Early radiological assessment of locally advanced pancreatic cancer treated with electrochemotherapy

Table 1 Characteristics of locally advanced pancreatic cancer patients treated with electrochemotherapy

Patients (n = 19)
Histotype, %
Adenocarcinoma	100 (19/19)
Location, %
Head	57.9 (11/19)
Body/tail	42.1 (8/19)
Largest diameter lesion, cm (range)	5.2 (2.2-9.9)
Venus involvement (SMV or PV), %
Yes	84.2 (16/19)
No	15.7 (3/19)
Arterial encasement, %
Yes	57.9 (11/19)
No	42.1 (8/19)

Table 2 Parameters for each magnetic resonance sequence

Sequence	Orientation	TR/TE/FA (ms/ms/deg.)	FOV (mm2)	Acquisition matrix	Slice thickness/gap (mm)
HASTE T2-W	Axial	1500/90/180	380 × 380	320 × 320	5/0
FLASH T1-W, in-out phase	Axial	160/4.87/70	285 × 380	192 × 256	5/0
FLASH T1-W, out phase	Axial	178/2.3/80	325 × 400	416 × 412	3/0
DWI	Axial	7500/91/90	340 × 340	192 × 192	3/0
VIBE T1-W	Axial	4.89/2.38/10	325 × 400	320 × 260	3/0
TWIST T1-W, Pre and post contrast agent injection	Axial	3.01/1.09/25	300 × 300	256 × 256	2/0

W: Weighted; TR: Repetition time; TE: Echo time; FA: Flip angle; AT: Acquisition time; HASTE: Half-Fourier acquisition single-shot turbo spin-echo; FLASH: Fast low angle shot; DWI: Diffusion-weighted imaging; VIBE: Volumetric interpolated breath hold examination; TWIST: Time-Resolved Angiography with Stochastic Trajectories.

Table 3 Tumor size before and after electrochemotherapy for individual patient evaluated by magnetic resonance and computed tomography

Patient No.	Age	Sex	Tumor size		Tumor response after ECT treatment
			CT (mm)	MR (mm)	1st radiological evaluation after ECT (CT); size (mm)	1st radiological evaluation after ECT (MR); size (mm)
1	48	M	99	95	90	87
2	63	F	43	48	38	43
3	71	F	59	64	54	57
4	61	F	22	26	19	23
5	72	F	51	49	49	-
6	80	F	48	-	45	-
7	60	F	33	-	24	-
8	62	F	30	-	22	-
9	67	M	99	-	-	-
10	57	M	56	-	46	-
11	74	M	56	58	59	51
12	67	M	63	68	55	55
13	59	M	28	30	28	24
14	79	M	50	41	46	38
15	71	M	35	34	56	-
16	80	M	53	-	49	-
17	80	M	64	55	49	46
18	59	F	51	51	66	65
19	62	F	53	53	50	49

ECT: Electrochemotherapy; CT: Computed tomography; MR: Magnetic resonance.

Table 4 Treatment response assessment based on response evaluation criteria in solid tumour 1.1 criteria evaluated by magnetic resonance and computed tomography, based on Choi criteria evaluated by computed tomography, based on perfusion and diffusion parameters evaluated by dynamic contrast enhanced-magnetic resonance imaging and diffusion weighted imaging data and based on positron emission tomography response criteria in solid tumors criteria evaluated by positron emission tomography/computed tomography

No.	ΔCT largest diameter	ΔHU	ΔMR largest diameter	ΔWIS	ΔWOS	ΔDt	Δfp	ΔDp	ΔSUVmax	Response assessment
1	11.6%	22.7%	8.4%	35.4%	40.0%	-78.1%	12.1%	61.9%	-177.8%	PR
2	9.1%	40.4%	10.4%	84.7%	85.0%	-32.7%	27.3%	78.7%		PR
3	8.5%	34.0%	11.5%	94.0%	74.4%	-64.4%	28.5%	50.3%	38.5%	PR
4	13.6%	7.8%	2.0%	88.0%	76.0%	-16.8%	32.7%	36.6%		PR
5	3.9%	48.7%
6	6.3%	18.9%
7	27.3%	49.5%
8	26.7%	51.6%
9
10	17.9%	42.6%							100.0%	PR
11	-5.4%	49.1%	12.1%	18.4%	9.7%	-20.4%	-33.3%	5.4%	66.5%	SD
12	12.7%	6.8%	19.1%	57.9%	98.0%	-34.2%	11.7%	12.0%	-17.9%	SD
13	6.7%	44.4%	20.0%	7.9%	-17.4%	32.5	2.2%	36.9%	46.8%	PR
14	8.0%	44.8%	7.3%	67.6%	110.0%	-32.9%	44.3%	92.0%	44.4%	PR
15	-60.0%	83.3%
16	7.5%	23.4%
17	23.4%	35.5%	16.4%	55.7%	307.1%	-18.0%	62.6%	32.2%	18.8%	PR
18	-29.4%	40.0%	-9.8%	34.9%	58.7%	-16.3%	46.7%	66.4%	17.0%	PR
19	5.7%	44.0%	7.5%	67.3%	-24.6%	-30.5%	-22.6%	-90.7%	32.3%	PR

