Efficacy of 18F-FDG PET/CT in the evaluation of patients with recurrent cervical carcinoma

Abstract

Purpose: Only a limited number of studies have evaluated the efficacy of 18F-FDG PET/CT for recurrent cervical carcinoma, which this study seeks to expand upon.

Methods: This is a retrospective study of 30 women with cervical carcinoma who had a surveillance PET/CT after initial therapy. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were calculated using a 2 × 2 contingency table with pathology results (76%) or clinical follow-up (24%) as the gold standard. The Wilson score method was used to perform 95% confidence interval estimations.

Results: The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of PET/CT for the detection of local recurrence at the primary site were 93, 93, 93, 86, and 96%, respectively. The same values for the detection of distant metastases were 96, 95, 95, 96, and 95%, respectively. Seventy-one percent of the scans performed in symptomatic patients showed true-positive findings. In comparison, 44% of scans performed in asymptomatic patients showed true-positive findings. But, all patients subsequently had a change in their management based on the PET/CT findings such that the effect was notable. The maximum standardized uptake value ranged from 5 to 28 (average: 13 ± 7) in the primary site and 3 to 23 (average: 8 ± 4) in metastases which were significantly different (p = 0.04).

Conclusion: This study demonstrates favorable efficacy of 18F-FDG PET/CT for identification of residual/recurrent cervical cancer, as well as for localization of distant metastases.

Fig. 1

PET/CT scan of a 60-year-old woman with cervical cancer. Maximum intensity projection (MIP, a), as well as transaxial CT (b), PET (c), and fused (d) images show the primary lesion. Widespread pulmonary, mediastinal, and hilar lymph node metastases are also seen on the MIP image. Of note, radiation treatment planning markers are also seen on the MIP image

Fig. 2

A 36-year-old woman with cervical carcinoma. Focal uptake in the region of the uterine cervix is worrisome for residual/recurrent disease. However, pathologic assessment subsequently showed granulation tissue. As such, this is an example of a false-positive finding with PET/CT

Fig. 3

Box-and-whiskers plot of the SUV_max values at the primary site and in distant metastases. Upper line upper limit, light grey box 75th percentile, black line 50th percentile, dark grey box 25th percentile, lower line lower limit. The median SUV_max of the metastases were significantly different from the SUV at the primary site (p value=0.04). Other comparisons were not significantly different

Fig. 4

Comparison of the sensitivity and specificity of PET/CT for the evaluation of recurrent cervical cancer from this and other published reports