Table 2.
Univariable and multivariable analyses of predictors of developing post-chemoradiation severe lymphopenia, 2015–2020 (N = 84).
|
Univariable Analysis |
Multivariable Analysis* |
Multivariable Analysis*# |
||||
|---|---|---|---|---|---|---|
| Variables | OR (95 % CI) | P | OR (95 % CI) | P | OR (95 % CI) | P |
| Dosimetric factors | ||||||
| Mean spleen dose, Gy (>40 vs ≤ 40) | 2.76 (1.01–7.54) | 0.048 | 1.13 (1.01–1.26) | 0.041 | – | – |
| Mean spleen dose, Gy (per unit increase) | 1.11 (1.00–1.23) | 0.060 | – | – | 1.15 (1.02–1.30) | 0.022 |
| Spleen V5, % (per unit increase) | 1.09 (0.70–1.69) | 0.698 | ||||
| Spleen V10, % (per unit increase) | 1.12 (0.92–1.38) | 0.262 | ||||
| Spleen V15, % (per unit increase) | 1.10 (0.99–1.23) | 0.080 | ||||
| Spleen V20, % (per unit increase) | 1.09 (1.00–1.17) | 0.072 | ||||
| Spleen V30, % (per unit increase) | 1.03 (1.00–1.07) | 0.075 | ||||
| Spleen V40, % (per unit increase) | 1.02 (1.00–1.05) | 0.105 | ||||
| Spleen V45, % (per unit increase) | 1.02 (1.00–1.04) | 0.109 | ||||
| Spleen volume, cm3 (per unit increase) | 0.99 (0.98–1.00) | 0.095 | ||||
| Mean spine dose, Gy (per unit increase) | 1.13 (1.00–1.27) | 0.713 | ||||
| Spine V5, % (per unit increase) | 1.10 (0.68–1.78) | 0.687 | ||||
| Spine V10, % (per unit increase) | 1.10 (0.94–1.29) | 0.219 | ||||
| Spine V15, % (per unit increase) | 1.04 (0.98–1.10) | 0.191 | ||||
| Spine V20, % (per unit increase) | 1.03 (1.00–1.07) | 0.084 | ||||
| Spine V30, % (per unit increase) | 1.02 (0.99–1.05) | 0.125 | ||||
| Spine V40, % (per unit increase) | 1.06 (1.01–1.11) | 0.024 | ||||
| Spine V45, % (per unit increase) | 1.06 (0.98–1.14) | 0.171 | ||||
| Spine volume, cm3 (per unit increase) | 1.00 (0.99–1.00) | 0.195 | ||||
| PTV, cm3 (per unit increase) | 1.00 (0.99–1.00) | 0.218 | ||||
| Patient factors | ||||||
| Age, year (≥60 vs < 60) | 0.78 (0.31–1.97) | 0.603 | ||||
| Sex (male vs female) | 0.22 (0.08–0.59) | 0.003 | 0.25 (0.09–0.70) | 0.008 | 0.29 (0.10–0.85) | 0.024 |
| Comorbidity (yes vs no) | 1.43 (0.51–4.00) | 0.501 | ||||
| Baseline white blood cell, K/μL (per unit increase) | 1.09 (0.79–1.49) | 0.605 | ||||
| Baseline ALC, K/μL (per unit increase) | 0.41 (0.15–1.10) | 0.078 | 0.33 (0.10–1.07) | 0.064 | ||
| Baseline ANC, K/μL (per unit increase) | 1.34 (0.91–1.97) | 0.141 | 1.62 (1.02–2.58) | 0.040 | 1.79 (1.09–2.94) | 0.021 |
| Baseline hemoglobin, K/μL (per unit increase) | 0.68 (0.48–0.98) | 0.036 | ||||
| Baseline platelet, K/μL (per unit increase) | 1.00 (1.00–1.01) | 0.423 | ||||
| Total chemotherapy dose, % (per unit increase) | 0.98 (0.96–1.01) | 0.144 | ||||
Abbreviations: ALC, absolute lymphocyte count; ANC, absolute neutrophil count; CI, confidence interval; CRT, chemoradiation; Gy, Gray; OR, odds ratio; PTV, planning target volume; Vx, volume of spleen receiving × Gy of radiation.
*
Due to the collinearity between MSD and other spleen dosimetric parameters and between mean spine dose and other spine dosimetric parameters, the only dosimetric parameters included in the multivariable analysis were mean spleen dose and spine V40.
#
Mean spleen dose was analyzed in multivariable model as a continuous variable.