Air Kerma Standards for Ir-192 and Electronic Brachytherapy Sources
Summary for MPD A.18.0
In the early 2000’s several new miniature electronic brachytherapy sources emerged for the treatment of interstitial, intercavitary, and surface malignancies.
Detailed Program Characteristics
Electronic brachytherapy sources used in the United States commonly use miniature x-ray tubes to generate a low-energy (70 kVP or below) bremsstrahlung spectra. Recently, one manufacturer of a miniature x-ray source (Xoft, a subsidiary of iCAD, Palo Alto, CA) worked with National Institute of Standards and Technology (NIST) to establish a standard for their source. However no other miniature x-ray sources have a national standard. The current air-kerma standard available for the Xoft miniature x-ray source has prepared the groundwork for establishing additional standards. The present standard utilizes a free-air-chamber (FAC) mounted on a rotating arm to assess the air-kerma as well as source anisotropy.
Manufacturers should be encouraged to work with NIST and secondary calibration laboratories to establish air-kerma standards for their sources. CIRMS can provide a channel for communication between the industrial sector and the academic/national laboratory setting.