Preoperative FDG PET/CT Helps Detect Distant Metastatic Disease in Cervical and Endometrial Cancer

New Radiology research indicates that preoperative PET/CT imaging can be used to accurately detect distant metastatic disease in women with advanced cervical and high-risk endometrial cancer and would be effective for use in standard staging.

Uterine cervical and endometrial cancer are two of the most common gynecologic malignancies, collectively responsible for over 65,000 new cancer cases and 14,000 cancer-related deaths in the U.S. every year, according to the National Cancer Institute (NCI).

“Standard CT imaging performed prior to surgery may not detect all distant sites of metastatic disease,” said researcher Michael S. Gee, MD, PhD, a radiologist at Massachusetts General Hospital, Boston, who led the study with colleague Susanna I. Lee, MD, PhD, chief of woman’s imaging at the hospital.

“If distant metastatic disease is detected prior to surgery, there is an early opportunity to direct therapy at the sites of metastatic disease and potentially avoid complications associated with procedures such as surgical lymph node dissection,” Dr. Gee said. “With this study, we wanted to see if combination PET-CT imaging before surgery improves detection of distant metastatic disease.”

Dr. Gee and colleagues reviewed PET/CT imaging as well as clinical data of patients originally enrolled in a prospective clinical trial sponsored by the American College of Radiology Imaging Network (ACRIN) and the Gynecologic Oncology Group (GOG). The primary trial, led by Mostafa Atri MD, a professor and division head of abdominal imaging at the University of Toronto, Ontario, evaluated the effectiveness of preoperative fluorine ¹⁸ fluorodeoxyglucose (FDG PET/CT) in detecting lymphadenopathy patients with local-regionally advanced cervical and high-risk endometrial carcinoma.

The ACRIN/GOG study, which received funding from the NCI, included 153 cervical cancer and 203 endometrial cancer patients recruited from 28 different medical centers across the country. Researchers found that 13.7 percent of cervical cancer patients and 11.8 percent of endometrial cancer patients had unsuspected distant metastases. Preoperative PET/CT detects the majority of cervical cancer (54.8 percent) and endometrial cancer (64.6 percent) distant metastases with high specificity and positive predictive value (both values > 90 percent), the study showed.

“Our results indicate that more than 10 percent of patients have distant metastatic disease at the time of cancer diagnosis that is detectable by PET/CT,” Dr. Gee said. “The study demonstrates that PET/CT should be an important part of the initial medical workup of cervical and endometrial cancer patients.”

FDG PET/CT as Standard Staging

Based on the study’s results, Dr. Gee recommends FDG PET/CT imaging for staging advanced cervical and high-risk endometrial cancer patients.

“A substantial proportion of patients in our study group with cervical or endometrial cancer had distant metastatic disease that was not known prior to imaging,” Dr. Gee said. “PET-CT played a critical role in treatment planning for these patients.”

Future studies are needed to determine how the results of preoperative PET-CT imaging affect treatment decision making and whether these decisions improve patient outcomes, Dr. Gee said.