Brachytherapy is a form of internal radiation therapy used to treat prostate cancer. The treatment involves placing radioactive sources directly into the prostate gland. This approach allows a high dose of radiation to target cancer cells while minimizing damage to nearby healthy tissues, such as the bladder and rectum.
There are two primary forms of brachytherapy for prostate cancer. Low-Dose-Rate (LDR) brachytherapy involves the permanent implantation of small radioactive “seeds,” each about the size of a grain of rice, into the prostate, which release a low dose of radiation over several months. High-Dose-Rate (HDR) brachytherapy is a temporary treatment where a high-activity radiation source is placed into the prostate for several minutes at a time and then removed.
Understanding Brachytherapy Success Metrics
One of the most common metrics is biochemical recurrence-free survival (bRFS). This is tracked by monitoring the level of Prostate-Specific Antigen (PSA), a protein produced by the prostate, in the blood after treatment has concluded. A sustained rise in PSA levels can indicate that the cancer may be returning.
Another important measure is cancer-specific survival, which refers to the percentage of patients who have not died from prostate cancer after a specific period following treatment. This metric focuses directly on deaths caused by the prostate cancer itself, excluding deaths from other causes. It provides a clear picture of the treatment’s ability to control the disease in the long term.
Finally, overall survival is a metric that tracks the percentage of patients who are still alive for a given period after treatment, regardless of their cause of death. This measure gives a broader view of the treatment’s impact on a patient’s lifespan.
Brachytherapy Efficacy Rates
The success of brachytherapy is well-documented, with outcomes often categorized by the patient’s initial risk group. For men with low-risk localized prostate cancer, brachytherapy used as a single treatment (monotherapy) demonstrates high efficacy. Studies show that 10-year biochemical recurrence-free survival rates for these patients are frequently reported to be between 90% and 95%.
For patients in the intermediate-risk category, brachytherapy also yields strong results. When used as a monotherapy, 10-year biochemical recurrence-free survival rates are typically in the range of 80% to 85%.
In cases of high-risk or more advanced prostate cancer, brachytherapy is often used as part of a combination therapy approach. It may be paired with external beam radiation therapy (EBRT) and sometimes androgen deprivation therapy (ADT). This combined approach has been shown to improve outcomes, with 5-year bRFS rates for high-risk patients often exceeding 80%.
Factors Influencing Treatment Outcomes
Several factors related to the cancer’s characteristics are considered to determine if a patient is a good candidate for this treatment. These include the tumor stage (T-stage), the pre-treatment PSA level, and the Gleason score, which grades the aggressiveness of the cancer cells.
Brachytherapy is most effective for men whose cancer is confined to the prostate gland, known as localized prostate cancer. Patients with a lower tumor stage, a PSA level generally below 10 ng/mL, and a Gleason score of 6 or 7 are considered ideal candidates.
The physical characteristics of the prostate gland itself also play a role. The size and shape of the prostate can affect the ability to place the radioactive seeds accurately. A very large prostate or one with a shape that makes even dose distribution difficult might make a patient a less suitable candidate for this specific procedure.
Side Effects and Post-Treatment Quality of Life
A patient’s experience of success with brachytherapy also involves their quality of life after the procedure. The treatment can lead to side effects, although many are manageable and may resolve over time.
Urinary issues are among the most common short-term side effects. Patients may experience increased urinary frequency, urgency, or a weaker stream. Some may also experience temporary incontinence. These symptoms often improve within several months to a year following the procedure as the initial inflammation from the radiation subsides.
Bowel problems can also occur, such as rectal irritation, diarrhea, or, less commonly, rectal bleeding. These side effects are typically mild and temporary.
Sexual dysfunction, including erectile dysfunction (ED), is another potential long-term side effect. The likelihood of experiencing ED depends on a patient’s age and sexual function before treatment.
Brachytherapy Compared to Other Prostate Cancer Treatments
Radical prostatectomy is the surgical removal of the prostate gland. For appropriate candidates, its long-term cancer control rates are comparable to those of brachytherapy. The side effect profiles differ, with surgery carrying a higher initial risk of urinary incontinence.
External beam radiation therapy directs radiation at the prostate from outside the body over a series of sessions. The side effect profiles can vary; for instance, EBRT may have a slightly different impact on surrounding tissues compared to the highly targeted nature of brachytherapy.
The choice between these treatments often depends on individual patient factors and preferences. Brachytherapy offers the convenience of a shorter treatment course, particularly LDR brachytherapy, which is a single procedure. This can be a significant advantage for some patients when weighing their options against the daily sessions required for EBRT or the recovery time associated with surgery.