The prognostic significance of pretreatment squamous cell carcinoma antigen levels in cervical cancer patients treated by concurrent chemoradiation therapy and a comparison of dosimetric outcomes and clinical toxicities between tomotherapy and volumetric modulated arc therapy

Table 5 Cox proportional hazards regression analysis for distant metastases–free survival

Variable	HR	95% CI	P value
Age ≥ 60 years	1.32	0.47–3.65	0.599
OTT of RT > 61 days	2.27	0.72–7.14	0.161
T3 or T4 disease	2.88	1.01–8.22	0.048
N1 or N2 disease	6.17	2.01–18.89	0.001
Pretreatment SCC Ag > 10 ng/mL	2.80	1.02–7.67	0.045
Post-treatment SCC Ag > 1.5 ng/mL	0.94	0.27–3.34	0.926
EQD2 of Point A ≥ 81 Gy	1.32	0.47–3.68	0.601
RT technique^a			0.662
VMAT	0.67	0.15–2.96	0.596
Tomotherapy	0.51	0.12–2.19	0.368

HR hazard ratio, CI confidence interval, OTT overall treatment time, RT radiation therapy, SCC Ag squamous cell carcinoma antigen, EQD2 equivalent dose in 2-Gy fractions, VMAT volumetric modulated arc therapy
^aReference category: 3DCRT, three-dimensional conformal radiation therapy

ISSN: 1748-717X