ProstRcision:
You want the best, most effective treatment for your prostate cancer. That is why you are researching all your options and getting second opinions. Learn all about ProstRcision®
and how it can provide you a better cure rate with fewer complications than any other treatment option.
- What is a seed implant and how is it done?
- How does the follow up radiation work?
- How is ProstRcision® tailored to your cancer?
As a newly-diagnosed man with prostate cancer you have questions. Learn more by calling the Radiotherapy Clinics of Georgia team at 800-952-7687.
Question 59:
What treatment is given at Radiotherapy Clinics of Georgia?
Answer:
We provide a treatment method called ProstRcision, which was developed at Radiotherapy Clinics of Georgia. ProstRcision (pronounced PROS-ter-si-shun) means destruction (excision) of prostate cells, normal and cancerous, with irradiation instead of with a knife (surgery). In other words, we kill all normal and cancerous prostate cells with ProstRcision, but, in contrast to radical prostatectomy, ProstRcision leaves behind the sex nerves and muscles that control urination. ProstRcision is based on the integration of two separate methods of irradiation in an attempt to get the best cure rate possible with the least complications. The two methods of irradiation are:
- Radioactive iodine (I-125) prostate seed implant, followed by,
- Linear accelerator irradiation using either the conformal beam or intensity modulated radiotherapy technique (IMRT).
Question 60:
What is an I-125 seed?
Answer:
A radioactive I-125 seed has radioactive iodine (125) attached to a very tiny bar of silver, all of which is placed in a small titanium capsule that is 1/5–inch long (4.5 mm) and 1 mm wide. Each seed produces a tremendous amount of low energy gamma radiation (28 KEV) within 2 – 4 mm of the seed, but then radiation drops off rapidly. Thus, each seed will irradiate an area about the size of a very small marble. Each radioactive I-125 seed slowly gives off clinical radiation for about one year and then is effectively “dead.” However, the silver bar and the titanium capsule will remain in the prostate forever.
Question 61:
What is an I-125 prostate seed implant? (See Figure 14.)
Answer:
A prostate seed implant is a minor surgical procedure, performed in an outpatient surgical center by a team of a urologist and radiation oncologist. After the patient is placed under general anesthesia, his legs are placed in stirrups and an ultrasound probe, which is connected to a television monitor, is inserted into the rectum. While watching the prostate on the television monitor, an average of 21 hollow, 8-inch long needles are inserted through the perineum (the area located between the anus and the testicles) into the prostate. Some needles are inserted into the seminal vesicles (an organ attached to the top of the prostate). Needle insertions are performed by a urologist while discussing the needle position with the radiation oncologist. The entire prostate seed implant takes 35-45 minutes to perform.
Question 62:
What happens after needle insertion? (See Figure 14.)
Answer:
The radiation oncologist inserts a cartridge of I-125 seeds into a seed implant device. Then, he attaches the seed implant device to one of the needles and injects a seed out of the end of the 8-inch long needle starting at the top of the prostate. After injection of the first seed, the needle is pulled back and another seed is injected. Seeds are continually injected until reaching the bottom of the prostate, after which the needle is pulled out of the patient. The radiation oncologist then goes to the next needle and repeats the same process until seeds have been injected through all needles. A different number of seeds are injected through each needle, depending on where the needle is located within the prostate. Additionally, seeds are injected into the seminal vesicles. Seeds are typically placed closer together to increase the amount of radiation in the prostate sections that have cancer, especially if there is a large amount of cancer or if the cancer is Gleason score 3+4 or higher. Thus, a radiation doctor can vary the amount of radiation within the prostate based on where the cancer is actually located, while covering all of the prostate with a low dose of radiation to destroy any cancer that may have been missed at biopsy, as well as to destroy all normal prostate cells to prevent the patient from getting a new cancer.
Question 63:
What happens next?
Answer:
After all seeds are inserted and all needles are removed, a cystoscope examination is performed by the urologist. To perform this procedure, the urologist inserts a tube, similar to a submarine periscope, through the urethra, which enables him to look inside the prostate and inside the bladder to check on these organs. After the cystoscope exam, a urinary catheter is inserted through the urethra into the bladder, and the patient is sent to the recovery room. After one to two hours, and when he is fully awake, the patient goes home. The patient can then eat, drink or do anything he wishes.
