Monday, September 6th, 2010

Prostate Cancer Treatment Options


Cancer of the prostate is a highly variable disease that is fatal and antagonistic in some patients, but in others it probably can be ignored. Recent literature has emphasized that it takes a lot of patients to be treated for it to benefit a few. But, in this country, the emphasis is on treating cancer as early as possible. Thus we are still in the process of learning who benefits and who does not. The decision has been made easier, since modern implant therapy and IMRT are more targeted and thus treat less normal tissue. This makes the decision a little easier, since the side effects are less onerous. In addition, some studies say that we should not screen using the PSA test, because you are finding more insignificant disease that does ‘not require’ curative treatment. Again, this is controversial and the issue is not settled.

What are the kinds of radiation treatments available?
External Beam Radiation using IMRT& IGRT: This is the most common form of therapy for prostate cancer. As IMRT-IGRT has become more refined and our equipment has improved, the results with radiation equals the results with surgery, at least in our older populations. We have improved our ability to avoid most of the rectum and bladder while giving very high doses of radiation to the prostate itself.

The first step is performing a planning CT to get the full 3 dimensional anatomy in place. This is then transferred to a planning comuter. Next the organs in the area are contoured and outlined on the computer so that we can target the radiation beams to hit the prostate and spare the normal bladder and rectum. The various beams and angles of radiation are tried on to the images on the computer representing your prostate.
 
Next the plan is checked to see if it covers the prostate and spares the rectum and bladder. See the red prostate partially covered by the blue which represents the radiation dose as an illustration. In order to track the position of the prostate during daily treatment, and knowing that the prostate can move on a daily basis, we put gold markers into the prostate to permit tracking of the position of the prostate each day and adjust the radiation beam to account for that movement.

Interstitial Implants or Brachytherapy: This has increased in usage and rivals the frequency of external beam radiation. Since our planning systems and treatment agility has improved dramatically, interstitial therapy has become quite reliable. The complications have decreased while the cure rates have increased. At least for low grade disease, the results are the same as external beam radiation and surgery. The use of this modality has increased dramatically. the doctor places radioactive seeds into the entire prostate gland and the computer systems tell us how evenly the dose of radiation is, while warning us if the normal tissues are getting too much radiation. The main advantage is that the entire treatment can be done in one sitting, and that little is lost in terms of treatment success for early cancers. The disadvantage is that the area around the prostate where cancer cells can reside, is not treated as well as by external radiation.

Radiation Seed Implants of the prostate. We are a member of the San Joaquin Seed Implant Group working together with urologists throughout this region to provide the latest technology in using radioactive seed implants for prostate cancer (Brachytherapy).
The patient is put in the following position on the operating table. The stepper unit is then positioned in the proper location at the level of the prostate. Then the needles are placed within the prostate and the seeds that are pictured on the finger below are inserted in a very precise way in order to deliver an even dose throughout the prostate, and spare the rectum, bladder and urethra.