Feature | February 03, 2014 | Pablo R. Ros, M.D., MPH, Ph.D.

Transforming Oncology Care With PET/MR

Following commercial availability of the Philips Ingenuity TF PET/MR in late 2011, University Hospitals Seidman Cancer Center continues to see the benefits of this hybrid modality

PET/MR

The PET/MR at the University Hospitals Seidman Cancer Center in Cleveland.

The advent of hybrid PET/MR in 2011 brought the promise of vastly improved imaging technology in the form of a new modality that combined whole body positron emission tomography (PET) with magnetic resonance (MR) technology. Following two years of using PET/MR, we are seeing clinical benefits with this system at the University Hospitals Seidman Cancer Center in Cleveland.

The University Hospitals Seidman Cancer Center opened in 2011 as one of the National Cancer Institute’s designated Comprehensive Cancer Centers, with a mission to set a new standard for cancer care. We knew this standard should include an innovative technology that we hoped would bring to bear in a single unit: all the best of MR, the most advanced anatomical display and PET, the most advanced physiologic display. We were fortunate to be one of the first to receive the Philips Ingenuity TF PET/MR and have continued to see the benefits of this system following its U.S. Food and Drug Administration (FDA) 510(k) clearance. 

PET/MR applications go beyond oncology, but we felt PET/MR would be the ultimate imaging system to have in place at a new oncologic center to diagnose, stage and evaluate response to therapy for oncologic processes. 

Bringing Personalized Medicine to Life

The Ingenuity TF integrates the molecular imaging capabilities of PET with the superb soft tissue contrast of MR. We have completed hundreds of PET/MR scans since installation and these scans are becoming part of the fabric of our oncology services. The majority of our PET/MR imaging has been for the diagnosis, treatment, staging and evaluation of disease progression in head and neck cancer and lung cancer, and we are beginning to find PET/MR useful in abdominal, rectal, ovarian and uterine cancers. Additionally, PET/MR has shown a particular advantage in some very poor prognosis cancers we treat, such as pancreatic cancer, as the system can help accurately stage the disease early in its development — a crucial step in oncology management. We are also finding PET/MR useful in accurately planning for radiation oncology treatments and are beginning to use the system in pediatric oncology and neuro-oncology.

One of the most compelling features of PET/MR is its ability to help bring personalized medicine to patients. PET/MR allows us to perform multi-parametric evaluations in oncology. In the past, we would quantify different parameters in separate settings at different times. Through PET, we could measure a tumor’s standard uptake values (SUV) and, through MR, determine the malignancy and aggressiveness of the tumor. We are beginning to see, in very aggressive cancers, that we can now use PET/MR to see multiple parameters with only one scan. This allows us to see very quickly, sometimes in as little as one week, if tumors are responding to therapy, and allows us to make any necessary adjustments early in the patient’s treatment process. We can never predict with certainty how a tumor or patient will respond to a particular regimen of therapy, but having the ability to monitor therapy and observe its efficacy without having to wait for a full six-week course of chemotherapy or radiation is of huge benefit to the patient and their prognosis.

The combination of multiple parameters, such as diffusion-weighted imaging, activity in PET or fluorodeoxyglucose assessment is remarkable. It is particularly helpful in liver metastases, allowing us to detect active disease and potentially guide therapy of percutaneous ablations.

The Evolution From PET/CT to PET/MR

Generally, in areas of the body where the primary diagnostic modality for staging and restaging is MR, we are finding several advantages in using PET/MR as a complement to, and, in some instances, in place of PET/CT. As part of our ongoing process to thoroughly understand the clinical value of this new technology, all of our PET/MR patients also receive a complementary PET/CT scan. In our evaluation of these images, along with additional research we have conducted here at Seidman, my team has not found any discrepancies between the systems from a clinical standpoint. In fact, in many of the cases at our facility, PET/MR has helped more than a PET/CT to find the location and extent of disease due to the higher soft tissue contrast and resolution of the MR.

We foresee that within the next year we will begin to deploy only PET/MR scans to patients (without the follow-up PET/CT), as our clinicians grow more comfortable with the system. Typically, patients who receive a PET/MR are those who would normally have undergone both an MR and a PET/CT. Our clinicians like that we can essentially spare these patients an additional procedure and also significantly reduce dose in those instances when CT is not used.

Our facility primarily uses PET/MR as a hybrid system; however, the Ingenuity TF PET/MR can also be used for stand-alone MR imaging. The sequential function offers a flexible and economic design. 

Overcoming Hurdles 

Preparing for and installing the PET/MR system in our facility took just over one year, allowing us time to assemble our team of nuclear medicine physicians, radiologists and research fellows in order to pave the ground for scientific activities and outstanding patient care. 

Before deploying PET/MR scans on patients, we implemented training and coordination between specialties. In the past, our radiology and nuclear medicine departments had minimal interaction, as PET/CT imaging allows nuclear medicine specialists to act independently. Now, depending on the part of the body, we have a team of specialists involved, sometimes including a neuroradiologist and nuclear medicine physician who collaborate to conduct the scan and interpret the findings.

One Hurdle Encountered

In addition to proper training and coordination across specialty groups, one of the biggest hurdles we had to overcome in implementing PET/MR imaging was that the modality requires more monitoring than a PET/CT scan. PET and PET/CT scans do not require physician monitoring — an initial dose is set and clinicians can return for the reading. MR imaging requires constant attention from the operator to adjust sequences and plans, making sure the area of interest is covered. This workflow change was an obstacle our team had to navigate following installation. 

