Some patients with head and neck cancer can be safely spared the risk and expense of surgery by undergoing a CT scan to predict whether the disease is in check after radiation therapy, according to study findings University of Florida doctors released today (Oct. 18) at the annual meeting of the American Society for Therapeutic Radiology and Oncology.
Researchers with the UF Shands Cancer Center have identified criteria doctors can use to evaluate CT scans four weeks after patients undergo initial treatment. If these criteria are met, there is a 94 percent likelihood a patient's lymph nodes are cancer free, said Stanley L. Liauw, M.D., a resident in radiation oncology. Using a CT scan was found to be much more accurate than relying on a physical exam to assess response to treatment.
Radiation therapy is commonly used to treat the more than 40,000 U.S. patients a year who develop advanced head and neck cancer. After radiation therapy, doctors often operate to remove affected lymph nodes. But UF physicians say in some cases surgery is unnecessary, and can increase recovery time, lead to infection and possibly compromise a patient's quality of life.
The current study builds on previous research involving 95 head and neck cancer patients. In two-thirds of the patients who underwent surgery after radiotherapy, the removed lymph nodes turned out to be cancer free, noted UF radiologist Anthony Mancuso, M.D. Mancuso collaborated with UF radiation oncologists Robert Amdur, M.D., Christopher Morris, M.S., and William Mendenhall, M.D.
By comparing nodes visualized on a CT scan with the same nodes after they were removed, the researchers developed criteria doctors could use to examine nodes using a non-invasive CT scan to identify whether the disease was knocked out. Nodes deemed to be clear of cancer were 1.5 centimeters or smaller and had borders that were sharply defined on the CT scan, rather than fuzzy.
In the current study, UF researchers examined the medical records of 549 patients who were treated with radiotherapy at UF for advanced head and neck cancer between 1990 and 2002; 341 patients later underwent surgery to remove lymph nodes. UF doctors, basing their treatment on the results of the previous research, did not remove lymph nodes in patients who met the CT scan criteria. Results confirmed that a CT scan could be used to reliably predict whether the lymph nodes would be negative for cancer.