3D conformal radiation therapy

Three-dimensional conformal radiation therapy, also known as 3D CRT, is a visualization and planning tool used to identify exactly where external radiation rays should be placed to treat tumors. It works with a machine, called a linear accelerator, that delivers external radiation from several directions with beams shaped, or conformed, to match the shape of a tumor. Three-dimensional conformal radiation is a time-tested and commonly used treatment for cancerous tumors and may be used for certain noncancerous tumors too.

The 3D CRT technique uses images from diagnostic tests, such as CT scans, MRI scans, or PET scans, and feeds them into specialized computer software to create a three-dimensional blueprint, or map, that conforms to the tumor. This map becomes a critical part of the treatment plan, guiding the exact placement of individual external radiation rays from different directions. By understanding the shape and size of the tumor, radiation oncologists and technicians have more control when treating tumors.

Our board-certified radiation experts at Penn Medicine have years of experience using 3D conformal radiation therapy, including intensity-modulated radiation therapy (IMRT) and image-guided radiation therapy (IGRT), along with other advanced radiation therapy technologies. They’ll consult with you on your individual case and decide whether 3D CRT is the best radiation treatment for you to eliminate cancer cells while limiting radiation exposure to healthy tissue.

Many types of cancer and some noncancerous tumors can be treated using 3D CRT. It’s an especially useful approach for tumors that cannot be treated through surgery. It may be used as part of a treatment plan to shrink tumors before surgery or to eliminate cancer cells after surgery. It’s frequently used to treat these cancers, among others:

• Anal cancer
• Rectal cancer
• Colorectal (colon) cancer
• Some head and neck cancers 
• Some digestive system cancers 
• Lung cancer 
• Prostate cancer

If you haven’t already had image scans of your tumor to guide radiation treatment, your doctor will recommend that you get scans. These scans will be fed into a specialized software program to create a 3D map of your tumor. The 3D map is then input into the linear accelerator machine that delivers your radiation to direct the path of the external radiation rays during each treatment session.

Prior to the start of your 3D CRT treatment, you may have a simulation session where your radiation oncology team reviews the 3D map of your tumor and sets up the machine’s settings for your treatment. You may be asked to lie on a treatment table to determine the optimal position of your body during treatment. Your care team may make marks, or place tattoos, on your skin to designate the target area for radiation.

During each radiation treatment session, your body will be positioned comfortably near the linear accelerator machine to provide the best access for delivering the external radiation beams precisely. The machine will not touch you during treatment but may rotate around you as the external radiation beams are delivered. You will not experience pain during treatment. 

Because 3D conformal radiation therapy is used for tumor visualization, there’s no recovery period associated with this planning and guidance tool itself. The accompanying external radiation therapy that you receive may produce side effects, including skin sensitivity, nausea, and fatigue. Consult with your radiation oncology team about what to expect after your radiation treatment based on the location, intensity, and duration of treatment. They can advise you on how to handle common side effects during your recovery period.

Penn Medicine offers every treatment option available in radiation therapy, with sophisticated technology and years of experience in treatment planning. Using specialized techniques, our cancer experts maximize the effects of radiation on cancer while reducing exposure to healthy tissues.

When you come to Penn Medicine for radiation therapy, you can expect to find:

• Team expertise in radiation therapy: With subspecialized training, our radiation oncologists, radiation physicists, dosimetrists, radiation therapists, and radiation oncology nurses have an international reputation for excellence in patient care and offer the most up-to-date treatment options.
• A focus on specific tumor types: You’ll receive care from radiation therapy experts who specialize in treating tumors in specific areas of the body. Your care team has the experience and insight to provide safe, effective treatment. 
• Nationally accredited radiation centers: Our facilities have earned accreditation by the American Society for Radiation Oncology. This recognition shows Penn Medicine’s commitment to the highest standards of safety and care.
• Improved care through research and education: We conduct research and participate in clinical trials aimed at improving treatment effectiveness and patients’ quality of life. As part of our commitment to improved cancer care, our radiation oncologists and other specialists teach the next generation of cancer doctors.