Brachytherapy
Radiation therapy typically is delivered as high-energy beams that are aimed directly at a patient’s tumor. This is known as external beam radiation.
Brachytherapy is different. It delivers radiation therapy with small pieces of radioactive material (usually about the size of a grain of rice) that are placed inside the patient’s body as close to the tumor as possible. This allows doctors to deliver very high doses of radiation directly to the patient’s tumor while limiting radiation exposure to healthy tissue.
Brachytherapy is used to treat several different diseases, including breast cancer, gynecologic cancers and prostate cancer.
Accelerated Partial Breast Irradiation
Accelerated partial breast irradiation, or APBI, uses radioactive seeds to kill breast cancer cells that may remain after lumpectomy surgery. APBI delivers a powerful dose of radiation while greatly reducing treatment time.
APBI is performed about one to four weeks after a lumpectomy. A specialized catheter is inserted into the cavity left behind after the tumor is removed. The device remains in place during the course of APBI treatment, usually about five to seven days.
During treatment, the seed, about the size of a grain of rice, is inserted into the catheter. It stays within the device in various positions for five to 10 minutes. It is withdrawn and then re-inserted six hours later, for a total of two treatments per day.
APBI is best for women who are over 50 years old. Their tumors should
- have clear margins
- measure three centimeters or less
- show no sign of the disease spreading to nearby lymph nodes
When compared with standard radiation treatment, APBI offers significant benefits. At less than a week, the treatment is far shorter than external beam radiation, which usually lasts four to six weeks. In addition, the radiation dose is concentrated on tissue surrounding the lumpectomy cavity. This spares normal tissue and critical organs such as the heart and lungs from unnecessary radiation.
Women with early stage breast
cancer have so many different treatment
options that the choices can be overwhelming. For almost all women
who choose to keep their breast (and avoid mastectomy), radiation
therapy is almost always a part of the treatment plan.
The radiation regimen for which we have the longest follow-up
data involves treating the whole breast, every day for five weeks,
typically with an additional one-week "boost" to the area
where the tumor used to be.
For women who want the most
conservative modality of radiation treatment, I recommend this longer
course of treatment.
The question has become, as
technology has improved, can we be more focal and efficient in how we
deliver radiation therapy. Accelerated
partial breast irradiation (APBI) lets me deliver relatively
higher doses of radiation to the area where the tumor used to be,
twice a day for five days.
This technique is still
actively being compared to the traditional longer course of whole
breast radiation. What we do have is follow-up data from multiple
institutions in the United States and Europe that have shown very high
rates of tumor control in appropriately selected patients, with 5-12
years of follow-up.
Who qualifies?
I use very strict criteria before offering APBI to patients and
encourage all of my patients to be treated on protocol. The patients I
treat with APBI have very early stage, small breast cancer that has
been completely removed by their surgeon. I also evaluate each of my
patients with a CT scan after surgery.
This lets me measure the exact dimensions of the area removed by the
breast surgeon and to calculate if the patient can be suitably treated
by one of the modalities we have available to deliver APBI.
How to receive APBI
At MD Anderson, we offer two main ways to deliver APBI to
patients, one that's internal and one that's external.
Brachytherapy is a way to deliver very focused
radiation inside the body in exactly the area where the tumor used to
be. This technique takes advantage of the joint expertise of the
breast surgeon and the radiation oncologist, and I enjoy being able to
collaborate closely with my colleagues in breast surgery on these
cases.
The surgeon places a catheter into the breast
using local anesthesia in an outpatient setting. I then work with a
medical physicist to design a treatment that is uniquely tailored to
the anatomy of the patient. I'm present at each treatment my patients
receive using a high-dose radioactive source that sits temporarily in
the catheters.
Some patients tell me they prefer to not
have a catheter placed inside the breast, in which case I offer APBI
using external techniques including either protons or photons. These
techniques use more than one beam of radiation to deliver focused
treatment to the area surrounding where the tumor used to be.
My patients with early stage breast cancer have a lot of
treatment options. I hope that in the conversations we have together
that my patients can choose the treatment that fits them best.
