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Tony Lambert delphine1939@videotron.ca

22 Dec. 2006

Prostate Cancer

Radiation Therapy

Radiation therapy is a primary treatment option for both localized and locally advanced prostate cancer. For early-stage disease, patients often have a choice between surgery and radiation, with similar outcomes. For larger or more aggressive tumors, radiation therapy may be used in combination with hormone therapy.

There are four types of radiation therapy used for prostate cancer:

External Beam Radiation is the most commonly used radiation therapy for prostate cancer. Pre-treatment planning with a CT scan determines the treatment field and where radiation beams will be aimed. The patient lies on a special bed designed to keep him immobile during treatment, and the radiation machine, or gantry, moves around the bed to deliver beams from eight different angles.
Intensity Modulated Radiation Therapy (IMRT), an advanced form of external beam radiation, is used to further focus radiation beams, with the goal of increasing the dose to the prostate while sparing normal tissue. IMRT has 80-100 tiny lead "leaves" on each side of the beam that are moved in or out to define the treatment field with pinpoint accuracy.
Radiation treatment involves 40 daily sessions (Monday through Friday) over the course of eight weeks. Sessions last about 30 minutes. Ultrasound is performed before each session to ensure that the prostate has not shifted between treatments.
Brachytherapy involves the use of tiny radioactive seeds implanted directly in the prostate, delivering a constant dose of radiation. Read More
Proton Therapy is a type of radiation that uses positively charged particles to treat the tumor. The beam can be directed to a prescribed depth in tissue to treat the prostate and avoid surrounding normal tissues, such as the bladder and rectum, as much as possible. Proton therapy may allow higher doses to be delivered to the prostate without complications. M. D. Anderson is opening its Proton Therapy Center in Spring 2006, one of only three such hospital-based facilities in the United States.

Treatment side effects are similar for all forms of radiation therapy, although they may be more intense for brachytherapy. Most patients will experience some side effects, but they generally are not severe and go away after treatment ends. The rectum and bladder are most likely to be affected in prostate cancer patients.

Possible side effects include:

  • Irritation of the bladder, urethra and/or rectum

  • Frequent urination, burning on urination, stronger urge to urinate

  • Rectum soreness (may be accompanied by slight bleeding)

  • More frequent bowel movements

Back to Prostate Cancer

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Hormone Therapy

The majority of prostate cancers are hormone-sensitive, which means they depend on the male hormone (testosterone) as fuel for tumor growth. Of the 230,000 men diagnosed with prostate cancer in the United States, about one-third will require hormone therapy, which removes all traces of testosterone from the body in an effort to reduce the tumor size.

Hormone therapies work best on early-stage, high-grade tumors (Gleason score of 8 or higher). However, there is disagreement over the length and timing of hormone therapy. Most studies have shown that suppression of testosterone at an earlier stage has a significant effect on patient survival. There are differing opinions on length of therapy, but M. D. Anderson oncologists agree that therapy spanning three years produces the best results.

There are three types of hormone therapies for prostate cancer:

Androgen ablation blocks the ability of cancer cells to interact with testosterone at the cellular level. Flutamide and Casodex® are two types of androgen ablation drugs. They are taken orally on a daily basis for up to three years. Their effects are permanent in most patients.
The standard of care for early-stage, high-grade disease is androgen ablation given at least two months before radiation therapy. The drugs make the tumor more responsive to radiation treatment, and reduce the number of cancer cells to be treated.
LHRH agonists work by overstimulating the pituitary gland to release luteinizing hormone-releasing hormone (LHRH), which signals the testicles to suppress testosterone production. Zoladex® and Leuprolide are LHRH agonist drugs, administered by regular injections ranging from once a month to once a year. A disadvantage of this therapy is that it causes a short spike in testosterone levels before suppression takes effect. However, its effects are not permanent, so patients who cannot cope with treatment side effects can be taken off the drug and can resume testosterone production.
Orchiectomy (surgical removal of the testicles) used to be the standard hormone therapy for prostate cancer. Because orchiectomy is an efficient, cost-effective and convenient method of reducing testosterone, it is still an option for certain patients, particularly elderly men.

