Brachytherapy is a type of radiotherapy used in the treatment of different types of cancer and involves placing the source of radiation directly in or near the cancerous tumor. This allows treatment to be more precise and reduces the damage to the healthy tissue around the tumor. Brachytherapy may be a standalone treatment option or may be combined with other treatments, such as external radiotherapy or surgery. Brachytherapy is commonly used to treat prostate cancer. Prostate brachytherapy may be offered as a high dose rate or low dose rate brachytherapy depending on your doctor's guidance.
When patients with Prostate Cancer are treated by external standard conventional radiation, the radiation beam will pass the skin, the surrounding tissue such as rectum and bladder to the prostate. As prostate cancer is dose responsive (the higher the dose of radiation, the better the result in cancer cell killing) the adjacent rectum and bladder tissues will have to expose to higher dose of radiation as well. This will result in radiation damage of those organs, some of which may not be reversible. The patients then may develop tenesmus, rectal bleeding, hemorrhagic cystitis, the incidences of which varies, from few percent to 10%. These complications are higher in patients who have underlying diabetes, hypertension, and are heavy chronic smoker. The Interstitial Brachytherapy reduces the chance of surrounding tissue injury as radiation sources are within the prostate gland. The character of the radiation source is that the radiation fall off rapidly according to the inverse square law. Thus the radiation emitted to the rectum and the bladder is low. As a result, the normal tissues are not damaged by radiation. Another advantage of radioactive source is they slowly but constantly emit the radiation. For example, the I-125 seed which is commonly used in prostate cancer brachytherapy has a half-life of 60 days. This constant radiation will overcome the periods of radio resistant of the cell cycle. Slowly release radiation does not damage the normal surrounding tissue as does the rapid high dose. Overall, the total radiation dose to the prostate gland is about twice that usually given by standard conventional radiation treatment.
-Possibility of permanently curing your cancer -Unlike external beam radiation therapy, usually only requires 1 treatment session
-Requires anesthesia to have the radiation-emitting device(s) implanted
-Depending on the type of brachytherapy, may require that you stay in the hospital for 1 to 2 days
-Side effects may include erectile dysfunction, urinary urgency and frequency, burning with urination, or trouble emptying the bladder -Less common side effects include bowel urgency and frequency, rectal bleeding, and rectal ulcers
It could be done by an open implantation after your urologist has exposed the prostate gland (by low abdominal incision). However, the most recent and convenient approach is by transperineal implantation using transrectal ultrasound guided to localize the prostate gland. The needles then are inserted into the prostate gland, followed by the insertion of radiation sources (which are in the form of the seeds) which will be passed through the hollow needles and implanted into the prostate gland. This sometimes is called interstitial brachytherapy.
To prepare for prostate brachytherapy, you will: -Meet with a doctor who treats cancer with radiation (radiation oncologist). The radiation oncologist will explain the available procedures and the possible risks and benefits of each. Together you can decide whether prostate brachytherapy is the best treatment for you. -Have tests to prepare for anesthesia. To help your doctors prepare for your treatment, you may have blood tests and heart tests to make sure your body is healthy enough for the medicine that puts you in a sleep-like state during the procedure. -Undergo scans to plan for treatment. Imaging scans of your prostate, such as ultrasound, computerized tomography (CT) and magnetic resonance imaging (MRI), help your radiation oncologist and other members of the treatment planning team decide the dose and positioning of the radiation. These tests can be done before your procedure or at the beginning of your procedure.
After prostate brachytherapy, you can expect some pain and swelling in the perineum. You may find relief by placing an ice pack over the area and taking pain medication prescribed by your doctor. You can resume normal activities when you feel up to it. Your doctor may give you instructions for your recovery, such as avoiding vigorous exercise and heavy lifting. After prostate brachytherapy, you may undergo follow-up blood tests to measure the level of prostate-specific antigen (PSA) in your blood. These tests may give your doctor an idea of whether treatment has been successful. It's not unusual for your PSA level to rise suddenly after prostate brachytherapy and then decline again (PSA bounce). Your doctor will likely continue monitoring your PSA level to make sure it doesn't continue to rise. Your doctor will notify you when you can expect to know whether your prostate cancer is responding to treatment.
There is still some chance of radiation reaction to the rectum, urethra (bladder tube) and bladder but much less than external standard radiation therapy. The procedure is performed under anesthesia (general or spinal) and the risk and complication from anesthesia is likely that of any other surgery. There is the chance of the seeds being migrated into vascular system into the lung but very very small and usually does not do any harm (like staple left in lung surgery). If one or two seeds get into the bladder, the urologist can remove them out by cystoscopy after finishing the procedure, or in case of subsequent event, the seeds would be coming out with the urine. However, the chance is almost nil in the experience hands.
Who is eligible for brachytherapy for prostate cancer?
Not every prostate cancer patients are suitable for this treatment. The ideal case is tumor confined within one lobe of the gland, low cancer grading, low PSA level and the size of the gland that is not too small (such as the case after transurethral resection of the gland due to bladder tube obstruction), or too large the gland size. However, in the patients who are not ideal, the treatment would be considered, depending on many factors and judgments of the physicians. Those whose prostate glands are large could be treated by hormone first so that the gland size is decreased. In the patients who have more advanced disease, the treatment needed is to cover the large area such as draining pelvis lymph nodes as well as the primary tumor in the prostate gland. However, the primary cancer which is larger in size, with more cancer cell burden will require higher dose of radiation to eradicate the disease. The Interstitial Brachytherapy can be used as supplement or boost to the prostate gland while sparing surrounding normal tissue of rectum and bladder. The boost dose by this technique is likewise higher than by standard external radiation and thus higher chance of tumor eradication. Another indication for Interstitial Brachytherapy is the salvage treatment in case the cancer has locally recurred after radical prostatectomy but has not yet has spread outside the primary prostate bed area. The other salvage treatment is for local recurrence after external radiation therapy when the rectum and bladder could not be exposed more to radiation.
How successful is brachytherapy for prostate cancer?
Brachytherapy has a high success rate for prostate cancer. The overall outlook for people with prostate cancer, regardless of treatment plan, is excellent. According to the American Cancer Society, the 5-year relative survival rate for people with localized or regional prostate cancer is almost 100 percent.
Will I need additional treatment?
Usually, no additional treatment is needed after radiation therapy. The need for additional treatment is determined by the PSA, Gleason score and stage of the prostate cancer and having your daily treatments as scheduled, particularly for external beam radiation therapy (EBRT). Regular post-treatment PSA evaluation plays an important role in monitoring and evaluating the need, if any, for additional treatment in the future. Should the cancer recur, options for treatment will in part depend upon the initial treatment. Additional or alternative forms of radiation therapy, prostatectomy, cryotherapy, hormone therapy or any of a number of treatments under evaluation in clinical trials may be recommended. Your team of doctors, including a radiation oncologist, urologist and medical oncologist, will discuss treatment options and recommendations with you.