Brachytherapy for gynecologic cancers
Brachytherapy is a common treatment for many gynecologic cancers, including cervical, uterine and vaginal cancers. It is standard for cervical cancer patients to receive brachytherapy after external beam radiation. Uterine cancer patients who can’t undergo surgery also get brachytherapy, and some patients with endometrial cancer will receive brachytherapy after surgery.
For patients who haven’t had surgery, gynecologic brachytherapy starts with the patient being put under general anesthesia. A radiation oncologist precisely places an applicator inside the patient’s vagina or uterus (depending on the type of cancer), as close to the tumor as possible. Advanced imaging technologies (such as MRI, ultrasound and CT Scans) help ensure the applicator is positioned to deliver the most effective dose of radiation, as well as determine the dose itself.
The applicator is then attached to a machine that holds a small radioactive pellet. The pellet is sent into the applicator for a short amount of time, where it irradiates the tumor before being pulled back into the machine.
Depending on the patient’s specific condition, doctors will recommend one of two approaches to this treatment. Pulsed-dose rate (PDR) brachytherapy is a two-day inpatient procedure that sends the radioactive pellet into the applicator for 15 minutes every hour. PDR patients undergo this process two times about two weeks apart.
High-dose rate brachytherapy uses a pellet with more active radiation. It is sent into the applicator just one time for 10 minutes. Patients undergo this procedure as an outpatient five times over two to three weeks. Your radiation oncologist can discuss the best approach for your treatment.
Brachytherapy is also used to treat endometrial cancer following a hysterectomy in order to eliminate any cancer cells that may remain after surgery. This is a simpler procedure where a small dome is placed into the vagina while the patient is awake. A radioactive source runs into this dome to deliver high-dose brachytherapy.
Though doctors do their best to prevent radiation from impacting healthy tissue, brachytherapy for gynecologic cancers can have some short term side effects, including soreness where the applicator was placed or a small amount of bleeding. In the long term, radiation can cause diarrhea and blood in urine or stool. If these symptoms develop and don’t resolve with medications, your oncologist may refer you to a gastroenterologist or urologist to diagnose or treat the problem.
Brachytherapy for prostate cancer
Brachytherapy is a common treatment for prostate cancer. In prostate brachytherapy procedures, several radioactive “seeds” are inserted into the prostate in order to match the exact shape and size of that organ. This ensures that the entire prostate gets the right amount of radiation. The seeds then remain in the patient, providing a long-term dose of radiation.
Brachytherapy has been used as a primary treatment for low- and intermediate-risk prostate cancer for several years. To qualify for this treatment, a patient’s cancer cannot have spread significantly outside the prostate. Doctors will also perform a physical exam, imaging exams, and evaluate current urinary symptoms to determine if this is the best treatment for the patient.
In addition, recent studies show brachytherapy is effective as an end-of-treatment “boost” for patients with high-risk diseases. This boost follows external beam radiation therapy and decreases the risk of the disease progressing.
After treatment, patients may experience temporary urinary side effects. These include burning, frequent urination, urgent urination and a weak stream. They are managed with medication and typically go away a few months after treatment.
Did You Know
For many years, brachytherapy
has been used to treat low-risk, intermediate-risk, and high-risk prostate cancer. But more recently, doctors
have been using a more advanced form of brachytherapy called MRI-assisted radiosurgery
(MARS), which enables them to deliver the radiation directly to the
tumor while protecting the healthy tissues nearby.
We discussed the benefits of MRI-Assisted Radiosurgery used with brachytherapy treatment with Steven Frank, M.D., who developed the Food and Drug Administration-approved positive-contrast MRI marker technology at MD Anderson for prostate cancer treatment.
What is brachytherapy?
Brachytherapy is a type of internal radiation therapy where tiny radioactive seeds are implanted in the body to destroy cancer cells. These seeds are about the size of a grain of rice.
When treating prostate cancer with brachytherapy, the implant is placed directly in the prostate as close to the tumor as possible. This allows us to deliver high doses of radiation directly to the tumor while limiting radiation exposure to healthy tissue.
What is MRI-assisted radiosurgery (MARS)?
