High intensity focused ultrasound treatment for patients with advanced pancreatic cancer: A preliminary dosimetric analysis

Figures & data

Table I.  Clinical data for 136 cases.

Characteristics		Number	Ratio (%)
General data
Gender	Male	89	65.4
	Female	47	34.6
Age (years)	Median	59
	Range	30–85
Karnofsky performance score	60	19	14.0
	70	65	47.8
	80	43	31.6
	90	9	6.6
Cancer characteristics
Cancer position	Head	47	34.6
	body or tail	89	65.4
Cancer size	<5 cm	72	52.9
	≥5 cm	64	47.1
TNM stage	III	43	31.6
	IV	93	68.4

Table II.  Statistical data for the treatment parameters.

Item	Value range (median)
Maximum diameter of tumour(cm)	2.0–10.0 (4.5)
Targeted volume, Vt (cm^3)	9.8–102.1 (31.1)
Average US power, Pavg (W)	117–399 (225)
Total energy of US, Etotal (kJ)	70.5–1195.2 (278.3)
Dose intensity of HIFU, DI (kJ/cm^3)	2.9–27.5 (7.9)
Treatment unit time, Tu (second/cm^3)	17.6–78.7 (35.4)

Figure 1. Illustration of greyscale changes induced by HIFU. (A) No change. (B) Punctiform change. (C) Lumpish change. (D) Lumpish hyper-echo change.

Figure 2. (A) An example of no change, US image obtained before HIFU (A1) and US image obtained after HIFU (A2), P_avg was 183 W and DI was 6.1 kJ/cm³. (B) An example of punctiform change, US image obtained before HIFU (B1) and US image obtained after HIFU (B2), P_avg was 217 W and DI was 8.8 kJ/cm³. (C) An example of lumpish change, US image obtained before HIFU (C1) and US image obtained after HIFU (C2), P_avg was 292 W and DI was 14.6 kJ/cm³. (D) An example of lumpish hyper-echo change, US image obtained before HIFU (D1) and US image obtained after HIFU (D2), P_avg was 275 W and DI was 11.3 kJ/cm³.

Figure 3. (A) MRI scan made before HIFU treatment which demonstrates a tumour in the body of the pancreas. (B) MRI scan demonstrating a vertebral injury (arrow) after HIFU treatment. P_avg of HIFU for this case was 208 W and DI was 6.9 kJ/cm³.

Figure 4. (A) Greyscale changes of HIFU obtained from real-time ultrasound (US) images during the HIFU procedure. (A1) US image obtained before HIFU showing a large pancreatic carcinoma lesion present in the body of pancreas. (A2) US images obtained immediately after the HIFU procedure showing a lumpish change (arrow) in one slice of the lesion. (B1) A CT scan made before HIFU demonstrating a tumour in the body of pancreas. (B2) A CT scan representing no significant size change one month after HIFU treatment and the necrotic area having the same greyscale change shown by US. (C1, D1) A PET-CT scan made before HIFU demonstrating a SUV_max of 7.8 g/mL. (C2, D2) The PET-CT scan made 1 month after HIFU showing coagulation necrosis of the tumour and a decrease in the SUV_max value to 3.5 g/mL. All images were taken from the same patient. The P_avg of HIFU for this patient was 237 W and DI was 9.9 kJ/cm³.

Figure 5. Changes in the mean DI for groups with different ultrasound image changes. The DI was significantly different (P < 0.01) between the echo change of the lumpish group (11.4 ± 4.9 kJ/cm³) and change of the non-lumpish group (7.8 ± 3.1 kJ/cm³).

Figure 6. Changes in the mean P_avg for groups with different ultrasound image changes. The P_avg was significantly different (P < 0.01) between the echo change of lumpish group (263 ± 54 W) and the change of the non-lumpish group (217 ± 49 W).

Table III.  Spearman correlation table.

Spearman correlation		Gender	Age	DI	Pavg	Tu	Position	Depth
Local response	r	−0.014	0.106	0.008	−0.034	0.005	0.131	0.046
	P	0.869	0.220	0.927	0.693	0.995	0.127	0.599
US change	r	−0.001	0.049	0.462	0.433	0.263	−0.007	−0.054
	P	0.994	0.568	0.000	0.000	0.002	0.934	0.532

Bold type = significant at P < 0.01.