Comparable Clinical Outcome Using Small or Large Gross Tumor Volume-to-Clinical Target Volume Margin Expansion in Neoadjuvant Chemoradiotherapy for Esophageal Squamous Cell Carcinoma

Table 3

Multivariate analysis of clinical outcomes.

Characteristics (comparison vs. reference)	Local control			Failure-free survival			Overall survival
	HR	95% CI	value	HR	95% CI	value	HR	95% CI	value
Age (continuous)	—	—	—	1.033	1.006–1.061	0.018	1.041	1.011–1.072	0.007
Upper thoracic involvement (yes vs. no)	—	—	—	—	—	—	0.759	0.398–1.445	0.401
Supraclavicular elective irradiation (yes vs. no)	—	—	—	0.671	0.382–1.180	0.166	0.798	0.399–1.593	0.522
Longitudinal length of primary GTV (continuous)	—	—	—	1.106	1.031–1.186	0.005	1.093	1.017–1.174	0.016
Chemotherapy completed (yes vs. no)	0.160	0.046–0.563	0.004	—	—	—	—	—	—
Field size (small margin vs. large margin group)	1.997	0.571–6.980	0.279	1.057	0.650–1.718	0.824	1.268	0.745–2.157	0.382

Abbreviations: HR, hazard ratio; CI, confidence interval; GTV, gross tumor volume.