Thermotherapy with a Photoacoustic/Ultrasound Dual-modality Agent
Journal
SPIE Photonics West 2011
Date Issued
2011-01
Author(s)
Abstract
A microbubble-based imaging/therapeutic agent is introduced. Specifically, gold nanoparticles (AuNRs) are encapsulated in microbubbles (MBs) for both ultrasound (US) imaging and laser-induced thermotherapy (LIT). In addition, this agent, AuNR-MB, takes albumin microbubble as a carrier and includes the AuNRs that maintain the original absorption peak at around 760nm. AuNR-MBs in different sizes are synthesized. Imaging is first performed to evaluate its feasibility. The enhanced PA and US signals in polyacrylamide gel for in vitro study are measured. The PA spectroscopy is then performed and the results generally agree with the measured optical absorption although its peak is slightly broadened and shifted possibly due to mixing. In phantoms, the contrast is 1.531, 2.447, 2.085, 1.994, 0.768, and 0.573 at wavelength of 720, 760, 800, 860, 900, and 940 nm respectively. Finally, the application of the new agent to LIT is presented. A continuous wave laser at 800 nm is used to heat the samples with the power at 1W. The photoacoustic (PA) intensity in the region of interest (ROI) is increased by an average of 5.2dB. The increased signal level implies that the temperature in the ROI can be increased to 44.3°C in aqueous filled setup. Furthermore, the dual-modality agent has the potential to be used in HIFU therapy, drug delivery and loading of DNA for gene transfer.
SDGs
Type
conference paper