Optical Dosimetry of Clinical Light Treatments

SPIE Short Course:  

Optical Dosimetry of Clinical Light Treatments

Prof. Anna N. Yaroslavsky

Department of Physics, University of Massachusetts, Lowell, USA

This lecture gives an introduction and overview of optical dosimetry, planning, and outcome assessment of emerging medical light treatments. Light-based therapies such as photobiomodulation therapy, photodynamic therapy, interstitial laser therapy, as well as vascular abnormality treatments and fractional laser rejuvenation of tissues and organs have been continuously explored during the last forty years. Rapid evolution of new light technologies, especially the advent of versatile fiber and hybrid lasers, has tremendously expanded the horizons of existing modalities and created new ones. The net result of these developments are more effective, faster procedures that manipulate significantly broader power and energy density ranges of light than was practical even a decade ago. As a result, the need of accurately predicting the course and outcomes of light based procedures is greater than ever.

The lecture will be sub-divided into two parts:

1. 1. Physics of the light propagation in biological media
2. Rapid development of photomedicine relies on the knowledge of tissue optical properties and the ability to predict light propagation and interaction with tissue.  Therefore, in the first part of the lecture the overview of the major tissue chromophores and their absorptive and scattering properties will be presented along with the methods used to determine these properties. Then, several practical approaches to predicting light propagation in complex biological systems will be outlined with focus on the Monte Carlo modeling  techqnique. Several instructive examples will illustrate the impact of the system geometry and chromophore optical properties on the fluence rate and absorbed power distribution within the biological systems.
2. 2. Example clinical applications

• In the second part of the lecture several example of clinical applications of the approach introduced in the first part of the lecture will be presented. In particular, we will walk over the essential steps of the treatment protocol development for extraoral photobiomodulation therapy of oral mucositis in pediatric patients. Then, several examples of the validation of interstitial laser therapy treatment of brain cancer in adult patients will be presented, dosimetry and optimization of portwine stain laser treatment will be analyzed, and outcome assessment of fractional skin rejuvenation treatment will be discussed.  

2. Learning objectives
2. This course will provide the participants with:
2. basic knowledge of the major tissue chromophores,  their optical properties, and the methods to determine these properties;
2. basic knowledge of the light-tissue interactions and methods for predicting light propagation and interaction with biotissues;
2. understanding of the importance of rigorous approach to light dosimetry for emerging clinical therapeutic application of light;

• basic knowledge of state of the art clinical applications of light and the role of the optical engineers and physicists in the development of clinically viable, novel treatment protocols and their optimization.

2. Intended audience

• Master and PhD students, postdocs, scientists from various disciplines, e.g. physicists, biologists, chemists, engineers, biomedical scientists, and clinicians.

2. Course level

• Intermediate

1. Short Course duration
2. Half a day

• Instructor
• Anna N. Yaroslavsky is Associate Professor of Physics and Director of Advanced Biophotonics Laboratory at the University of Massachusetts, USA. Her expertise is in biomedical optics and medical imaging. Her research is focused on the development of optical and multimodal technologies for medical applications. She graduated summa cum laude from Saratov State University, Russia, in 1990 with Masters Degree in Physics. Between 1990 and 1999, she conducted research at Twente University in Enschede (The Netherlands), Heinrich-Heine University in Dusseldorf (Germany), and Louisiana State University Medical Center in Shreveport, LA (USA). During that time, she pioneered development of individualized, image-based methods of laser dosimetry and planning for brain tumor treatment, formulated concept and implemented full inverse Monte Carlo technique for reconstruction of tissue optical properties, and investigated light scattering by complex biological structures. In 1999, she earned PhD degree in Biophysics from Saratov State University. In 2000, she joined Wellman Center for Photomedicine at Harvard Medical School, where she progressed from Instructor to Assistant Professor. Her research at Wellman Center concentrated on the development of combined polarization, fluorescence and elastic scattering methods for diagnostics of cancers. Since 2010, Anna is an Associate Professor with tenure at the University of Massachusetts. She published more than 60 manuscripts in top-tier international journals and authored several internatinal patents. She participated as principal investigator in 11 externally funded projects. She served as a reviewer on various NIH panels and has been elected senior member of SPIE.