TABLE 2

Subgroup Analyses

Endpoint	Volumetric parameters	Factor	No. of studies	HR	95% CI of HR	Heterogeneity, I² (%)	Model used
EFS	MTV	VOI:
		• Tumor	5	3.03	2.22–4.13	0	Random effects
		• Tumor + LN	3	3.15	1.80–5.51	0	Fixed effect
		Tumor delineation:
		• Fixed SUV2.5	6	3.17	2.30–4.36	0	Random effects
		• Others	2	2.78	1.66–4.66	50	Fixed effect
		Cutoff values:
		• ROC	3	4.30	2.46–7.54	0	Fixed effect
		• Others	5	2.75	2.02–3.75	0	Random effects
	TLG	Tumor delineation:
		• Fixed SUV2.5	3	3.45	2.33–5.12	0	Fixed effect
		• Others	2	2.59	1.55–4.31	12	Fixed effect
OS	MTV	VOI:
		• Tumor	6	3.19	2.28–4.48	0	Random effects
		• Tumor + LN	2	4.71	2.60–8.54	0	Fixed effect
		Tumor delineation:
		• Fixed SUV2.5	4	4.09	2.63–6.36	0	Random effects
		• Others	4	3.23	1.95–5.34	32	Random effects
		Cutoff values:
		• ROC	4	4.57	2.89–7.25	0	Random effects
		• Others	4	2.93	2.0–4.29	0	Random effects
	TLG	Tumor delineation:
		• Fixed SUV2.5	3	3.90	2.45–6.21	0	Fixed effect
		• Others	3	2.46	1.51–4.02	0	Fixed effect