Radioactive Prostate Seed Implant Therapy
Prostate seed implantation (PSI) is an effective, one-time outpatient procedure that involves implanting low-activity, radioactive seeds directly into the prostate gland in order to kill cancer cells while minimizing radiation exposure to the surrounding healthy tissues.
This type of treatment also is called brachytherapy, which comes from the Greek word "brachy," which means near or close to. In other words, therapy that is near or close to the tumor. Seed implants can deliver two to four times more radiation than external beam radiation.
Holy Cross Hospital Expertise
Holy Cross Hospital helped to pioneer radioactive seed implantation in the region by becoming one of the first hospitals in suburban Maryland to use it to successfully treat prostate cancer. Our specialists have performed more than 2,500 prostate seed implants, which is more than any other medical practice in the Washington, D.C., metropolitan area.
The Holy Cross Hospital Radiation Treatment Center, located in Silver Spring, Md., is an area leader in prostate seed implants. Holy Cross Hospital uses high-quality transrectal ultrasound imaging, which has revolutionized prostate seed implantation by allowing physicians to more accurately place the radioactive seeds in the prostate gland. For this reason, the local control rates are now very high (95 percent to 99 percent). This allows the radiation dose to be concentrated in the prostate thereby avoiding radiation to the healthy surrounding normal tissues.
Learn More About Radioactive Prostate Seed Implant Therapy:
To find a radiation oncologist with expertise in radioactive prostate seed implants, use our Find a Physician service or call the Holy Cross Hospital Radiation Treatment Center at 301-681-4422.
Benefits of PSI
Seed implants offer the advantage of delivering high doses of radiation to the prostate by placing tiny radioactive pellets directly into the prostate. The radioactive seeds (Palladium-103 or Iodine-125) emit very low energy radiation, which does not travel very far.
Radioactive seed placement is performed as an outpatient procedure. Patients can return to their normal activities, including work, within a couple of days. Long-term complications are uncommon.
Radioactive seed implantation involves the precise placement of small, rice-sized radioactive seeds directly into the prostate gland using transrectal ultrasound guidance.
Two radiation isotopes are commonly used:
Palladium-103 (Pd-103), which has a half-life of 17 days and emits most of the radiation over two months.
Iodine-125 (I-125), which has a half-life of 60 days and emits most of its radiation over six months.
During these time periods, the prostate gland receives continuous irradiation. When a seed implant is performed alone, without external beam radiation, it is called "monotherapy."
Preparation and Planning for Treatment
Approximately two weeks prior to implantation, the patient will have routine blood tests and may also undergo an EKG, chest X-ray and a urinalysis. If there is any history of heart disease or other significant medical problems such as hepatitis, diabetes or lung disease, you should let your doctors know as soon as possible, as it may be necessary to get clearance from your internist, cardiologist or other medical specialists. Sometimes this can take several weeks. If you have any history of a heart attack or angina, a thallium stress test may be required.
All anti-inflammatory medications, such as aspirin, Motrin, Advil, ibuprofen, Aleve or naprosyn must be discontinued at least two weeks prior to the implant. You can take Tylenol for pain. If you are on Coumadin®, this must be discontinued five to seven days prior to the implant, under the direct supervision of the physician who prescribed this medication. In many cases another medication is substituted for Coumadin.
Prior to the implant, you will be instructed to take laxatives or enemas (a bowel prep). It is very important for the rectum to be empty at the time of seed placement. Both stool and gas will interfere with ultrasound imaging of the prostate. If your physician has not given you these instructions, please let us know several days before the implant.
Before an implant can be performed, the patient must undergo a volume study. This study involves placing a transrectal ultrasound into the rectum and making measurements and taking pictures. Unlike the biopsy no needles are used. This procedure takes a few minutes. This measurement will provide the necessary information so that the radiation oncologist can order the proper number of seeds for the seed implant.
The Implant Procedure
The implantation of radioactive prostate seeds is performed by a urologist and radiation oncologist, both of who have undergone special training in prostate seed implantation.
What to Expect
When you arrive at the hospital, you should already have completed your bowel prep. After completing your registration you will go to the pre-op area and will meet with the anesthesiologist to discuss the kind of anesthesia that is most appropriate for you.
When it is time to start the procedure, you will be taken to an operating room that is specially equipped for urological procedures. Anesthesia will be administered. A Foley catheter will be placed into the bladder. The skin of the perineum, an area located between the rectum and scrotum, will be cleaned with an antibacterial solution. In order to further reduce the risk of infection, the hair may be shaved from this area.
