User:Vdanquah/Management of prostate cancer

Radiation therapy[edit]

Radiation therapy, also known as radiotherapy, is often used to treat all stages of prostate cancer. Approximately half of all cancer patients utilize radiation therapy as a primary treatment when diagnosed with prostate cancer. It is also often used after surgery if the surgery was not successful at curing the cancer.^{[citation needed]} : Radiotherapy treats cancer cells in localized areas.Radiotherapy uses ionizing radiation to kill prostate cancer cells. When absorbed in tissue, ionizing radiation such as gamma and x-rays damage the DNA in cancer cells, which increases the probability of apoptosis (cell death). Normal cells are able to repair radiation damage, while cancer cells are not. Radiation therapy exploits this fact to treat cancer. Radiation therapy used in prostate cancer treatment include external beam radiation therapy and brachytherapy (specifically prostate brachytherapy).BT monotherapy is given at low-doses and is recommended as a treatment for favorable and unfavorable intermediate-risk prostate cancer.

External beam radiation therapy[edit]

External beam radiation therapy for prostate cancer is delivered by a linear accelerator, such as this one. External beam radiation therapy (EBRT) uses a linear accelerator to produce high-energy x-rays that are directed in a beam towards the prostate. A technique called Intensity Modulated Radiation Therapy (IMRT) may be used to adjust the radiation beam to conform with the shape of the tumor, allowing higher doses to be given to the prostate and seminal vesicles with less damage to the bladder and rectum. External beam radiation therapy is generally given over several weeks, with daily visits to a radiation therapy center. New types of radiation therapy such as IMRT have fewer side effects than traditional treatment. However, in the short term, EBRT has been associated with acute worsening of urinary obstructive and bowel symptoms. These symptoms have been shown to decline over time. Thirty-Six centers in the United States are now using proton therapy for prostate cancer, which uses protons rather than X-rays to kill the cancer cells. Researchers are also studying types of stereotactic body radiotherapy (SBRT) to treat prostate cancer^{[medical citation needed]}

Brachytherapy[edit]

Main article: Prostate brachytherapy

Permanent implant brachytherapy is a popular treatment choice for patients with low to intermediate risk features, can be performed on an outpatient basis, and is associated with good 10-year outcomes with relatively low morbidity. It involves the placement of about 100 small "seeds" containing radioactive material (such as iodine-125 or palladium-103) with a needle through the skin of the perineum directly into the tumor while under spinal or general anesthetic. These seeds emit lower-energy X-rays which are only able to travel a short distance. Although the seeds eventually become inert, they remain in the prostate permanently. The risk of exposure to others from men with implanted seeds is generally accepted to be insignificant. However, men are encouraged to talk to their doctors about any special temporary precautions around small children and pregnant women.

Uses[edit]

Radiation therapy is commonly used in prostate cancer treatment. It may be used instead of surgery or after surgery in early-stage prostate cancer (adjuvant radiotherapy). Radiation treatments also can be combined with hormonal therapy for intermediate risk disease, when surgery or radiation therapy alone is less likely to cure the cancer. Some radiation oncologists combine external beam radiation and brachytherapy for intermediate to high-risk situations. Radiation therapy is often used in conjunction with hormone therapy for high-risk patients.

For men over 64 with prostate cancer limited to the pelvis, using fewer, larger doses of radiation (hypofractionation) results in similar overall survival rates. The risk of dying from prostate cancer or having acute bladder side effects may be similar to that of longer radiation treatment. Others use a "triple modality" combination of external beam radiation therapy, brachytherapy, and hormonal therapy. In advanced stages of prostate cancer, radiation is used to treat painful bone metastases or reduce spinal cord compression.

Radiation therapy is also used after radical prostatectomy either for cancer recurrence or if multiple risk factors are found during surgery. Radiation therapy delivered immediately after surgery when risk factors are present (positive surgical margin, extracapsular extension, seminal vesicle involvement) has been demonstrated to reduce cancer recurrence, decrease distant metastasis, and increase overall survival in two separate randomized trials.

Side effects[edit]

Side effects of radiation therapy might occur after a few weeks into treatment. Pelvic toxicities that are common are issues with gastrointestinal (GI) and genitourinary (GU)

Both types of radiation therapy may cause diarrhea and mild rectal bleeding due to radiation proctitis, as well as potential urinary incontinence and impotence. Symptoms tend to improve over time except for erections which typically worsen as time progresses.^{[citation needed]}

A new method to reduce rectal radiation injury in prostate cancer patients involves the use of an absorbable spacer placed between the prostate and rectum. MRI showing hydrogel spacer pushing the rectum away from the prostate during radiotherapy. Such spacers are commercially available in some regions and are undergoing clinical trials in others. By temporarily altering the anatomy these products have the potential to allow for improved cancer targeting while minimizing risk to neighboring healthy tissues. Prostate rectum spacers should be compatible with all prostate cancer radiotherapy treatments including 3D conformal, IMRT and stereotactic radiation and brachytherapy.^{[citation needed]}