Karmanos - Crittenton Cancer Center

Permanent I-25 Seed Implants

There are many information sources available to prostate cancer patients and their families. One of our goals is to provide background information on prostate cancer and common treatment options for localized disease with an emphasis on Radioactive Seed Implants. In the year 2000 roughly 35% of all men diagnosed with local prostate cancer in the U.S. were treated with permanent radioactive seed implants compared with only about 4% in 1995. The rapid increase in the number of men treated with seeds is largely attributed to patient demand. Men and their families are often attracted to seed implants because of the patient benefits such as: Seed implantation is typically an outpatient procedure allowing the patient to go home the same day and return to normal activities within a few days; long-term results (10+ years) comparable to radical prostatectomy (RP) and external beam radiation therapy (EBRT); men treated with seed implants generally have less chance of developing impotence and/or incontinence than men treated with RP or EBRT. Patient demand has increased each year and the clinical experience with seed implants has grown to include thousands of men treated each year.

What is prostate cancer?

Like all cancers, prostate cancer is basically uncontrolled growth of the cells in the body, occurring when one or more normal prostate cells mutate into a tumor cell. Those tumor cells begin to divide and form more cancer cells. Localized prostate cancer is when the tumor cells are still within the prostate and local region. Once the cancer cells have penetrated the outer layer of the prostate, they will initially migrate to the surrounding normal organs, including the bladder, rectum, sex nerves and muscles that control urination. Metastatic prostate cancer is when some tumor cells have migrated through the blood stream and lodged in a distant part of the body where they continue to divide and form more cancer cells. Physicians refer to prostate cancer by the stage and grade of the disease. The stage refers to the physical location of the disease within the body and is based on clinical information from diagnostic procedures performed by a physician. The staging system commonly used in the U.S. is called the TNM System, which describes the size and location of the primary tumor (T), the absence or presence of tumor migration to nearby lymph nodes (N) and the absence or presence of distant metastases (M).

T Stages:

T1: This refers to cancer that the physician cannot feel during a digital rectal exam (DRE) but is found by other diagnostic methods such as a prostate biopsy. T1 tumors can be futher subclassified as T1a, T1b and T1c. These subclassifications indicate how the cancer was initially found. When physicians classify a tumor to be T1 stage they believe it is still confined to the prostate.
T2: This refers to the cancer the physician can feel during a DRE. T2a means the tumor involves only the right or left side of the prostate. T2b indicates that both the left and right sides of the prostate are involved. When physicians classify a tumor to be T2 stage they believe it is still confined to the prostate.
T3: These are cancers the physician believes have spread outside the prostate, but only to the connective tissue next to the prostate and/or to the seminal vesicles (two small sacs that store semen). T3a indicates cancer has spread only to the connective tissue and not to the seminal vesicles. T3b indicates the cancer has spread to the seminal vesicles.
T4: These are cancers the physician believes have spread to additional tissues next to the prostate, such as the bladder, the rectum or the wall of the pelvis.


N Stages:

N stages indicate whether or not the physician believes the disease has migrated to any lymph nodes. N0 means the cancer has not spread to any lymph nodes. N1 indicates the disease has migrated to one or more regional lymph nodes in the pelvic area.

M Stages:

M Stages indicate whether or not the physician believes the disease has metastasized beyond the lymph nodes in the pelvic area. M0 indicates the disease has not metastasized beyond the pelvic area lymph nodes. M1 indicates metastases are present in distant parts of the body such as other lymph nodes, bones, lungs, liver or brain. Prostate cancer grades refer to the rate of growth for the disease. Prostate cancer grades (also referred to as Gleason Scores) range from 2 for the less aggressive cancers through 10 for the most aggressive cancers.

What causes prostate cancer?

The causes of prostate cancer are not well understood. However, there are certain known risk factors. The incidence rate greatly increases with age. More then 75% of all prostate cancers are diagnosed in men over the age of 65. The disease is common in North America and Northwestern Europe but is rare in Asia, Africa, and South America. African Americans have the highest incidence of prostate cancer in the world. Recent genetic studies suggest that strong family predisposition may account for 5-10% of prostate cancer cases. International studies suggest that dietary fat also may be a factor. Detection of prostate cancer: The American Cancer Society (ACS) recommends that men over the age of 50 have a digital rectal exam of the prostate gland and a prostate-specific antigen (PSA) blood test every year. Men who are at high risk of prostate cancer (African American men or men who have a family history of the disease) should consider beginning these tests at an earlier age. The introduction of PSA blood testing has lead to earlier diagnosis in men without any symptoms. Early stage prostate cancer may have no symptoms at all. However, as the disease progresses, symptoms of prostate cancer might include weak or interrupted urine flow; difficulty starting or stopping urine flow; the need to urinate frequently, especially at night; blood in the urine; pain or burning during urination; continual pain in the lower back, pelvis or upper thighs. Most of these symptoms are nonspecific and may be similar to those caused by benign conditions such as infection or enlargement of the prostate.

