Quantitative SSTR-PET/CT for predicting response and survival outcomes in patients with pancreatic neuroendocrine tumors receiving CAPTEM

Ingenerf, Maria; Karim, Homeira; Auernhammer, Christoph; Zacherl, Matthias; Wenter, Vera; Winkelmann, Michael; Ricke, Jens; Berger, Frank; Schmid-Tannwald, Christine

doi:10.2478/raon-2023-0055

Figures & Tables

72-year-old male with responding liver metastases of pancreatic neuroendocrine tumor. on the pretherapeutic PET/CT (A, B) there were high tumor-to-liver (t/l) ratios. after three months of treatment with CAPTEM, both liver metastases showed a shrinkage in size, but also a significantly reduced uptake of 68ga-dotatate compared to pretherapeutic PET/ CT (C, D).CAPTEM = capecitabine and temozolomide

Cox regression analysis for overall survival (OS)

	Univariable			Multivariable

	Exp (B)	95% CI	p-value	Exp (B)	95% CI	p-value
Baseline
Age (years)	1.059	1.003–1.118	0.039	1.054	0.996–1.115	0.071
Sex	2.326	0.486–11.4	0.291
Grading
G1			0.64
G2	0	0	0.988
G3	2.137	0.442–10.325	0.345
Ki-67	1.033	0.979–1.09	0.24
Chromgranin	1	1.0–1.0	0.572
Hepatic tumor burden	1.005	0.974–1.036	0.776
SUVmax LM	0.982	0.949–1.016	0.294
SUVmean LM	0.951	0.894–1.012	0.114
SUVmax Pankreas	0.962	0.916–1.011	0.125
SUVmean Pankreas	0.912	0.813–1.023	0.115
Tmax/Lmean	0.988	0.856–1.142	0.874
Tmean/Lmean	0.879	0.653–1.184	0.396
Tmax/Smean	0.83	0.516–1.336	0.443
Tmean/Smean	0.615	0.239–1.581	0.313
% change
CgA	1.006	1.0–1.012	0.046	1.003	0.996–1.01	0.448
SUVmax LM	1.004	0.99–1.018	0.563
SUVmean LM	1.006	0.99–1.022	0.493
HU LM	0.986	0.956–1.017	0.374
SUVmax Pankreas	1.006	0.998–1.013	0.118
SUVmean Pankreas	1.007	0.998–1.015	0.132
Tmax/Lmean	1	0.989–1.011	0.986
Tmean/Lmean	1.001	0.988–1.013	0.933
Tmax/Smean	1.014	1.002–1.026	0.02	1.008	0.971–1.046	0.68
Tmean/Smean	1.017	1.003–1.032	0.02	1.011	0.973–1.05	0.58
Size LM (mm)	1.011	0.991–1.031	0.289
Size Pancreas	1.004	0.986–1.023	0.672
Size total (RECIST)	1.009	0.988–1.031	0.409

