Single- and double-plane iridium-192 interstitial implants: implantation guidelines and dosimetry

Area of Science:

• Medical Physics
• Radiotherapy
• Nuclear Medicine

Background:

• Brachytherapy utilizes radioactive sources for localized radiation treatment.
• Accurate dose calculation is crucial for effective and safe brachytherapy.
• Iridium-192 (Ir-192) is a commonly used radionuclide in brachytherapy.

Purpose of the Study:

• To determine optimal geometric parameters for single- and double-plane Ir-192 implants.
• To develop standardized dose rate curves for clinical application.
• To facilitate quicker and more accurate dose estimations in planar brachytherapy.

Main Methods:

• Computerized dosimetric simulations were conducted for Ir-192 planar implants.
• Variations in source and ribbon/plane separations were analyzed for dose homogeneity.
• Standard dose rate curves were generated based on optimized parameters.

Main Results:

• Optimal source and ribbon separation for single-plane implants was found to be 1.0 cm.
• Optimal ribbon and plane separation for double-plane implants was 1.5 cm, with 1 cm source separation.
• Generated dose rate curves provide rapid dose estimation for various planar implant sizes.

Conclusions:

• The identified optimal separations enhance dose homogeneity in Ir-192 planar brachytherapy.
• Standardized dose rate curves offer practical clinical value for physicists and radiotherapists.
• These tools reduce the need for extensive individual dosimetry, improving efficiency.