SURLAS: A new clinical grade ultrasound system for sequential or concomitant thermoradiotherapy of superficial tumors: Applicator description

Petr Novák, Eduardo G. Moros, William L. Straube, Robert J. Myerson

Research output: Contribution to journalArticlepeer-review

26 Scopus citations


A new ultrasound applicator with three-dimensional power distribution control was developed for simultaneous thermoradiotherapy. The system was named SURLAS for Scanning Ultrasound Reflector Linear Arrays System. In this paper, the hardware of the first clinical grade SURLAS applicator is described with emphasis on clinically important static acoustic characteristics and on construction aspects not reported before. Functionally, the SURLAS applicator consists of two parallel opposed ultrasound linear arrays aiming their acoustic beams to a V-shape scanning ultrasound reflector, which deflects the beams coming from opposite directions toward the treatment area. The reciprocating motion of the reflector in-between the arrays spreads the ultrasonic energy over the target area scanned. Control of power deposition over the 16 cm by 16 cm treatment window area is achieved by adjusting the power input into the transducer elements of the arrays as a function of the position of the scanning reflector. Furthermore, the arrays operate at significantly different frequencies (1.9 and 4.9 MHz) so that intensity modulation of beams of different frequencies can be exploited to adjust the depth of energy penetration. With this design, external electron or photon beams can be concurrently delivered with hyperthermia by irradiating through the applicator's body. Safety features were implemented into the applicator's design to monitor its performance during operation. A detailed description of the applicator including impedance matching circuits/filters, radiation force balance power measurements, hydrophone pressure field distribution measurements, as well as safety test results are reported.

Original languageEnglish
Pages (from-to)230-240
Number of pages11
JournalMedical physics
Issue number1
StatePublished - Jan 2005


  • 3D power deposition control
  • Electron beams
  • Frequency blending
  • Hyperthermia
  • Hyperthermia applicator
  • Hyperthermia system
  • Photon beams
  • Scanned ultrasound
  • Simultaneous thermoradiotherapy
  • Superficial tumors
  • Ultrasonic heating


Dive into the research topics of 'SURLAS: A new clinical grade ultrasound system for sequential or concomitant thermoradiotherapy of superficial tumors: Applicator description'. Together they form a unique fingerprint.

Cite this