Paper
17 October 2006 Interstitial doppler OCT monitoring of microvascular shutdown during photodynamic therapy in a Dunning prostate model: irradiance rate dependences
Beau A. Standish, Xiao Jin, Jurek Smolen, Adrian Mariampillai, Nigel R. Munce, I. Alex Vitkin, Victor X. D. Yang
Author Affiliations +
Proceedings Volume 6386, Optical Methods in the Life Sciences; 63860V (2006) https://doi.org/10.1117/12.686277
Event: Optics East 2006, 2006, Boston, Massachusetts, United States
Abstract
Microcirculatory changes, such as vascular shutdown, may be a predictor to the therapeutic efficacy of photodynamic therapy (PDT). The aim of this study was to measure the tumour vascular response to varying irradiance rates during PDT deep within prostate tumour xenograft, via interstitial Doppler optical coherence tomography (DOCT). DOCT provides micron-scale spatial resolution allowing visualization of structures at near histological levels, and yields flow velocity resolution of ~20 μm/s. Current in vivo DOCT imaging probes are limited to intraluminal and near-surface sites. To improve the accessibility of DOCT to anatomically relevant sites deep within the body (e.g., prostate), an interstitial (IS) needle (~700μm diameter) probe was developed for minimally invasive monitoring of the microvascular response to PDT (irradiance administered superficially) within tumour tissue. Rats were given a photosensitizer drug, Photofrin, and 20-24 h later the tumours were exposed to light (635nm) with an irradiance rate of 8-133 mW/cm2 for 25 minutes to a total irradiance of 12-200 J/cm2. Results illustrated different rates of vascular shutdown within the tumour as imaged by IS-DOCT, related to the administered PDT irradiance rate and total irradiance. Controls (probe only, probe + light) showed no significant microvascular changes. IS-DOCT was able to detect and monitor microvascular changes during PDT. Microvascular shutdown occurred at different rates and showed correlation with PDT light dose and irradiance rate. These dependencies may play an important role in PDT treatment planning, feedback control for treatment optimization, and post treatment assessment.
© (2006) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Beau A. Standish, Xiao Jin, Jurek Smolen, Adrian Mariampillai, Nigel R. Munce, I. Alex Vitkin, and Victor X. D. Yang "Interstitial doppler OCT monitoring of microvascular shutdown during photodynamic therapy in a Dunning prostate model: irradiance rate dependences", Proc. SPIE 6386, Optical Methods in the Life Sciences, 63860V (17 October 2006); https://doi.org/10.1117/12.686277
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Photodynamic therapy

Control systems

Optical coherence tomography

Prostate

Doppler tomography

In vivo imaging

Blood circulation

Back to Top