Seattle Prostate Institute

Appointments 206.386.2356

Treatment Options

Am I A Candidate?

Seed implantation, like radical surgery or external beam radiation, is intended for the treatment of men with early stage prostate cancer, that is, where medical evidence suggests a strong likelihood that the cancer is either (a) confined to the prostate or (b) has not spread very far beyond the prostate. The important issue here is that the cancer has not spread to other parts of the body.

The question of if or how far a cancer may have spread is very difficult to answer and, in reality, can never be determined with absolute certainty. However, we know that patients whose cancers have favorable characteristics such as a very early clinical stage a low PSA, and low Gleason scores are very unlikely to have spread very far beyond the prostate. Patients with more aggressive or advanced disease have a greater likelihood of having more distant cancer and these patients often need additional testing in the form of specialized scans to search for possible spread.

A number of factors are involved in determining whether or not a patient is a good candidate for a seed implant. Some have to do with the nature of the cancer itself, while others take into account a variety of clinical indicators such as prostate size, pelvic structure, current urinary function, life expectancy and other related items.

Based on the best thinking of the SPI medical team and inquiries from patients and visitors to our web site, we hope that the criteria described below will help you get a good general idea of whether seed implantation could be a treatment option for you. 


Age, in itself, is not a major consideration in evaluating eligibility for implantation. At SPI, we have implanted men ranging in age from the mid 40’s to the early 90’s. Instead, the key issue for physicians is whether someone has a reasonable expectation of 10 or more years of life. If so, the long-term benefits of treatment can be fully realized. With a life expectancy below 10 years, however, the benefits have to be more carefully weighed against the risks and costs of treatment. Furthermore, it can take many years for the cancer to advance to the point where it materially affects one’s quality of life or becomes life threatening. Determining whether an individual has a 10-year life expectancy is difficult and is often an educated guess based on a patient’s age and general health status. 

In our experience, brachytherapy has led to a durable cure and has been safe and efficacious in younger men. Since brachytherapy only became available in the U.S. in the late 1980’s, most of the follow data is limited to 15 years. It is possible that there still may be risks of radiation that might not surface until 20 or 30 years after treatment. We will continue following patients in our database beyond 15 years, to know if there are any such concerns. However, we feel the chance of new side effects or recurrences becoming more common this far out from treatment is slim. The Seattle Prostate Center has published the longest follow-up on patients treated with brachytherapy.  

Serious medical conditions

Experience has shown that the seed implant procedure is gentle enough on the body that it can be an option for men who, for reasons of serious illness or medical history, might not be eligible for surgery or other treatments. At SPI, we have successfully implanted patients with serious heart disease (including major heart surgery), diabetes, kidney failure, stroke patients and others with a variety of challenging conditions.

Prior prostate surgery

Men who have had a transurethral resection of the prostate (TURP) to relieve urinary problems associated with non-malignant prostate enlargement (BPH) can still be considered for implantation. In a TURP procedure, tissue from the central area of the prostate is removed. This relieves the blockage caused by the enlarged prostate but leaves a cavity in the center of the gland. A seed implant can be performed after a TURP provided that there is enough prostate tissue remaining to hold a sufficient number of seeds. The main concern with implanting men who have had the TURP procedure is that they face a slightly higher likelihood of urinary incontinence than do men who have not had a TURP. Our ultrasound volume study can help determine if brachtherapy will be possible. 

Prostate size 

Experience has shown that when a prostate gland is more that 60 cc in volume, there is a high probability that a portion of the gland will be lodged behind the pubic bone, preventing the insertion of the seed-carrying needles. At SPI, the size of the prostate and its position relative to the pubic bone is determined at the time of the initial visit by performing a prostate ultrasound volume study. If the volume study indicates the likelihood of pubic bone interference, several months of treatment with hormones will usually shrink the prostate enough to make the implant technically possible. If the prostate is exceedingly large, often surgical excision is the best treatment option.

Risk of cancer outside of the prostate 

In this, most crucial part of the patient selection process, physicians generally think in terms of low, intermediate, and high risk groups, where risk means the probability that the cancer has spread beyond the prostate. With seed implantation, as with surgery and external beam radiation, the low risk patients will have the best chance for cure. 

The assignment of patients to a given risk category is generally a function of three principal measures used in the field of prostate cancer, Clinical Stage, Gleason Score (or grade), and PSA. The generally accepted definitions of these three risk groups are as follows: 

  • Low Risk: Clinical Stage T1a-T2b, Gleason Score 6 or less, PSA 10 or less. At SPI, approximately 60% of patients fall into the low risk category. For the most part, they are treated with seed implantation alone.

  • Intermediate Risk: Modifies the low risk criteria by substituting one of the following – Clinical Stage T2c-T3, Gleason Score 7 or higher, or PSA greater than 10. For example, T1c / GS 5 / PSA 20 would describe an intermediate risk patient. Approximately 30% of SPI patients are in this group and they generally receive seed implantation preceded by a short course of external beam radiation.

    The combination of seeds with external beam therapy is recommended because intermediate risk patients have more aggressive cancers. This means that there is not only a higher probability that cancer has spread outside of the prostate, but it is also more probable that the cancer has moved beyond the distance that can be covered by the radiation provided by seeds alone. The addition of external beam in these cases extends the effective range of radiation by at least several inches.

  • High Risk: Modifies the low risk criteria with two or the following – Clinical Stage T2c-T3, Gleason Score 7, or higher, PSA (greater that 10). For example, T2a / GS 8 / PSA 20 would indicate a high-risk patient. About 10% of SPI patients are in the high-risk group.

    Patients with high-risk disease are much more difficult to cure with any type of treatment because of the increased risk that the cancer has spread well beyond the prostate. Treatment of these patients usually involves multiple combined treatment approaches. At a minimum, high-risk patients receive combined seed implant/external beam therapy, as do patients in the intermediate risk group. In addition, it is very common to add hormone treatment so that every possible attempt is made to cure the disease.

    The discussion and definitions above represent generally accepted guidelines. They are not absolute rules. Based on a comprehensive medical evaluation of all relevant information, it is possible, for example, for a man, whose stage, Gleason Score, and PSA place him at the upper end of the low risk group, to receive combined implant/external beam treatment. Likewise, there could be circumstances in which it might be reasonable for someone at the lower end of the intermediate group spectrum to opt for seed implantation alone.

For a more complete discussion of seed implantation, including selection criteria, the procedure itself, side effects, and long-term survival results, see About Seed Implantation.

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