The implant procedure is initiated by placing the ultrasound probe into the rectum and attaching it to a stabilization unit and the seed implantation system. The next step involves a careful mapping of the prostate gland. This allows physicians to determine how many seeds are required and where the seeds are going to be placed.
During the course of the implant, approximately 16 to 26 needles are inserted through the perineum into the prostate. The implant needles are easily seen on the ultrasound screen. This allows precise placement into specific locations within the prostate under direct visualization. A template, or guidance system, is attached to the ultrasound probe outside the patient next to the perineum. The template is used to guide the needles into precise locations in the prostate as is called for by the plan. The template (Figure 1) has a series of holes, coded A through G horizontally and 1 through 6 vertically. The dots correspond to holes in the template, which are used to guide the implant needles into precise locations within the prostate.
The template coordinate grid seen above is activated so that it appears on the ultrasound screen (Figure 2). The prostate is aligned so that it is superimposed onto the template grid in such a way that the "D" row is centered in the central portion of the prostate and the "1" row is aligned along the back edge of the prostate.
Here is an example of how the template is used in a prostate implant: If the implant is to start at the location of "F2" on the grid, the needle is placed through the "F2" aperture in the template and, under the guidance of the ultrasound, is directed into the prostate at the "F2" location as seen on the ultrasound screen. If the needle does not hit the "F2" coordinate, it can be easily steered into the proper location. Depending upon the size of the prostate, 16 to 26 needles are used to implant 60 to 140 seeds.
Once the procedure is completed, the patient is transferred to the recovery room. After the anesthesia has worn off, you will be discharged. In most cases, the Foley catheter is removed prior to discharge.
You will be scheduled to have a CT scan of the prostate so that computerized dose calculations can be performed. This will allow your radiation oncologist to evaluate the actual dose delivered to the prostate gland as a result of the implant. These calculations are called post-implant dosimetry. The post-implant CT scan does not involve the injection of any dyes or contrast. You will not be required to drink any barium or use any laxatives or enemas. This test only takes about five minutes.
As part of your follow-up care, you will be instructed to see both your urologist and radiation oncologist. They will help you to get through the side effects as comfortably as possible. After three months they will perform routine DREs. The first PSA will be drawn about three months after the implant. Bone scans, CT scans and MRI scans are not part of the routine follow-up. They may be ordered if your prostate specific antigen (PSA) rises.
Both of the radiation isotopes commonly used in radioactive prostate seed implants, Palladium-103 and Iodine-125, emit continuous radiation. Since the radiation is very low energy, most of the radiation is confined to the prostate gland and the immediate surrounding area. Parts of the body that are more than a few inches away do not receive enough radiation to be damaged.
Bodily wastes such as urine and stool are not radioactive unless a seed is present. On rare occasions, a seed may be lost during urination. If a seed passes, it will most likely occur in the first week following the implant procedure.
Small amounts of radiation can reach other people. For most people, this is not a cause for concern. For example, if your significant other sleeps with you every night, they will get less radiation from you than they would get from a chest X-ray or mammogram. Therefore, there are no restrictions when it comes to adults.
Growing children and a growing fetus within a pregnant woman are sensitive to the effects of radiation. Radiation can cause cancer in growing tissues and can cause birth defects. If such people are exposed to you, we advise that you keep a distance of six or more feet, until about 75 percent of the isotope has decayed. Pd-103 has a half-life of 17 days, and we suggest that you follow these guidelines for five weeks. I-125 has a half-life of 60 days, and therefore decays more slowly. Additionally, the radiation energy of I-125 is slightly higher and more penetrating than Pd-103; and therefore, in the case of I-125 we suggest that you follow these guidelines for four and a half months. Stricter guidelines are advised for sleeping with pregnant women, or holding infants or small children in your lap. You should avoid these activities for two months with Pd-103 and seven months for I-125. Brief encounters for hugging or saying hello are allowed.
If there are infants at home or if you have frequent contact with grandchildren or other small children, you may want to consider purchasing lead-lined underwear. These garments weigh about one pound. They can be worn when you plan to have extended contact with children or kids in your lap. We have taken measurements, and no radiation could be detected outside this garment. They are worn over your regular underwear. Some seed implant patients come into close, frequent contact with pregnant women at work. The lead-lined underwear may serve to allay any fears that your coworkers may have. They cost about $100.
A condom is recommended during sexual intercourse for the first several encounters or for three to four months in the case of Pd-103 and 12 months in the case of I-125. Occasionally, seeds that are implanted into the seminal vesicles may enter the patient's semen, and be ejaculated. We have had several patients report that seeds were found in the semen, but the actual frequency of this event is not known.
Possible Side Effects and Complications
Side effects of radioactive prostate seed implant therapy vary widely from one patient to the next. Long-term complications are uncommon.
Possible Side Effects
- Perineal Symptoms
Most patients experience tenderness in the perineum for several days following the implant. Bruising and discoloration can extend into the scrotum. This should not be alarming. The perineal discomfort is usually mild to moderate and can be managed with Tylenol, Aleve or ibuprofen. These medications are okay to take after an implant.
- Urinary Symptoms
In the first 24 to 48 hours after the implant, there may be moderate to severe burning on urination and the urinary stream may be very weak. About 5 percent of the patients find it impossible to urinate at night and must return to the hospital emergency room for placement of a Foley catheter. If urinary blockage occurs during the day, please contact your urologist. He or she may be available to place a catheter in their office.
- For several weeks or months after the implant patients may experience urinary urgency, frequency and irritation. These symptoms can be mild, moderate or severe and tend to be worse at night. Initially, most men find that they get up at night to urinate two to four times more than they did before the implant. Men who have burning on urination usually report that this discomfort is felt on the tip of the penis. This is not the result of any injury to the penis, but rather these sensations are being referred to the penis from the prostate. Medications called alpha-blockers (Flomax, Hytrin or Carduria) are particularly helpful in relieving these symptoms. These medications help the prostate to relax, allowing the urine to pass more freely through the swollen and inflamed gland. Anti-inflammatory medications such as Aleve or ibuprofen can also be very helpful. Occasionally, there is bladder irritation. In that case, patients may benefit from Pyridium, which numbs the bladder.
- Urinary urgency can be rather severe for a month or two after the implant, and if not careful, an accident might occur. In order to avoid urinary leakage it is best to set-up a schedule and void every hour while awake. Severe urgency is often triggered by standing up or touching water. So be prepared to rush to the bathroom in those situations. Be prepared to quickly find a bathroom when you hop out of the car. If you have been sitting in a meeting at work for more than an hour, be prepared to rush to the bathroom when you stand up. Never pass up the opportunity to use the men's room.
- The urinary symptoms can last for many months. They tend to last longer with I-125 seeds than with Pd-103 seeds. However, at some point, usually six to eight weeks after the implant, the symptoms will begin to improve. By three months, most men who have a Pd-103 prostate seed implant, will say that their urinary function is 90 percent back to normal, and that they are getting up at night one extra time or the same number of times as they did before the implant. Urinary burning may last only a few days, however, as the radiation dose builds up in the prostate, the burning sometimes returns between the third and sixth week after the procedure. If this is the case, the burning usually resolves by three months. The last symptom to go away is the weak stream. The strength of the stream is usually pretty good by three months, but it may take another couple of months for the stream to fully return to normal. Alpha-blockers are usually discontinued between the third and fourth month. Occasionally the urinary stream never fully recovers and patients may stay on long-term alpha-blocker medication.
- The most common urinary complaint is frequent urination at night, which can significantly interfere with sleep. Patients report that they will get up many times to urinate, but that the stream is weak and that they cannot empty their bladder. This will cause them to get up again soon thereafter. Sometimes patients are unable to get their stream started for five to ten minutes. Infrequently patients have severe burning and say that urination feels like they are "peeing through razor blades." Alpha-blockers are very helpful for nighttime symptoms, and unless a patient is instructed otherwise, it is best to take these medications about one hour after dinner. It is also helpful to avoid fluids in the evening to reduce urination frequency during the night.
- Rectal Symptoms
Some patients occasionally experience rectal urgency, frequency, discomfort or bleeding. Bleeding is more likely to occur in patients with hemorrhoids. Ointments or suppositories can help with these symptoms. These symptoms are usually mild.
- Sexual Functions
It is not necessary to abstain from sexual activity, however, a condom should be used for the first several sexual encounters or for the first several months to avoid ejaculating a radioactive seed into another person. Erectile dysfunction (ED), or difficulty with erection during sex, may occur immediately after the implant. This is likely due to bruising of the nerve to erection. This may recover spontaneously. In the meantime, ED can be treated very successfully with Viagra, Cialis or Levitra. Some patients report a mixture of pleasure and pain during orgasm. Usually the discomfort resolves by three to four months. The semen is almost always discolored (dark) for several months due to the presence of old blood. The ejaculatory ducts may become blocked, and semen production by the prostate may be impaired, resulting in a marked diminution in the volume of ejaculatory fluid at the time of orgasm.
- Miscellaneous Symptoms
Patients usually experience some fatigue. It usually resolves within three to four months. Blood counts are not affected by this treatment. There will be no hair loss.