The Future of PET/MR

In a little more than one year post-FDA clearance, we have seen numerous benefits and advancements in oncology imaging through the use of PET/MR and are pleased with the potential this system has demonstrated in practice. As mentioned, we are beginning to use PET/MR for neuro and pediatric oncology, and sarcomas. We are seeing the potential for very detailed and precise evaluations. Although a PET/MR system may not be an appropriate choice for all healthcare facilities, the larger oncology, cardiovascular and neurology centers will benefit from incorporating PET/MR into their nuclear medicine and radiology protocols. Eventually, we may see this revolutionary imaging system become a mainstream technology, similar to the adoption of PET/CT over the past decade. 

Pablo R. Ros, M.D., MPH, Ph.D., is chairman of the Department of Radiology University Hospitals Case Medical Center, Case Western Reserve University School of Medicine in Cleveland. He has served or serves as president, committee chair or on the board of directors of several radiological societies, such as The Radiological Society of North America (RSNA); Association of University Radiologists; Interamerican College of Radiology (CIR); Society of Gastrointestinal Radiologists; American College of Radiology; and New England Roentgen Ray Society. 

Related Content

Dual-Agent PET/MR With Time of Flight Detects More Cancer

Tc-99m MDP bone scan (left) is negative for osseous lesions. NaF/FDG PET/MRI (right and second slide) confirms absence of bone metastases, but shows liver metastases. Image courtesy of Stanford University.

News | PET-MRI | June 20, 2017
Simultaneous injections of the radiopharmaceuticals fluorine-18 fluorodeoxyglucose (18F-FDG) and 18F-sodium fluoride (...
PET/CT

The Philips Ingenuity TF PET/CT system leverages multiple technologies.

Feature | Radiation Oncology | May 05, 2017 | By Lola Koktysh
The continuum of personalized care, covering individualized prevention and therapy, translates into multiple changes to...
Northwestern Memorial Hospital, MR-PET scanner, first in Illinois, Siemens Biograph mMR
News | PET-MRI | March 31, 2017
Northwestern Memorial Hospital is now home to the Chicago area's first combined magnetic resonance (MRI) and positron...
University of Arizona, Cubresa, NuPET, PET/MRI scanner installed, tumor assessment

Panel A shows a flank A549 lung tumor in a nude mouse with combined 18F-FDG PET uptake (signal intensity in color) and T2-weighted anatomical MRI (grayscale). Panel B shows a similar tumor image with a relative permeability map for the tumor (color code) overlaid on a corresponding anatomical MRI reference. Regions identified as necrotic were not included in the DCE MRI analysis. Image courtesy of the University of Arizona Department of Medical Imaging.

News | PET-MRI | October 13, 2016
Cubresa Inc. recently announced the successful installation of their compact positron emission tomography (PET) scanner...
PET/CT

There is a growing focus on early diagnosis and prevention. Here, PET/CT imaging is used to look inside the stress center of the brain.

Feature | Imaging | September 07, 2016 | By Kirill Shalyaev, Ph.D.
Advanced imaging and hybrid modalities, such as computed tomography (CT), magnetic resonance imaging (MRI), positron...
PET, PET imaging, PET-CT, FDG PET, PET cancer assessment, nuclear imaging, molecular imaging

A PET-CT head and neck cancer scan showing various image reconstructions. The top left image is the separate CT scan showing the anatomy. The top right scan shows the fused PET and CT scans with false color added to help interpret the image. The bottom left scan is an initial FDG PET image showing tracer hot spots in the neck and a lymph node in the right jaw due to cancer. The right bottom image is a delayed enhancement scan showing tracer uptake over time, with normal hot spots in the bladder, kidneys, testicles and brain, which normally have higher metabolic activity. The low-grade gray shading of the anatomy is due to the normal cellular metabolism uptake of the FDG throughout the body. 

Feature | PET Imaging | July 26, 2016 | Dave Fornell
Positron emission tomography (PET) is a nuclear imaging technology (also referred to as molecular imaging) that enabl
News | Prostate Cancer | June 17, 2016
Decatur Memorial Hospital, Decatur, Ill., is now offering C-11 choline positron emission tomography (PET)/computed...
PET, PET imaging, PET-CT, FDG PET, PET cancer assessment

A PET-CT head and neck cancer scan showing various image reconstructions. The top left image is the separate CT scan showing the anatomy. The top right scan shows the fused PET and CT scans with false color added to help interpret the image. The bottom left scan is an initial FDG PET image showing tracer hot spots in the neck and a lymph node in the right jaw due to cancer. The right bottom image is a delayed enhancement scan showing tracer uptake over time, with normal hot spots in the bladder, kidneys, testicles and brain, which normally have higher metabolic activity. The low-grade gray shading of the anatomy is due to the normal cellular metabolism uptake of the FDG throughout the body. 

Feature | PET Imaging | June 03, 2016 | Dave Fornell
Positron emission tomography (PET) is a nuclear imaging technology (also referred to as molecular imaging) that enabl

Early detection of cancer lesions with the latest generation of PET/CT scanners supports improved patient management. Yet much of PET’s potential, particularly for following patients and as a component in PET/MR, remains unrealized. (Image courtesy of Siemens Healthcare and the University of Tennessee, Knoxville)

Feature | Imaging | April 29, 2016 | Greg Freiherr
Adopting medical technology because it is new or novel lost its luster a long time ago. It is little wonder then that...
Mirada Medical, The Christie Hospital, England, PET-MRI, radiation therapy
News | Nuclear Imaging | April 20, 2016
Mirada Medical announced a new agreement to work with the clinicians and physicists at The Christie Hospital in...
Overlay Init