Question 64:
Following the procedure, when does the patient see a doctor?
Answer:
The morning after the seed implant, the patient returns to Radiotherapy Clinics of Georgia, and the urinary catheter is removed. X-rays and CAT scans of the seeds are made and shown to the patient, and questions are answered. The patient may resume normal activities the day after the implant, which include eating a normal diet, playing golf, going to the gym, as well as sexual activity. The only medication required is antibiotics. This is not a painful procedure, and pain medication is rarely required.
Question 65:
How many seeds are injected at each prostate I-125 seed implant?
Answer:
An average of 74 seeds, but this can range from 45 to 230. Each implant is tailored for each prostate cancer patient depending on the size and shape of his prostate, location, aggressiveness and extent of the cancer based on the prostate biopsy pathology report as well as any pre-existing bladder or rectal problems.
Question 66:
The radiation from the seeds helps destroy the cancer cells and normal prostate cells inside the prostate. Do the seeds have any other use?
Answer:
Yes. The seeds have another very important function — they serve as a TARGET for the subsequent beam radiation since the seeds are actually tiny pieces of metal. To understand this you should know that the prostate is not visible on X-rays. However, by placing an average of 74 metal seeds throughout the prostate, you can “see” the prostate outlined by these pieces of metal. To see the prostate even better, we inject three non-radioactive gold seeds during the seed implant. The combination of the silver in the iodine seeds and the gold seeds serves as a perfect target for precise IMRT beam radiation later delivered with the linear accelerator.
Question 67:
How long do you wait after the prostate seed implant before starting the follow-up IMRT beam radiation?
Answer:
The IMRT (Intensity Modulated Radiation Therapy) beam radiation is started three weeks
(21 days) after the seed implant. We wait three weeks to allow some reduction of the swollen prostate, which is traumatized when the 8-inch long needles are inserted. The half-life of radioactive iodine is 60 days. By beginning the beam radiation 21 days after the implant, the beam radiation is still given during the first half-life of the radioactive iodine seeds.
Question 68:
How do you give the follow-up linear accelerator irradiation?
Answer:
First, we make X-ray pictures to document where the seeds, gold and iodine, are located. Then, we calculate the radiation dose coming out of the iodine seeds to each area in and around the prostate, including the urethra, rectum, bladder and sex nerves. With the seeds as a target, we plan the follow-up accelerator irradiation. Thus, we are logically integrating both forms of radiation to get the maximum cure rate with the least complications. Accelerator irradiation treatments are given daily, Monday through Friday, and not on weekends. Patients are administered 30 to 35 treatments, depending on the extent and location of their cancer.
Question 69:
What is IMRT beam radiation?
Answer:
IMRT is a more advanced technique of linear accelerator beam irradiation due to the greater use of computers to determine the irradiation dose. The primary effect of IMRT is to reduce the amount of radiation to the adjacent organs, such as the rectum and bladder, while increasing the amount of radiation within the prostate by shaping the beam of irradiation to a man’s prostate.
Question 70:
How do you shape the radiation to a man’s particular prostate?
Answer:
Using the gold and I-125 seeds to outline the prostate, we cross-fire the prostate from five or more different angles with beam irradiation so that the surrounding normal organs — hips, bladder, rectum and sex nerves — receive a relatively small amount of radiation. Using computers to calculate irradiation doses and to adjust blocks inside the linear accelerator to shape the beam radiation to a particular man’s prostate and seminal vesicles based upon the gold and iodine seeds, the IMRT beam radiation is delivered precisely to the prostate and the surrounding tissue for possible microscopic capsule penetration.
Question 71:How is the daily IMRT given with the linear accelerator?
Answer:
Treatment is similar to getting a pelvic X-ray each day. After a patient is placed on the table under the linear accelerator, the gold and I-125 seeds are targeted. The accelerator is turned to the correct angle, and the computers inside the accelerator shape the X-ray beam according to the patient’s prostate shape and size from that angle. After treatment is given through one location, the accelerator is turned to a different angle, and this process is repeated until the prostate gland has been cross-fired from multiple directions. Daily adjustments to the position may be needed because the prostate can move within a man’s pelvis. This is easily detected using the gold and iodine seeds. After the patient’s treatment is finished, which usually takes less than 10 minutes, he may go back to his normal daily activites such as work, golf, the gym or anything else he would like to do. The patient returns the next day, and the process is repeated.
