Radiation Oncology: What Goes on Behind the Scenes

Daphne Palmer, MD, FACRO, Radiation Oncology Medical Director
Daphne Palmer, Radiation Oncology Medical Director

When a patient is referred to the cancer center, he or she will frequently consult with a radiation oncologist to determine if radiation should play a role in the treatment. This begins a series of back and forth consultations and discussions to design the best possible personalized program of care that may involve surgery, drug therapy and radiation therapy.

The doctors assess the stage of the tumor, age of the patient, and general medical status of the patient. They also work with the patient to determine the patient’s goals, how well the treatment process is comprehended, and the “social history”. Those considerations include family concerns, the patient’s ability to get to a series of treatments, pre-existing conditions, lifestyle and level of anxiety. All those factors enable the radiation oncologist to determine if the patient is a good candidate for radiation. The patient’s family or close friend is encouraged to attend these discussions to help the patient understand, remember facts, and ask questions.

A common next step is to present the case at Tumor Board. Tumor Board is a patient-focused multidisciplinary conference with surgeons, medical oncologists, radiation oncologists, geneticists, nutritionists, pathologists, radiologists, and primary care physicians designed to assist in creating a treatment plan. As founding members in the UC Davis Cancer Care Network, we participate with their specialists in virtual tumor boards almost daily.

Once the decision to proceed with radiation has been made, a simulation is scheduled. This starts with a half body cast that is molded to help keep the patient stationary but comfortable during treatment. The mapping and measuring of the treatment area is done with a CT scan, generating a three-dimensional view of the patient's anatomy. The raDaphne Palmer standing in front of CT scannerdiation oncologist works with a medical physicist to fuse this planning scan with all other scans (PET/CT, MRI, etc.) that the patient may have received so far to create the most comprehensive image of the tumor. The radiation oncologist then contours the area that needs to be treated as well as all the critical structures that need to be avoided on every CT slice.

This is then sent back to the medical physicist who creates the formal treatment plan that will drive the radiation machine, a linear accelerator. The plan is designed to balance the radiation dose delivered to the tumor with the necessary trade-offs needed to protect nearby critical structures as outlined by the radiation oncologist. There is usually a good deal of back and forth discussion and fine tuning of the treatment plan.

As a final check, the radiation treatment plan is then presented to the radiation oncology department at UC Davis for their review. Both the UC Davis physicians and physicists input their suggestions and the final modifications are made before the plan is approved by the radiation oncologist.

After this complex and collaborative process of creating and fine-tuning the treatment plan, treatment can begin. The radiation therapists operate the machine and deliver the treatment in 5 minutes or less. Images are taken at least weekly and sometimes daily during treatment to ensure the patient's anatomy has not changed. This image-guided radiation is possible because the treatment machine has a CT scanner built right into it.

Radiation Oncology Treatment Plan

Daphne Palmer, MD, FACRO, is the Radiation Oncology Medical Director at Gene Upshaw Memorial Tahoe Forest Cancer Center. She is skilled in treating a wide range of tumors and has completed comprehensive training with experience in stereotactic radiosurgery, including SBRT, and IMRT. She and her team are most excited about the center’s Varian True Beam accelerator, which allows for 4D treatments with respiratory gating. Dr. Palmer is board certified by the American College of Radiology.