What is High Dose Rate (HDR) Prostate Brachytherapy?
High Dose Rate Brachytherapy is a safe and effective temporary internal radiation treatment of localized cancer of the prostate that has advantages over the other major treatment choices for this disease.
High dose rate brachytherapy treats cancer from the inside out by using a sealed radioactive source inserted into hollow treatment catheters that have been placed in the prostate. Under controlled conditions a computerized robot positions the source with millimeter precision at multiple points throughout the array of implanted catheters to give a high dose to a limited volume. This significantly avoids normal, healthy tissues, delivering the treatment directly to the cancer site. After treatment, the catheters are removed. No radioactive material is left inside the patient.
The success rate is the same as surgery, external beam radiation and permanent seeds and there are fewer side effects. It is a form of radiation treatment from the inside out so less tissue is irradiated, there is no residual radioactivity to worry about, the anatomy remains intact and the treatment course is only a few days. (See HDR Method)
Less Rigorous than Surgery
It is far less physically demanding than robotic prostatectomy or standard radical prostatectomy since no incisions are made and there is no prolonged hospital stay or extended post surgical healing. The anatomy remains intact so there is far less risk of urinary incontinence or impotence.
More Precise and Less Time Consuming than External Beam Radiation
External beam radiation requires elaborate treatment setup and treatment every day five days a week for eight to nine weeks. It is very challenging to get the human body into the exact same position day after day let alone account for slight changes in prostate position due to fullness of the bladder, gas in the rectum, breathing, etc. High dose rate brachytherapy is delivered through a matrix of treatment catheters implanted in the prostate so concerns about day to day targeting accuracy is not problematic. The matrix goes wherever the prostate goes so accuracy is addressed by the nature of the treatment method. The total treatment time is eight days compared to eight to nine weeks with external beam radiation. Most important it has a lower side effect profile than external beam which directs a beam of radiation through the entire thickness of the pelvis to a target the size of a walnut. (see Advantages of HDR)
More Refined than Permanent Seed Implant
Permanent seed implant is an older form of brachytherapy where multiple seeds are manually inserted into deformable soft tissue, either as free seeds or in strands according to provisional preplan or real time calculations during the implant. The problem is that if the final locations of the sources are different than planned they cannot be changed. Permanent seed sources are all of uniform strength so it is much more difficult to avoid “hot” or “cold” spots within the target. With permanent seeds the patient is radioactive for a period of time while the implanted seeds decay down to a safe level. During that time the patient must stay away from his partner and not have children on his lap. Permanent seeds can migrate out of position over time. In contrast High dose rate brachytherapy is delivered through a stable matrix of catheters with an unlimited choice of treatment points so the dose is more precise and can cover the prostate plus a margin around the target. The catheters are removed after treatment so the patient is not radioactive. There is no need for radiation precautions. Finally there are no seeds left in the patient so there is no worry about seed migration. (see Advantages of HDR)