Question 72:
How much radiation do you give with the seeds?
Answer:
On average, 9,000 cGy are administered. Additionally, we place extra seeds, which means increased radiation, in the cancerous areas within the prostate. The middle of the cancer may receive as much as 20,000 to 25,000 cGy of radiation from the seeds. Thus, we tailor the irradiation to each man’s cancer, which goes back to the importance of the Second Opinion Pathology Report. See Questions 23–28.
Question 73:
How much radiation do you give with the accelerator treatment after the seed implant?
Answer:
We administer from 4,500 to 5,250 cGy. Thus, the total amount of radiation we give to the prostate is at least 15,000 to 15,750 cGy. More importantly, by performing an I-125 implant first, which has a 60-day half-life, and starting accelerator irradiation 21 days after the implant, both methods of irradiation can be given simultaneously. This produces a dose intensification or synergistic effect (instead of 1+1=2, think 1+1=5). The effect of radiation with dose intensification or seed activation (synergy) is more intense than simply adding the amount of radiation from each method.
Question 74:
Doesn’t giving two forms of radiation mean twice as much radiation?
Answer:
No. With ProstRcision, we reduce the seed implant dose to 9,000 cGy, as compared to the dose of 16,000 cGy typically given when men are treated only with seeds. Likewise, we reduce the accelerator radiation dose to 4,500 cGy, as compared to the 7,500 to 8,600 cGy men are given when treated only with accelerator irradiation. By reducing the dose of both seed and accelerator radiation, you can combine both treatment methods and compensate for the disadvantages of either, producing dose intensification or dose synergy (seed activation).
Question 75:
Explain dose intensification (or synergistic effect). (See Figure 15.)
Answer:
I-125 seeds have a 60-day half-life, which means they give off half their radiation during the first two months. The accelerator radiation begins 21 days after the seed implant, and it is administered for six to seven weeks, during the first half-life of the I-125 seeds. Thus, both methods of irradiation are given at the same time, which intensifies the irradiation dose. Although the seeds are already radioactive, the I-125 seeds are activated a lot more with the accelerator irradiation. Dose intensification (or seed activation) is needed because most cancer cells are located inside the prostate capsule, and dose intensification is also required to destroy all normal prostate cells.
Question 76:
To summarize, what is the purpose of the I-125 seeds as a part of ProstRcision?
Answer:
Based on the prostate biopsy, we know cancer cells are located inside the prostate. Even with cancer cell leakage, most cancer cells are inside the prostate capsule. The seeds irradiate inside the prostate but do not effectively irradiate microscopic capsule penetration cancer cells, which would be left untreated with only a seed implant. To summarize:
- Advantages of the seeds — Irradiate inside the prostate and act as a target for the beam accelerator irradiation.
- Disadvantage of the seeds — Prostate cancer cells that may have leaked outside the prostate capsule are under-treated by seeds alone.
Question 77:
What is the purpose of the follow-up linear accelerator radiation using IMRT or conformal beam?
Answer:
There are two basic purposes:
- Dose intensification or seed activation inside the prostate (seeds and accelerator irradiation).
- Irradiation of cancer cells that leak outside the prostate (microscopic capsule penetration).
Question 78:
When a prostate biopsy is performed, can cancer cells stick to the needle and be pulled through the capsule and outside the prostate either into the rectum or to the area below the prostate?
Answer:
First, it is unknown whether or not cancer cells can be pulled outside the prostate by either the biopsy needles or the seed implant needles. However, if cancer cells could be pulled outside the prostate by either of these needles, it would make no difference with ProstRcision. A very small part of the rectum adjacent to the prostate gland receives irradiation from the external beam and, thus, would destroy any prostate cancer cells pulled out of the prostate because of a prostate biopsy. Since with ProstRcision beam irradiation is given after the implant, any cancer cells that could be pulled outside the prostate by the implant needles would later be irradiated by the external beam portion. Thus, pulling cancer cells outside the prostate by either the biopsy needle or implant needles would not make any difference with ProstRcision. But this issue could be a problem for men treated with radical prostatectomy, men who were treated with seed implant only, and men given beam radiation before the seed implant.
