Differentiation between recurrent tumor and benign conditions after treatment of gynecologic pelvic carcinoma: value of dynamic contrast-enhanced subtraction MR imaging.

Abstract

To compare dynamic contrast material-enhanced subtraction and T2-weighted spin-echo (SE) magnetic resonance (MR) imaging in the differentiation of fibrosis from tumor recurrence during the follow-up of treated gynecologic pelvic malignancy. Thirty-four patients (aged 24-82 years) with 18 benign and 35 malignant lesions confirmed by means of surgery (n = 18), biopsy (n = 25), or 18-month follow-up examination (n = 10) underwent dynamic contrast-enhanced subtraction and T2-weighted SE MR imaging. Contrast material enhancement of an abnormal pelvic structure within the first 90 seconds on dynamic contrast-enhanced subtraction images or high signal intensity on T2-weighted SE images was considered indicative of malignancy. The sensitivity, specificity, accuracy, and positive and negative predictive values were 91%, 67%, 83%, 86%, and 86%, respectively, for dynamic contrast-enhanced subtraction imaging and 91%, 22%, 68%, 70%, and 57%, respectively, for T2-weighted SE imaging. More lesions were correctly classified with dynamic contrast-enhanced subtraction imaging than with T2-weighted SE imaging (P < .01). Dynamic contrast-enhanced subtraction imaging is more accurate than T2-weighted SE imaging for differentiating fibrosis from tumor recurrence during the follow-up of treated gynecologic pelvic malignancy. However, use of both sequences is recommended.