PASADENA, CALIF. — Imaging for gynecologic cancer has been greatly improved with fusion techniques that combine the structural and anatomic information from ultrasound, MRI, and CT with metabolic clues highlighted by PET scans.
“This is really the wave of the future,” Dr. Robin Farias-Eisner, professor and chief of gynecology at the University of California, Los Angeles, said at a meeting of the Obstetrical and Gynecological Assembly of Southern California.
Advances in traditional imaging techniques over the past 2 decades have been “great, but not good enough,” in terms of their overall sensitivity, specificity, and accuracy, Dr. Farias-Eisner said.
A major problem has been the difficulty of identifying microscopic disease in lymph nodes using modalities that depict anatomy and structure. Lymph node metastases not only have an impact on survival, they also dictate treatment, particularly in cervical cancer.
It is here, said Dr. Farias-Eisner, that positron emission tomography with
He displayed a magnetic resonance image of a 63-year-old woman with stage IIB uterine cervical carcinoma that appeared to show lymphadenopathy. A transaxial PET scan of the same patient showed abnormally high uptake of the FDG isomer, and a fusion scan of the images superimposed on each other demonstrated high uptake in both internal iliac lymph nodes, as well as in the sigmoid colon.
In case after case, the fused image completed the picture, demonstrating metabolic tumor activity in a precise location.
Another advantage of incorporating FDG-PET into the work-up is that it provides an evaluation of the whole body.
Finally, it can point to disease in patients whose normal anatomic landmarks have been lost to surgery or radiation.
Dr. Farias-Eisner also expressed enthusiasm about lymphoscintigraphy, in which technetium is injected to help localize the sentinel lymph node in cervical, endometrial, and vulvar cancers.
Advances in ultrasonography are also being studied internationally, including the use of a microbubble contrast agent that enhances the intensity of malignant tissue, when compared with benign tissue, Dr. Farias-Eisner said.