CT: Computed tomography; HU: Hounsfield unit; MR: Magnetic resonance; WIS: Wash-in slope; WOS: Wash-out slope; Dt: Diffusivity; fp: Perfusion fraction; SUVmax: Maximum standardized uptake value.

Table 5 Spearman correlation coefficient for each couple of imaging parameters

		ΔCT maximum diameter (%)	ΔHU (%)	ΔMR maximum diameter (%)	ΔWash-in (%)	ΔWash-out (%)	ΔDt (%)	Δfp (%)	ΔDp (%)	ΔSUVmax
ΔCT maximum diameter (%)	Correlation coefficient	1.000	-0.183	0.227	0.418	0.655a	-0.273	0.364	-0.036	-0.127
	P value		0.468	0.502	0.201	0.029	0.417	0.272	0.915	0.726
	n	18	18	11	11	11	11	11	11	10
ΔHU (%)	Correlation coefficient	-0.183	1.000	0.027	-0.373	-0.373	0.318	-0.291	0.064	0.758a
	P value	0.468		0.937	0.259	0.259	0.340	0.385	0.853	0.011
	n	18	18	11	11	11	11	11	11	10
ΔMR maximum diameter (%)	Correlation coefficient	0.227	0.027	1.000	-0.345	-0.082	-0.036	-0.409	-0.391	0.183
	P value	0.502	0.937		0.298	0.811	0.915	0.212	0.235	0.637
	n	11	11	11	11	11	11	11	11	9
ΔWash-in (%)	Correlation coefficient	0.418	-0.373	-0.345	1.000	0.527	-0.436	0.318	0.209	-0.150
	P value	0.201	0.259	0.298		0.096	0.180	0.340	0.537	0.700
	n	11	11	11	11	11	11	11	11	9
ΔWash-out (%)	Correlation coefficient	0.655a	-0.373	-0.082	0.527	1.000	-0.264	0.709a	0.291	-0.383
	P value	0.029	0.259	0.811	0.096		0.433	0.015	0.385	0.308
	n	11	11	11	11	11	11	11	11	9
ΔDt (%)	Correlation coefficient	-0.273	0.318	-0.036	-0.436	-0.264	1.000	0.118	-0.164	0.417
	P value	0.417	0.340	0.915	0.180	0.433		0.729	0.631	0.265
	n	11	11	11	11	11	11	11	11	9
Δfp (%)	Correlation coefficient	0.364	-0.291	-0.409	0.318	0.709a	0.118	1.000	0.545	-0.400
	P value	0.272	0.385	0.212	0.340	0.015	0.729		0.083	0.286
	n	11	11	11	11	11	11	11	11	9
ΔDp (%)	Correlation coefficient	-0.036	0.064	-0.391	0.209	0.291	-0.164	0.545	1.000	-0.167
	P value	0.915	0.853	0.235	0.537	0.385	0.631	0.083		0.668
	n	11	11	11	11	11	11	11	11	9
ΔSUVmax	Correlation coefficient	-0.127	0.758a	0.183	-0.150	-0.383	0.417	-0.400	-0.167	1.000
	P value	0.726	0.011	0.637	0.700	0.308	0.265	0.286	0.668
	n	10	10	9	9	9	9	9	9	10

^aP < 0.05 was considered statistically significant. CT: Computed tomography; HU: Hounsfield unit; MR: Magnetic resonance; WIS: Wash-in slope; WOS: Wash-out slope; Dt: Diffusivity; fp: Perfusion fraction; SUVmax: Maximum standardized uptake value.