MARS is currently the most advanced form of brachytherapy. This modern technique, used for treating prostate cancer, provides more precise delivery of radiation and fewer radiation-related side effects.
MRI-assisted radiosurgery destroys the tumor within the prostate. Radiosurgery is a very precise form of therapeutic radiation therapy where the prostate is not removed.
Before MARS was developed, brachytherapy was done using CT scans and ultrasounds for imaging. However, because the implanted radioactive seeds are difficult to view with conventional imaging, it’s harder to ensure precise placement of the seed, which can influence the effectiveness of the therapy.
So, in 2009, a permanent implantable positive-contrast MRI marker was created for use in prostate brachytherapy to improve quality assurance of the treatment. This marker enabled the use of MRI in treatment planning, delivery, and post-implant assessment and the development of MRI-assisted radiosurgery, also known as MARS.
Now, with the use of MRI to assist in placing seeds in prostate cancer patients, our experts can better visualize the tumor during treatment so we can avoid radiation to surrounding healthy tissues near the prostate.
What is the difference between low-dose and high-dose rate brachytherapy?
Depending on the complexity of the tumor, brachytherapy treatment uses either:
- low-dose rate radioactive seeds, which are implanted permanently, or
- high-dose rate radioactive seeds, which are temporary.
Both are done as outpatient procedures, with little downtime for patients.
How does MARS work?
MRI is used at every step of the quality assurance process from diagnosis, treatment simulation, contouring, treatment planning, treatment delivery, and assessment afterward. MRI markers allow physicians to accurately locate the implanted seeds within the prostate. This helps make the delivery of the internal radiation treatment very precise.
Which cancer patients are most likely to benefit from MARS brachytherapy?
MARS brachytherapy has been used to treat low-risk, intermediate-risk, and high-risk localized prostate cancer for several years. Doctors will perform a physical exam and imaging exam to evaluate current urinary symptoms and determine if this is the best treatment approach for each patient.
What does the treatment regimen look like for patients who receive MARS?
Patients with early-stage disease are treated with MARS brachytherapy alone to deliver precisely targeted radiation to the tumor. For patients with more advanced-stage disease, the MARS implant takes place after the patient completes four weeks of external beam radiation treatment with either proton therapy or intensity-modulated radiation therapy in combination with hormone therapy. This is done to increase the radiation dose to the tumor, with the goal of reducing the risk of the disease progressing.
What are the benefits of MARS?
By using MRI at each step of the MARS treatment process, our experts can better see the tumor and the surrounding organs to ensure very accurate placement of the seeds. This will help to optimize cure while minimizing both acute and long-term side effects after treatment. Without MARS, the external urethral sphincter cannot be seen with standard CT or ultrasound imaging.
What are the side effects associated with MARS?
Side effects from MARS are minimal. Most patients return to normal activities the day after the procedure. After treatment, patients can return to normal sexual activity. Incontinence is rare, but some patients may experience temporary urinary side effects. These include burning, frequent or urgent need to urinate. These side effects can be managed with medication and typically resolve a few months after treatment.
Disclosure: Steven Frank, M.D., and MD Anderson Cancer
Center licensed IP related to MARS to C4 Imaging, LLC, and
Dr. Frank holds equity in the company and currently serves as the
Chairman of their board of directors.
Request an appointment at MD Anderson online or by calling 1-877-632-6789.
For many years, brachytherapy has been used to treat low-risk, intermediate-risk and high-risk prostate cancer. But more recently, doctors have been using a more advanced form of brachytherapy called MRI-assisted radiosurgery (MARS), which enables them to deliver the radiation directly to the tumor while protecting the healthy tissues nearby.
We discussed the benefits of MRI-Assisted Radiosurgery used with brachytherapy treatment with Steven Frank, M.D. , who developed the FDA-approved positive contrast MRI marker technology at MD Anderson for prostate cancer treatment .
What is brachytherapy?
Brachytherapy is a type of internal radiation therapy where tiny radioactive seeds are implanted in the body to destroy cancer cells. These seeds are about the size of a grain of rice.
