Investigating the Physical Principles, Clinical Applications, and Dosimetric Precision of Brachytherapy
Brachytherapy, often referred to as internal radiation therapy, is a technique in radiation oncology where a sealed radioactive source is temporarily or permanently placed directly into or adjacent to the area requiring treatment, allowing for the delivery of a very high dose of radiation precisely to the tumor volume while minimizing exposure to surrounding healthy tissues.
Its fundamental advantage lies in the principle of the inverse square law, where the radiation dose falls off rapidly with distance from the source, creating a highly localized, conformal dose distribution that is particularly effective for treating cancers in accessible sites such as the prostate, cervix, breast, and skin.
Brachytherapy is typically categorized into Low Dose Rate ($\text{LDR}$), where sources remain implanted for a prolonged period (e.g., permanent seeds for prostate cancer), and High Dose Rate ($\text{HDR}$), where a single, high-activity source is delivered via a computer-controlled afterloader for short, highly precise treatment fractions…
