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Back ground: Endometrial cancer is currently the most common gynecologic malignancy of the female pelvis in the world. The extent of lymph node (LN) metastasis is an important prognostic factor, MRI can help accurately for the distinction non-metastatic and metastatic LNs in endometrial cancer; and can provide supplementary information to determine therapeutic strategies.

Purpose: The aim of this study to demonstrate diagnostic value of MRI imaging in discrimination of metastatic and non-metastatic pelvic lymph nodes in endometrial cancer.

Materials & Methods: In this retrospective study, 33 patients with proved endometrial cancer were studied in MRI ward of the imaging center of Imam Khomeini Hospital in Tehran. The subjects, selected by purposeful sampling method, underwent the pelvis imaging before the surgery. T1W and T2W, T1-W sequence with contrast enhancement, and the diffusion technique (b= 50, 400 and 1000 s/mm2) were used in the imaging. And for each lymph node ADC values: ADC max, ADC min, ADC mean and rADC.

Result: Average (± standard deviation) mean, maximum and relative ADC region value (0.757±0.247, 0.915±0.290 and 0.58±0.20 ×10-3 mm2/s) of metastatic sites (n=17) were significantly lower than those of non-metastatic ones (n=31; 1.10±1.47, 1.40±0.212 and 0.91±0.23; p-value = <0.001). Sensitivity, specificity, positive and negative predictive value and accuracy were respectively for the; morphology (94, 83, 76, 96 and 87%) T1W (88, 83, 75, 92, and 85%) T2W (82, 77, 66, 88 and 79%) DWI (100, 80, 73, 100 and 78%) ADC mean at Cutoff point ≤1000 (94, 94, 89, 97 and 94%). Short axis size at cutoff point ≥10 mm was respectively (76, 87, 76, 87 and 38%). As for the contrast enhancement the AUC was Difference of signal intensity after contrast 0.68 and Percentage of Signal intensity difference after contrast 54 (P-Values=0.037and 0.69 respectively).

Conclusion: MRI useful means for differentiation between metastatic and benign LNs in patients with endometrial cancer, by several Standard criteria in addition to DWI with ADC values well be improve the accuracy percentages, to be a promising noninvasive modality for evaluating lymph nodes in patients with endometrial cancer.

Key Words:

MRI; Diffusion-weighted imaging endometrial cancer; non-metastatic and metastatic; Pelvic lymph nodes

Supervisors: V. Changizi, Professor

Advisors: Dr. H. Sourosh

External Reviewers: Dr. R. Paydar

Internal Reviewers: Dr. F. Pak