Close collaboration between radiation oncologists and diagnostic radiologists has led to important advances in radiation therapy for cancer, helping patients live longer with fewer complications, according to a leading expert who spoke at RSNA 2020.
Erickson
The close ties between the two disciplines – and the progress they are making in cancer advancements – was the focus of the Annual Oration in Radiation Oncology delivered by Beth A. Erickson, MD, a professor in the Department of Radiation Oncology at the Medical College of Wisconsin (MCW) in Milwaukee, and chief of brachytherapy services at MCW.
In her lecture, “Imagers and Images: My friends; My Indispensable Guide,” Dr. Erickson recounted the many ways that diagnostic radiologists helped radiation oncologists as imaging became essential to the successful design and delivery of radiation therapy for cancer.
She pointed to two critical junctures in radiation oncology: the arrival of CT-based treatment planning in the 1970s and the incorporation of MRI-based planning a decade later.
“With each wave of technological advancement, radiation oncologists found themselves needing the skills of their diagnostic colleagues,” Dr. Erickson said. “If we did not define the tumor and its extensions, it would not be treated and if we did not correctly identify the organs at risk, they would not be spared.”
Advances in Treating Cervical Cancer
A prime example of this fruitful partnership is found in the treatment of cervical cancer, one of the most common cancers among women worldwide.
Through precise imaging, radiation oncologists like Dr. Erickson have been able to escalate the dose to the cancer while carefully controlling the dose to the adjacent organs at risk. MRI made it possible to monitor the location and change in tumor volume over the course of brachytherapy as well as the variable positions of the adjacent organs, allowing dose adaptation with each fraction.
“Cure with preservation of function can be achieved with the implementation of image-based brachytherapy,” Dr. Erickson said.
Promising new technologies in cervical cancer treatment also rely on advanced imaging. MR spectroscopy before and after radiation could help to reveal the persistence or recurrence of cervical cancer, enabling timely salvage treatment, Dr. Erickson said. Radiomic features, or quantifiable data extracted from images, may also assist in determining prognosis.
“Our hope is that some of these features will inform us of disease response while we are still treating these patients to actively guide treatment intensity,” Dr. Erickson said.
Imaging is also driving progress in the treatment of pancreatic cancer, a disease that carries a poor prognosis. Improvements to radiation therapy mean it can now be used with chemotherapy before surgery to improve outcomes.
“In patients who have gone on to surgery, we have seen amazing pathologic responses,” Dr. Erickson said. “Whereas 50 to 70% of patients have nodal disease with upfront surgery, in our patients this was reduced to 30% with a surgery-last approach.”
A Fruitful Partnership
Imaging is also helping to deliver radiation therapy to people with inoperable disease by providing improved visualization of the tumor and its extensions.
With imaging advances arriving to the clinic every year, the partnership between diagnostic radiology and radiation oncology is likely to bear more fruit in the decades ahead.
“Radiation oncologists remain essentially and integrally aligned with our diagnostic colleagues and friends in our mutual quest to cure cancer,” Dr. Erickson said. “Imagers and the images they analyze are an extraordinary resource for which radiation oncologists and their patients remain ever grateful.”
For More Information
View the Annual Oration in Radiation Oncology, Imagers and Images: My friends; My Indispensable Guide — PS40 at RSNA2020.RSNA.org.
