News | Oncology Diagnostics | June 23, 2016

CT-Based Calculations Improve Accuracy of PET for Cancer Patients

Novel method of measuring lean body mass using computed tomography increases precision of molecular imaging

PET-CT, advanced cancer, lean body mass, LBM, SNMMI 2016 study

June 23, 2016 — Cancer patients often experience significant fluctuations in weight and lean body mass (LBM). Neglecting to account for these changes can prevent clinicians from obtaining precise data from molecular imaging, but a new method of measuring LBM takes changes in individual body composition into account for better staging of disease and therapy monitoring, said researchers at the 2016 Annual Meeting of the Society of Nuclear Medicine and Molecular Imaging (SNMMI), June 11-15 in San Diego.

Positron emission tomography (PET) has become a standard of care in cancer patient management. Fluorine-18 fluorodeoxyglucose (F-18 FDG) is a radiotracer that closely resembles the metabolic activity of glucose in cells throughout the body. F-18 FDG emits a signal that is detected by the PET scanner. Image reconstructions of these signals let clinicians know where there are areas of abnormally increased metabolic activity, quantified by standardized uptake values (SUV). Accurate tumor SUVs enable clinicians to assess disease progression, reflected by an increased SUV; stable disease, reflected by no significant changes in SUV; and successful response to therapy, reflected by a decrease in SUV.

Radiotracer tumor SUVs are quantitatively measured using patient weight. However, F-18 FDG is distributed almost exclusively in LBM, not fatty tissue. Current methods of SUV normalization tend to focus on overall weight and may significantly over- or underestimate LBM in cancer patients. For this study, researchers developed a computed tomography (CT) technique that determines patient-specific LBM. This method of SUV normalization, using patient-specific LBM, is termed SULps.

“Patients with advanced cancer tend to lose muscle and may gain fat, and these changes in body composition can significantly modify PET results, independent of the actual metabolic activity of the tumor,” said Alexander McEwan, M.D., principal author of the study from the University of Alberta Edmonton in Alberta, Canada. “Our study shows that CT-derived SULps is a more robust measurement for patients with advanced cancer undergoing PET imaging. If adopted, this simple change in imaging protocol could lead to significantly more effective care for cancer patients.”

Researchers analyzed CT scans in three-month intervals to gauge changes in body composition of patients with advanced cancer. A total of 1,080 intervals of CT were evaluated and just over 50 percent, or 546 intervals, reflected stable LBM. Of this smaller group with stable LBM, 40 percent experienced a decrease in adipose tissue, 35 percent showed no change in adipose tissue, and 25 percent showed an increase in adipose tissue. These changes affect SUV using all calculations except SULps, which accurately reflected metabolic activity via F-18 FDG PET/CT.

More precise PET measurements made with the use of CT data, could increase the accuracy of PET imaging interpretation in ground-breaking clinical trials for new cancer therapies and for more personalized medicine in the clinic.

For more information: www.snmmi.org

Related Content

Amazon Comprehend Medical Brings Medical Language Processing to Healthcare
News | Artificial Intelligence | February 15, 2019
Amazon recently announced Amazon Comprehend Medical, a new HIPAA-eligible machine learning service that allows...
Videos | Radiation Therapy | February 15, 2019
ITN Associate Editor Jeff Zagoudis speaks with Vinai Gondi, M.D., director of research and CNS neuro-oncology at the
Micro-Ultrasound and Artificial Intelligence Combining to Detect Prostate Cancer
News | Prostate Cancer | February 12, 2019
Cambridge Consultants has partnered with Exact Imaging, makers of the ExactVu micro-ultrasound platform, as the two...
Oxford University Hospitals Employs Barco Synergi for Multi-disciplinary Cancer Conferences
News | Oncology Diagnostics | February 06, 2019
Oxford University Hospitals (OUH) is trialing clinical collaboration technology from Barco for its Multi-disciplinary...
News | PET-CT | February 06, 2019
Technological advancements in positron emission tomography/computed tomography (PET/CT) offer both clinicians and pat
Study Assesses Risk of MRI Exams for Patients With Tattoos
News | Magnetic Resonance Imaging (MRI) | February 01, 2019
A new European study concluded that magnetic resonance imaging (MRI) exams pose little risk for people with tattoos,...
Stereotactic Radiotherapy Improves Long-Term Survival in Stage-IV Cancers
News | Stereotactic Body Radiation Therapy (SBRT) | January 31, 2019
The first report from a phase II, multi-center clinical trial indicates stereotactic radiation can extend long-term...
ImaginAb Enrolls First Patient in Phase II PET Agent Clinical Trial
News | Radiopharmaceuticals and Tracers | January 30, 2019
ImaginAb Inc. announced the enrollment of the first patient in the Phase II clinical trial of the company’s CD8+ T Cell...
Videos | Lung Cancer | January 29, 2019
Gregory Videtic, M.D., staff physician in radiation oncology at the Cleveland Clinic, and David Johnstone, M.D., prof