Public Release: 

FDG-PET imaging clearly predicts lung cancer patients' response to chemotherapy

Repeating molecular imaging studies provides valuable information for better patient care, say researchers in May Journal of Nuclear Medicine

Society of Nuclear Medicine

RESTON, Va. -- An earlier indication of whether chemotherapy benefits non-small cell lung cancer patients--provided by positron emission tomography (PET) imaging--can guide doctors in offering them better care, according to researchers in the May Journal of Nuclear Medicine.

"Our study demonstrates that patients who respond to chemotherapy can be identified early in the course of their treatment, and these patients will generally exhibit prolonged overall survival," explained Claude Nahmias, professor of radiology and medicine at the University of Tennessee Medical Center in Knoxville. "Although we studied a relatively small number of patients--and our results should be interpreted with caution--it is clear that a repeat PET study with the radiotracer fluorodeoxyglucose (FDG) at the end of the first cycle of chemotherapy would allow the identification of those patients for whom the therapy was futile," he said. "The ability to provide an early indication of therapeutic response has the potential to improve patient care by identifying those patients who do not benefit from their current treatment," explained Nahmias. "Patients would benefit from either having chemotherapy and its associated toxic side effects stopped or going on to a different, and hopefully more adequate, therapeutic approach," added the co-author of "Time Course of Early Response to Chemotherapy in Non-Small Cell Lung Cancer Patients With 18F-FDG PET/CT."

Non-small cell lung cancer is the most common type of lung cancer, usually growing and spreading more slowly than small cell lung cancer. Lung cancer is the second most common cancer and the most common cause of cancer-related death in both men and women in the United States. In 2007, about 213,380 new cases of lung cancer (both small cell and non-small cell) are expected in the United States, and about 160,390 people will die of this disease. For most patients with non-small cell lung cancer, current treatments do not cure the cancer.

"With non-small cell lung cancer--since the relatively modest increase in survival must be balanced against the toxicity of the chemotherapeutic treatment--the case for monitoring therapeutic response is especially compelling," said Nahmias. "To assess the response to chemotherapy in patients with advanced non-small cell lung cancer, all of the studies published thus far have evaluated the patients at one, or at most two, time points after the initiation of chemotherapy," said Nahmias. "In our study, we evaluated 15 patients weekly--for seven weeks--as they started their chemotherapy regiment. In spite of the persuasive findings of several studies investigating PET for monitoring response to cancer therapy, until now no published reports have clearly demonstrated that PET results were used to alter treatment," he noted.

PET is a powerful molecular imaging procedure that noninvasively demonstrates the function of organs and other 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.

"Our result--that PET studies one and three weeks after initiation of cancer therapy can predict success or failure of the therapy--should be validated in a larger study in which patients are enrolled with the intention of applying it in patient management," said Nahmias. He added, "I am forever grateful to all the patients who came back week after week to undergo our PET scans."

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"Time Course of Early Response to Chemotherapy in Non-Small Cell Lung Cancer Patients With 18F-FDG PET/CT" appears in the May issue of the Journal of Nuclear Medicine, which is published by SNM, the world's largest molecular imaging and nuclear medicine society. Other co-authors are Wahid T. Hanna, Misty J. Long, Karl F. Hubner and David W. Townsend, departments of Medicine and Radiology, University of Tennessee, Knoxville, and Lindi M. Wahl, Department of Applied Mathematics, University of Western Ontario, London, Canada.

Media representatives: To obtain a copy of this article, please contact Maryann Verrillo by phone at (703) 652-6773 or send an e-mail to mverrillo@snm.org. Current and past issues of the Journal of Nuclear Medicine can be found online at http://jnm.snmjournals.org. Print copies can be obtained by contacting the SNM Service Center, 1850 Samuel Morse Drive, Reston, VA 20190-5316; phone (800) 513-6853; e-mail servicecenter@snm.org; fax (703) 708-9015. A subscription to the journal is an SNM member benefit.

About SNM--Advancing Molecular Imaging and Therapy SNM is an international scientific and professional organization of more than 16,000 members dedicated to promoting the science, technology and practical applications of molecular and nuclear imaging to diagnose, manage and treat diseases in women, men and children. Founded more than 50 years ago, SNM continues to provide essential resources for health care practitioners and patients; publish the most prominent peer-reviewed journal in the field (the Journal of Nuclear Medicine); host the premier annual meeting for medical imaging; sponsor research grants, fellowships and awards; and train physicians, technologists, scientists, physicists, chemists and radiopharmacists in state-of-the-art imaging procedures and advances. SNM members have introduced--and continue to explore--biological and technological innovations in medicine that noninvasively investigate the molecular basis of diseases, benefiting countless generations of patients. SNM is based in Reston, Va.; additional information can be found online at http://www.snm.org.

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