What is often delivered through internal radiation methods in cancer therapies?

Internal radiation methods primarily utilize brachytherapy for the treatment of cancer. Brachytherapy involves placing radioactive sources directly into or very close to the tumor. This allows for a high dose of radiation to be delivered directly to the cancerous tissue while minimizing exposure to the surrounding healthy tissue. This targeted approach can lead to better treatment outcomes and fewer side effects compared to other methods.

In contrast, the other options provided do not align with the concept of internal radiation. Chemotherapy drugs are typically administered systemically through the bloodstream and not through an internal radiation method. External beam treatments involve directing radiation from outside the body towards the tumor and do not fall under the category of internal radiation. Hormone therapies, while used to treat certain cancers, do not involve direct radiation and work through different mechanisms. Thus, brachytherapy is the definitive method that corresponds to internal radiation therapy in this context.