFE	0.914	1.910		0.854	2.727		0.782	2.912		0.850	2.516
Basic + MHARF	0.915	1.883		0.848	2.961		0.784	2.756		0.849	2.533
FCFDiff-Net	0.916*	1.917		0.860*	2.571*		0.786*	2.581*		0.854*	2.356*

Higher DSC scores (↑) indicate better segmentation, whereas lower HD95 values (↓) indicate better performance. The top result is marked with asterisk (*). BraTS, brain tumor segmentation; DSC, Dice similarity coefficient; ET, enhancing tumor; FCFE, full-conditional feature embedding; HD95, Hausdorff distance at the 95th percentile; MHARF, multi-head attention residual fusion; TC, tumor core; WT, whole tumor.