Extrapulmonary metastases impact survival outcomes of thermal ablation for colorectal lung oligometastases: A multicenter study

Table 2 Radiological findings for colorectal lung metastases, mean ± SD/n (%)

Variables		Variables
Tumor size (mm)	17.9 ± 10.8	Peridiaphragmatic tumors	30 (8.9)
Tumor size > 3 cm	66 (19.6)	Near parietal pleural
Tumor number		Near mediastinal pleural
1 tumor	135 (40.2)	Peribronchial tumors	52 (15.5)
2 tumors	104 (31.0)	Perivascular tumors	65 (19.3)
3 tumors	71 (21.1)	Emphysema	51 (15.2)
4 tumors	26 (7.7)	CT imaging features
Lung location		Routine features	243 (72.3)
Left lung	131 (39.0)	Air bronchograms	35 (10.4)
Right lung	167 (49.7)	Cavitation, air bubbles, or bullae	37 (11.0)
Bilateral involvement	38 (11.3)
Lung field		Calcifications	12 (3.6)
Central	31 (9.2)	Inflammatory changes	9 (2.7)
Peripheral	297 (88.4)	CT density characteristics
Across multiple field	8 (2.4)	GGO	4 (1.2)
Lung zone		Solid lesions	293 (87.2)
Inner zone	39 (11.6)	Mixed-density lesions	39 (11.6)
Middle zone	72 (21.4)	Near interlobar fissure	106 (31.5)
Outer zone	134 (39.9)	Hilar lymph nodes (+)	46 (13.7)
Across multiple zones	91 (27.1)	Mediastinal lymph nodes (+)	54 (16.1)

CT: Computed tomography; GGO: Ground-glass opacity. Tumor number and distribution (e.g., unilateral vs bilateral, central vs peripheral, lung zones) were recorded to reflect anatomical complexity. Lesions adjacent to critical structures including pleura, vessels, bronchi, and diaphragm were classified due to their potential influence on ablation efficacy. Computed tomography features such as cavitation, air bronchograms, calcification, and lesion density (solid, mixed, or ground-glass opacity) were assessed to describe tumor morphology. Lymph node status was included for its prognostic relevance.