SURLAS

Scanning Ultrasound Reflector Linear Array System

The SURLAS (Scanning Ultrasound Reflector – Linear Arrays System) is a
superficial ultrasound hyperthermia system for simultaneous thermoradiotherapy.
After considerable developmental and testing efforts, we are in the process of
laboratory testing (incl. FDA) of a clinical system. The overall system
consists of an applicator, a 16-channel RF generator, a 16 channel-thermometry
unit, a PC with controlling software, and other supporting electronics. The
major functional parts of the applicator are two parallel-opposed ultrasound
arrays with electrical impedance matching networks, a scanning slider connected
to a dual-face acoustic reflector, slider scanning unit with magnetic movement
sensors, and the applicator’s acrylic body with a custom-molded silicone
membrane bolus. The ultrasound arrays (Navy Type I) operate at frequencies 1.9
MHz and 4.9 MHz. The water filled acrylic body with scanning reflector
(Styrofoam on acrylic plate) minimally perturbs/absorbs electron/photon beams
from a Linac. Each array has 8 independent elements. The treatment window is 16 cm x 16 cm. This configuration provides 3D power deposition controllability.
An electrical impedance matching network was designed for every piezoelectric
element separately to achieve a maximum output power from the ultrasound
arrays. The slider/reflector moving unit, the supporting electronics, and the
software assure an accurate, stable, and acoustically noiseless positioning of
the reflector. The SURLAS PC-based software monitors the proper operation of
the entire system, and coordinates all peripheral devices. The software is able
to communicate with the thermometry unit as well and provides multi-level
security, quality assurance, and treatment control features.

Support: NIH grant R01-CA63121

Published papers:

P. Novak, E. Moros, W. Straube and R. Myerson: Treatment delivery software for a new clinical grade ultrasound
system for thermoradiotherapy. Medical Physics, 2005;32(11): pp 3246-3257.

P. Novak, E. G. Moros, W. L. Straube and R. J. Myerson: SURLAS: A new clinical grade ultrasound system for
sequential or concomitant thermoradiotherapy of superficial tumors: Applicator description. Medical Physics,
2005;32(1): pp 230-240.

E.G. Moros, X. Fan, and W.L. Straube, “Experimental assessment of power and temperature penetration
depth control with a dual frequency ultrasonic system,” Med Phys 1999:26, 810-817.

E.G. Moros, X. Fan, W.L. Straube, and R.J. Myerson, “Numerical and in vitro evaluation of temperature
fluctuations during reflected-scanned planar ultrasound hyperthermia,” Int J Hyperthermia 1998:14, 367-382.

E.G. Moros, X. Fan, and W.L. Straube, “An investigation of penetration depth control using parallel
opposed ultrasound arrays and a scanning reflector,” J Acoust Soc Am, 1997:101, 1734-1741.

E.G. Moros, W.L. Straube, and R.J. Myerson, “A reflected-scanned ultrasound system for external
simultaneous thermoradiotherapy,” IEEE T Ultrason Ferr 1996:43, 441-449.

E.G. Moros, W.L. Straube, and R.J. Myerson, “Potential for power deposition conformability using
reflected-scanned planar ultrasound,” Int J Hyperthermia 1996:12, 723-736.

E.G. Moros, W.L. Straube, E.E. Klein, M. Yousaf, and R.J. Myerson, “Simultaneous delivery of electron
beam therapy and ultrasound hyperthermia using scanning reflectors: a feasibility study,” Int J Radiat
Oncol Biol Phys 1995, 31, 893-904.