Table 5 Multivariable Cox Analysis of predictors for Loco-regional recurrence (LRR), distant metastasis (DM), any progression and overall survival (OS) for patients with limited stage small cell lung cancer (LS-SCLC) treated with chemoradiation, (n = 105)

RT fractionation

2.08 (1.03–4.23)

0.04^c

Maximum 3D tumor diameter (cm)

1.20 (1.10–1.30)

< 0.001^c

Pack-years

1.01 (1.00–1.02)

0.10

Concurrent chemotherapy

0.24 (0.08–0.69)

0.008^c

HR (95% CI)

p-value

Maximum 3D tumor diameter (cm)

1.20 (1.01–1.40)

0.02^c

Tumor Volume

1.01 (1.00–1.01)

0.03^c

Maximum 2D tumor diameter sagittal (cm)

0.95 (0.94–1.01)

0.08

Maximum 2D tumor diameter axial (cm)

0.95 (0.95–1.01)

0.08

HR (95% CI)

p-value

T stage^b

0.58 (0.32–1.05)

0.07

Performance status ≥1

2.54 (1.27–5.09)

0.009^c

 Yes

0.61 (0.34–1.09)

0.10

Pack-years

1.01 (1.00–1.02)

0.12

Median RT dose

1.03 (1.00–1.06)

0.09

Maximum 3D tumor diameter (cm)

1.10 (1.01–1.10)

0.03^c

HR (95% CI)

p-value

Performance status ≥1

2.47 (1.31–4.67)

0.005^c

 Yes

0.57 (0.34–0.95)

0.03^c

T stage^b

0.61 (0.35–1.05)

0.07

Maximum 3D tumor diameter (cm)

1.10 (1.01–1.10)

0.01^c

HR (95% CI)

p-value

Overall stage^a

1.09 (0.58–2.07)

0.78

T stage_b

0.53 (0.31–0.90)

0.02^c

 Male

0.34 (0.20–0.56)

< 0.001^c

Performance status ≥1

3.16 (1.71–5.85)

< 0.001^c

RT fractionation

0.58 (0.35–0.97)

0.04^c

Concurrent chemotherapy

0.43 (0.21–0.89)

0.02^c

Maximum 3D tumor diameter (cm)

1.10 (0.99–1.10)

0.09