For 60Co in brachytherapy, what is the exposure rate constant?

The exposure rate constant for cobalt-60 (60Co) in brachytherapy is crucial for calculating the radiation exposure delivered to tissues. Cobalt-60 is a commonly used radioisotope in brachytherapy due to its effective energy and half-life.

The correct value of the exposure rate constant for cobalt-60 is approximately 13 R cm²/mCi hr. This value indicates the amount of exposure in roentgens at a distance of one centimeter from a source of one millicurie of cobalt-60 over the course of one hour. This constant is used in dosimetric calculations when determining patient doses and assessing the safety of therapeutic applications.

Understanding this constant is fundamental for medical dosimetrists as they need to accurately compute the delivered dose to ensure effective treatment while minimizing the risk of overexposure to surrounding healthy tissues.