Brachy is derived from the Greek word meaning short. Brachytherapy delivers an intense form of radiation over a short distance through small needles or catheters directly into the tumor site, or near the site, to destroy cancer cells. Under ultrasound visualization, the seeds are delivered to the tumor with precise accuracy. Brachytherapy differs from the standard external beam radiation treatment, which is delivered by a beam of radiation from an external machine. For some patients a combination of external beam radiation and brachytherapy is most effective. Brachytherapy may help cure cancer or help relieve pain associated with some cancers.