What Is Radiation Therapy?
Radiation therapy uses large doses of radiation to kill cancer cells and shrink tumors. The radiation passes through the body and delivers dose to the affected area while minimizing dose to the skin and tissue it passes through.
Although the radiation affects both cancer and normal cells, it has a greater effect on the cancer cells, damaging their genetic material and making impossible for these cells to continue to grow and divide. Normal cells can repair the damage while cancer cells cannot. Treatment aimed to cure will give the highest possible dose of radiation to the cancer area to attempt to kill all the cancer cells. Sometimes smaller doses are used in palliative care, where the aim is to reduce the size of a tumor and/or to relieve symptoms like pain or bleeding.
Electrons are used to treat skin cancers and other superficial lesions, as they are absorbed by the first few centimeters of skin, leaving very little dose to pass into the body. Radiation therapy is used to both cure disease and alleviate the symptoms of cancer. There are several non-malignant conditions treated using radiation therapy.Advantages of Radiation TherapyThanks to advances in radiation therapy technology, treatment is more precise than ever. Advantages of our radiation technology include:
- quicker and more precise treatments which allow us to target the tumor with a high level of accuracy while leaving healthy tissue unharmed, and
- imaging techniques allow the radiation oncologist to closely track tumors, before and during radiation allowing for personalized treatment plan adjustments as needed.
Radiation therapy may be given alone or in combination with other treatments, such as surgery, chemotherapy, hormone therapy or immunotherapy. Because each cancer type requires a different approach, each patient’s treatment plan is customized to their unique needs and treatment goals.
Dr. Samuel Hughes, Saint Mary’s board-certified radiation oncologist. Behind Dr. Hughes is the advanced Elekta Synergy system, a radiation therapy system used in the fight against cancer at Saint Mary’s Cancer Center.
What Happens During Radiation Therapy?
Radiation therapy is a process. The steps you will follow are:
1. INITIAL VISIT
Saint Mary’s radiation oncologist will review your medical records and perform a medical exam. He will talk with you about the risks and benefits of radiation therapy, and you may be asked to undertake additional diagnostic procedures. These can include X-rays, computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET) scans, biopsies, and blood tests. Once the radiation oncologist has determined the most effective type of radiation therapy for you, a treatment regimen will be planned and prescribed.
This process determines the best patient positioning to better pinpoint the exact location of the cancer. A CT scan will be performed for treatment planning. These images may be combined with other scans, MRIs, or PET scans you received during the diagnostic workup.
3. TREATMENT PLANNING
Once images are taken, your physician develops the best treatment plan for you. The treatment plan is created using treatment planning software that calculates the position, dose, and frequency of treatment. Before it commences, the treatment may be simulated (i.e., a treatment set-up performed in the treatment room to ensure the correct treatment can be reproduced as planned). This includes imaging to compare with the treatment plan images.
We will discuss with you exactly how long and how frequently you will need radiation therapy sessions or fractions. These fractions are typically 30 minutes or less and can occur as a single treatment or occur daily over several weeks. Radiation therapists will deliver your treatment fractions according to your personalized treatment plan. It is imperative that you adhere to the prescription and treatment plan, as any missed treatment may affect its overall success. Treatment is monitored regularly and may be adjusted if a patient suffers from adverse side effects or loses too much weight.For the radiation treatment, you will lie under the equipment on a couch (table). You’ll be asked to remain still during the actual treatment. The treatment is completely painless. Radiation cannot be seen or felt while it is given.
5. IMAGE-GUIDED RADIATION THERAPY (IGRT)
Daily images are taken prior to treatment; each daily image is compared to treatment plan images. These images are used to verify both the patient position and the accuracy of the treatment beam. Once accurately aligned, the patient’s treatment is delivered.
6. WEEKLY APPOINTMENTS
You will meet with the nurse practitioner and/or radiation oncologist each week to evaluate your response to radiation therapy. Your medical team will discuss and help manage any side effects or symptoms you experience.
Once treatment is complete, you will attend follow-up clinics for up to five years. These clinics are held to help patients manage any post-treatment side effects and to monitor disease regression or progression. You may be referred back to your medical oncologist, surgeon, or primary care physician for annual follow-ups, as appropriate.