Precise Radiation for Breast Cancer
Breast cancer is the most common cancer in women in the United States. Treating it typically requires surgery, followed by radiation therapy to destroy any remaining cancer cells.
A physician’s ability to confidently detect lesions, determine the best course of treatment and prevent recurrence comes from the quality of information she has. Positron Emission Mammography (PEM), the next generation of PET scans specifically designed for small areas such as the breast, allows enhanced visualization of the affected area—greatly enhancing diagnosis, staging, treatment planning and treatment monitoring.
When it comes to treatment, older radiation delivery methods can expose nearby, healthy tissue to damage. Cutting-edge therapies such as High Dose Rate (HDR) brachytherapy, Intensity Modulated Radiation Therapy (IMRT) and Image-Guided Radiation Therapy (IGRT) enable physicians to deliver higher doses of precisely focused radiation to cancerous tumors while sparing nearby healthy tissue. This is particularly significant for left-breast cancer, where the heart and lungs are at risk.
Women who elect Breast Conservation Therapy (BCT) receive an additional dose of localized radiation in efforts to eliminate pre-cancerous cells in the surrounding tissue and prevent the cancer from returning. Newer technology such as AccuBoost® provides this “boost dose” with greater accuracy and precision than older methods of electron boost radiation.
What Is Breast Cancer?
Breast cancer is an uncontrolled growth of breast cells that leads to the formation of a tumor. Some breast tumors are benign (non-cancerous) and do not cause harm. They grow slowly and do not spread to other areas of the body. Malignant breast tumors are cancerous; left unchecked cancer cells can make their way into the underarm lymph nodes, which provides a pathway for them to spread to other areas of the body.
Each breast has 15-20 sections, called “lobes,” connected by thin tubes called “ducts.” Breast cancers include:
- Ductal carcinoma, which begins in the ducts and is the most common type.
- Lobular carcinoma, which begins in the lobes and is found in both breasts more often than other types of breast cancer.
- Inflammatory breast cancer, which is rare.
- Recurrent breast cancer, which is cancer that has returned. It can occur in remaining breast tissue, but also in other sites such as the lungs, liver, bones or brain. Even if tumors are in a new location, it is still called breast cancer.
Who Gets Breast Cancer?
According the American Cancer Society, breast cancer affects approximately 13% (1 in 8) of American women. Death rates have been declining since 1990; thanks to increased awareness, earlier detection and advances in treatment, only one in 35 are likely to die from the disease. Today, there are approximately 2.5 million breast cancer survivors across the country.
The most significant risk factors for breast cancer are gender and age. Women are 100 times more likely to develop breast cancer than men, and two of three women diagnosed are over age 55. Other risk factors include:
- Heredity – a woman’s risk doubles if a first-degree relative (mother, sister, daughter) has had the disease.
- Race – white women are more likely to develop breast cancer than African American women, but less likely to die from it. Women of other ethnic backgrounds are less likely to develop or die from the disease than white women or African American women.
- Varied factors such as dense breast tissue, early menstruation, prior chest radiation, prior breast cancer (recurrence), significant weight gain after menopause and treatment with—or exposure to—the drug DES.
- Some studies show that certain lifestyle factors—no children or children later in life, recent use of birth control pills, post-menopausal hormone therapy, not breast feeding, alcohol use, overweight or obese, lack of exercise—can increase the chance of developing breast cancer.
How Do I Know If I Have Breast Cancer?
The size of the breast cancer tumor and how far it has spread are the best indicators for survival. Therefore, early detection is important. Because breast tumors are often painless, the American Cancer Society (ACS) recommends the following for women without symptoms:
- breast self-exams beginning in their 20s.
- clinical breast exam at least every three years for women in their 20s and 30s .and annually for women over 40.
- annual mammogram for women over age 40.
If breast cancer does cause symptoms, they can include:
- skin irritation or dimpling.
- breast pain.
- nipple pain or the nipple turning inward.
- redness, scaliness, discoloration or thickening of the nipple or breast skin.
- nipple discharge other than breast milk.
- a lump in the underarm area.
- swelling, redness and warmth, which may indicate inflammatory breast cancer.
There are several tests physicians can use to further the diagnostic process and look for breast cancer. These include diagnostic mammogram, MRI, breast ultrasound or ductogram, which is a special X-ray that is helpful in determining the cause of nipple discharge.
As with other cancers, the only way to know for sure is with a biopsy—a procedure in which a sample of the tumor is sent to the lab to be examined under a microscope. With a needle biopsy, a needle is used to remove a small amount of fluid and tissue from the suspect area.
