Advances in magnetic resonance imaging of endometrial cancer

Abstract

Endometrial cancer is the most commonly diagnosed gynaecological malignancy in affluent societies [1]. It occurs most frequently in white women, with peak incidence between ages 55 and 65. Risk factors include unopposed oestrogen intake, use of tamoxifen, nulliparity, obesity, and diabetes. The incidence of endometrial cancer in the United Kingdom has increased by more than 40% between 1993 and 2007. This significant rise is predominantly due to a large increase in incidence in women aged 60-79 [1]. These trends are very similar for most European countries [2]. The increase in prevalence of obesity and decreases in fertility may partly account for the observed rapid increase in incidence and imply that endometrial cancer in postmenopausal women will become a more substantial public health problem in the future.Prognosis depends on a number of factors, including stage, depth of myometrial invasion, lymphovascular invasion, nodal status and histological grade. Depth of myometrial invasion is the single most important morphologic prognostic factor, correlating with tumour grade, lymph node metastases and overall patient survival. Incidence of lymph node metastases increases from 3% with superficial myometrial invasion (stage IA) to 46% with deep myometrial invasion (stage IB) [3]. Preoperative knowledge of these factors is crucial in tailoring the surgical approach. The histological grade can be determined at endometrial sampling, whereas depth of myometrial invasion can only be assessed preoperatively by MRI. Therefore, MRI can assist in preoperative assessment and treatment planning by accurately predicting depth of myometrial invasion, cervical stromal invasion and lymph node involvement. This information allows selection of patients for pelvic or para-aortic lymph node sampling whilst obviating the need for surgery in patients with low risk disease. MRI can also provide additional useful information such as uterine size, tumour volume, ascites and adnexal pathology which in turn may determine whether the surgical approach is transabdominal, transvaginal or laparoscopic.Lymphadenectomy in early (stage I) endometrial cancer remains a controversial issue. Two large prospective multicentre studies investigated whether pelvic lymphadenectomy could improve survival of women with endometrial cancer [4,5]. Both studies reported no benefit in overall or recurrence free survival in the patients randomized to lymphadenectomy. Conversely, the SEPAL study [6] showed that in patients with intermediate or high risk of endometrial cancer recurrence, combined pelvic and paraaortic lymphadenectomy reduced the risk of death compared with pelvic lymphadenectomy alone. The authors acknowledged that MRI is an important factor for predicting lymph node metastasis, and in combination with tumour grade and histology could be helpful to discriminate patients with very low risk of recurrence. Therefore,

Standard 1.5-T MRI of endometrial carcinomas: modest agreement between radiologists

“…The evaluation of myometrial invasion was primarily based on contrast-enhanced T1-weighted imaging acquired in the equilibrium phase (2-min delay) as opposed to dynamic contrast-enhanced series used in the studies giving data for contrast-enhanced T1-weighted imaging [17,18]. The equilibrium phase is, however, optimal for assessment of deep myometrial invasion [28,29]. As the revised FIGO staging system [22] does not discriminate between tumour confined to the endometrium and tumour invading the inner 50% of the myometrium, merged as FIGO stage 1A in the 2009 revision, it has been advocated that early enhanced images, suited to detecting superficial myometrial invasion, are unnecessary [29].…”

“…The equilibrium phase is, however, optimal for assessment of deep myometrial invasion [28,29]. As the revised FIGO staging system [22] does not discriminate between tumour confined to the endometrium and tumour invading the inner 50% of the myometrium, merged as FIGO stage 1A in the 2009 revision, it has been advocated that early enhanced images, suited to detecting superficial myometrial invasion, are unnecessary [29]. Thus, it is unlikely that the differences in protocols have greatly affected the results of myometrial invasion assessment.…”

PET/MRI and PET/CT in advanced gynaecological tumours: initial experience and comparison

“…MRI, due to its higher soft tissue contrast, was proven superior for characterization of adnexal masses and loco-regional tumour staging, e.g. the identification of parametrial invasion in cervical cancer or the depth of myometrial invasion of endometrial carcinoma [7][8][9][10]. However, there is still a controversial discussion concerning advantages of MRI compared to CT and PET/CT for detection of suspicious lymph nodes [2,14].…”

Optimization of MR Imaging for Pretreatment Evaluation of Patients with Endometrial and Cervical Cancer

“…Patients that present with an early stage low or intermediate risk disease, which includes stage IA grade 1, 2 and 3, and stage IB grade 1 or 2 endometroid histology can be treated appropriately with minimally invasive laparoscopic hysterectomy and bilateral salpingoophorectomy. This approach leads to reduced morbidity and hospital stay, and in this group has comparable outcomes to the more extensive surgical resection, which should be reserved for high risk patients with stage IB grade 3 endometrioid, or stage II and above, and all grades non-endometrioid histology, or (4-7). However, the effective implementation of this treatment approach relies heavily on accurate pre-surgical staging.…”