Treatment-duration is related to changes in peripheral lymphocyte counts during definitive radiotherapy for unresectable stage III NSCLC

Table 4 Univariate and multivariate logistic regression of factors associated with SL during radiation treatment

Characteristic	OR (95% CI)	P
Univariate analysis
Sex (female vs male)	0.814 (0.193–3.425)	0.778
Age (< 65 years vs ≥ 65 years)	1.124 (0.531–2.382)	0.760
ECOG (0–1 vs 2)	1.439 (0.621–3.334)	0.395
Underlying respiratory system disease (No versus Yes)	1.586 (0.744–3.383)	0.233
Smoker (No vs others)	1.275 (0.518–3.139)	0.597
Induction chemotherapy (No vs Yes)	2.432 (0.963–6.142)	0.06
Concurrent chemotherapy (No vs Yes)	0.703 (0.308–1.607)	0.404
Systemic Corticosteroids (No vs Yes)^a	0.867 (0.357–2.106)	0.752
Pre-RT TLCs (cells/μL)	0.998 (0.998–0.999)	< 0.001
GTV (< 22 cm³vs ≥ 22 cm³)	3.867 (1.276–11.714)	0.017
PTV(< 48 cm³ vs ≥ 48 cm³)	1.478 (0.464–4.706)	0.509
Mean lung dose (< 1150 cGy vs ≥ 1150 cGy)	2.720 (1.239–5.969)	0.013
Heart V5 (< 6 vs ≥ 6)	3.704 (1.273–10.777)	0.016
BED (Gy)	1.026 (0.927–1.137)	0.616
OTT (LTRT vs STRT)	0.289 (0.117–0.715)	0.007
IMRT (vs 3DCRT)	1.048 (0.412–2.665)	0.922
HT (vs 3DCRT)	0.829 (0.353–1.946)	0.667
Stage IIIB (vs IIIA)	0.900 (0.299–2.712)	0.851
Stage IIIC (vs IIIA)	0.884 (0.325–2.403)	0.809
Multivariate analysis^b
Pre-RT TLCs (cells/μL)	0.998 (0.997–0.999)	< 0.001
GTV (< 22 cm³vs ≥ 22 cm³)	6.909 (1.729–27.612)	0.006
Mean lung dose (< 1150 cGy vs ≥ 1150 cGy)	3.633 (1.349–9.787)	0.011
Treatment duration (LCRT vs SCRT)	0.322 (0.115–0.908)	0.032

Abbreviations: SL severe lymphopenia, OR Odds ratio, CI confidence interval, ECOG Eastern Cooperative Oncology Group, RT radiotherapy, TLCs total lymphocyte counts, GTV gross tumor volume, PTV planning target volume, Heart V5 the percentage of total heart volume receiving at least 5 Gy, BED biological effective dose, OTT overall treatment time, LTRT long-term radiotherapy, STRT short-term radiotherapy, 3DCRT 3D conformal radiotherapy, IMRT Intensity modulated radiotherapy, HT Helical Tomotherapy
Note: ^aequivalent to approximately 60–120 mg of prednisone
^bMultivariate analysis includes sex, age, ECOG, induction chemotherapy, Pre-RT TLCs, GTV, mean lung dose, Heart V5, and treatment duration

ISSN: 1748-717X