Woodruff School of Mechanical Engineering

NRE 8011/8012 and MP 6011/6012 Seminar

Nuclear & Radiological Engineering and Medical Physics Programs


Radio-sensitive and Heat-sensitive Gel Dosimeters


Mr. Arsalan Siddiqi


Emory University


Thursday, November 11, 2010 at 11:00:00 AM


Boggs Building, Room 3-47 (3rd Flr)


Sang Hyun Cho


Irradiation of tumors loaded with gold nanoparticles has shown to cause dose enhancement resulting from increased photoelectric cross section of gold. One of the conceivable ways to demonstrate the dose enhancement over a volume is to use three dimensional dosimeters such as gel dosimeter that can record possible dose enhancement within itself. A widely used radio-sensitive polymer gel is methacrylic and ascorbic acid in gelatin initiated by copper known as MAGIC gel. In the current investigation, this gel was used to capture dose enhancement resulting from gold nanoparticles. Additionally, few computational models currently exist to predict heat production and dissipation in tissue when a tumor containing optically-tunable gold nanoparticles such as nanoshells or nanorods is illuminated with near infrared (NIR) laser. One of the possible ways to validate the model is through the heat measurements within a phantom made with tissue-equivalent heat-sensitive gel. Currently, there are a few recipes available for this type of gel and the majority of them use severely toxic ingredients. In this investigation, two new types of heat-sensitive gels, using relatively non-toxic substances, were developed and tested for the in-phantom validation of computational models.


Arsalan Siddiqi received his BS degree in Materials Science and Engineering from Georgia Tech. Later, he received his MS degree in Medical Physics from Georgia Tech as well. Mr. Siddiqi is currently a Medical Physics resident at Emory University's Department of Radiation Oncology. As a graduate student in MP program, he worked on gel dosimetry characterizing novel heat-sensitive gel using MRI. He has also investigated radio-sensitive gel to capture dose enhancement utilizing gold nanoparticles.