Lymph nodes are olive-shaped glands that can carry cancer from one part of the body to another. The first node to which cancer spreads is called the “sentinel node.” In breast cancer, the sentinel node is usually one that is under the arm. Removing the sentinel node during a biopsy can provide physicians with better information for diagnosing and treatment planning, and can potentially reduce the amount of surgery needed.
What Are My Treatment Options?
Physicians use the results of the diagnostic tests to determine the site of the cancer and to stage it—or tell how far it has spread. This helps determine the outlook for recovery and the best course of treatment. New technologies such as Positron Emission Mammography (PEM), offered by Century Cancer Centers, can greatly enhance diagnosis, staging and treatment planning as well as more effectively monitor treatment and for recurrence of disease.
While breast cancer is often treatable, it can be life threatening. Therefore, patients should work together with their physician to choose among several treatment options that may be used alone or in combination, and understand the risks and benefits of each.
Surgery is the most common form of treatment for breast cancer. It is often followed by radiation and sometimes chemotherapy and/or hormone therapy.
Breast Conserving Surgery There are two types of surgery aimed at sparing the breast:
- Lumpectomy – also called an “excisional biopsy,” a lumpectomy removes the lump as well as some of the healthy tissue around it to check for any remaining cancer cells.
- Partial Mastectomy – this surgery is more extensive and removes the area of the breast containing cancer, some of the tissue around it, the lining of the chest wall underneath the tumor and any affected lymph nodes.
Mastectomy With a mastectomy, one or both of the breasts are removed in their entirety, along with any affected lymph nodes. In 80% of cases, breast reconstruction or implant surgery is performed at the same time.
The female hormones, estrogen, progesterone and estrodial can promote the growth of breast cancer tumors. Hormone therapy uses drugs such as tamoxifen, fulvestrant and aromatase inhibitors, given orally or via IV, to counter the effects of these hormones or stop the body from producing them. They can be used as an adjunct to other therapies and also to reduce the threat of cancer for women at high risk. Another form of hormone therapy is removing the ovaries of a woman who has not reached menopause. Side effects of hormone therapy include fatigue, nausea, hot flashes, vaginal discharge, and mood swings.
Chemotherapy (also called “chemo”) employs oral or injected drugs to kill cancer cells. These drugs enter the bloodstream and travel throughout the body, making the treatment useful for cancers that have spread to distant organs. For breast cancer, chemo is most often used before surgery to shrink large tumors so that a lumpectomy can be performed instead of a mastectomy. It is also often used after surgery to kill any remaining cancer cells and lower the risk of recurrence. It is the primary treatment for breast cancers that have spread (metastasized).
Because chemo kills some normal cells in addition to malignant ones, it can cause side effects that vary depending on the type of drug used. These include, but are not limited to, fatigue, nausea, vomiting, loss of appetite, hair loss, mouth sores, changes in menstrual cycle and infertility. It can also cause low white blood cell and platelet counts resulting in higher risk of infection and easy bruising/bleeding.
This treatment uses natural or synthetic drugs to help the body’s own immune system fight the cancer. Biological therapy is sometimes called biological response modifier (BRM) therapy or immunotherapy.
Radiation that kills or shrinks tumors may be used alone or in combination with other treatments. For breast cancer, radiation is often used to shrink tumors prior to surgery or to kill any cancer cells that remain in the breast, chest wall or underarm afterwards. It can also be used to treat tumors in difficult locations. Radiation therapy can be delivered internally or externally. Side effects are usually limited to irritation around the radiation site, although many patients also report fatigue.
Brachytherapy With brachytherapy, low-dose radioactive seeds (pellets) are placed into the breast tissue, next to the cancer. The seeds give off small amounts of radiation over several weeks. This radiation method carries small risks associated with seed migration within the body.
Like traditional brachytherapy, HDR brachytherapy delivers radiation from within the body to destroy cancer cells. Unlike traditional brachytherapy, HDR brachytherapy uses a higher dose of radioactive material that is delivered directly to the tumor during a series of outpatient treatments. The precision of this method more effectively destroys tumors with less damage to surrounding tissue, such as the lungs and opposite breast. Because of the high dose of internal radiation, treatment can typically be completed in just 1 week. While its short duration makes HDR brachytherapy an appealing option for all breast cancer patients, this treatment is most appropriate for those with small to medium-sized cancers and little involvement of the lymph nodes.