Imaging and clinical parameters on baseline and follow-up imaging

	Responder			Non-Responder			Baseline R vs. NR

	Baseline	Follow-up	*p-value baseline vs.* FU**	Baseline	Follow-up	*p-value baseline vs.* FU**	p-value
Age (years)	66 (56–75)			69 (57–82)			0.44
Grading	13 (7–20)			10 (4–15)			0.33
G1	0			1
G2	6			11
G3	4			0
Ki-67 (%)	12.5 (7.3–20)			10 (4.3–15)			0.33
Male sex	7 (70%)			10 (83%)
Chromogranin A	796 (512–2756)	270 (102–1136)	< 0.04	178 (90–845)	198 (96–1071)	< 0.02	0.06
Bilirubin (mg/dl)	0.6 (0.60.88)	0.85 (0.5–1.1)	0.64	0.6 (0.43–0.9)	0.55 (0.33–0.88)	> 0.99	0.45
Hepatic tumor burden (%)	35 (5–40)	13 (5–33)	0.16	13 (5–38)	15 (5–38)	0.25	0.42
SUVmax LM	47 (24–62)	21 (13–46)	< 0.04	24 (13–43)	21 (11–39)	0.15	< 0.02
SUVmean LM	30 (15–38)	15 (11–24)	0.04	14 (9–22)	11 (8–17)	0.40	< 0.0004
Tmax/Lmean	6.9 (3.2–11.3)	2.8 (1.6–8.3)	0.03	3.6 (2.0–5.8)	3.2 (1.5–5.5)	0.6	0.0192
Tmean/Lmean	4.8 (2.0–6.8)	1.9 (1.2–3.9)	0.02	2.1 (1.4–2.9)	1.6 (1.1–2.6)	0.05	0.0061
Tmax/Smean	2.0 (1.4–4.1)	0.9 (0.5–3.0)	0.01	1.3 (0.5–1.9)	1.3 (0.4–2.2)	0.12	0.0469
Tmean/Smean	1.4 (0.8–2.1)	0.7 (0.4–1.5)	0.007	0.7 (0.4–1.1)	0.6 (0.3–1.1)	0.19	0.0094
Size LM (mm)	32 (24–42)	20 (14–32)	< 0.0001	27 (17–36)	30 (18–43)	0.12	0.10
HU LM	106 (88–116)	106 (95–126)	0.41	92 (85–108)	90 (68 –104)	0.02	0.09
SUVmax pNET	26 (14–47)	26 (16–41)	0.94	30 (12–59)	28 (16–45)	0.2	0.68
SUVmean pNET	17 (9–22)	18 (13–28)	0.81	15 (9–33)	15 (15–30)	0.57	0.98
Size pNET	35 (25–38)	20 (14–37)	0.03	34 (20–47)	34 (23–54)	0.81	0.92
HU pNET	105 (77–113)	94 (88–98)	0.79	107 (81–117)	92 (81–100)	0.15	0.89

Cox regression analysis for progression free survival (PFS)

	Univariable			Multivariable

	Exp (B)	95% CI	p-value	Exp (B)	95% CI	p-value
Baseline
Age (years)	1.037	0.995–1.082	0.084
Sex	1.105	0.324–2.528	0.849
Grading
G1			0.251
G2	0	0	0.985
G3	2.913	0.827–10.625	0.096
Ki-67	1.02	0.978–1.063	0.362
Chromogranin	1	1	0.989
Hepatic tumor burden	0.98	0.955–1.006	0.125
SUVmax LM	0.979	0.951–1.007	0.134
SUVmean LM	0.982	0.94–1.025	0.41
SUVmax Pancreas	0.983	0.956–1.01	0.21
SUVmean Pancreas	0.975	0.93–1.023	0.3
Tmax/Lmean	0.922	0.821–1.037	0.175
Tmean/Lmean	0.886	0.72–1.09	0.251
Tmax/Smean	0.588	0.373–0.927	0.022	0.626	0.365–1.076	0.09
Tmean/Smean	0.474	0.223–1.004	0.051
% change
CgA	1.004	1–1.008	0.056
SUVmax LM	1.002	0.99–1.013	0.792
SUVmean LM	0.998	0.986.1.009	0.686
HU LM	0.999	0.975–1.024	0.948
SUVmax Pancreas	1.002	0.996–1.008	0.451
SUVmean Pancreas	1.002	0.995–1.009	0.512
Tmax/Lmean	1.003	0.992–1.013	0.623
Tmean/Lmean	0.99	0.989–1.009	0.836
Tmax/Smean	1.006	0.99–1.013	0.079
Tmean/Smean	1.006	0.998–1.013	0.149
Size LM (mm)	0.999	0.983–1.015	0.908
Size Pancreas	1.018	1.001–1.034	0.037	1.009	0.99–1.009	0.37
Size total (RECIST)	1.014	0.993–1.036	0.183

Patient characteristics

Sex
Male	17 (77%)
Female	5 (23%)
Median age, years (range)	66 (40–85)
Grading
G1	1 (5%)
G2	17 (77%)
G3	4 (18%)
Median Ki-67 (ng/ml, range)	12 (2–40)
Treatment with CAPTEM
Duration of treatment (month, range)	7.5 (3–20)
Prior treatment	16 (73%)
pNET resected	6 (27%)
Prior medical treatment	9 (41%)
Prior PRRT	6 (27%)
Prior liver targeted therapy	6 (27%)

Quantitative SSTR-PET/CT for predicting response and survival outcomes in patients with pancreatic neuroendocrine tumors receiving CAPTEM

Figures & Tables

FIGURE 1.

Cox regression analysis for overall survival (OS)

Imaging and clinical parameters on baseline and follow-up imaging

Cox regression analysis for progression free survival (PFS)

Patient characteristics

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