Radiation Therapy for Prostate Cancer

 

Podcast: New Approaches to Prostate Cancer Treatment with Drs. Louis Kavoussi and Louis Potters

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About Prostate Cancer

The Prostate

Diagnosing Prostate Cancer

Early Vs. Late Stage

Risk Factors

Incidence/Mortality

Treating Prostate Cancer: Know Your Options

Expectant Management

Seed Implant Overview

External Beam: IMRT/IGRT

 

Meet our prostate cancer specialists:
Louis Potters, MD John W. Ames, MD Lucille Lee, MD David Schwartz, MD


About Prostate Cancer

Prostate cancer is the most common cancer diagnosed in men in the United States. Because of blood tests such as the PSA blood test (Prostate Specific Antigen) and a greater awareness for screening, many more men are being diagnosed with early stage prostate cancer. That means the disease is confined to the prostate gland without metastasis, or spread beyond the prostate.

There are several different approaches for the treatment of prostate cancer and the decision process  for the patient can be overwhelming. Early stage disease may be treated with surgery, called radical prostatectomy where the prostate is removed, or with less invasive procedures such as radiation thearpy. Radiation may be given by two different methods; internal or external radiation.

Prostate cancer is common in older men. By age 50, about one-third of American men have microscopic signs of prostate cancer. By age 75, half to three-quarters of men will have some cancerous changes in their prostate glands. Most of these cancers remain latent, producing no signs of symptoms, or grow so slowly, that they never become a serious threat to health.

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The Prostate

The prostate is located at the base of the penis just below the bladder and in front of the rectum. It surrounds the upper part of the urethra, the tube that carries the urine and assists in the transport of semen during ejaculation.

The size of the prostate can vary; usually it is about the size and shape of a walnut.

Male sex hormones affect the prostate gland. They stimulate the production of prostate cells and the activity of the prostate. The most abundant male hormone is called testosterone.

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Diagnosing Prostate Cancer

The Digital Exam

Since the prostate is close to the rectum, the physician can feel for abnormalities on the surface of the prostate by examining the patient's rectum. During the digital rectal exam (DRE), the physician feels the size and shape of the prostate gland for irregularities that may require further testing.

PSA Blood Test

Men with prostate glands have PSA (Prostate Specific Antigen) in their blood. An abnormally high PSA (greater than 4 ng/ml) may indicate the presence of prostate cancer. The PSA can also be elevated with benign enlargement of the prostate (BPH) or with inflammation of the prostate (prostatitis). In general, it is recommended that a PSA blood test be performed starting at age 50.

Prostate Biopsy

If either the digital rectal exam or the PSA value is abnormal, your physician may request that a prostate biopsy be performed to rule out prostate cancer. During this exam, your physician will remove a small sample of the prostate to determine if it contains cancerous cells. If cancerous cells are found, the pathologist will "score" them through a system called the Gleason Score. This gives a result between 2-10 and generally reflects the aggressiveness of the cancer cells.

Transrectal Ultrasound

The Transrectal Ultrasound (TRUS) is a test that shows the size and shape of the prostate. It can also help identify areas within the prostate that appear abnormal. This test is performed by inserting a probe into the rectum to transmit pictures of the prostate.

Established Diagnosis

When the diagnosis of Prostate Cancer is established by the biopsy, your physician may request that either a CT scan and/or Bone Scan be performed to make sure that the disease has not spread beyond the prostate. Other tests that may give helpful information include an MRI study of the prostate or a PET scan .

In general, these tests may be helpful but in patients with a favorable PSA and Gleason score, they may not be necessary.

Currently, most men are diagnosed with early stage, localized prostate cancer where the risk of spread beyond the prostate gland is quite low. This affords the patients an opportunity to select various definitive treatment options with the intent to cure and eradicate the disease permanently. In patients with advanced prostate cancer, where the disease is spread beyond the prostate gland to either lymph nodes or bones, the treatment modalities are different than that for localized cancer.

