[¹⁸F]FDG PET immunotherapy radiomics signature (iRADIOMICS) predicts response of non-small-cell lung cancer patients treated with pembrolizumab

Figure 1

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Patient demographic and clinical data_ The data is presented for all patients, responders (overall survival [OS] > 14_9 months), and non-responders (OS < 14_9 months)_ The reported p-value is the result of Mann-Whitney U-test (MWU) (continuous variables) and Fisher exact test (categorical variables) comparing differences between responders and non-responders

Characteristic	All patients median (range)	Responders (OS > 14.9 months) median (range)	Non-responders (OS < 14.9 months) median (range)	p-value
Number of patients	30	16	14
Age [years]	65 (46–77)	67 (48–76)	61 (46–77)	0.298
PD-L1 TPS [%]	75 (3–100)	77.5 (3–100)	75 (10–100)	0.933
Sex				0.715
Female	15	9	6
Male	15	7	8
Histology				0.532
Adenocarcinoma	17	8	9
Squamous cell carcinoma	8	4	4
Other	5	4	1
Smoking status				0.672
Never	1	0	1
Former > 3 years ago	12	7	5
Former < 3 years ago	5	3	2
Until current disease	8	3	5
Current smoker	4	3	1
ECOG PS				0.162
0	8	2	6
1	18	12	6
2	4	2	2
Line of treatment (immunotherapy)				0.096
1st	15	10	5
2nd	13	4	9
3rd	2	2	0
Palliative RT during treatment				0.657
No	24	12	12
Yes	6	4	2

Baseline radiomics features of primary tumours – Mann-Whitney U-test (MWU) and receiver operating characteristic (ROC) curve analysis_ Patients were dichotomized into 2 groups: responders (OS > 14_9 months) and non-responders (OS < 14_9 months)_ For each radiomics feature median value, range, p-value of MWU, and the area under the ROC curve (AUC) with the corresponding 95% confidence interval (CI), are reported_ See also Figure 1

Feature	Responders (OS > 14.9 months) median (range)	Non-responders (OS < 14.9 months) median (range)	p-value	AUC (95% CI)
Volume [cm3]	27.9 (2.64–351)	44.4 (7.81–792)	0.098	0.69 (0.49–0.89)
SUVmax [g/ml]	20.6 (5.21–32.1)	15.6 (9.54–37.0)	0.185	0.65 (0.43–0.87)
Sum entropy	3.69 (3.53–3.77)	3.7 (3.54–3.76)	0.387	0.60 (0.38–0.82)
Entropy-GLCM	4.07 (3.99–4.15)	4.11 (4.03–4.14)	0.046	0.72 (0.52–0.92)
Difference entropy	2.98 (2.74–3.07)	2.89 (2.74–3.06)	0.080	0.70 (0.49–0.90)
Small Run Emphasis (SRE)	0.0382 (0.00962–0.0615)	0.0163 (0.00854–0.0303)	0.001	0.85 (0.69–1.00)

Baseline radiomics features of primary tumours – univariate and multivariate Cox proportional hazards regression analysis (Cox PH)_ For each radiomics feature, the hazard ratio (HR), corresponding 95% confidence interval (CI), and p-value of univariate analysis are reported_ The 2-variable multivariate regression model was chosen based on the Akaike information criterion (AIC)_ In order to achieve comparable HRs, all radiomics features were normalized into z-scores

Feature	Univariate HR (95% CI)	Univariate p-value	Multivariate HR (95% CI)	Multivariate p-value
Volume	1.6 (1.1–2.4)	0.015
SUVmax	0.77 (0.46–1.3)	0.320
Sum Entropy	0.96 (0.60–1.5)	0.860
Entropy-GLCM	1.4 (0.82–2.3)	0.230
Difference entropy	0.62 (0.40–0.97)	0.037	0.54 (0.31–0.93)	0.026
Small Run Emphasis (SRE)	0.46 (0.26–0.81)	0.007	0.39 (0.20–0.76)	0.006