WEDNESDAY, July 6, 2005 (HealthDay News) -- Positron emission tomography (PET) scans detect vaginal cancer more often than CT scans, says a study by researchers at Washington University School of Medicine in St. Louis.
The study found that PET picked up twice as many primary tumors and cancerous lymph nodes in vaginal cancer patients as did CT scans. The findings appear in the July 1 issue of the International Journal of Radiation Oncology.
Vaginal cancer is relatively rare, making up 3 percent of all gynecological malignancies, according to the American Cancer Society. Like cervical cancer, it is linked to infection with the human papillomavirus (HPV) and is highly curable if detected early, before it has spread.
The St. Louis team said their study results suggest that the use of PET would allow for much more accurate diagnosis of vaginal cancer, leading to better treatment decisions. Currently in the United States, Medicaid, Medicare and many private health insurers specify CT only for the diagnosis and monitoring of vaginal cancer.
Until the U.S. Centers for Medicaid and Medicare Services (CMS) reviews and approves the procedure, vaginal cancer patients will most likely not be evaluated using PET scans, the study authors said. However, they're hopeful their findings will help encourage CMS acceptance of PET scans for vaginal cancer patients.
"CT scans are useful in many cases, but they have a limit to their resolution," study author Dr. Perry W. Grigsby, a professor of radiation oncology and radiology, said in a prepared statement. "When you're evaluating lymph nodes for cancer using CT, the node has to be at least a centimeter for it to be considered abnormal. But PET scans can detect much smaller nodes that have cancerous cells."
PET scans are also more effective than CT at detecting small tumors, the researchers said.
The American Cancer Society has more about vaginal cancer.