Quantitative PET imaging finds early determination of effectiveness of cancer treatment

“In our study, we demonstrated that a quantitative assessment of therapeutic response for patients with diffuse large B-cell lymphoma (DLBCL) is more accurate than visual analysis alone when using the radiotracer FDG (fluorodeoxyglucose) with PET scans,” said Michel Meignan, professor of nuclear medicine at Henri Mondor Hospital in Creteil, France.

“The ability to predict tumor response early in the course of treatment is very valuable clinically, allowing intensification of treatment in those patients who are unlikely to response to first-line chemotherapy,” he added. “Similarly, treatment could possibly be shortened in those patients who show a favorable response after one or two cycles of chemotherapy, and quantification also may help identify the disease’s transformation from low-grade to aggressive stage,” he explained. “However, visual interpretation of PET scans will always be the first step of analysis and will prevail in case of difficulties to quantify images,” added Meignan.

Diffuse large B-cell lymphoma is a fast-growing, aggressive form of non-Hodgkin lymphoma, a cancer of the body’s lymphatic system. Although there are more than 20 types of NHL, DLBCL is the most common type, making up about 30 percent of all lymphomas. In the United States, about 63,190 people are expected to be diagnosed with non-Hodgkin lymphoma in 2007, according to recent statistics.

Ninety-two patients with DLBCL were studied before and after two cycles of chemotherapy, and tumor response was assessed visually and by various quantitative parameters, explained the co-author of “Early 18F-FDG PET for Prediction of Prognosis in Patients With Diffuse Large B-Cell Lymphoma: SUV-Based Assessment Versus Visual Analysis.” Meignan said, “We found that quantification of tumor FDG uptake (the ratio of tissue radioactivity concentration) can markedly improve the accuracy of FDG PET for prediction of patient outcome.” Additional studies need to be done, said Meignan, reiterating that the future monitoring of cancer tumor response will probably include a combination of quantitative analysis and visual assessment.

PET is a powerful molecular imaging procedure that uses very small amounts of radioactive materials that are targeted to specific organs, bones or tissues. When PET is used to image cancer, a radiopharmaceutical (such as FDG, which includes both a sugar and a radionuclide) is injected into a patient. Cancer cells metabolize sugar at higher rates than normal cells, and the radiopharmaceutical is drawn in higher amounts to cancerous areas. PET scans show where FDG is by tracking the gamma rays given off by the radionuclide tagging the drug and producing three-dimensional images of their distribution within the body. PET scanning provides information about the body’s chemistry, metabolic activity and body function.

Source: Society of Nuclear Medicine

Dual-Mode Nanoparticles Image Tumors Using MRI and PET
Medical imaging represents one of the most used and useful procedures in the oncologist’s diagnostic toolkit, even though each of the most useful techniques—magnetic resonance imaging (MRI), computerized tomography x-ray imaging (CT), and positron emission tomography (PET) scanning—has its own set of limitations.
Patient's own infection-fighting T cells put late-stage melanoma into long-term remission
Case is first to show safety and effectiveness of using cloned cells alone to kill tumors
Researchers describe the first successful use of a human patient's cloned infection-fighting T cells as the sole therapy to put an advanced solid-tumor cancer into long-term remission. A team led by Cassian Yee, M.D., an associate member of the Clinical Research Division at Fred Hutchinson Cancer Research Center, reports these findings in the June 19 issue of the New England Journal of Medicine.
Researchers develop new PET scanning probe that will allowing monitoring of the immune system
Researchers at UCLA's Jonsson Comprehensive Cancer Center have modified a common chemotherapy drug to create a new probe for Positron Emission Tomography (PET), an advance that will allow them to model and measure the immune system in action and monitor response to new therapies.
PET confirmed as valuable cancer diagnostic and disease-staging tool
The recent release of data by the National Oncologic PET Registry (NOPR) showing that positron emission tomography (PET) produced scans revealing disease at a molecular level, which then caused physicians to change treatment plans for more than one-third of participating patients, has corroborated decades of nuclear medicine research.
Researchers find benefit for lymphoma patients in combined PET-CT scanning
Combined positron emission tomography (PET) and computed tomography (CT) imaging of lymphoma patients is a more effective method to evaluate response to radiation therapy, and may help patients avoid unnecessary follow-up treatments, a study by researchers at the University of Southern California (USC) suggests.
Protein shines light on cancer response
A technique that specifically “tags” tumors responding to chemotherapy may offer a new strategy for determining a cancer treatment’s effectiveness within days of starting treatment, according to a new study by Vanderbilt-Ingram Cancer Center investigators.
Post-treatment PET scans can reassure cervical cancer patients
Whole-body PET (positron emission tomography) scans done three months after completion of cervical cancer therapy can ensure that patients are disease-free or warn that further interventions are needed, according to a study at Washington University School of Medicine in St. Louis.
Unique Collaboration Funded To Develop Nanotechnology For Melanoma
A unique collaboration between electrical engineers, mechanical engineers and cancer researchers may be the perfect combination to improve diagnosis, treatment and follow-up of patients with melanoma.

Quantitative PET imaging finds early determination of effectiveness of cancer treatment

Related stories:

News discussion: