Conformal Radiation Therapy
Modern radiation therapy is designed with 3-dimensional virtual reality computer programs. The imaging technology used by radiation oncologists shape the radiation treatment beams to the shape of the breast. Known as conformal radiation therapy, this technology gives doctors more control when treating breast cancer.
In conformal radiation
, a special computer uses CT imaging scans to create 3-D maps of the breast and the normal organs to be avoided, like the lung and heart. The system permits delivery of radiation from several directions and the beams can then be shaped, or conformed, to match the shape of the breast. Conformal radiation therapy limits radiation exposure to nearby healthy tissue as well as the tissue in the beam's path.
Deep Inspiration Breath Hold
This very specialized method for breast radiation is used for women with left-sided breast cancer.
The radiation is timed carefully to the respiration cycle of the woman — during a deep inspiration.
This method may cause the lung to expand and move the heart farther away from the left breast than without a breath hold. In this way, less dose is given to the heart.
A woman is given special training in how to do this and works with her therapists to do this correctly every day of treatment.
Image-Guided Radiation Therapy (IGRT)
Image-guided radiation therapy (IGRT) uses frequent imaging during a course of radiation therapy to improve the precision and accuracy of the delivery the radiation treatment. In IGRT, the linear accelerators (machines that deliver radiation) are equipped with imaging technology that take pictures of the tumor immediately before or even during the time radiation is delivered.
Specialized computer software compares these images of the tumor to the images taken during the simulation to establish the treatment plan. Necessary adjustments can then be made to the patient's position and/or the radiation beams to more precisely target the breast and avoid the healthy surrounding tissue.
Intensity-Modulated Radiation Therapy (IMRT)
Intensity-modulated radiation therapy (IMRT) is an advanced mode of high-precision radiotherapy utilizing computer-controlled linear accelerators to deliver precise radiation doses to tumors or specific areas within the tumors.
Using 3-D computed tomography (CT) images of the patient in conjunction with computerized dose calculations, IMRT allows for the radiation dose to conform more precisely to the three-dimensional shape of the breast tumor by controlling—or modulating—the intensity of the radiation beam in multiple small volumes. The therapy allows higher radiation doses to be focused to regions within the breast while minimizing the dose to surrounding normal critical structures.
IMRT may be used in some cases of IDC instead of 3D conformal planning when the greater computer-assisted planning will help shape the dose treating the breast or spare normal tissue better.
is an internal method of partial breast radiation.
MammoSite is a targeted radiation therapy treatment in which a small, soft balloon attached to a thin catheter is placed inside the lumpectomy cavity through a small incision in the breast. The implant is placed while the patient is in a hospital operating room.
During therapy, the portion of the catheter that remains outside of the breast is connected to a computer-controlled high dose rate machine that inserts a radiation "seed" to deliver the therapy to the area where cancer is most likely to recur.
The patient is not radioactive in between treatments outside the room or home. After the radiation is finished, the catheter is easily removed in the office.
Partial Breast Radiation Therapy
There has been research for over a decade into decreasing the target for radiation to the area immediately around the lumpectomy cavity. This is because most recurrences are in the vicinity of the original lumpectomy location.
The risk of breast cancer in other parts of the breast away from the lumpectomy site may be very low in some patients.
Women with very favorable outcomes may now be candidates for accelerated partial breast irradiation (APBI). APBI may also reduce cost of post-lumpectomy radiation, and will improve the convenience of radiation therapy by reducing the overall length of time required to one week.
There are two ways APBI can be delivered.
- External beam radiation therapy, or
- Delivery of radiation through sources placed inside temporary internal catheters inside the breast.
External beam APBI is non-invasive and can treat most lumpectomy cavity shapes and locations and breast sizes.
Internal catheter APBI also gives a highly conformal and localized dose to the lumpectomy site but requires a source to be placed in the breast.
For many women with large or pendulous breasts, and left-sided breast cancer, radiation can be planned and delivered with the patient lying on her stomach instead of her back.
The breast hangs down with gravity into an opening in the treatment table. This method can reduce the dose to the heart from radiation.
There may also be less immediate skin reactions from radiation with prone position in common areas like the underside of the breast by reducing skin folds.
is an external method of partial breast radiation.
Unlike conventional radiation that can affect surrounding healthy tissue as it enters the body and targets the tumor, proton therapy's precise, high dose of radiation is extremely targeted. This targeted precision causes less damage to healthy, surrounding tissue.
When aimed at cancer tumors, protons pack impressive power. Protons release their energy completely once they enter a tumor, limiting the radiation dose beyond the tumor, causing less damage to the healthy surrounding tissues and resulting in fewer side effects.
Even if you've already had a course of conventional radiation and are unable to receive more, you may still be able to receive proton therapy.
More facts about proton therapy:
- Proton therapy offers fewer reported side effects and complications
- Normal, healthy, surrounding tissues receive 50% to 70% less radiation
- Proton therapy offers an increased safe dose delivered to tumors
- Cure rates may be increased with proton therapy
- Proton therapy can re–treat tumors after recurrences
- Thanks to its marvelous precision, proton therapy is perhaps the most advanced treatment for cancer tumors located close to critical organs and highly sensitive areas, such as the spinal cord, heart and brain.
Proton therapy is also an important treatment option for cancers that cannot be completely removed by surgery.
Whole Breast Radiation Therapy
Radiation therapy stops cancer cells from dividing and growing, thus slowing or stopping tumor growth. In many cases, radiation therapy is capable of killing all of the cancer cells.
For more than 25 years, breast-conserving surgery and radiation therapy have been standard alternatives to mastectomy for women with early stage breast cancer. Radiation after a lumpectomy reduces the risk of a recurrence in the breast.
Historically, radiation therapy after lumpectomy has treated the whole breast — this may make sense as radiation was replacing another whole breast treatment (mastectomy). For many women, after radiation is given to the whole breast, an additional more focused dose of radiation is given to the lumpectomy cavity, called a cone down or boost.
Shorter Radiation Schedule with Hypofractionation
Conventional treatment schedules involve daily radiation Monday through Friday for five to six weeks.
Hypofractionation, however, uses fewer, larger dose radiation treatments (also called fractions) usually given over a shorter time period when compared to standard radiation fraction sizes.
This type of radiation therapy reduces the length of a course of treatment by two to three weeks compared to standard schedules. This reduced length of treatment reduces cost, reduces travel or lost days of work, and reduces the inconvenience of a course of radiation. In addition, studies show that there are no significant differences in cosmetic appearance of the breast or other negative side effects in women treated with a shorter course of radiation.