Prostate cancer is generally a slow growing cancer. A patient initially diagnosed with prostate cancer, unlike some other types of cancers, will have time to make an informed decision regarding treatment without the fear of the disease spreading. Being comfortable with a treatment decision is possibly more important than the treatment itself.

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Early Vs. Late Stage

All cancers are staged according to definitions established by the AJCC (American Joint Committee on Cancer 2002). Staging a cancer, generally from stage I to IV allows the physician to better select appropriate treatment.

Prostate cancer is initially staged by a digital exam. The digital exam provides feedback to allow the doctor to assess the extent of disease in the gland. For patients who udergoing surgery, the pathology report helps to 'pathologically' stage the disease. 

Tumor staging:

T1: Clinically inapparent tumor neither palpable nor visable by imaging T1a: Tumor incidental in less than 5% of resected tissue. T1b: Tumor incidental in more than 5% of tissue resected. T1c: Tumor identified by needle biopsy (e.g., because of elevated PSA)

T2: Tumor confined within the prostate T2a: Tumor involves 1/2 of one lobe or less T2b: Tumor involves more than 1/2 of one lobe but not both lobes T2c Tumor involves both lobes

T3: Tumor extends through the prostate capsule T3a: Extracapsular extension (unilateral or bilateral) T3b: Tumor invades seminal vesicle(s)

T4: Tumor is fixed or invades adjacent structures other than seminal vesicles; bladder neck, external sphinter, rectum, levator muscles, and or pelvic wall

Clinical prostate cancer in 2004:

The majority of men diagnosed with prostate cancer have T1c or T2a tumors, or localized cancer, that are confined to the prostate gland. When tumors are beyond the capsule of the prostate (T3 and T4), they are considered locally advanced.

Treatment decisions are based on the tumor extent and staging.

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Risk Factors

In addition to clinical staging  of prostate cancer, other disease related factors are important. This includes the pretreatment PSA value and the pathology Gleason score. Factors such as race, patient age, alkaline phosphatase level and others, are less reliable risk factors than the PSA and Gleason score.

Several studies have developed various combinations of risk factors to define low, intermediate and high risk disease. This concept may be used to suggest various treatment approaches.

A different statistical method for calculating outcome is to use the nomogram outcome tool. This factors into the prediction model, the PSA value, Gleason score and clinical stage, but does so in a non-intuitive, unbiased way. Five-year outcomes for Brachytherapy, radiation and surgery can be calculated and compared.

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Incidence/Mortality

Incidence:

Incidence rates for prostate cancer have modestly increased from 1973-1986, rapidly increased from 1987-1992, and declined from 1993-1995. The increase in incidence rates from 1986-1993 are believed to be related to the use of the prostate-specific antigen (PSA) blood test as a screening tool.

Black men have about a 60 percnet higher incidence rate than white men.

Incidence of distant stage prostate cancer peaked in 1985 and by 1995 declined by 56 percent.

Mortality:

Death rates from prostate cancer had increased over the last 20 years, peaking in 1991 and 1993 for white and black men, respectively. However, the death rates have decreased in recent years. This decline in the absolute number of deaths was first noted in 1995. It is not clear whether screening and early detection are the main factors associated with the decrease in mortality.

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Treating Prostate Cancer: Know Your Options

An important consideration to factor into your treatment decisions is that success is not guaranteed. In some me, the apparently localized cancers turn out, at surgery, to have already spread. And up to one-fourth, despite apparently successful surgery, will produce a recurrence over the next several years. Thus, while aggressive treatment will be unnecessary for some men, it will prove inadequate for others.

In coming to a decision, you may find it helpful to thoroughly discuss your treatment options, including benefits and side effects, with your wife/partner/family member. You may also consider contacting your local prostate cancer support group after consulting with your primary care physician and one or more specialists. Getting a second opinion and different perspectives can be very helpful.

Your decision does not need to be rushed. Take time to explore all your options. You may prefer a teaching hospital or a cancer center for treatment, and a surgeon or Radiation Oncologist who has extensive experience in the newest, least traumatizing techniques. You may want to take part in a clinical trial evaluating new approaches. You will also want to keep abreast of new developments. Ultimately, the decision rests with each individual. Each man has his own priorities and knows best which choices feel most comfortable for him.

