Preoperative ultrasound study in predicting lymph node metastasis for endometrial cancer patients

Objective. The objective of this study was to evaluate the efficacy of preo perative ultrasound (US) findings such as tumor size, status of myometrial invasion, and intratumoral "resistance index" (RI) in predicting lymph node metastasis in endometrial carcinoma patients. Methods. Forty-two patients with endometrial cancer were enrolled. All pati ents underwent total abdominal hysterectomy, pelvic lymph node dissection o r sampling, and para-aortic lymph node sampling. Two-dimensional and color Doppler US were performed before surgery to measure tumor size, depth of my ometrial invasion, and intratumoral arterial RT. Formalin-fixed, paraffin-e mbedded pathologic slides from surgical specimens were reviewed by a senior pathologist to evaluate histologic type and grade, depth of myometrial inv asion, cervical involvement, lymphvascular emboli, and status of lymph node metastasis. Results. There were 12 patients with pelvic andlor para-aortic lymph node m etastases and 30 patients without nodal metastases. Patients with tumors la rger than 2.5 cm by US (11/12 vs 14/30, P = 0.008), more than half myometri al invasion by US (9/12 vs 5/30, P < 0.001), and intratumoral RI values les s than 0.4 by US (12/12 vs 4/30, P < 0.001) had a significantly higher inci dence of nodal metastases as compared with patients with tumors smaller tha n 2.5 cm, no or superficial myometrial invasion, and RI values higher than 0.4, respectively. Multiple regression analysis showed that only intratumor al RI values less than 0.4 were significantly correlated with nodal metasta sis (P < 0.001, r(2) = 0.650). We used the intratumoral RI value as the par ameter to evaluate nodal metastasis in endometrial cancer patients. Twelve of sixteen patients with intratumoral RI values <0.4 had a high incidence o f nodal metastases. None of the 26 patients with intratumoral RI values >0. 4 had nodal metastases. Conclusions. Preoperative ultrasound features can offer important informati on for predicting lymph node metastasis in endometrial cancer patients. Pat ients with tumors with intratumoral RI values less than 0.4 should be highl y suspected of having lymph node metastases and further management such as pelvic lymph node dissection or postoperative pelvic radiotherapy would be needed for these patients. (C) 1998 Academic Press.