The findings from an Ontario clinical study shows that PET scanning can be used in addition to the more conventional CT imaging to stage locally advanced cervix cancer to potentially change treatment plans in freshly diagnosed women.
The research was published in JAMA Network Open recently. Co-principal investigators of the study are Dr. Anthony Fyles, a radiation oncologist at Princess Margaret Cancer Centre and Dr. Lorraine Elit, a gynecologic oncologist at Hamilton Health Sciences’ Juravinski Cancer Centre. They explain: “We met our goal of determining whether adding PET detects more extensive disease and influences treatment. The study showed that patients who had PET were twice as likely to have a change in their treatment.”
Locally advanced cervix cancer – about 40-50 per cent of all cervix cancers – is inoperable, but potentially curable with chemotherapy and radiation therapy. Women eligible for PET have involved or suspicious lymph node metastases on CT, in which case PET can show additional nodal disease not seen on CT.
Dr. Fyles, also a professor of Radiation Oncology, University of Toronto, says: “With PET we always learn more about disease, but does that knowledge change what we do in treating patients? In this instance it did and it’s extremely gratifying to provide new evidence that changes clinical practice.”
“This trial was a team effort,” says Dr. Elit, professor of Obstetrics and Gynecology, McMaster University. “It is an example of how physicians who treat women with cervical cancer can work together to carry out a high-quality study, the results of which ultimately change practice in our province. As a result of our research, the access to PET scans for women with this disease has expanded in Ontario.”
Study author Dr. Mark Levine, professor of Oncology, and director, Ontario Clinical Oncology Group (OCOG) at McMaster, adds that although previous studies showed PET scanning could detect more tumours than usual tests, the Ontario randomized trial is the first to evaluate whether PET leads to a change in clinical management.
The study was conducted between 2010-2014, enrolled 171 women at six regional cancer centres – Princess Margaret, Odette Sunnybrook, Juravinski, London, Ottawa and Thunder Bay – and was coordinated by OCOG and funded by Cancer Care Ontario.
Study participants were over 18 and newly diagnosed. Half of the women received a CT, which shows abnormalities or disease in the body area scanned. The other half received a CT plus a PET scan, which reveals “hot spots” of cell activity or growth that can indicate cancer. About twice as many women in the PET arm received more extensive radiation then their counterpart that only had a CT scan.