Magnetic Resonance Imaging (MRI) In Clinical Staging Of Endometrial Carcinoma

Purpose To evaluate the performance of magnetic resonance imaging (MRI) in the detection of deep myometrial invasion and cervical extension for clinical staging of endometrial carcinoma and the value of guiding the choice of surgery; to investigate the potential factors that are associated with the accuracy of MRI.Materials and Methods In this dissertation,the retrospective analysis consisted of 38 patients with endometrial cancer by preoperative diagnostic curettage(D&C) and pelvic MRI, because of vaginal irregular hemorrhage or postmenopausal vaginal hemorrhage or abnormal thickening of endometrium by Doppler ultrasonography, during January 2004 and February 2011 at Shandong university affiliated province hospital(1 patients of MRI and 13 patients of D&C who were done in other hospitals were consulted by doctors in the hospital).The clinical information including the reports of MRI, D&C, ultrasound, surgery, postoperative pathology of these patients was collected by referring to case history. The common sequences of MRI were T1WI, T2WI, FS-T2WI, FS-T2WI, GD-DTPA, COR, TRA, SAG. Postoperative histological diagnosis was taken as the gold standard.Depending on the results of D&C, the patients were divided into three groups: non-endometrial carcinoma group, suspicious group and endometrial carcinoma group), then the accuracy of clinical staging by MRI and the rationality of surgery were evaluated, respectively. In addition, the potential factors influencing on MRI were studied.Statistical treatment:SAS statistical software. Results(1)Predicting deep myometrial and cervical invasion by MRI:For deep myometrial invasion, MRI reached the accuracy of 32/37 (86.8%),the rate of missed diagnosis of 2/8 (25%)and the rate of misdiagnosis of 3/29 (10.3%);for cervical invasion, the accuracy of 27/37 (73.0%),the rate of missed diagnosis of 2/3 (66.7%)and the rate of misdiagnosis of 8/34 (23.5%).In patients with deep myometrial and/or cervical and/or parauterine invasion by MRI, the percent of high risk ones was 14/17 (82.4%); meanwhile,patients with deep myometrial invasion by MRI, high risk ones was 100%.(2)Clinical staging by MRI:In non-endometrial carcinoma group (3 patients),1 patient was stage 0 and 2 stageⅠa/Ⅰb respectively. In suspicious group (10 patients), 9 patients were stage la and 1 stage II (with deep myometrial invasion).In endometrial carcinoma group (25 patients),2 persons had no abnormal signal of uterus,8 ones were stageⅠa,7 ones were reported deep myometrial invasion (4 for stageⅠb,1 forⅡ,2 forⅢ),5 ones were stageⅡand 3 for stageⅢ.(3)The postoperative pathology:One person was complex hyperplasia and thirty seven were endometrial carcinoma. The accuracy of D&C was 34/38 (89.5%) and rate of missed diagnosis 3/37 (8.1%); after combining with MRI, the accuracy was 36/38 (94.7%), and rate of missed diagnosis 1/37 (2.7%).(4)The accuracy of clinical staging by MRI:Compared with postoperative pathological staging, the overall coincidence rate of clinical staging by MRI was 24/38 (63.2%), of which la was 16/18 (88.9%), Ib 3/5 (60%),Ⅱ1/7 (14.3%), andⅢ3/5 (60%). Postoperative histological upstaging was demonstrated in 4/38 (10.5%); MRI over-staging was in 10/38 (26.3%).(5)The performance of surgery:4 of 11 patients (36.4%) with non-rational lymphadenectomy had been related to the inaccuracy of preoperative assessment by MRI (mainly the incorrect diagnosis ofⅡ).(6)The factors influencing MRI:Endometrial polyp were significantly associated with incorrect deep myometrial invasion by MRI (p<0.01), the rate of incorrect deep myometrial invasion was significantly higher in persons with high histological grade and menostasia (p<0.01, p<0.01); the rate of incorrect cervical extesion by MRI was obvously higher in patients with high histological grade and non-endometrioid adenocarcinoma (p<0.01, p<0.01). The rates of incorrect myometrial and cervical invasion in patients with stageⅠwere significantly lower than ones withⅡ/Ⅲ(p<0.01, p<0.01).Conclusion MRI plays a very important role in clinical staging of endometrial carcinoma. (1) MRI can accurately detect the deep myometrial invasion, which could predict high risk patients and help the decision of surgical extent and lymphadenectomy. (2) MRI assists in the preoperative assessment of patients who got uncertain results from D&C, and increases more accuracy in clinical staging of early patients. (3) Wrong assessment of MRI is not the crucial factor resulting in the non-rational lymphadenectomy. (4) Because of its poor sensitivity and accuracy in predicting cervical invasion, so, more attention should be paid to choose methods of surgery for patients with clinical stageⅡ. (5) The interference effect of some factors, such as myoma, adenomyosis, high histological grade and non-endometrioid adenocarcinoma et al, should be considered when assessing by MRI. (6) Up to now, statistical data shows that PET might be superior to MRI in the detection of lymph node metastasis, but it needs more cases to investgate because of its high expense.