One option for men with locally advanced prostate cancer (in which lymph nodes or other nearby tissues are involved) is radiation therapy plus hormonal therapy, which several studies have shown is more effective at fighting the cancer than hormonal therapy alone. In addition, men with this condition and a higher risk of recurrence should be informed that radiation therapy after a radical prostatectomy decreases their risk of cancer recurrence or progression, according to national guidelines issued in May 2013. Issued jointly by the American Society for Radiation Oncology and the American Urological Association, the guidelines also state that doctors should offer “salvage radiotherapy” to patients whose PSA levels rise, or who have a local recurrence after prostatectomy but show no evidence of distant metastases.
In 2015, the National Comprehensive Cancer Network (NCCN) issued new guidelines for patients. These guidelines recommend EBRT as a staple of treatment for men with various stages of the disease: as a first-line treatment for those at low risk for developing metastatic disease and who are expected to live 10 years after diagnosis; as a first-line or adjuvant therapy for many categories of men at intermediate risk, and for many groups of men with high-risk disease.
Other high-tech options include three-dimensional conformal radiation therapy (3D-CRT), image-guided radiation therapy and intensity-modulated arc therapy. The shared element among these therapies is a careful mapping of the exact size, shape and location of the prostate gland and tumor using imaging tests, such as computed tomography and magnetic resonance imaging scans or X-rays. This information helps doctors determine precisely where to aim higher and lower doses of radiation for maximum effectiveness and minimum side effects. One recent comparative study showed that IMRT offers a disease-control advantage over 3D-CRT.
Stereotactic body radiation therapy (SBRT), which is often referred to by the names of the machines that administer the radiation, including CyberKnife, Gamma Knife and X-Knife, is a form of EBRT that delivers large doses of radiation to the prostate. Although the benefit of SBRT is that its entire treatment course is days and not several weeks, some studies have shown side effects to be worse with this form of therapy.
Another promising, yet controversial, form of EBRT is proton beam therapy, which aims protons (the heavy, positive parts of atoms) at tumors and releases their energy after traveling a specific distance, thereby causing less damage to tissues they pass through. Although research is inconclusive about whether proton therapy reduces sexual complications, one study did find that men aged 60 or younger treated with this modality experienced little sexual dysfunction; in comparison with the findings of other studies cited in the paper, the amount of dysfunction was comparable to that in populations treated with EBRT in general, but better than that in men treated with prostatectomy.
But other research has suggested limited advantages of proton therapy. A 2012 study comparing IMRT with proton therapy found that the newer therapy was no more effective in getting cancer in check. In addition, experts warn that proton beam therapy is not only more expensive than other forms of radiation (primarily due to costly machinery), but also might not be the best choice to treat prostate cancer because “critical structures, such as the rectum and urethra, will still get radiation no matter how perfect your particle is,” Yu explains.
HDR brachytherapy, a newer approach, is administered through temporary catheters, in which a high-activity source is placed for just minutes to deliver HDR radiation.
Experts have placed some caveats on these treatments. Current guidelines from the NCCN recommend that brachytherapy as a standalone treatment be limited to low-risk or intermediate-risk cases.
Contribution by Yaribeth Galvez club memberships white coat
In 2015, the National Comprehensive Cancer Network (NCCN) issued new guidelines for patients. These guidelines recommend EBRT as a staple of treatment for men with various stages of the disease: as a first-line treatment for those at low risk for developing metastatic disease and who are expected to live 10 years after diagnosis; as a first-line or adjuvant therapy for many categories of men at intermediate risk, and for many groups of men with high-risk disease.
Many Types of EBRT
Most radiation options fall under the umbrella of EBRT, which is typically administered over a seven- to nine-week period, according to the ACS. Among EBRT therapies, intensity modulated radiation therapy (IMRT) is the most common and has been adopted extensively over the past 15 years. This approach uses a machine that moves around the patient, shaping the beams and aiming them from several angles. In this way, the dose of radiation can be adjusted, directing higher doses to the places where there are cancerous cells.Other high-tech options include three-dimensional conformal radiation therapy (3D-CRT), image-guided radiation therapy and intensity-modulated arc therapy. The shared element among these therapies is a careful mapping of the exact size, shape and location of the prostate gland and tumor using imaging tests, such as computed tomography and magnetic resonance imaging scans or X-rays. This information helps doctors determine precisely where to aim higher and lower doses of radiation for maximum effectiveness and minimum side effects. One recent comparative study showed that IMRT offers a disease-control advantage over 3D-CRT.
Stereotactic body radiation therapy (SBRT), which is often referred to by the names of the machines that administer the radiation, including CyberKnife, Gamma Knife and X-Knife, is a form of EBRT that delivers large doses of radiation to the prostate. Although the benefit of SBRT is that its entire treatment course is days and not several weeks, some studies have shown side effects to be worse with this form of therapy.
Another promising, yet controversial, form of EBRT is proton beam therapy, which aims protons (the heavy, positive parts of atoms) at tumors and releases their energy after traveling a specific distance, thereby causing less damage to tissues they pass through. Although research is inconclusive about whether proton therapy reduces sexual complications, one study did find that men aged 60 or younger treated with this modality experienced little sexual dysfunction; in comparison with the findings of other studies cited in the paper, the amount of dysfunction was comparable to that in populations treated with EBRT in general, but better than that in men treated with prostatectomy.
But other research has suggested limited advantages of proton therapy. A 2012 study comparing IMRT with proton therapy found that the newer therapy was no more effective in getting cancer in check. In addition, experts warn that proton beam therapy is not only more expensive than other forms of radiation (primarily due to costly machinery), but also might not be the best choice to treat prostate cancer because “critical structures, such as the rectum and urethra, will still get radiation no matter how perfect your particle is,” Yu explains.
LDR AND HDR Brachytherapy Round Out Options
Men with early stage, slow-growing tumors who would prefer fewer radiation treatments — or even just a single treatment — might be candidates for traditional brachytherapy, which places radioactive seeds directly, and permanently, into the prostate gland during a short surgical procedure. Radiation is then delivered slowly, for months, at a low-dose rate (LDR); eventually, the seeds lose their radioactivity.HDR brachytherapy, a newer approach, is administered through temporary catheters, in which a high-activity source is placed for just minutes to deliver HDR radiation.
[Photo by Liza Bishop, VCU Massey Cancer Center]
Contribution by Yaribeth Galvez club memberships white coat
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