Cross-sectional and longitudinal assessment of muscle from regular chest computed tomography scans: L1 and pectoralis muscle compared to L3 as reference in non-small cell lung cancer

Figures & data

Table 1 Computed tomography measurements of muscle

Transverse level	Baseline (cm^2)	Follow-up (cm^2)	Delta absolute (cm^2/100 days)	Delta relative (%/100 days)	P-value
Pectoralis muscle	36.0±10.1	33.9±9.8	−4.5±12.9	−4.3±13.3	<0.001
L1 muscle	116.1±24.5	112.8±22.7	−5.7±20.1	−2.3±7.7	<0.001
L3 muscle	134.8±28.0	130.6±27.3	−7.6±18.8	−2.9±6.7	<0.001

Note: Data are expressed as mean ± SD.

Abbreviations: L1, first lumbar vertebra; L3, third lumbar vertebra.

Figure 1 Skeletal muscle area on transverse computed tomography images at (A) pectoralis, (B) first lumbar level, and (C) third lumbar level.

Table 2 Computed tomography measurements of adipose tissue compartments

Transverse level	Baseline (cm^2)	Follow-up (cm^2)	Delta absolute (cm^2/100 days)	Delta relative (%/100 days)	P-value
L1 SAT	107.0±73.5	104.5±73.5	−3.6±33.5	−1.4±25.5	0.076
L3 SAT	160.8±85.1	155.3±84.9	−9.6±61.8	−2.1±19.9	0.021
L1 VAT	100.1±65.5	100.1±69.8	−1.3±78.1	4.9±33.2	0.979
L3 VAT	106.9±70.4	104.8±70.5	−5.5±56.9	2.6±29.0	0.386

Note: Data are expressed as mean ± SD.

Abbreviations: L1, first lumbar vertebra; L3, third lumbar vertebra; SAT, subcutaneous adipose tissue; VAT, visceral adipose tissue.

Figure 2 Kaplan–Meier overall survival curve for patients with loss of muscle mass compared to patients without loss of muscle mass at the level of (A) pectoralis, (B) L1, and (C) L3.

Abbreviations: L1, first lumbar vertebra; L3, third lumbar vertebra; OS, overall survival.

Table 3 Multivariate analysis for predictors of overall survival

	B	HR (95% CI)	P-value		B	HR (95% CI)	P-value		B	HR (95% CI)	P-value
Gender	0.44	1.6 (0.90–2.69)	0.112	Gender	0.48	1.6 (0.94–2.80)	0.085	Gender	0.53	1.7 (0.97–2.98)	0.064
Age (years)	0.01	1.0 (0.98–1.04)	0.577	Age	0.01	1.0 (0.98–1.04)	0.621	Age	0.01	1.0 (0.98–1.04)	0.762
Charlson comorbidity index	0.12	1.1 (0.96–1.33)	0.144	Charlson comorbidity index	0.11	1.1 (0.95–1.31)	0.169	Charlson comorbidity index	0.09	1.1 (0.93–1.29)	0.293
Δ L3 muscle (%/100 days)	−0.05	0.9 (0.91–0.98)	0.005	Δ L1 muscle (%/100 days)	−0.06	0.9 (0.91–0.98)	0.002	Δ pectoralis muscle (%/100 days)	−0.02	1.0 (0.96–1.01)	0.126

Note: Statistically significant numbers (≤0.05) are in bold.

Figure S1 Scatter plot and Bland–Altman plot of skeletal muscle with data from pre-chemotherapy scans.

Note: (A) Intermeasurement correlation of pectoralis and L3, (B) Bland–Altman plot of pectoralis and L3, (C) intermeasurement correlation of L1 and L3, and (D) Bland–Altman plot of L1 and L3.

Abbreviations: CSA, cross-sectional area; L1, first lumbar vertebra; L3, third lumbar vertebra.

Figure S2 Scatter plot and Bland–Altman plot of adipose tissue with data from pre-chemotherapy scans.

Note: (A) Intermeasurement correlation of SAT at L1 and L3, (B) Bland–Altman plot of SAT at L1 and L3, (C) intermeasurement correlation of VAT at L1 and L3, and (D) Bland–Altman plot of VAT at L1 and L3.

Abbreviations: CSA, cross-sectional area; L1, first lumbar vertebra; L3, third lumbar vertebra; SAT, subcutaneous adipose tissue; VAT, visceral adipose tissue.