Possible Complications of Seed Implant Therapy
Complications refer to long-term or permanent problems. If a complication occurs, that does not mean that there was an error in the treatment. Whenever cancer cells are being "killed," normal healthy cells can be temporarily or permanently damaged. The same holds true for hormone therapy, external beam radiation and radical prostatectomy.
- Urinary Incontinence
After the urinary urgency has resolved, urinary incontinence, the involuntary loss of urine, is infrequently seen (less than 1 percent of patients). However, patients who have had a prior transurethral resection of the prostate (TURP), sometimes called a "roto-rooter job," have an increased risk of incontinence of about 5 percent. Patients with large TURP defects are not implant candidates. If incontinence develops following a seed implant, it is usually mild, requiring no more than one to two pads per day.
- Urinary Structure
About 5 percent of patients develop a urinary stricture or bladder neck fibrosis. This means that scar tissue has formed, and has caused narrowing of the urethra, or scarring of that portion of the bladder, which is near the prostate. This results in a weak urinary stream, frequent bathroom visits at night or inability to urinate. Initially the treatment of choice is alpha-blockers. If the urinary flow is completely blocked, a temporary catheter is placed. Surgery is not often required, and should be considered a treatment of last resort. When surgery is contemplated it is best to wait one year.
The procedures most commonly used are: 1) a "mini-TURP"; 2) a trans-urethralincision of the prostate (TUIP); 3) a bladder neck incision; or 4) a trans-urethralneedle ablation (TUNA). Before any surgery is contemplated, the patient's urologist should consult with his radiation oncologist. Experience has shown that in many cases the blockage will resolve by itself without surgery. The primary risk of these surgical procedures is permanent and sometimes severe urinary incontinence.
- Rectal Injury
The most common rectal injury is chronic rectal bleeding. Rectal bleeding may result from pre-existing hemorrhoids, a rectal cancer, or from fragile blood vessels that form on the rectal wall as a result of the radiation. These fragile blood vessels are not dangerous and can usually be treated successfully with suppositories. If rectal bleeding occurs, please notify your radiation oncologist. You may need to see a gastroenterologist (a GI doctor).
- IT IS OF THE UTMOST IMPORTANCE THAT YOU INFORM YOUR GI DOCTOR THAT YOU HAVE HAD A PROSTATE SEED IMPLANT. IT IS NOT SAFE TO HAVE HEMORRHOID SURGERY OR CAUTERY ON YOUR RECTUM. THERE HAVE BEEN CASES WHERE SUCH PROCEDURES HAVE RESULTED IN SEVERE RECTAL INJURIES REQUIRING A COLOSTOMY. WE ADVISE YOU TO SHOW THIS PAGE TO ANY PHYSICIANS TREATING YOU FOR RECTAL BLEEDING.
- There are new laser therapies, which are very superficial and are more likely to be safe, but this should only be used in cases of severe rectal bleeding that cannot be controlled by more conservative means.
- Rectal ulcers are very uncommon. The first sign of an ulcer may be moderate to severe rectal pain, which is usually associated with bleeding. However, these symptoms can also occur with hemorrhoids. RECTAL ULCERS MUST NOT BE CAUTERIZED, LASERED OR OPERATED ON.
- THE MOST SEVERE RECTAL INJURY IS A FISTULA. Fortunately, fistula are very uncommon. A rectal fistula is a hole that develops between the rectum, and the bladder or urethra. The first signs are pain associated with the leakage of urine through the rectum. Usually a colostomy must be done. FOLLOWING SEED IMPLANTS, RECTAL FISTULAS CAN BE CAUSED BY CAUTERY FOR RECTAL BLEEDING, OR HEMORRHOID SURGERY. THESE MUST BE AVOIDED.
- Erectile Dysfunction
Erectile dysfunction (ED) is the most common complication following all treatments of prostate cancer. The good news is that most cases of ED following seed implant therapy can be successfully treated with medication (Viagra, Levitra or Cialis). If a patient has good erections prior to treatment, the probability that he will maintain an erection satisfactory for sexual intercourse after treatment is about 80 percent; however, the majority of patients will use one of these medications at least some of the time. If the erection is already impaired prior to the seed implant, these drugs are less likely to work. If they are unsuccessful, other treatments such as penile injections may prove effective.
For several months following the implant, the ejaculate may be discolored. Usually the color is very dark as the result of old blood. Eventually, most patients report that the ejaculate dries out, and that very little semen is ejaculated. Fortunately, the quality of the orgasm is usually not affected.