Thermal therapy for breast tumors by using a cylindrical ultrasound phased array with multifocus pattern scanning: A preliminary numerical study
Journal
Physics in Medicine and Biology
Journal Volume
52
Journal Issue
15
Pages
4585-4599
Date Issued
2007
Author(s)
Abstract
The purpose of this study is to investigate the feasibility of using a 1 MHz cylindrical ultrasound phased array with multifocus pattern scanning to produce uniform heating for breast tumor thermal therapy. The breast was submerged in water and surrounded by the cylindrical ultrasound phased array. A multifocus pattern was generated and electrically scanned by the phased array to enlarge the treatment lesion in single heating. To prevent overheating normal tissues, a large planning target volume (PTV) would be divided into several planes with several subunits on each plane and sequentially treated with a cooling phase between two successive heatings of the subunit. Heating results for different target temperatures (Ttgt), blood perfusion rates and sizes of the PTV have been studied. Furthermore, a superficial breast tumor with different water temperatures was also studied. Results indicated that a higher target temperature would produce a slightly larger thermal lesion, and a higher blood perfusion rate would not affect the heating lesion size but increase the heating time significantly. The acoustic power deposition and temperature elevations in ribs can be minimized by orienting the acoustic beam from the ultrasound phased array approximately parallel to the ribs. In addition, a large acoustic window on the convex-shaped breast surface for the proposed ultrasound phased array and the cooling effect of water would prevent the skin overheating for the production of a lesion at any desired location. This study demonstrated that the proposed cylindrical ultrasound phased array can provide effective heating for breast tumor thermal therapy without overheating the skin and ribs within a reasonable treatment time. © 2007 IOP Publishing Ltd.
Other Subjects
Cooling; Heat treatment; Scanning; Sensor arrays; Skin; Tissue; Ultrasonics; Blood perfusion rate; Breast tumors; Cylindrical ultrasound phased array; Planning target volume (PTV); Tumors; article; blood flow; breast tumor; burn; heating; human; hyperthermic therapy; mathematical analysis; priority journal; skin temperature; thermal conductivity; treatment duration; ultrasound; water temperature; Breast Neoplasms; Computer Simulation; Equipment Design; Equipment Failure Analysis; Female; Humans; Hyperthermia, Induced; Models, Biological; Pilot Projects; Radiometry; Radiotherapy Dosage; Relative Biological Effectiveness; Therapy, Computer-Assisted; Treatment Outcome; Ultrasonic Therapy
Type
journal article