Visual analysis of 18F-FDG PET Scans: Effective prognostic tool for cervical cancer patients

When developing a treatment plan for cervical cancer, it is important to be able to determine a patient’s prognosis, ideally at the time of diagnosis. Existing methods to arrive at a prognosis can be time consuming, inaccurate and may require specialized software. Therefore, doctors from the Washington University School of Medicine developed – and validated – an accurate, reproducible and quick prognostic system.

The researchers created a grading scale to use in conjunction with a simple visual analysis of 18F-FDG PET scans. The grading system considered the size and shape of the primary tumor, as well as the heterogeneity of 18F-FDG uptake and presence of lymph nodes. A cutoff value was established to separate the women with “good” and “bad” prognoses, and Kaplan-Meier analysis provided a guideline both for progression-free survival and for overall survival. Researchers also examined whether knowledge about the presence of lymph notes impacted the efficacy of the system.

The retrospective study was conducted using data from 47 patients. Three independent observers, who had no knowledge of the patients, evaluated and graded the PET scans. The close scores and survival prognoses of the three observers demonstrated the reproducibility of the test. A comparison of the observers’ projected outcomes and the actual outcomes verified the accuracy and the power of this visual analysis; for example, 80% of those women who were predicted to have a bad diagnosis did not survive while only 10% with a good prognosis died. The information about the presence of lymph nodes increased the accuracy only slightly compared to the analysis of tumor characteristics alone.

Improved Prognostic Value of 18F-FDG PET Using a Simple Visual Analysis of Tumor Characteristics in Patients with Cervical Cancer, published in the February 2003 issue of The Journal of Nuclear Medicine, describes a simple qualitative technique for developing a prognosis for women with cervical cancer. The article was written by: Tom R. Miller, MD, PhD, Edward Pinkus, MD, and Farrokh Dehdashti, MD, Mallinckrodt Institute of Radiology as well as Perry W. Grigsby, MD, Department of Radiation Oncology, all from the Washington University School of Medicine, St. Louis, Missouri.

Copies of the article and images related to the study are available to media upon request to Kimberly A. Bennett. Copies of the current and past issues of The Journal of Nuclear Medicine are available online at jnm.snmjournals.org. Print copies can be obtained at $15 per copy by contacting the SNM Service Center, Society of Nuclear Medicine, 1850 Samuel Morse Drive, Reston, VA 20190-5315; phone: 703-326-1186; fax: 703-708-9015; e-mail: servicecenter@snm.org. A yearly subscription to the journal is $170. A journal subscription is a member benefit of the Society of Nuclear Medicine.

The Society of Nuclear Medicine is an international scientific and professional organization of more than 14,000 members dedicated to promoting the science, technology, and practical applications of nuclear medicine. The SNM is based in Reston, VA.