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Harvard Transrectal Ultrasound Brachytherapy for Prostate Cancer
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Three Dimensional Dose Distribution: Urethral Sparing Ultrasound-MRI
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 What is seed implantation? Prostate Brachytherapy involves the placement of radioactive seeds (Iodine-125)
directly into the prostate gland for the treatment of prostate cancer. The advantage of
brachytherapy is the ability to specifically irradiate an organ that contains tumor while
protecting the normal tissue of other organs. The goal of seed implantation is to deliver
radiation to the prostate in such a way as to gain control of the cancer while minimizing
side effects from treatment. Seed implantation represents a minimally invasive treatment
for prostate cancer as it only requires a one day hospital stay and patients can return to
their normal level of activity three days after the procedure. The physician first uses an ultrasound device (TRUS) to create a three-dimensional grid map of the prostate. A computer then is used to calculate the volume of the gland, the number of radioactive implants (called "seeds") that will be needed and where they should be placed. The procedure, performed on an outpatient basis, takes 45 to 60 minutes and is done under general anesthesia. From 50 to 100 rice-sized seeds are then inserted by a special needle through the perineum and into the prostate in a preplanned pattern, guided by the TRUS and grid map. The seeds contain a radioactive isotope, usually Palladium 103 or Iodine 125, which emit radiation for about three months before decaying to an inert state. Brachytherapy patients can be discharged the same day and usually resume normal activity within a day or two. A small proportion, generally those over 70, experience incontinence or impotence problems. But brachytherapy has been found to deliver a higher and better focused dose of radiation with fewer side effects and at substantially lower cost than external beam therapy. Is seed implantation new? The concept of insertion of radioactive sources into the prostate for the treatment of prostate cancer has a long history and dates back to the turn of the century. Many patients with prostate cancer were treated by this method in the 1960s and 1970s. At that time the radioactive seeds were placed in the prostate through an open surgical incision in the lower abdomen. Because of the uncertainty of seed placement by this method, this technique was abandoned. By the late 1980s, technologic and scientific advances in trans-rectal ultrasound imaging had revived interest in seed implantation for the treatment of prostate cancer. The introduction of trans-rectal ultrasound probes made possible real time interactive placement of radioactive seeds into the prostate. In addition, the development of 3-D simulation software ( similar to 3D glasses used for film viewing) allows accurate determination of the dose delivered to the prostate and surrounding structures, bladder, urethra and rectum. These new tools have permitted the refinement of interstitial brachytherapy for prostate cancer and have resulted in a more accurate method of delivering the dose to the prostate gland. Who is a candidate for seed implantation? Men with clinically localized prostate cancer (stages A and B) are candidates for seed implantation for treatment of their disease. Because interstitial therapy is localized to the prostate, patients who have disease outside the prostate (stages C and D) should not be treated with an implant alone. Consultation with the physicians at Care Group will be helpful in determining whether seed implantation is an option for treatment of the patient's prostate cancer. During this consultation, the doctors will explain all treatment options available for clinically localized prostate cancer. They will present the existing data (including results, complications, risks and benefits) of these treatment options and outline a course of treatment specific to the patient's situation and disease. Significant others will also be given the information with the patient to support and assist with their decision and care at home. How is seed implantation performed? You must first undergo a planning trans-rectal ultrasound volume study which will be arranged by your urologist. This test is done a few weeks prior to the actual brachytherapy procedure. The shape of the prostate is measured to determine the number of seeds for treatment to be placed in the prostate and their location. Approximately two weeks later, the seed implantation is performed. The procedure requires either a general or spinal anesthetic and takes between one and two hours to complete. Needles are placed into the prostate through the perineum (the area between the scrotum and rectum). The number of I-125 seeds implanted will depend on the size and shape of the prostate gland and treatment protocol. The seeds are placed into the prostate through special needles. The needles which hold multiple seeds are placed while visualizing the prostate using the trans-rectal ultrasound. After all the seeds are placed (between 50 to 100+ seeds) the needles are removed. No incision or sutures (stitches) are required. The perineum will have antibiotic cream placed on it where the needles were inserted and a foley catheter (a tube placed through the urethra to drain the bladder of urine) remains in place after the procedure. The foley is removed the morning after the procedure. The urologist will give you medication to help with the ease of bowel movements and any minimal discomfort you may experience after the procedure. You will remain in the hospital the night of the procedure and be discharged from the hospital the following day. It is required that you have a ride home. Who performs the seed implantation? Seed implantation at Care Group (Beth Israel Deaconess Medical Center, Mt. Auburn Hospital, and New England Baptist Hospital) is performed as a team approach by both a urologist and radiation oncologist. Your Care Group physicians are present throughout the procedure and communicate as an adjunctive team during the surgery. Are the seeds removed? The type of seeds (Iodine-125) used are permanent implants and are not removed. The half life of the seeds is approximately 60 days. Therefore, only fifty per cent of the activity will remain two months after the procedure. For practical purposes, all activity has ceased by one year after the procedure.
INTRAOPERATIVE TREATMENT PLANNING FOR RADIOACTIVE SEED IMPLANT THERAPY FOR PROSTATE CANCER KAPLAN, I.D.*, HOLUPKA, E.J.*, MESKELL P.*, SOON, S.J.++SALTZMAN, B.**, CHURCH, P.** , KEARNEY, G. P. +
*Joint Center for Radiation Therapy, Harvard Medical School, Boston
MA Purpose: To describe a procedure for the development and evaluation of ultrasound guided 125I or 103Pd radioactive seed implant treatment plans in the operating room. Materials and Methods: 170 radioactive seed implants for the treatment of prostate cancer have been preformed at Care Group Hospitals (Beth Israel Deaconess Medical Center, New England Baptist Hospital) and the Joint Center for Radiation Therapy in Boston, MA. The pre-planning Transrectal Ultrasound study (TRUS), which is traditionally performed out of the operating room in advance of the operating room procedure, is performed in the operating room after which a full three dimensional treatment plan is developed and evaluated. Results: The average time for the interoperative procedure is 1.44 hours with a standard deviation of 0.28 hours. Dose volume histograms (DVH) were generated in five patients both as a separate pre-planning procedure and during the procedure. There is no significant difference in dose coverage to the prostate. Dose to normal tissues (rectum and urethra) is also similar with both techniques Conclusions: Intraoperative treatment planning for radioactive seed implantation eliminates the need for the additional pre-planning TRUS by bringing the procedure into the operating room. Adequate plans are generated with acceptable OR times WORDS: Seed implant, prostate cancer, interoperative planning
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Prostate
Ultrasound
Ultrasound Probe
& Template
IIsodose
Curves overlaid on MR Ultrasound Fusion Isodose
Display
Three
Dimensional Reconstruction Dose
Volume Histogram
Postoperative CT
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