Seed implants are a form of brachytherapy, the term applied to placement of localized radiotherapy sources. Their promise lies in their ability to deliver a high radiation dose with precision, thus delivering a higher tumor dose while sparing surrounding, normal tissue. In fact, recurrences of cancer were more frequent with surgical seed implants than when using external beam radiation, which delivered a more even dose of radiation through the prostate. Then, about ten years ago, a group of Seattle, WA, physicians pioneered the technique used today. Using a grid system and rectal ultrasound guidance, the urologist and radiation oncologist implant the seeds with a needle.
Patients typically experience few late side effects.
While implants to some other sites are temporary and removed when the appropriate radiation dose has been delivered, prostate seed implants are left in the body permanently. The seeds deliver a high dose of radiation as long as the radioactive material remains active. We now have five or six years of follow-up data on sufficient numbers of patients to suggest that it has outcomes equivalent with surgery or external beam radiation. However, it's important to note that this is just one of the choices we have to offer patients with prostate cancer. The 'best' therapy is very much an individual matter that depends on age, disease stage, and many other factors.