Facts About Prostate Cancer:

Prostate cancer is the most common cancer among American men. One out of every 10 men will develop prostate cancer at some point during their life. According to the American Cancer Society, 244,000 new cases of prostate cancer - resulting in 40,400 deaths - will be diagnosed in 1995. Prostate cancer is the second leading cause of cancer death in men after lung cancer. Five-year survival rates for patients with localized cancer (confined to the prostate) is: 86% in African Americans, and 93% in Caucasian patients. Survival rates for all stages is: 64% in African American, and 79% in Caucasian patients. Improved diagnostic tests account for a 50% increase in reported incidence rates between 1980 and 1990. Black men have a 30% higher incidence rate then whites. Though the majority (80%) of cases occur in men over the age 65, many cases also occur in younger men who sometimes have more aggressive cancer. The American Urological Association recommends that every man over the age of 50 have a digital rectal exam (DRE) and a prostate specific antigen (PSA) blood test each year. African Americans and others with a family history of prostate cancer should have both tests beginning at age 40. There are usually no symptoms in the early states of prostate cancer. When the tumor growth becomes more advanced, urinary symptoms may develop. These include:

  • Frequent urination (especially at night)
  • Weak Urinary stream
  • Inability to urinate
  • Interruption of urinary stream (stopping and starting)
  • Pain or burning on urination
  • Blood in the urine

    • Many of these symptoms are similar to benign prostate hyperplasia (BPH), another common prostate condition in which the prostate enlarges. Treatment of prostate cancer varies depending on the stage of the disease, but generally includes surgery, radiation therapy (external beam radiation and/or radioactive "seed" implants), hormone therapy or chemotherapy. In certain cases where the cancer is slow growing or is diagnosed in early patients with less then 10 years life expectancy, "watchful waiting," to see how the cancer progresses, is the preferred treatment.

    Summary of common treatment options for localized prostate cancer

    Radical Prostatectomy (RP):

    This is a major surgical technique to remove the prostate gland and some of the surrounding tissue. In some cases, the physician will attempt to remove the prostate without removing the small bundles of nerves on either side of the gland that control the ability to have an erection. The patient is usually under general anesthesia (asleep and totally unconscious) and the operation takes about 2 to 4 hours. Most patients have a catheter inserted through the penis into the bladder to aid in urination while healing. The catheter typically stays in place for about two to three weeks. The average hospital stay is three days and the average time away from work is three to five weeks.

    External Beam Radiation Therapy (EBRT):

    This treatment focuses a beam of radiation from outside the body on the area affected by the cancer. Because the radiation has to pass through normal tissue to reach the cancer, the treatment is given in small daily doses over a period of time. Typically, EBRT treatment is given on an outpatient basis five days a week for seven to eight weeks, with each treatment lasting a few minutes. The procedure itself is painless.

    Permanent Seed Implantation:

    This treatment places tiny radioactive "seeds," slightly smaller, but the same shape as a grain of rice directly into the prostate. Thin needles are passed through the skin into the prostate to place the seeds. It is an outpatient procedure which typically takes one to two hours to perform. The patient usually goes home the same day and is able to return to work in two to three days.

    Watchful Waiting:

    This approach involves regularly and carefully monitoring the cancer without any active treatment. Watchful waiting may be recommended if a cancer is not causing any symptoms, is expected to grow very slowly and is contained within one area of the prostate. Because prostate cancer often grows very slowly, elderly men who have the disease may not ever need treatment (they are more likely to die with the disease, not because of it). Some men choose watchful waiting because they feel the side effects of aggressive treatment outweigh the risk. Watchful waiting is particularly suited for men who are elderly or have other serious health problems.

    What is involved in Permanent Seed Implantation?