While traditional external beam radiation therapy is typically not the best option for breast cancer, IMRG/IGRT can be very effective. These methods deliver higher radiation doses more precisely to cancerous tumors while avoiding healthy tissue. With IMRT/IGRT, physicians can more effectively treat breast cancer while reducing the chance of side effects caused by damage to surrounding tissue, such as the unaffected breast and other organs. IMRT/IGRT can also potentially shorten the duration of therapy and enable physicians to treat some breast cancers for which traditional radiation therapy was not an option.
Your Breast Cancer Treatment Partner
At Rainier Cancer Center, we offer patients a variety of treatment options, including cutting-edge therapies such as HDR brachytherapy and IMRT/IGRT that may not be widely available in other treatment centers. Regardless of the treatment path, we pride ourselves on providing each patient with the best outpatient experience in the most comfortable atmosphere. Treating breast cancer can be a complicated process, so our personal Cancer Navigators help guide each patient through their journey.
Rainier Cancer Centers Breast Cancer Treatments Services
For years, positron emission tomography (PET) scans have helped doctors accurately diagnose and treat cancer. The Naviscan™ positron emission mammography (PEM) scanner used by Rainier Cancer Center facilities is a special form of PET designed for imaging breasts and other small body parts. It is the only high-resolution PET scanner specifically designed to provide metabolic visualization of abnormal breast tissue and can see tumors as small as 2mm—about the size of a grain of rice.
When compared to other diagnostic tools, such as MRI, PEM technology can provide a much more accurate picture of abnormal tissue. It better differentiates between benign and cancerous lesions, reducing false positives and preventing unnecessary biopsies or surgeries. It also better differentiates between scar tissue (from surgery) and tumor, to better monitor for recurrence. Because of the gentle immobilization of the breast during the procedure, PEM can prevent issues with body motion that can skew results. It is also an excellent imaging tool for women who are unable to tolerate an MRI or those who have pacemakers or other implanted devices that preclude an MRI.
Overall, PEM is a better tool for:
- earlier detection
- guided biopsy – to determine the type of cancer
- pre-treatment planning and staging
- monitoring response to therapy
- monitoring for recurrence of disease
How PEM Works
- PEM is a nuclear imaging technology that uses radioactive material to visualize body tissues.
- Because cancer cells accumulate sugar faster than healthy tissue, a sugar-based radioactive substance is injected into the body; physicians can see this accumulation and use it to gather information about a suspicious mass.
- PEM captures a “snapshot” of the cellular activity occurring within a mass or cancerous tissue, so not only does it reveal the size, shape and location of a suspicious lesion, it is over 90%* accurate in determining if the lesion is cancerous or not based on its bioactive properties.
- Repeat scans performed during a course of therapy can help determine change in tumor size or property to gauge the results of treatment.
- Repeat scans performed every six months after a course of therapy can help quickly identify recurrence.
What to Expect During a PEM Scan
A typical PEM exam takes about two hours, so be sure to plan your day accordingly.
During the PEM procedure, you will receive an injection containing a small amount of radioactive sugar. In order for your body to absorb the radioactive sugar, you will be instructed not to eat or drink for six hours before the procedure.
You should wear loose, comfortable clothing, but will remove your top and bra and wear a hospital gown during the procedure.
When you arrive, a nurse or technologist will take a drop of blood from your finger to ensure your blood sugar levels are within acceptable range. If so, a small amount of the radioactive sugar will be injected into your arm. You will be directed to a quiet room and asked to remain comfortably still for 60 minutes, giving your body time to absorb the sugar.
During the procedure, you will sit in a chair and the technologist will scan each breast separately, positioning each in the PEM scanner very similarly to a mammogram. Each breast will be gently immobilized for 6 – 10 minutes per scan. A typical PEM exam includes at least two scans per breast.
A radiologist will read your images and send a report to your doctor within 48 hours. Your doctor will inform you of the results.
Quick and painless, external-beam radiation has long been used to destroy cancer cells. The latest methods—Intensity Modulated Radiation Therapy (IMRT) and Image-Guided Radiation Therapy (IGRT)—provide the most advanced technology for fighting breast cancer. Used alone or together, these therapies allow higher doses of radiation to be delivered with greater precision and accuracy without destroying surrounding, healthy tissue. For instance, they are extremely helpful with the challenges of left-sided breast cancer, where traditional radiation therapy presents risks to the heart and lungs.
