Preoperative tumor size at MRI predicts deep myometrial invasion, lymph node metastases, and patient outcome in endometrial carcinomas

Feasibility of a reduced field-of-view diffusion-weighted (rFOV) sequence in assessment of myometrial invasion in patients with clinical FIGO stage I endometrial cancer

PURPOSE

To compare the clinical usefulness of reduced field-of-view diffusion-weighted imaging (rFOV) with other imaging techniques in determining the depth of myometrial invasion (DMI) in endometrial cancer.

MATERIALS AND METHODS

In this prospective study we reviewed 3T magnetic resonance images of 51 patients with clinical Stage I endometrial cancer who underwent total abdominal hysterectomy with bilateral salphingoopherectomy within 3 days after imaging. rFOV with apparent diffusion coefficient reconstruction was obtained in three standard planes followed by sagittal T2 -weighted (T2 WI) images and 3D dynamic T1 -weighted and contrast-enhanced imaging (DCE MRI). Two radiologists with expertise in imaging gynecologic cancers evaluated images independently. The DMI was recorded on imaging and correlated with surgical pathology results. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for DMI were calculated (<50% vs. >50%).

RESULTS

Compared with sagittal T2 WI + DCE MRI, rFOV imaging yielded greater specificity (82.2% vs. 90.0%, positive predictive value (42.8% vs. 60.0%), and accuracy (84.0% vs. 92%) for DMI determined by reader 1 and greater the sensitivity (83.3% vs. 100%) for DMI determined by reader 2. The error of measurement of DMI as a continuous variable in millimeters did not differ significantly between the rFOV and pathology results (P < 0.21). However, there was a statistically significant difference for the DMI measured on the dynamic sequence. The DMI on DCE was greater than that seen on pathology at P = 0.02.

CONCLUSION

rFOV can be used to assess DMI in clinical Stage I endometrial cancer.

Metabolic Tumor Volume on 18F-FDG PET/CT Improves Preoperative Identification of High-Risk Endometrial Carcinoma Patients

Our objective was to prospectively explore the diagnostic value of (18)F-FDG PET/CT for preoperative staging in endometrial carcinomas and to investigate whether (18)F-FDG PET-specific quantitative tumor parameters reflect clinical and histologic characteristics.

METHODS

Preoperative (18)F-FDG PET/CT was prospectively performed on 129 consecutive endometrial carcinoma patients. Two physicians who did not know the clinical findings or staging results independently reviewed the images, assessing primary tumor, cervical stroma involvement and metastatic spread, and determining maximum and mean standardized uptake value (SUVmax and SUVmean, respectively) for tumor, metabolic tumor volume (MTV), and total lesion glycolysis (TLG). All parameters were analyzed in relation to histomorphologic and clinical tumor characteristics. Receiver-operating-characteristic curves for identification of deep myometrial invasion and lymph node metastases were generated, and MTV cutoffs for predicting deep myometrial invasion and lymph node metastases were calculated.

RESULTS

The sensitivity, specificity, and accuracy of (18)F-FDG PET/CT for the detection of lymph node metastases were 77%-85%, 91%-96%, and 89%-93%, respectively. SUVmax, SUVmean, MTV, and TLG were significantly related to deep myometrial invasion, presence of lymph node metastases, and high histologic grade (P < 0.015 for all) and independently predicted deep myometrial invasion (P < 0.015) and lymph node metastases (P < 0.025) after adjustment for preoperative histologic risk (based on subtype and grade) in endometrial biopsies. Optimal cutoffs for MTV in predicting deep myometrial invasion (20 mL) and the presence of lymph node metastases (30 mL) yielded odds ratios of 7.8 (P < 0.001) and 16.5 (P = 0.001), respectively.

CONCLUSION

(18)F-FDG PET/CT represents a clinically valuable tool for preoperatively evaluating the presence of lymph node metastases in endometrial carcinoma patients. Applying MTV cutoffs for the prediction of deep myometrial invasion and lymph node metastases may increase diagnostic accuracy and aid preoperative identification of high-risk patients, enabling restriction of lymphadenectomy for patients with a low risk of aggressive disease.