    If you have chosen permanent seed implantation, you will be treated by a team typically consisting of a Urologist, Radiation Oncologist and Medical Physicist. Some physicians utilize a pre-planning procedure which involves preparing an ultrasound-based "map" of your prostate and a dose plan specifying how many seeds, their strength and the positioning in the prostate prior to the implant procedure. However, a significant number of physicians prefer to plan the implant in the operating room which involves developing a dose plan on the day of the implant procedure. In either case, the average patient receives about 80 to 120 seeds depending on the size of their prostate. The actual procedure usually takes about 1 - 2 hours. During the implant procedure, the patient will either be under general anesthesia (to numb the lower half of the body) with sedation. You will lay on your back on a special table with your legs up in stirrups. An ultrasound probe is placed in the rectum and the image of your prostate is shown on a TV monitor. The implant procedure does not require an incision. Instead, thin needles are passed into the prostate gland through the skin between the scrotum and rectum. As the needles penetrate through the prostate they are seen on the ultrasound screen and can be accurately guided to their final position. When each needle is in its correct position in the prostate, the needle is slowly withdrawn and the individual seeds are pushed through the needle and deposited into the prostate gland. The ultrasound probe and the needles are removed when the procedure has been completed. After the implant you will stay in a recovery room until you recover from the anesthesia. Since seed implants are an outpatient procedure you can usually go home after recovery from the anesthesia. For about a week following the insertion of the needles, you may have some pain in the perineal area and may have red-brown discoloration in the urine. You can usually resume eating and have visitors as soon as you wish, but you should avoid strenuous physical activity for the first couple of days you are home. After that, you will probably be ready to return to your normal activities. Your physician will provide you with detailed information on what to expect before and after the procedure.





    How does a seed implant kill the cancer cells?

    In general, radiation kills cells by damaging the genetic material in cells as they reproduce. Dividing (reproducing) cells are more sensitive to radiation damage than non-dividing cells. In adults there is little cellular growth (we are done growing) so the only cells that are actively reproducing are the cancer cells. Since normal cells are not reproducing, they are more resistant to radiation. The goal of radiation therapy is to deliver a lethal dose to the tumor, while preserving the surrounding normal tissue. The strategy for seed implantation is to appropriately position seeds throughout the prostate so a sufficient dose of radiation is given regardless of where the cancer is in your gland. Since the seeds give off a low energy type of radiation the nearby normal tissue receives a much lower dose then the localized tumor which is surrounded by seeds. Because EBRT must pass a high energy beam of radiation through normal tissue to reach the prostate, seed implants are capable of delivering up to two times the dose of radiation to the prostate and tumor.

    What about side effects of treatment for localized prostate cancer?

    Radical Prostatectomy (RP):

    For many years RP has been considered the gold standard of treatment due to the number of men treated and the favorable long-term (10+ years) clinical results. The drawback has always been the severity of the operation itself combined with its side effects. As with any major surgery, RP carries the risk of potential for heart attack, stroke and blood clots that can travel to the lungs. The main side effects of RP are incontinence and impotence. Up to 35% of men can expect to have a permanent case of mild stress incontinence. Around 10% of men have more serious stress incontinence, which may be permanent. About 20% of men treated with RP use absorbent pads because of incontinence. After standard RP between 65% and 90% of men will become impotent, depending on their age. For men who receive a nerve sparing RP the impotence rate may be lower, but different studies offer conflicting results.

    External Beam Radiation Therapy (EBRT):

    Side effects during the seven to eight week treatment may include diarrhea, rectal leakage and colitis (irritated large intestine). Occasionally, normal bowel function does not return after the treatment is ended. Almost 10% of men in one study reported bowel problems after treatment had ended. Other common side effects during treatment include frequent urination, burning sensation while urinating and blood in the urine. It is common for frequent urination to persist in about one third of the patients. Incontinence occurs less frequently then in RP. In one study, 7% of men treated with EBRT reported using absorbent pads due to incontinence. About 40% to 60% of men developed some degree of impotence.

    Approach to considering treatment Options for localized prostate cancer:

    Men and their families are often confused by the number of treatment options and the sometimes conflicting information about them. It is often recommended that you consult with more than one physician as part of your decision making process. It is natural that a specialist such as a urologist or radiation oncologist will view treatment options in the context of their areas of expertise. It can be helpful to consult with your family physician to assist in making your treatment decision. The goal of localized prostate cancer treatment is to cure the disease while producing as few side effects as possible. Depending on their age and physical condition some men cannot undergo the more physically demanding treatment options such as surgery. Some are concerned entirely with long-tern results and side effects do not weigh heavily in their decision, while other men could not even consider living with side effects such as impotence or incontinence. In the past, most physicians agreed that RP offered men with localized disease the best chance for cure. Although there have been no randomized clinical trials to prove it, most physicians now feel that seed implants, RP and EBRT are about equally effective in treating localized prostate cancer.