Side Effects of Hormone Therapies

  • Impotency, loss of sex drive

  • Loss of muscle mass, weakness

  • Decreased bone mass (osteoporosis)

  • Shrunken testicles

  • Depression

  • Loss of self-esteem, aggressiveness/alertness and higher cognitive functions such as prioritizing or rationalization

The severity of side effects increases with the length of hormone therapy. M. D. Anderson researchers are exploring other alternatives to minimize side effects, including earlier administration of hormone therapy before the disease has advanced, or using it intermittently to achieve similar results to continuous therapy.

Advanced Disease
For men with advanced or metastatic prostate cancer, hormone therapies provide relief from pain and other cancer-related symptoms. In these patients, the symptoms of advancing cancer outweigh the side effects of hormone therapy.

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Brachytherapy for Prostate Cancer

Brachytherapy involves the use of tiny radioactive seeds, each smaller than a grain of rice, implanted directly in the prostate. Typically 80 to 100 seeds are placed in the prostate, delivering a high dose of radiation which kills the cancer cells.

A perineal template-guided transrectal ultrasound is performed to plan the exact placement of each radioactive seed within the prostate. The procedure is performed under anesthesia on an outpatient basis and generally takes two hours.

Advantages of prostate brachytherapy:

  • High cure rates comparable to surgery and external beam radiation therapy

  • Fewer side effects in comparison to other treatment modalities

  • Outpatient procedure (1 day) with no extended treatment duration

  • Most patients resume normal activities within days after treatment

Who can have brachytherapy?

Brachytherapy is a standard treatment option for selected patients with localized prostate cancer. When determining if brachytherapy alone is appropriate, several factors are considered including prostate size, urinary obstructive symptoms, and staging work-up. During the initial consultation visit, a physical examination, a pubic arch CT scan, and a transrectal ultrasound volume study will be performed to determine if the patient is an appropriate candidate.

Candidates for brachytherapy treatment alone have:

  • A PSA level of 10 or less

  • A Gleason score of 6 or less

  • Stage T1c or T2a disease

M. D. Anderson is currently evaluating patients for a clinical trial to determine the outcomes of patients receiving brachytherapy alone who have PSA levels of 10 to 20, a Gleason score of 7, or clinical stage T2b disease.

M. D. Anderson's brachytherapy team is led by Steven Frank, M.D. For more information brachytherapy treatment, call (713) 563-6933. Or, call toll-free at 1-800-392-1611 and ask for a radiation oncology brachytherapy representative.

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The Proton Therapy Center

The future of radiation therapy for cancer is in Houston, Texas. The Proton Therapy Center at The University of Texas M. D.

Night Photo of Proton Therapy Center

Anderson Cancer Center is now accepting patients for the most advanced form of radiation treatment available in the Southwest. Proton therapy provides M. D. Anderson radiation oncologists with a new weapon in their arsenal to fight cancer.

Proton therapy allows for the most aggressive cancer therapy possible, while keeping the harm to healthy tissue and side effects to a minimum. Combined with M. D. Anderson's more than 60 years of expertise and pioneering research in radiation therapy, The Proton Therapy Center is the premier destination for cancer patients desiring the best treatment by the most experienced radiation oncologists.

The Proton Therapy Center is a 94,000 square foot facility including three treatment rooms with gantries that administer proton beams from 360-degree angles, a fixed-beam treatment room, 16 exam rooms and a simulation suite with positron emission tomography, computed tomography, and magnetic resonance imaging for accurate treatment planning. Amenities also include plentiful free parking right outside the Center for convenience and easy access.

The Proton Therapy Center allows M. D. Anderson to offer the complete range of advanced proton therapies and provides research opportunities to maximize the capabilities of proton treatment on a variety of cancers.

The Proton Therapy Center is part of M. D. Anderson’s Red and Charline McCombs Institute for the Early Detection and Treatment of Cancer, six unique centers dedicated to Making Cancer History® through genomics, proteomics, screening, diagnostic imaging and biotechnology.

To find out more about The Proton Therapy Center, call toll-free: 1-866-632-4PTC (4782),

 

 


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