What to expect during your seed implant
Steps of the implant:
1) General anesthesia is induced
2) The patient lies flat and the hips and knees are fully flexed with the legs spread apart and raised and padded. This exposes the perineum (area in front of the anus to the scrotum).
3) A sterile catheter is placed into the bladder by the urologist.
4) A prostate ultrasound is introduced into the rectum.
5) A ultrasound "volume" study is done and "captured"(recorded) into a computer for "real-time" dosimetry calculations. A volume study takes individual images of the prostate at 5 mm increments starting at the bladder (prostate base) and working to the end of the prostate (apex). The computer and the ultrasound both calculate a volume of the prostate with these images. The Radiation Oncologist and Radiation Physicist program the computer with the planned radiation dose taking into account post op IMRT/IGRT (if it is planned). The radioactive seeds have been already been checked for their radioactivity (strength of the seed) and sterilized in cartridges. Rechecks are done of to make sure the correct seeds are present for the correct patient.
6) In the cross-wise view of the ultrasound (transverse), the first series of hollow needles are placed in the perimeter (margin) of the prostate by the Urologist and Radiation Oncologist. Depth of the needles is checked on the length-wise (longitudinal) view of the ultrasound. Each needle is marked on the computer and ultrasound.
7) A repeat volume study is done with the ultrasound and these images are recorded into the computer. The computer now has a 3 dimensional view of the prostate and the needles. It can now calculate the position for the seeds based on the prescription radiation dose (planned dosimetry).
8) A device is attached to each needle individually and radioactive seeds are pushed down the hollow needle and out the tip in the prescribed location. Each seed position is recorded into the computer for continuous recalculation of the dosimetry. This is the "real time" portion of the procedure. With the position of each seed recorded, the computer can calculate the position for the next seed to keep the prescription dose high inside the prostate and low on the outside (rectum and bladder).
9) A second series of needles is then placed in the interior of the prostate. Models of the seeds and needles are created on the computer prior to their insertion. This way, the best location can be determined for the lowest dose to the urethra while maximizing the prostate dose.
10) If indicated, marker seeds (fiducial seed markers) are placed for the IMRT/IGRT to locate when it is used after the seed implant. The computer in the IMRT/IGRT can look at these markers with a very quick CT scan just milliseconds before delivering the radiation dose, allowing for a very tight contour of radiation to just the prostate.
11) The catheter is removed and the patient is sent to the recovery room. (sometimes the catheter is removed in recovery). A 35 minute watch in recovery is followed by another observation phase in post-op. The patient has to void before discharged. Medications are prescribed in recovery and at discharge to help the patient void with minimal discomfort.
Question: How many seeds and needles are inserted?
Answer: The number of seeds and needles depends on the size of the gland, the configuration of the gland (e.g. pear shaped, egg shaped) and the strength of the individual seeds (taking into account the prescribed dosimetry).
Question: Are all seeds the same strength?
Answer: All the seeds in an individual patient are the same strength, but seed strength differs between patients. Some centers order all the seeds the same, but our center orders custom orders seed strength based on the size and configuration of the gland taking the planned dosimetry into account.
Question: Do seeds migrate to the lung and other parts of the body?
Answer: Very rarely a seed can migrate to the pelvis and even more unlikely, the lung. That is as far as a seed can migrate. The occurrence has never caused any documented damage.
Question: What is the radiation risk to my friends and family?
Answer: The amount of radiation to a bystander is not of a health risk but common sense dictates precaution around children and pregnant women for 2 months after insertion.
Question: What preparation is needed for a seed implant procedure?
Answer: Because anesthesia is used, the patient cannot eat after midnight before the procedure. Preoperative evaluation with routine blood tests, chest X-ray, and EKG are often required the week prior to the procedure. These are common preparatory items for any general anesthetic. An enema is required the morning of the procedure to clear the rectum of stool to provide the best visualization of the prostate.
Question: What can I expect after the seed implant?
Answer: Most patients can expect mild burning on urination for 1-3 days. Less commonly, urgency to void, frequency and nocturia (getting up at night to void) can occur. Each patient is different. The more urinary symptoms the patient has before the implant, the more he will have after the implant. The larger prostates tend to have more side effects. One in twenty men has obstruction to urination requiring a catheter overnight. Very rarely, a patient will require longer catheterization.
Question: How much work will I miss for the seed implant?
Answer: Most patients take two days off for the procedure, including the day of the procedure.
Question: Can I have a colonoscopy after the radioactive implant?
Answer: Yes but caution the gastroenterologist not to biopsy the rectal wall directly over the prostate.