PET Can Identify Effectiveness Of Chemotherapy Early In High-risk Breast Cancer Patients

PET imaging performed at baseline and after the initiation oftreatment “allowed prediction of response as early as after the firstcycle of chemotherapy,” said Norbert Avril, M.D., chief of the divisionof nuclear medicine at the University of Pittsburgh Medical Center,Pittsburgh, Pa. Conventional imaging procedures, such as computedtomography (CT), magnetic resonance imaging (MRI), plain filmradiography and ultrasound, do not reliably predict therapy responseearly in the course of treatment, explained the co-author of “EarlyPrediction of Response to Chemotherapy in Metastatic Breast CancerUsing Sequential ¹⁸F-FDG PET.”

Metastatic breast cancer is the most advanced stage of breastcancer. Cancer cells have spread past the breast and underarm lymphnodes to other areas of the body, continuing to grow, multiply andpossibly spread to other regions of the body. Chemotherapy, which usesdrugs to stop the growth of cancer cells, either by killing the cellsor stopping the cells from dividing, is typically used with patients.At this advanced stage of the disease, the aim of treatment is toimprove survival and quality of life, since the disease is generallynot curable, said Avril. It’s essential to identify those individualswho don’t respond to chemotherapy early “to avoid ineffective therapiesand unnecessary side effects,” he noted. This ability to individualizetreatment gives patients and physicians options not previouslyavailable, added Avril, indicating that additional studies are neededto determine how to use ¹⁸F-FDG PET in a clinical setting.

PET is a powerful medical imaging procedure that noninvasivelydemonstrates the function of organs and other tissues. It is usedprimarily as a diagnostic tool in cardiology, neurology, oncology andmany other medical specialties. To image cancer, a radiopharmaceuticalsuch as fluorodeoxyglucose (FDG), which includes both sugar(metabolized at a higher rate by cancer cells) and a radionuclide, isinjected into the patient. Because cancer cells metabolize sugar athigher rates than normal cells, the radiopharmaceutical is drawn inhigher concentrations to cancerous areas. The PET scan shows where theradiopharmaceutical is by tracking the gamma ray signals given off bythe radionuclides.

Avril co-wrote “Early Prediction of Response to Chemotherapy in Metastatic Breast Cancer Using Sequential ¹⁸F-FDGPET” with Joerg Dose Schwarz, M.D., Michael Bader, M.D., GabrieleHemminger, M.D., and Fritz Janicke, M.D., department of gynecology, andLars Jenicke, M.D., department of nuclear medicine, all at theUniversity Hospital Hamburg-Eppendorf, Hamburg, Germany.