Ask Mayo Clinic: Here's how radiation therapy has changed - why it matters for cancer patients

AdviceThis Mayo Clinic Q&A represents inquiries this healthcare expert has received from patients. For more information, visit www.mayoclinic.org. (Tribune News Service)Tribune News ServiceDear Mayo Clinic: Radiation therapy has been used to treat cancer for decades, but I’ve heard treatments today are much more advanced than they used to be. How has radiation therapy changed?Answer: Radiation therapy has changed significantly over the years. Advances in technology allow healthcare teams to plan and deliver treatment with greater precision while limiting radiation exposure to surrounding healthy tissue.One common misconception is that external-beam radiation therapy makes patients radioactive. It does not. During this type of treatment, a machine outside the body directs high-energy beams toward the cancer. Patients don’t feel the radiation as it’s delivered, and many treatments are provided in an outpatient setting.One of the biggest advances has been the ability to target tumors more precisely. Modern imaging, including CT, MRI and PET scans, allows physicians to create a detailed three-dimensional map of the tumor and surrounding anatomy. These images are combined with computer planning to shape the radiation dose around the cancer while limiting exposure to nearby healthy organs and tissues.For patients with head and neck cancers — where tumors often sit only millimeters from structures responsible for speech, swallowing, hearing and vision — that precision can make a meaningful difference. The goal isn’t only to treat cancer but also to preserve functions that affect quality of life afterward.Technology has made radiation more individualized. Rather than relying on a one-size-fits-all approach, physicians consider the type of cancer, its molecular characteristics, imaging findings, prior treatments, a patient’s overall health and personal goals.Those goals may include preserving speech or swallowing, maintaining the ability to work or participate in daily activities, or minimizing side effects that could affect quality of life. If anatomy changes because a tumor shrinks, a patient’s weight changes or the position of nearby organs and tissues shifts during treatment, the plan can be adapted.Another important advancement is that some treatment courses now can be completed in fewer visits. While certain cancers still require several weeks of care, selected tumors can be treated with stereotactic radiation therapy in as few as one to five sessions. This approach uses specialized equipment and careful positioning to deliver a highly focused dose while helping spare nearby healthy tissue. Depending on the area being treated, customized masks, molds or other immobilization devices may help keep a patient in the same position for each treatment.Imaging performed before or during treatment also can help the care team confirm the tumor’s location and adjust positioning before radiation is delivered. Delivery often takes only a few minutes, with most of the appointment devoted to positioning and verifying accuracy.Greater accuracy can help reduce side effects. By limiting unnecessary radiation to healthy tissues, many patients may experience fewer long-term complications. Side effects still vary depending on the location being treated, the dose and nearby healthy tissues.For example, radiation for head and neck cancers can affect saliva production, taste and swallowing because the salivary glands and structures involved in swallowing may be close to the tumor. Radiation to the chest can cause irritation of the esophagus or lungs in some patients. Radiation is increasingly used alongside surgery, chemotherapy and immunotherapy as part of coordinated cancer care. Depending on the cancer, it may be used to cure disease, reduce the risk of recurrence, preserve organs or relieve symptoms. Sometimes medicines control most of a cancer, but it continues to grow in a few areas. Radiation may treat those specific areas while an otherwise effective drug therapy continues.Looking ahead, advances may make radiation therapy even more precise and personalized. Some of these advances include:Artificial intelligence, which can assist healthcare teams with treatment planning.Adaptive radiation, which allows a treatment plan to be adjusted as a tumor or surrounding anatomy changes.Proton therapy, which uses proton particles rather than conventional X-rays and can reduce radiation exposure to healthy tissues near a tumor.Carbon ion therapy, an emerging form of particle therapy that researchers are studying for certain tumors that may be difficult to treat with conventional radiation.Radiation therapy has changed dramatically over the past several decades. Advances in imaging, planning and delivery have made care more precise, personalized and, in many cases, more convenient. Every patient’s plan is unique. The goal is to deliver the right amount of radiation to the right place while protecting healthy tissue and helping patients return to the lives they want to live.— Adam Holtzman, M.D., Radiation Oncology, Mayo Clinic Research, Jacksonville, FloridaMayo Clinic Q&A is an educational resource and doesn’t replace regular medical care. This Mayo Clinic Q&A represents inquiries this healthcare expert has received from patients. For more information, visit...