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Expectant Management

Expectant Management is based on the premise that cases of localized prostate cancers may advance so slowly that they are unlikely to cause men -especially older men-any problems during their lifetimes. Some men who opt for watchful waiting, also known as "observation" or "surveillance," have no active treatment unless symptoms appear. They are often asked to schedule regular medical checkups and to report any new symptoms to the doctor immediately.

Expectant Management has the obvious advantage of sparing a man with clinically localized cancer- who typically has no symptoms- the pain and possible side effects of surgery or radiation. On the minus side, watchful waiting risks decreasing the chance to control disease before it spreads, or postponing treatment to an age when it may be more difficult to tolerate. Of course, treatments may also improve over time if watchful waiting is chosen. Another potential disadvantage is anxiety; some men don't want the worry of living with an untreated cancer.

The most obvious candidates for Expectant Management are older men whose tumors are small and slow growing, as judged by low grade or Gleason score and low stage.
Many men who choose Expectant Management live for years with no signs of disease. A number of studies have found that, for at least 10 or even 15 years, the life expectancy of men who opt for Expectant Management (primarily older men with less lethal forms of prostate cancer) is not substantially different from the life expectancy of men treated with surgery or radiation-or, for that matter, of the population at large.


Expectant Management at North Shore-LIJ:

As an academic center, patients should be assured that if they are a candidate for, and select expectant management as their first choice, they will be followed closely, and should there be any hint of disease progression, will be managed quickly and appropriately.

Patients will seen every 3 months for a PSA test and a digital examination. If there is no change, after about 12 months, the patient will be asked to repeat the biopsy. If there is no change, the patient may remain on Expectant Management program.

If the PSA rises or a suspicious lesion is felt on examination, the patient will be coached on which treatment options are best.

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Seed Implant Option

Based on an experience of over 3000 implants over a 17 year period, coupled with over 55 peer reviewed articles on prostate Brachytherapy.  Dr. Potters has pioneered a new approach for seed implantation called Real-Time Dynamic Prostate Brachytherapy,  the 'Potters' Technique. This revolutionary approach utilizes state of the art computer planning software in the operating room that analyzes the implant as it is being performed for correct seed placement before the patient is removed from the table.

In general, the implant is a minor surgical procedure performed in the operating suite. Patients are given a spinal anesthetic and placed on their backs with the legs raised in stirrups. An ultrasound is utilized in the operating suite to visualize the prostate. Needles are then inserted directly into the prostate through the perineum, the skin between the scrotum and rectum. The seeds are then injected through the needles into the prostate. The entire prostate gland is implanted even if only one area of the prostate was positive for cancer.

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Video Description Of The Prostate Implant Process at NSLIJ


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External Radiation for Prostate Cancer

External Beam Radiation therapy uses high-energy photons delivered by a linear accelerator. The radiation treatment sessions are short and are given on weekdays for up to 9 weeks. When used together with Brachytherapy, the external beam sessions are for 5 weeks. The treatment itself is painless and lasts only several minutes per day.

A new technique called Intensity modulated radiation therapy (IMRT) delivers higher doses of radiation than conventional external radiation without contributing to added toxicity. With added image guidance, we can better track and assure the accuracy of each treatment fraction. Data from these techniques of delivering radiation is early, but shows improved cancer control as compared to the conventional doses.

Click here for more information on the Calypso System for prostate treatment

Side effects from External Beam Radiation may include fatigue, skin reaction in the treatment area, frequent and/or uncomfortable urination, a change in bowel habits and rectal irritation. Most of these side effects will improve after the treatment stops. Your Radiation Oncologist will discuss any possible long-term side effects with you.

At North Shore-LIJ, we monitor and track each treatment with a revolutionary technology, called Calypso. The Calypso beacons track the motion and position of the prostate to assure the most accurate set up.

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Last Update

September 27, 2012
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