What is the dose rate specification for low-dose rate (LDR) treatments?

In low-dose rate (LDR) treatments, the dose rate is typically defined as being in the range of 0.4 to 2 Gy per hour. This specification is important because LDR brachytherapy is designed to deliver radiation at a slower rate over a longer period of time, allowing for more significant cancer control while minimizing damage to surrounding healthy tissues. This approach is especially beneficial in treating certain types of cancers, such as prostate cancer, where prolonged exposure to lower doses can be effective without overwhelming the patient's normal tissue tolerances.

The rationale for using the defined range of 0.4 to 2 Gy per hour is tied to the biological response of tissues to radiation. At lower dose rates, there is a greater opportunity for the surrounding normal cells to repair some of the damage caused by radiation, which is less likely to occur when higher dose rates are used. Therefore, the well-established range for LDR treatments is crucial for optimizing patient outcomes and balancing treatment efficacy with safety.