The CyberKnife System delivers high doses of radiation directly to the prostate. The CyberKnife System offers patients a minimally invasive, alternative prostate cancer treatment. Prostate cancer treatments with the CyberKnife System are performed on an outpatient basis with five treatments, requiring no overnight hospital stays. Most patients experience minimal to no side effects with a quick recovery time.
The prostate is a male sex gland that is about the size of a walnut. It produces a thick fluid that is a normal component of semen in men. Prostate cancer is the most common cancer among men in the United States after non-melanoma skin cancer, and is the third leading cause of cancer-related deaths. Prostate cancer is expected to be diagnosed in 186,320 men in 2008.1 Because of widespread screening efforts, the majority of newly diagnosed prostate cancers are found early when they are still confined to the prostate gland, thus the number of prostate cancer-related deaths has decreased.
For patients with early stage prostate cancer that is confined to the prostate itself, treatment options include CyberKnife® Radiosurgery, surgery, external beam radiation therapy (EBRT), brachytherapy (LDR and HDR), hormonal therapy and watchful waiting. Each of these options is explained in detail below.
Find out why Mr. Williams, a patient at NCH, chose CyberKnife Radiosurgery for his prostate cancer treatment.
Radiosurgery devices, such as the CyberKnife Robotic Radiosurgery System, offer patients a new option for the treatment of prostate cancer. The challenge that doctors face in treating prostate tumors is that the prostate moves unpredictably as air passes through the rectum and as the bladder empties and fills. Minimizing any large movements of the prostate can help reduce unnecessary irradiation of surrounding healthy tissue. The CyberKnife System is able to overcome this challenge by continuously identifying the exact location of the prostate throughout the course of the treatment.
Prostate cancer surgery:
Prostate cancer surgery involves complete removal of the prostate and some of the adjacent tissues (radical prostatectomy). There are two types of surgery common for prostate cancer: open radical prostatectomy and laparoscopic prostatectomy.
Open radical prostatectomy:
There are two approaches to performing an open radical prostatectomy, a radical retropubic approach and a radical perineal approach. During a radical retropubic prostatectomy, a long incision is made in the lower abdomen and the surgeon removes the entire prostate with some surrounding tissues. Nerves in the surrounding tissues can be easily damaged during this procedure, resulting in impotence, so surgeons often use techniques to preserve the nerves around the prostate that control erections. Nerve-sparing techniques have been shown to decrease the incidence of impotence following radical prostatectomy, but there is still a high risk of impotence following surgery. The radical perineal approach involves the surgeon making an incision in the perineum, the skin between the testicles and the anus. Nerve-sparing techniques are more difficult in this approach. Patients that undergo open radical prostatectomy typically spend three to four days in the hospital and can expect to have a catheter remain in their urethra for three to four weeks to help with urination. Either surgical approach poses a significant risk of possible complications for patients, such as infection, bleeding, lengthy hospital stays, urinary side effects and impotence. In general, open prostatectomy is a highly effective modality for controlling prostate cancer, with long-term (10-15 years) overall survival ranging from as high as 97%.2-5, 29 Urinary complications are common shortly after surgery, and in the long term urinary incontinence may occur in 5-15% of patients and impotence has been reported to occur in 50-80% of patients.6, 7
Laparoscopic prostatectomy is becoming more popular because it is less invasive. During this procedure, surgeons make several small incisions in the abdomen. Instruments are inserted through the small incisions and are used to remove the prostate and surrounding tissues. There is little evidence that laparoscopic prostatectomy is superior to open surgery in its ability to control the disease but does have a reduction in complications.8, 9, 30, 31 Laparoscopic prostatectomy may be robotic-assisted; in some reports of this method complications have been reduced relative to non-robotic prostatectomy (urinary incontinence has been reported in 1-20% of patients, and impotence rates have ranged from 17-40%).10-14, 32 Patients who undergo laparoscopic prostatectomy typically are hospitalized for two to three days with a catheter in place in the urethra and have a shorter post-surgical recovery time compared to open surgery.
External beam radiation therapy:
Radiation therapy is a non-invasive procedure that uses radiation to kill prostate cancer cells. Prior to treatment, CT and MRI images are taken to determine the exact location of the prostate and surrounding structures. A treatment plan is then created to deliver the radiation to the prostate and some of the surrounding tissue. It is necessary to irradiate some of the surrounding healthy tissue during this treatment because there is a significant amount of variability in the day-to-day location of the prostate and because the prostate can move inside the body from the effects of gas in the rectum and fluid in the bladder, which cause uncertainties in the exact position of the prostate. Each treatment session lasts several minutes and is painless. Treatments are typically delivered on an outpatient basis, five days a week, for 6 to 8 weeks.
The Calypso system is a way of using Image Guided Intensity Modulated Radiation Therapy. The system uses a GPS system to pinpoint the exact location of the tumor volume during treatment. Three beacon transponders are placed by the physician in the prostate during an out patient procedure. These transponders emit a unique radiofrequency signal to the Calypso system.
Brachytherapy is an invasive procedure that delivers radiation to the prostate from a source that is implanted within the prostate. There are two approaches to brachytherapy treatments, low dose rate (LDR) brachytherapy and high dose rate (HDR) brachytherapy.
In LDR brachytherapy, small radioactive seeds about the size of a grain of rice are placed into the prostate and remain there permanently. Typically, 40 to 100 seeds are placed into the prostate through a needle, which is inserted through the skin. To relieve discomfort, the procedure is done using spinal anesthesia or general anesthesia. The procedure is performed on an outpatient basis. The seeds emit low dose radiation to the prostate over several weeks or months, and the patient is radioactive while the radiation is being emitted by the seeds. LDR brachytherapy results in a high rate of long-term survival, ranging from 85-94% in published reports.4, 24, 25 Patients may experience low rates of urinary and rectal side effects (3-5%), and sexual dysfunction has been reported in 20-50% of patients.8 In very rare situations, the seeds have become dislodged from the prostate, enter the blood stream and migrate to other distant organs, but this does not typically pose health complications.
Male hormones, known as androgens, are produced normally by men and help support the growth of prostate cancer cells. The goal of hormonal therapy is to decrease the amount of these specific hormones produced, in order to control the growth of the prostate cancer cells. Hormonal therapy is usually prescribed in combination with other treatments, including external beam radiation therapy, brachytherapy or before surgery to help shrink the size of the tumor. Side effects associated with hormonal therapy can include decreased libido, impotence, hot flashes, osteoporosis and breast tenderness.
Prostate cancer is often a slow-growing cancer. Doctors may recommend that a patient receive no immediate treatment, instead just closely monitoring the patient with PSA testing, rectal exams, and repeat biopsies. Some men, especially those who are older or have other health problems, may never need prostate cancer treatments.