Understanding Radiation Therapy in Cancer Treatment
Radiation therapy is a common treatment for various cancers, utilizing high-energy rays to target and destroy cancer cells. This approach works by damaging the DNA within cancer cells, which prevents them from growing and dividing.
Over time, these damaged cells die and are removed by the body, leading to tumor shrinkage or elimination. The treatment can be delivered in different ways, either from a source outside the body or from radioactive materials placed inside the body. Radiation therapy is often employed to cure cancer, prevent its return, or to manage symptoms by shrinking tumors. It is a localized treatment, affecting only the targeted area.
Understanding Boost Radiation Treatment
A “boost” in radiation treatment refers to an additional, concentrated dose of radiation delivered to a specific, smaller area within the original treatment field. Its primary goal is to deliver a higher cumulative dose to the tumor or tumor bed, maximizing the destruction of remaining cancer cells while limiting exposure to healthy tissues.
This additional dose typically follows an initial course of radiation therapy, which might have covered a broader region. The boost specifically targets the area at the highest risk for cancer recurrence, such as the site of a removed tumor. By focusing the extra radiation, the treatment seeks to enhance local control of the disease, reducing the likelihood of cancer returning in that specific spot.
Conditions When a Boost is Used
Boost radiation is commonly employed in specific cancer types and scenarios to enhance treatment effectiveness. For instance, in breast cancer, a boost is often given to the tumor bed after a lumpectomy to reduce the risk of local recurrence. This is particularly relevant for patients with certain risk factors.
Similarly, boost treatments are beneficial for prostate cancer, especially for intermediate to high-risk cases. An additional external beam radiation dose delivered directly to the visible tumor can lower the risk of recurrence without increasing side effects. Boosts are also utilized in head and neck cancers, where they can target the tumor bed to further reduce the risk of cancer cells remaining. The decision to use a boost is based on the specific characteristics of the tumor and the patient’s overall risk profile.
How a Boost is Delivered
Delivering a radiation boost involves advanced techniques to ensure precision and maximize effectiveness. External beam radiation therapy (EBRT) is a common method, where machines aim radiation from outside the body. Techniques like Intensity-Modulated Radiation Therapy (IMRT) and Stereotactic Body Radiation Therapy (SBRT) use computer-generated images to shape radiation beams, allowing higher doses to be delivered to the target while sparing surrounding healthy tissues.
Internal radiation therapy, known as brachytherapy, is another precise method for delivering a boost. This involves placing radioactive sources directly inside or very close to the tumor or tumor bed. For example, in breast cancer, small radioactive seeds or a balloon device can be temporarily placed in the surgical cavity. In prostate cancer, brachytherapy can deliver a high dose directly to the prostate, often in combination with EBRT, further enhancing local control.
What to Expect During and After Boost Treatment
A boost treatment course is generally shorter than the initial radiation therapy. For breast cancer, this might mean an extra 2 to 8 days of treatment. During each session, patients lie in a precise position, and while the radiation delivery itself is painless, the setup can take 15-45 minutes to ensure accurate targeting.
Side effects from a boost are often localized to the treated area and can include intensified skin reactions such as redness, itching, peeling, or blistering, similar to a sunburn. Swelling and pain in the treated area, along with fatigue, are also common. These effects typically improve weeks after treatment concludes, although some can persist longer. Patients are advised on skin care and monitored by their oncology team to manage any side effects.