For patients, IMRT/IGRT means:
- more effective treatment focused on cancer cells
- less radiation exposure to normal tissue
- potentially fewer and milder side effects
- treatment for some tumors that couldn’t previously be treated by radiation
How IMRT Works
IMRT is a specialized radiation therapy that uses powerful treatment planning software to calculate precise beam angles, shapes and exposure times tailored to each tumor. The radiation beam can be broken up into many smaller beams and the intensity of each small beam can be adjusted individually. This may allow a higher dose of radiation to be delivered to the tumor with less risk to nearby healthy tissue, potentially decreasing the duration of treatment and increasing the chance of a cure.
How IGRT Works
Tumors can move during a course of treatment. IGRT combines imaging and treatment capabilities on a single machine. This way, tumors can be tracked between, as well as during, treatments, allowing radiation to be focused more precisely. Images captured before each radiation session are compared to previous sessions so that clinicians know the exact location of the tumor each time. IGRT software also accounts for breathing and motion during treatment, ensuring the radiation stays focused on the tumor.
What to Expect During Treatment
The treatment process is similar for IMRT and IGRT.
First, we’ll schedule an appointment with a radiation oncologist. During this visit, we’ll perform a simulation of the treatment. You will be positioned on the treatment machine the same way you will be for actual treatment. The radiation oncologist will determine the need to use an immobilization device (such as a cast, mold or headrest) to keep you in the same position during treatment. Then, we’ll take a CT scan to precisely map your anatomy. Using information from the CT scan, the radiation therapist will mark the area(s) to be treated, either on your skin or on the immobilization device. Simulation sessions take 30 to 60 minutes and may be repeated at intervals throughout your course of treatment.
Next, your radiation oncologist and treatment team will design a treatment plan tailored to you. They will use information from the simulation session, anatomical maps obtained from the CT scan, previous medical tests and, in many cases, sophisticated treatment planning software.
For breast cancer, radiation therapy is typically administered 5 days per week for a total of 30 to 33 treatments. However, your treatment team will determine the best course of treatment for you. During each session, positioning takes from 5 to 15 minutes. Actual treatment time lasts about 10 minutes and is painless. The radiation is delivered using a machine called a “linear accelerator” which generates x-rays or photon radiation. The linear accelerator moves so that patients can lie comfortably without being re-positioned during treatment.
The treatment room is spacious, and you will not be completely enclosed by equipment. A radiation therapist will position you to ensure successful treatment then go to an adjoining control room. From there, he or she will monitor you closely during radiation treatment using video cameras. The therapist can hear you at all times, and the treatment can be immediately discontinued if you feel uncomfortable or ill. If IMRT/IGRT are employed, the therapist may move the machine or treatment table during treatment to best target the exact area of the tumor. Once each treatment is complete, you can return to your normal daily activities.
A follow up exam with your radiation oncologist will be scheduled after your last treatment to discuss side effects. From there, your physicians will determine the proper course of ongoing treatment.
Fighting Breast Cancer in Less Time with Greater Precision
Brachytherapy has long been used to destroy cancer cells by delivering radiation within the body. However, traditional methods involve placing a weak source of radiation at the tumor site, and patients are usually confined to a specially shielded hospital room for many days until the course of therapy is complete. The latest method—High Dose Rate (HDR) brachytherapy—provides the most advanced technology for fighting breast cancer. This therapy allows higher doses of radiation to be delivered with greater precision and accuracy without destroying surrounding, healthy tissue. When appropriate, it is the treatment option of choice as it takes only 1 week to complete therapy (vs. 6-7 weeks with traditional radiation therapy), and therapy is performed on an outpatient basis. At Rainier Cancer Center, we employ the latest HDR brachytherapy technology, which allows treating physicians more flexibility in their treatment options and reduces the length of each individual treatment session for patients.
For patients, HDR brachytherapy means:
- Greatly shortened duration of therapy
- More effective treatment focused on cancer cells
- Less radiation exposure to normal tissue, particularly the lungs and opposite breast
- Potentially fewer and milder side effects, particularly skin irritation from external radiation
- No delays in other treatments, such as chemotherapy
How HDR Brachytherapy Works
The overall goal of HDR brachytherapy is to deliver short and precise amounts of high-dose radiation to cancerous tumors while minimizing exposure to healthy tissue. Under CT and x-ray guidance, a catheter is inserted into the body up to the site of the tumor; the other end of the catheter is left outside the body. During therapy, the end of the catheter outside the body is connected to a computerized machine that passes a small, radioactive pellet (or “seed”) through the catheter and guides it to the tumor site. The positioning of the seed and the duration of time it is left in the body is used to control and precisely shape the radiation dose for different parts of the tumor.
