Radiation Therapy

Radiation therapy consists of using very high energy x-rays.  They are delivered by an external beam from a machine or actually implanted in the prostate to kill cancer cells. 

External Beam Radiation Therapy

This treatment can also be used to treat men whose prostate cancer tumors have advanced into the pelvis and can’t be removed with surgery if they have no indication of lymph node invasion.   Radiation therapy can also reduce tumors and relieve pain for men who have advanced disease.

External beam radiation therapy treatments are usually conducted 5 days a week for up to 6 or 7 weeks.  The treatments are painless with each session lasting just a few minutes.  Sometimes, if the tumor is extremely large, hormonal therapy may begin during the radiation therapy and can continue for several years.

Hormonal therapy prevents cancer cells from receiving the hormones that feed their growth.  In prostate cancer, male hormones are blocked with hormonal drugs or by surgically removing the testicles.

The prime target of the external beam radiation is the prostate gland itself as well as irradiating the seminal vesicles as they are a common area of cancer spread.  It was once believed that irradiating the lymph nodes in the pelvis was necessary, but the long term benefits have proven that this only applies to certain situations.

Since a radiation beam is passed through normal tissue to reach the prostate, there is the risk of killing healthy cells.   Diarrhea is a side affect when radiation is applied to the rectum but diarrhea, in addition to fatigue caused by the radiation, will usually disappear when treatment is completed.

One of the long term affects of radiation is proctitus.  This is an inflammation of the rectum, bleeding or bowel problems such as diarrhea and cystitis (which is an inflammation of the bladder).  This usually leads to problems with urination. 

Radiation therapy also results in impotency for 40 to 50% of men treated.

Some of these side effects may be minimized by using higher energy radiation beams that can be more precise in targeting the affected area.  Coupled with computer technology, treatments are tailored to exactly match the anatomy of the man being treated.  This type of state of the art equipment is not always readily available.

Internal Radiation Therapy

Internal Radiation Therapy is a procedure that delivers a very high dose of radiation to tissue in the immediately affected area and minimizes the damage to healthy tissue like the rectum and the bladder. 

This is accomplished by inserting dozens of tiny seeds that are radioactive directly into the prostate gland.  The therapy depends on ultrasound or CT that guides placement of very thin needles through the skin of the perineum.  The needles deliver the tiny seeds (made up of radioactive palladium or iodine) directly into the prostate using a pre-determined, customized pattern created by extremely sophisticated computer programming.  This high tech process allows the needles and seeds to directly conform to the size and shape of each prostate.

This procedure is normally completed in just an hour or two.  It is done under a local anesthesia and the patient goes home the same day.

Radiation is emitted from the seeds for up to several weeks.  Once insertion is complete, the seeds remain in place causing no harm whatsoever. 

Some physicians use a different approach.  They will use a more powerful radioactive seed and implement over several days.  These are temporary implants.  This procedure requires hospitalization and may be combined with low doses of external beam radiation.

Long term results are not yet in on this procedure primarily due to the fact that internal radiation therapy is still a recent process and is limited to just a few patients.  However, after 5 years more than 90% of patients treated still remain cancer free.

The procedure is not recommended for large, advanced tumors or for men who were previously treated with transurethral resection of the prostate (TURP) or Benign Prostatic Hyperplasia (BPH).  These men are at a higher risk for urinary problems.  When a man has small, well-differentiated tumors it is an option that has fewer side effects as well as being less invasive.  It is less costly than external radiation or surgery and requires a shorter hospital stay.

Discomfort experienced post-implant is usually controlled by oral painkillers and a man can expect a few weeks of incontinence.  Long term problems like prostatitis (inflammation of the prostate gland) are infrequent and usually not severe in nature.  Only 15% of men under the age of 70 experience sexual impotence and 30 to 35% of men over the age of 70.