When using brachytherapy to treat prostate cancer , the implant is placed directly into the prostate as close to the tumor as possible. This allows us to deliver high doses of radiation directly to the patient’s tumor while limiting radiation exposure to healthy tissue.
What is MRI-assisted radiosurgery (MARS)?
MARS is the most advanced form of brachytherapy. This modern technique used for treating prostate cancer, provides a more precise delivery of radiation and a reduction of radiation-related side-effects.
MRI-assisted radiosurgery is an ablation of the prostate. Radiosurgery is a very precise form of therapeutic radiology where the prostate is not removed.
Before MARS was developed, brachytherapy was done using CT scans and ultrasounds. However, because the implanted radioactive seeds are difficult to view through conventional imaging, it’s harder to ensure precise placement of the seed which can impact the therapy’s effectiveness.
So, in 2009, a permanent implantable positive contrast MRI marker was created for use in prostate brachytherapy to improve quality assurance of the treatment. This enabled the use of MRI in treatment planning, delivery, and post-implant assessment and the development of MRI-assisted radiosurgery, also known as MARS.
Now with the use of MRI to assist in the seed placement in prostate cancer patients, our experts have better visualization of the tumor during treatment so we can avoid surrounding healthy tissues near the prostate.
What is the difference between low-dose and high-dose rate brachytherapy?
Depending on the complexity of the tumor, brachytherapy treatment uses either a low-dose or high-dose rate radioactive seed. Both are done as outpatient procedures so that little downtime is required for patients.
In low-dose rate brachytherapy, the seed is implanted permanently into a patient’s body. After implant, patients are treated with a low dose of radiation for hours at a time. This is now a standard option for the curative treatment of prostate cancer.
With high-dose rate brachytherapy, the seed is implanted into the prostate temporarily. The patient is then treated with a higher dose of radiation delivered to the tumor in a short burst. This lasts only a few minutes and may be repeated several times over one or more weeks.
How does MARS work?
MRI markers allow physicians to accurately locate the implanted seeds within the prostate. This helps make the delivery of the internal radiation treatment very precise. A radioactive source is then placed inside the applicator and irradiates the immediate area of the cancer before being removed.
Which cancer patients are most likely to benefit from MARS brachytherapy?
Brachytherapy has been used to treat low-risk, intermediate-risk and high-risk prostate cancer for several years. For a patient to qualify for this treatment, the cancer cannot have spread significantly outside the prostate. Doctors will perform a physical exam and imaging exam to evaluate current urinary symptoms and determine if this is the best treatment approach for the patient.
What does the treatment regimen look like for patients who receive MARS?
Patients with low-risk and intermediate-risk disease are treated with MARS brachytherapy alone, while patients with advanced-stage disease receive external beam radiation therapy such as proton therapy for four weeks. Then, two weeks after they’ve completed external radiation, patients receive a radioactive seed implant through MRI-assisted radiosurgery.
The MARS implant is given after the patient completes external beam radiation treatment. This is done to increase the radiation dose to the tumor. This also decreases the risk of the disease progressing. When patients are not candidates for proton therapy or have a more advanced disease, MARS can be used as a precise targeted radiation to the tumor.
What are the benefits of MARS?
MARS ensures the precise placement of the radioactive seed during the procedure. By using MRI during the treatment process, our experts can better see the surrounding organs to provide very accurate placement of the seed. This also minimizes side effects for treatment of both early and advanced stage prostate cancer. Without MARS, the urethra is not visible using a CT scan or ultrasound.
What are the side effects associated with MARS?
Side effects from MARS are minimal and most patients return to normal activities the day after the procedure. After treatment, patients can return to normal sexual activity. Incontinence is rare, but some patients may experience temporary urinary side effects. These include burning, frequent or urgent need of urination. These side effects can be managed with medication and typically resolve a few months after treatment.
Disclosure: Steven Frank, M.D., and MD Anderson Cancer Center licensed IP related to MARS to C4 Imaging, LLC, and Dr. Frank holds equity in the company and currently serves as the Chairman of their board of directors.
Request an appointment at MD Anderson online or by calling 1-877-632-6789.