Plasmonic photothermal therapy is a new cancer thermotherapy method based on surface plasmon resonance of nanoparticles. It is important to measure the temperature during thermotherapy for safety and efficacy. In this study, we apply a photoacoustic (PA) method for real-time, non-invasive temperature measurements. In particular, this method can be effectively combined with a photothermal therapy system that we developed in parallel. The method is based on the fact that the PA pressure amplitude is linearly related to temperature. To explore its potential, a home-made, 20 MHz PA transducer was used, in which an optical fiber was inserted in its center for emitting laser pulses while the PA signal was simultaneously detected. Continuous wave (CW) laser was used to heat the subject, including both phantoms and mice. The temperature of the region of interest was also measured by a fine-needle thermal couple. Results show that the temperature was linearly proportional to the PA signal with good correlation with the CW laser irradiation. The in vivo study also demonstrated potential of this technique.

Date Published: 12 February 2009
PDF: 11 pages
Proc. SPIE 7177, Photons Plus Ultrasound: Imaging and Sensing 2009, 71771S (12 February 2009); doi: 10.1117/12.809973

Published in SPIE Proceedings Vol. 7177:
Photons Plus Ultrasound: Imaging and Sensing 2009
Alexander A. Oraevsky; Lihong V. Wang, Editor(s)