Which type of radiation is commonly used in brachytherapy?

Brachytherapy involves placing radioactive sources close to or within the tumor tissue itself, allowing for a targeted delivery of radiation. Among the forms of radiation available, gamma rays are the most commonly used in this treatment modality. Gamma rays have high penetrating power, which makes them effective in treating tumors located deep within the body while sparing surrounding healthy tissues.

Gamma sources, such as cesium-137 and iridium-192, are typically employed in brachytherapy due to their ability to deliver a concentrated dose of radiation over a relatively short distance. This is particularly beneficial in managing various cancers, including prostate, cervical, and breast cancers, where localized treatment minimizes the risk to adjacent structures.

In contrast, other types of radiation like alpha particles, although powerful, have limited penetration capabilities and are primarily used in targeted alpha therapy rather than brachytherapy. X-rays are more commonly associated with external beam radiation therapy, where the radiation is delivered from outside the body rather than being placed within or near the tumor. Electrons are utilized in superficial treatments and skin lesions due to their limited penetration capacity, further distinguishing their application from that of gamma rays in brachytherapy.