Intravascular brachytherapy delivered at the time of angioplasty has been proven to be effective in preventing restenosis induced by interventional recanulazation procedures. The overall objective of this proposed project is to improve the efficacy of intravascular brachytherapy with minimized associated toxicity, by exploring the use of various isotopes. The scheme proposed in this project to improve the treatment efficacy and to decrease the risk of late tissue damage is to optimize the dosimetry by exploiting different isotope characteristics so that highly localized radiotherapy can be delivered with minimal toxicity to surrounding normal tissue. The specific approaches are: (1) To determine the accurate and precise dose distributions of 90Sr, 90Y, 125I and 192Ir sources. (2) To explore potential beta emitters, 106Ru/Rh and 144Ce/Pr, by assessing their dose distributions, within the target cells as well as adjacent non-target normal tissues using dosimetric methods in microscopic scale. We will perform precision dosimetric studies for these radionuclides (a) in homogeneous tissue equivalent medium and (b) with heterogeneities present in the vessel, such as blood, contrast medium, calcified plaque and stainless steel stents. Two complementary means will be employed: (a) measurement using a new type of x-ray film, called GafChromic film, and (b) calculations using a Monte Carlo simulation code, MCNP. The effect on the dose distributions by the heterogeneities will be studied and quantified. We will devise an improved methodology of treatment planning calculations to incorporate the dose modifying functions for general shape and dimensions of the heterogeneities.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
7R01HL057923-02
Application #
2857920
Study Section
Radiation Study Section (RAD)
Project Start
1998-04-15
Project End
2001-03-31
Budget Start
1998-06-01
Budget End
1999-03-31
Support Year
2
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Beth Israel Medical Center (New York)
Department
Type
DUNS #
075255364
City
New York
State
NY
Country
United States
Zip Code
10003
Patel, Neil S; Chiu-Tsao, Sou-Tung; Shih, J Allen et al. (2004) Treatment planning dosimetric parameters for 192Ir seed at short distances: effects of air channels and neighboring seeds based on Monte Carlo study. Med Phys 31:1521-8
Chiu-Tsao, Sou-Tung; Duckworth, Tamara L; Patel, Neil S et al. (2004) Verification of Ir-192 near source dosimetry using GAFCHROMIC film. Med Phys 31:201-7
Chiu-Tsao, Sou-Tung; Duckworth, Tamara; Zhang, Chuanfang et al. (2004) Dose response characteristics of new models of GAFCHROMIC films: dependence on densitometer light source and radiation energy. Med Phys 31:2501-8
Chiu-Tsao, Sou-Tung; Duckworth, Tamara L; Hsiung, Chih-Yun et al. (2003) Thermoluminescent dosimetry of the SourceTech Medical model STM1251 125I seed. Med Phys 30:1732-5
Patel, Neil S; Chiu-Tsao, Sou-Tung; Ho, Yunsil et al. (2002) High beta and electron dose from 192Ir: implications for ""gamma"" intravascular brachytherapy. Int J Radiat Oncol Biol Phys 54:972-80
Patel, N S; Chiu-Tsao, S T; Fan, P et al. (2001) The use of cylindrical coordinates for treatment planning parameters of an elongated 192Ir source. Int J Radiat Oncol Biol Phys 51:1093-102
Patel, N S; Chiu-Tsao, S T; Tsao, H S et al. (2001) A new treatment planning formalism for catheter-based beta sources used in intravascular brachytherapy. Cardiovasc Radiat Med 2:157-64
Patel, N S; Fan, P; Chiu-Tsao, S T et al. (2001) Ytterbium-169: a promising new radionuclide for intravascular brachytherapy. Cardiovasc Radiat Med 2:173-80
Patel, N S; Chiu-Tsao, S T; Fan, P et al. (2001) Treatment planning dosimetric parameters for a (90)Y coil source used in intravascular brachytherapy. Cardiovasc Radiat Med 2:83-92
Fan, P; Chiu-Tsao, S T; Patel, N S et al. (2000) Effect of stent on radiation dosimetry in an in-stent restenosis model. Cardiovasc Radiat Med 2:18-25