By Patrick Linson M.D., MPH and Debbie Klein RN, MSN, OCN
Stereotactic Radiosurgery (SRS) utilizes highly precise targeted beams of radiation to destroy tumors and lesions in the brain and body. While this technology was initially designed to treat brain tumors, it is now being applied to treat tumors anywhere in the body, including the prostate.
Prostate cancer is the most commonly diagnosed cancer in men and the second leading cause of cancer death in men in the United States. Unlike traditional surgery for prostate cancer, treatment with CyberKnife SRS can be done quickly, painlessly, with little downtime, no anesthesia, or hospital stays.
Despite the name CyberKnife Radiosurgery, there is no surgery or knife involved. The treatments employ precisely targeted x-rays which are painless, therefore, they do not require anesthesia. Cyber refers to the robotic arm which directs the beams with sub millimeter accuracy.
Dr. David Hodgens, of CyberKnife of Southern California at Vista (CSCV), introduced stereotactic radiosurgery to San Diego County almost 20 years ago. The physicians of CyberKnife of Southern California at Vista (Dr. David Hodgens, Dr. Patrick Linson, Dr. Eva Lean, Dr. Anuradha Koka, Dr. Ken Shimizu, and Dr. Jean Mefferd) have since treated thousands of patients with SRS from Southern California with SRS treatments, roughly 80% of the County’s patients. Of the 200 CyberKnife centers in the world, CyberKnife of Southern California at Vista was the only center in Southern California to be cited as one of the top 10 CyberKnife Centers by Accuray Inc., the manufacture of the CyberKnife system.
While conventional radiation therapy has been used for prostate cancer treatment for decades, only recently have we seen the results from CyberKnife SRS as a prostate cancer treatment. Recent CyberKnife studies from Stanford Medical Center and Naples, Florida have shown CyberKnife SRS to be a highly effective tool for treatment of prostate cancer. Both studies showed excellent cancer success rates (100% and 98%) with limited side effects. The 2009 Stanford Medical Center study showed CyberKnife treatment for prostate cancer could be performed safely when given over 1 to 2 weeks. The study had patients who were treated in as early as 2003. A second CyberKnife study out of Naples, Florida published in 2009, showed 98% cancer treatment success with limited side effects in a one-week treatment course. In the Naples study over 82% of men who were sexually potent before treatment were able to maintain sexual function after CyberKnife treatment. Erectile dysfunction is a common side effect associated with most forms of prostate cancer treatment. Both of these studies showed no risk of incontinence of urine, a common side effect seen in other forms of prostate cancer treatments.
Prostate cancer is the most common cancer to affect a man in his lifetime. Approximately 200,000 men in the United States will be diagnosed with prostate cancer in 2010. Once diagnosed with prostate cancer a patient will meet with cancer specialists and discuss the risks and benefits of the different forms of prostate cancer treatment. With PSA (prostate specific antigen) screening most men are diagnosed with cancer confined to the prostate. When prostate cancer is limited to the prostate it is considered curable. The optimal treatment for cancer confined to prostate that ensures cancer cure with the least risk for side effects is controversial. Until recently, standard treatment options for men with organ confined prostate cancer included radical prostatectomy (surgical removal), radiation therapy (external beam radiation therapy or prostate brachytherapy), hormonal therapy, and active surveillance (watchful waiting). The recent studies indicate Cyberknife SRS can be another prostate cancer treatment option.
The risks and benefits of each of these prostate cancer treatment options are discussed with the patient. Often time patients choose external beam radiation treatment as the risk for incontinence is far less common compared with surgical resection. Some patients who are not medically fit to undergo surgical resection often proceed onto external beam radiation treatment as well. Until recently, if a patient chose external radiation they would be looking a treatment course from seven to nine weeks. Standard radiation treatments are out-patient and performed daily, five days per week. CyberKnife stereotactic radiosurgery (also called stereotactic radiation therapy) allows treatment to be given over one week. Unlike standard external beam radiation which generally employs 5 to 9 beams, CyberKnife often uses 150 to 250 precisely directed x-ray beams of radiation to destroy tumors. The accuracy with CyberKnife can be up to 1/100 of an inch in directing the beams. With that accuracy there is the advantage of delivering a more precise dose to the prostate and less dose going to the bladder and rectum. Therefore, treatments can be delivered in a few days instead of months, with the potential for fewer side effects.
The physicians at CyberKnife of Southern California at Vista are treating patients with prostate cancer. Dr. Patrick Linson, a Harvard educated and trained radiation oncologist, serves as the medical director of CyberKnife of Southern California at Vista. He has teamed up with phyisicians from Harvard Medical School, Georgetown, and The Swedish Hospital in Seattle, as well as other select centers with CyberKnife technology to treat prostate cancer patients this approved multi-institutional cancer treatment protocol listed on clinicaltrials.gov. The CyberKnife prostate cancer treatment protocol is modeled after the successful Stanford and Naples studies. This new 5 day treatment for prostate cancer continues to offers an exciting new treatment option for prostate cancer patients.
For additional information please feel free to call 760 734-3750 or toll free at 888 542-9237 or email Dr. Linson at plinson@post.harvard.edu.
To learn more about the protocol you can visit the website
www.clinicaltrials.gov/ct2/show/NCT00643994?term=cyberknife&rank=1 or go to www.cyberknifeofsocal.com
