PET, a technology that produces images of the metabolic function of tissue, was used in a study of 64 patients with oesophageal cancer. The patients were tested for cancer after treatment with a combination of chemotherapy and radiation (chemoradiation).
"While additional multi-centre studies are needed, the research clearly shows that PET is a useful tool for identifying patients who respond well to chemoradiation," said Edward A. Levine, M.D., lead investigator. "Being able to identify these responders may alter the need to take some patients to surgery."
Over the past two decades, the most common treatment for oesophageal cancer has been chemoradiation followed by surgery. Even with these treatments, the prognosis is poor for most patients, with long-term control rates of 25 to 35 percent. Some patients, however, respond well to chemoradiation and have improved long-term survival.
Identifying which patients will respond to chemoradiation alone – and perhaps avoid surgery – has been difficult. Conventional imaging, including both computed tomography (CT) and endoscopic ultrasound (EUS), are poor predictors of response to chemoradiation.
Recently, PET was shown to be more accurate than CT and EUS in evaluating newly diagnosed patients to determine the extent of the disease. So, the researchers decided to evaluate its ability to determine response to chemoradiation.
The study was conducted between 2000 and 2004 in patients whose cancer had not spread beyond the oesophagus and lymph nodes. Patients had a PET scan both before and after chemoradiation. Then, four to six weeks later, eligible patients had surgery to remove part of the oesophagus. The surgical pathology reports from 41 patients were compared to PET results – and PET was found to be 88 percent accurate at correctly identifying patients without disease.
MEDICA.de; Source: Wake Forest University Baptist Medical Center