For breast cancer, HDR brachytherapy can be performed in one of two ways, depending on the size and location of the tumor in relationship to the size and shape of the breast:
- Balloon-catheter brachytherapy involves inserting a single catheter into the breast under local anesthetic. An inflatable balloon at the end of the catheter is positioned inside the cavity left behind after lumpectomy. During each treatment session, a tiny radioactive source is directed with millimeter precision into the center of the balloon.
- Multiple-catheter brachytherapy is similar to the balloon-catheter method, except that several small catheters without balloons are inserted into the breast. The radioactive material is delivered into each catheter simultaneously.
What to Expect During HDR Brachytherapy Treatment
First, we’ll schedule an appointment with a radiation oncologist to discuss the type of HDR brachytherapy that will be used. The catheter(s) that will be used to guide the radioactive material to the tumor site must be implanted prior to your first treatment. This can be done at the time of your lumpectomy or shortly thereafter.
Next, your radiation oncologist and treatment team will design a treatment plan tailored to you. A few days after the catheter is inserted, they will obtain CT images of the implant to make sure the catheter is in the right place and to take precise measurements of the treatment area. They will combine this information with sophisticated computer planning software to outline your course of treatment. For breast cancer, HDR brachytherapy is administered on an outpatient basis, typically 2 times daily for 5 days. However, your treatment team will determine the best course of treatment for you.
Prior to each session, an x-ray of your breast will be taken to check the catheter position. Then, you will be taken to the spacious treatment room where you will lie comfortably on an x-ray couch. The therapist will connect your catheter to the HDR machine (called an “afterloader”) which stores the radioactive source. During your treatment, the radiation source will come out of the machine and go into your catheter. The radiation staff will leave the room during treatment, but will watch you closely on a monitor. They can hear you at all times and you can talk to them if you feel uncomfortable or ill. The entire process lasts about 1 hour and is painless.
During your course of therapy, you will be given a surgical bra or a prescription for one. It is for comfort, support and protecting the catheter, and should be worn even during sleep. You may do your normal activities, but should take caution not to get the breast wet, particularly when bathing. You should also avoid carrying or lifting anything with the arm on your affected side.
A follow up exam with your radiation oncologist will be scheduled after your last treatment to discuss success and side effects. If therapy is considered complete, the catheter(s) will be removed with no lasting radiation in your body. From there, your physicians will determine the proper course of ongoing treatment and follow-up care.
More and more women diagnosed with breast cancer are choosing Breast Conservation Therapy (BCT) in efforts to preserve their breast. BCT starts with a surgical procedure called a “lumpectomy” to remove the cancerous tumor, followed by daily sessions of Whole Breast Radiation (WBR).
To minimize the chance of recurrence, physicians recommend an additional course of treatment, which always includes radiation with or without chemotherapy and/or hormone therapy. Part of the radiation therapy protocol is a “boost dose” of radiation, aimed at the tissue cavity that used to contain the tumor. This is the area at greatest risk for the cancer to return. Clinical studies show that the “boost dose” results in a significant decrease in the recurrence of cancer. However, it is estimated that traditional methods for providing this “boost dose” miss the tumor bed 50% of the time and can expose surrounding tissue and underlying organs, such as the lungs and heart, to unnecessary radiation.
AccuBoost is a revolutionary system that delivers the “boost dose” more accurately than ever before. It combines mammographic image guidance with high-dose rate brachytherapy (a form of internal radiation) so that physicians can see exactly what they are treating during each treatment session. Unlike the traditional “electron boost” method that delivers radiation into the chest wall, AccuBoost precisely positions the breast so that radiation is delivered parallel to the chest wall, which means a lower dose to critical underlying organs. Image-guided applicator size and positioning allows the boost dose to accumulate directly in the intended area.
For patients, treatment with AccuBoost means:
- Lower skin dose and toxicity
- Fewer side effects
- Less radiation exposure to heart, lungs and other neighboring tissue/organs
- Reduced chance of cancer recurrence while preserving the breast
AccuBoost: What to Expect During Treatment
- Treatment will take place in a comfortable, spacious treatment room.
- You will be seated at the AccuBoost machine; similar to a mammogram, your breast will be positioned between paddles for immobilization.
- Your breast will be imaged to carefully identify the lumpectomy site in need of the boost dose of radiation.
- The AccuBoost applicators will be positioned on opposing sides of your breast to deliver a focused radiation field to the lumpectomy site.
- Following the first delivery of radiation, the applicators will be re-positioned to target radiation to the lumpectomy site from a different direction.
- Treatments typically begin before your course of whole breast radiation (WBR).
- Treatment sessions are daily; most patients undergo 5 – 8 sessions.