Killing prostate cancer cells using radiation energy forms an important modality of prostate cancer treatment. Radiation therapy for prostate cancer is either curative (to cure the disease) or palliative ( to control the disease)
If someone’s prostate cancer is localized that is confined into the prostate and low grade (slow growing and not aggressive) then radiotherapy (RT) to prostate gives a cure identical to that of radical prostatectomy (surgery)
RT along with hormone therapy (HT) to prostate cancer which has grown into its nearby tissues gives a longer life to the patient.
If cancer recurs into the prostate area after radical prostatectomy (RP) or following RP if margin comes +ve, then RT helps to control the disease.
Some times if a bone metastasis in a particular area causes significant bone pain, then local RT to that particular area helps control pain.
In extensive painful bone metastasis some times medicine containing radiation is injected into the vein to relieve bone pain.
There are two types of radiation delivery techniques
- External beam radiation (EBRT)
- Internal radiation (Brachytherapy)
External beam radiation (EBRT)
Radiation energy is delivered into the prostate using machine from outside the body. Usually given over 5 days a week for few weeks. Procedure is painless and carried out as an out patient procedure. As radiation therapy damages surrounding tissues thus causing many side effects continuous research or modification in techniques have emerged where radiation beams or rays are shaped and aimed at the prostate from several directions thus delivering more energy to the cancer area and significantly reducing the dose to the surrounding tissues. There is called 3D CRT or THREE DIMENSIONAL CON FORMAL RT. They are known as IMRT, SBRT ( Gamma knife, cyber knife). Advantages of gamma knife is that treatment is over within days, where as in IMRT treatment takes weeks.
Internal radiation (Brachytherapy)
Here radiation seeds are implanted into the cancerous prostate using special technique. This is generally done in men with early stage slowly growing cancer. These are again 2 types :
1. Permanent low dose (LDR) therapy
2. Temporary high dose (HDR) therapy
In LDR seeds are left in the prostate and they scatter low dose radiation over a period of time and the seeds remain life long. In HDR seeds deliver high energy radiation and seeds are removed after a few days.
Brachythearpy side effects are less and repeated visits to the hospital not required. Not suitable for all patients (especially after prostate surgery like TUR’P’ and patients with irritative bladder symptoms)
Possible side effects of EBRT (external beam radiation)
Main side effects involve rectum and urinary bladder as surrounding tissues also get radiated.
Bowel problems: radiation proctitis causes diarrhea, blood in the stool. If cancer has already reached the wall of the rectum then rectal leakage may happen. Most of the symptoms go away with passage of time but may remain for life.
Urinary problems: Radiation cystitis causes increased frequency of urine, urgency & urinary leakage, blood in urine. Again symptoms get better with time but may remain. In addition narrowing of the urine pipe or urethra may occur (stricture urethra).
Other side effects: Fatigue, lack of appetite, local skin reactions usually happens. Over a period of time erectile dysfunction or impotence may develop.