Theoretical investigation of transgastric and intraductal approaches for ultrasound-based thermal therapy of the pancreas

Table 3 Treatment parameters for patient-specific cases

Case	Tumor location	Tumor length (cm)	Tumor volume (cm³)	Approach	Treatment	Applicator configuration	Treatment time (min)	Mean power (W)	% volume treated
1	Body	4.8	17.0	Transgastric	Ablation	2x10 mm, 270°	20	10.1–11.9	60.0
2	Body	4.8	17.0	Intraductal	Ablation	2x10 mm, 210°	30	8.8–11.6	55.3
3	Tail	1.9	3.3	Transgastric	Ablation	2x7.5 mm, 270°	10	13.3	72.7
4	Head 1	2.5	4.4	Intraductal	Hyperthermia	2x15 mm, 360°	N/A	3.8	89.9
5	Head 1	2.5	4.4	Intraductal	Ablation	2x15 mm, 360°	8	9.7	83.3
6	Head 2	2.0	4.4	Transgastric	Ablation	2x10 mm, 360°	9	10.5	81.6
7	Head 3	3.9	11.4	Intraductal	Hyperthermia	3x15 mm, 360°	N/A	3.5	94.7
8	Head 4	3.2	7.9	Transgastric	Ablation	2x15 mm, 270°	10	10.0	67.1

Four different tumors in the head of the pancreas were modeled, and are numbered. Tumor length is defined as the tumor dimension along the applicator axis. The applicator configuration gives the number of transducers, the length of the transducers, and the sector size. Regions over 52 °C for ablation and 40 °C for hyperthermia are considered to be treated. Powers for Cases 1 and 2 were adjusted at each applicator position. Power for each time-dependent ablation study was varied continuously by a PI controller, so mean power is reported. Hyperthermia treatments were modeled as steady-state simulations, so a single value for power was simulated, and a specific treatment time is not applicable

ISSN: 2050-5736