“Can you tell me what radiation therapy is?” my patient, a retired healthcare worker, quickly but quietly asked me as soon as I entered the exam room. I knew before I had even entered the room that she had just been diagnosed with a lung cancer. She was clearly overwhelmed by her diagnosis, and even though she had worked in the healthcare field for decades of her life, she had never come across radiation therapy or even a radiation oncologist.
A diagnosis of cancer may be the first and only time a patient will meet with a radiation oncologist – a physician who specializes in the sophisticated use of X-ray, proton, or electronbased radiation therapy to treat cancerous or non-cancerous diseases. One of the most important aspects of radiation therapy is the rapid and significant advancements that have been made in the delivery of radiation.
Radiation oncology has advanced faster than most fields of medicine. When radiation therapy for patients first began in 1956 in the USA, it was very rudimentary. A highly potent X-ray machine was positioned to be approximately covering a tumor, and the machine was turned on. The trouble was that radiation oncologists couldn’t always treat the entire tumor with this method and, many times, the side effects were too severe.
As technology improved, we began to utilize CT and MRI scans to help us identify the specific location of the tumor and the surrounding normal tissues (like your heart, lungs, liver, among many others) – this helped us create much more effective radiation treatment plans that could cover the entire tumor with multiple fields of radiation therapy, while reducing radiation to normal parts of the body. We also improved our ability to utilize brachytherapy, a form of radiation where radiation sources are placed directly into or next to the tumor. With better imaging, our ability to treat prostate cancer, gynecologic cancers, breast cancer, and skin cancers with brachytherapy has improved significantly with little side effects.
More recently, however, we have now developed radiation machines that can more accurately treat the tumor while minimizing radiation dose to the normal body. We now use numerous beam angles to shape the radiation dose to the specific size and shape of the tumor. This is the most sophisticated form of radiation and is called volumetric-modulated arc therapy (or VMAT). Our newest radiation machine in Green Valley, AZ can deliver this type of radiation treatment with millimeter accuracy.
Improvements in our ability to deliver this VMAT therapy now means that we can deliver very high doses of radiation in just a few treatments. We utilize CT scans to guide the radiation treatment, so treatments are done with even better accuracy and are delivered in just a few treatments rather than over several weeks. This form of treatment is called stereotactic body radiation therapy (or SBRT), and our cancer center in Green Valley now offers this treatment. For some cancer patients, this advanced type of therapy offers an excellent opportunity to control the cancer, reduce symptoms, and improve quality of life.
As we finished our discussion, my patient with lung cancer began to feel much more comfortable as she began to understand the advanced and targeted ways we can now treat her lung cancer with radiation.
Author: Nikhil Thaker, MD is a Radiation Oncologist treating patients in our Green Valley and St. Mary’s offices. Dr. Thaker attended medical school at Rutgers University and completed his residency at The University of Texas MD Anderson Cancer Center, Houston, Texas.