Prostate HDR Brachytherapy
There are two main types of brachytherapy that are used to treat prostate cancer: Low dosage rate (LDR) and high dosage rate (HDR). The former is used the most often in the treatment of prostate cancer and makes use of seed implantation; here we take a look at the use of HDR brachytherapy for prostate cancer.
There are two main ways in which prostate HDR brachytherapy may be given:
- HDR Monotherapy (usually used for localized, and early stage cancers, or upon recurrence of cancer).
- Combined HDR and EBRT.
In the first case the HDR brachytherapy is used as a standalone treatment for the condition, whereas in the second case it is combined with external beam radiation therapy (EBRT).
HDR Monotherapy for Prostate Cancer Treatment
This form of treatment is usually given to people in low risk groups in two distinct sessions, about one week apart. Research at the UCLA urology labs suggests that it is a safe and effective treatment and that there is a 95% tumor control rate. This form of HDR brachytherapy is used for the treatment of localized cancer and requires the following criteria to be met.
- PSA of less than 15
- Gleason score of 2 to 7 (3+4 max)
- Staging of T1c, T2a or small T2b
Combination of EBRT and HDR Brachytherapy
This is used for people who have a more advanced stage of the condition. The addition of EBRT allows for treatment in a less localized way and helps to destroy the disease in areas surrounded the prostate that may or may not have been detected. The treatment usually consists of two factions of HDR brachytherapy a week apart. This is followed by a one week EBRT prostate cancer course about a month later.
Prostate HDR Brachytherapy Procedure
Here follows a simplified version of the basic HDR procedure:
- A blood and pre-operation examination is taken the day before the planned implant of the HDR brachytherapy seeds.
- During the brachytherapy procedure the patient is given a spinal anesthesia.
- Flexiguide catheters are then placed around and through the prostate.
- Catheters are also placed in the bladder and rectum.
- A radiographic image is then taken to visualize the exact location of the catheters.
- Iridium-192 is then delivered to the prostate by use of an after loader via transfer tubes through the catheter.
- After approximately 10 minutes, the radiation source is removed from the patient.
- Following the procedure the patient is kept as an inpatient overnight; during this stay he is not allowed to sit upright during this time because the flexiguide catheters remain in place.
- The second HDR radiation treatment is given the following morning (following a fluoroscopy).
- A third treatment may be given in the case of HDR monotherapy.
- The catheters are removed.
- Upon successful urination the patient is allowed to return home.
- The HDR Brachytherapy Procedure is repeated a week later.
Side effects of HDR brachytherapy
Side effects from the procedure are usually transient and last from two weeks to about a month in most cases. HDR side effects include urinary retention, dysuria, changes in urination frequency, penile numbness, rectal irritation, and a tender perineal area. These side effects are usually treated by medication.