Radiation Therapy for Prostate Cancer. Part 2

Radiotherapy

Once you decide to give radiotherapy a chance, you will need to make an appointment with a radiation oncologist. He or she will give you several options depending on your stage of disease.

The staging of prostate cancer is broken down into three important distinctions. First is the size of the cancer and if it has broken through the capsule and/or invaded local organs. TI is the earliest and smallest cancer. With T2 the cancer involves about half of either the right or left lobe of the prostate up to both lobes. T3 extends through the capsule and into the seminal vesicles. T4 invades surrounding structures such as the rectum or bladder.

The next markers for staging are the lymph nodes and/or any chance of distance spread. This is checked by CT scans and bone scans done after the diagnosis is made.

After diagnosing prostate cancer, the pathologist studies the differentiation (maturity) and growth pattern of the population of the cancer cells. This shows the aggressiveness of the disease. The Gleason grading system is used for this with 2 being the least aggressive and 10 being the most. For example, after a man has all of his pre-staging work-ups completed, he might have a stage of T2; No (lymph nodes are negative), Mo (no distance spread), Gleason 6, PSA12. These are the numbers that the doctors should use to determine the form of treatment.

Now that the staging is done and you’ve made your appointment with a radiation oncologist, what can you expect to hear?

In radiation therapy, high-energy rays are used to damage cancer cells and stop them from growing. The radiation is directed at the prostate and can be delivered in a variety of ways. The patient and the radiation oncologist should decide the type of radiation therapy used. Based on the patient’s stage of disease and the chance of extracapsular involvement, the following choices are available.

External Beam Irradiation: This consists of daily radiation therapy for about eight weeks. The treatments are Monday through Friday and take about 20 minutes a day. Diarrhea and bladder irritations are frequent side effects. Complications may include ulcerations of the rectum, but this happens in less than three percent of patients. New conformal therapies maximize the radiation to just the prostate and spare the rectum even more. Incidences of impotence are around 10 to 30 percent. Doses delivered are about 7000cGy.

External Beam Irradiation and Temporary Brachytherapy: This procedure consists of six weeks of external beam irradiation. Then the doctor temporarily places radioactive material into the prostate. This can be done using high doses of radiation over a few hours or lower doses over a few days. While in the hospital for either, trans-rectal ultrasound guides the doctor in placing long hollow needles into the prostate. This is done under anesthesia. After the needles are placed in the prostate, either low dose or high dose ribbons of radioactive material are slid into the needles thereby irradiating the prostate. Because the treatment is tailored to correspond to the location of the disease, local control rates (controlling cancer inside the prostate) of 90 percent can be achieved. Impotence rates drop to 10 percent. The side effects of diarrhea and bladder irritation and rectal damage are reduced. The dose to the prostate is increased to be biologically equivalent to 10,000 cGy without any additional external to the surrounding organs.

Note: If your doctor has hyperthermia it can be used during this procedure. Hyperthermia is a unique heating treatment that works very well on large prostatic tumors. It also works for benign prostatic hypertrophy (BPH). Many men have both prostate cancer and an enlarged prostate. While an enlarged prostate is benign by nature, it can still disrupt the flow of urine and can be addressed while the doctor is treating the cancer. The biological equivalent of an implant with hyperthermia is approximately 12,000 cGy to the prostate.

Permanent Iodine Seed Implant: Before deciding on this procedure, make sure to review the Partins Table with your doctor. (See the discussion later in this article.) This procedure was all the rage some years ago, but fell out of favor because of poor local control. Today, because of better diagnostic work-up, it is being offered again. But it should only be for men with T1 or T2a lesions with Gleason < 6 and a PSA of <10. The biological equivalent is 11,000 cGy.

For this procedure, the doctor will use ultrasound to permanently place very low levels of radioactive seeds into the prostate. Its main advantages are that it doesn’t require any external beam irradiation and is an easy outpatient procedure. However, you must be wary of any doctor who offers it to all of their patients. Only the earliest stage patients should have this procedure. It will not adequately treat any disease that extends beyond the capsule and if it does those patients will not be cured by seed implants alone.

To summarize, deciding a course of treatment needs to be based on the patient’s stage of disease, not the doctor’s specialty. Make sure to talk to both a surgeon and a radiation oncologist before deciding on a treatment. If, because of scheduling problems or insurance delays (or your just too confused to decide which way to go) and the treatment isn’t going to happen soon, there is a third option that can buy you some time. As mentioned before the prostate is fed by testosterone. If you take away this hormone, the prostate cancer will starve and rapidly shrink. It DOES NOT cure the disease, but hormone therapy takes three months to be delivered, and while it is shrinking your prostate cancer, you’ll have three months to decide what to do. Of course, there are side effects with the hormones, so discuss this option with your doctor. But you must eventually decide. Nothing, of course, is black and white. Different stages of disease need different treatments. I would love to be able to tell you exactly which treatment option to choose, but without specific details that would be impossible. I have, however, talked to hundreds of men with prostate cancer and have heard all of the pros and cons of the treatments out there, and I would definitely choose radiation over surgery.