Question 79:
How would ProstRcision cure a man with these medical findings? Twelve needle cores were taken at prostate biopsy, and four showed cancer — two with Gleason score 3+4=7 and two with Gleason score 6. PSA was 7.5 and stage T1c disease.
Answer:
For discussion purposes, let’s assume there were 100 prostate cancer cells. Based on the prostate biopsy report, we know that most, if not all, of the cancer cells are located in the prostate, but we also know there is at least a 41% risk for having microscopic capsule penetration (Partin tables29), which means leakage of prostate cancer outside the prostate, near the rectum or bladder, because of cancer in four of 12 needles, two with Gleason score 3+4. To cure this man of prostate cancer, we must destroy all 100 prostate cancer cells. We know cancer cells are inside the prostate capsule, and there is a 41% chance of cancer cell leakage outside the prostate.
Question 80:
How does ProstRcision work? (See Figure 16.)
Answer:
Because it is impossible before any treatment to know if a man has microscopic capsule penetration, we always assume that a man may have cancer cell leakage through the capsule; and because you essentially have only one chance to be treated for cure, you do not want to miss or under-treat prostate cancer. Let’s assume that of the 100 cancer cells, 90 are in the prostate and 10 have leaked outside the prostate. Since most cancer cells (90) are inside the prostate, more irradiation is required within the gland. This is accomplished by the irradiation from the iodine seeds combined with the IMRT beam radiation, which creates a synergistic effect on radiation dose intensification. Since there are fewer microscopic capsule penetration cancer cells (10 cells), the IMRT beam radiation (which radiates both inside and outside the prostate) would also destroy cancer cell leakage. Thus, we would destroy all 100 cancer cells, and this man would be cured of his cancer. See Figure 16. This differs from radical prostatectomy. (See Question 94 for further information.) Additionally, the synergistic effect of the seeds and beam radiation inside the prostate would destroy all normal prostate cells to prevent a new prostate cancer. After all, whatever caused prostate cancer the first time could do it a second time. Destroying all normal prostate cells and the seminal vesicles will have no effect on a man, nor will it affect sexual function except that he will produce little or no semen on ejaculation because semen is produced by normal prostate cells.
Question 81:
Do you tailor treatment according to the Second Opinion Prostate Biopsy Report and other cancer findings? (See Figure 17.)
Answer:
Yes. How we treat a man with ProstRcision and the chance of curing his prostate cancer depends on his cancer findings, especially his prostate pathology report, which is why the Second Opinion Pathology Report is so important. For example, a man with an average size prostate, Gleason score 6 cancer and 10% in one of 12 needles with no perineural invasion would receive 68 seeds followed by six weeks of beam radiation. On the other hand, consider a patient who had Gleason score 4+3=7 with five needle cores positive, 40–70% cancer in each needle with 60–70% grade 4 and perineural invasion. This patient would receive an average of 85 seeds with extra seeds implanted in the area of the prostate that had the 4+3=7 Gleason score cancer. This would give extra irradiation to the 4+3 cancer. Additionally, he would receive seven weeks of beam radiation after the implant. As you can see, treatment is different for each patient and is tailored to a man’s individual cancer findings, especially the pathology report.
Question 82:
What would happen to the PSA of 7.5 ng/ml after treatment with ProstRcision?
Answer:
Since PSA is produced only by prostate cells, both normal and cancerous, destruction of all normal prostate cells and the 100 cancer cells would mean there would be no cells in this man’s body to make PSA. Therefore, the PSA of 6.8 ng/ml after ProstRcision would fall to PSA 0.2 ng/ml or lower and remain at this level forever.
Question 83:
What happens to the prostate gland after a man is treated with ProstRcision?
Answer:
We do not precisely know. We speculate that both cancerous and normal prostate cells are destroyed with the prostate shrinking and turning into scar tissue. The debris from the destroyed prostate cells can be either excreted from the body or the prostate cell components be used to make new, normal cells someplace else.