**3.2 Imaging**

## **3.2.1 Ultrasound**

Most patients with endometrial cancer will have a transvaginal ultrasound (TVS) as it is the imaging procedure of choice to assess post-menopausal bleeding, the most common presenting symptom. TVS is a non-invasive, readily available and inexpensive test that has a very high sensitivity of 96% for raising suspicion about the presence of endometrial cancer when using a cut-off of ≥5mm endometrial thickness. Its specificity varies between 61% and 81% for all endometrial diseases (Fleischer, 1997; Smith-Bindman et al., 1998). False-negative rates have been reported at around 1% and are due to adenomyosis or distortion of the endometrial lining by fibroids (Smith-Bindman et al., 1998). If morphologic features such as endometrial heterogeneity were added to endometrial thickness, then specificity and the false-negative rate might be improved (Dubinsky, 2004).

After the diagnosis of endometrial cancer is made, TVS could provide information about the depth of myometrial invasion. Loubeyre et al. (2011) reviewed the correlation between the depth of myometrial invasion on TVS and the final pathology in eight studies with a total of 605 patients with endometrial cancer. They found the sensitivity to be 80% (range 58% to 95%) and so too the specificity (range 71% to 92%). Evaluation of cervical involvement by TVS is less informative, with sensitivities varying between 54% and 88% and specificity between 87% and 100% (Celik et al., 2010; Lee et al., 2011; Loubeyre et al., 2011).

The weaknesses of TVS are that it is operator-dependent and lymph nodes cannot be properly evaluated.

#### **3.2.2 CT**

102 Cancer of the Uterine Endometrium – Advances and Controversies

patient-related factors as well as the definitive pathological findings identified to be associated with increased risk of lymph node metastasis and recurrence to group patients into low-, intermediate- and high-risk categories. Other determinate factors are age, tumor grade, non-endometrioid subtype and extension of the disease, including depth of myometrial invasion and lymphovascular space invasion (LVSI) (Creasman et al., 1987;

Low Ia, Grade I & II <3 <5

The disadvantage of this system is that lymph node metastasis is presumed rather than known for certain, and a proportion of patients will be over-treated with adjuvant treatment. Furthermore, if removal of the affected nodes has a therapeutic value, and evidence suggests it has (please refer to section 6), patients would miss out on the survival advantage conferred by a systematic lymphadenectomy. Having access to information about lymph node status pre-operatively would allow surgery to be tailored accordingly. Below, we discuss the currently available methods for pre-operative assessment of the

Four studies have evaluated the role of CA 125 in evaluation of patients with endometrial cancer. All four conclude that a high CA 125 cut-off, ranging from 20 to 40U/ml., is an independent risk factor for extra-uterine disease or lymph node metastasis. Nevertheless, its sensitivity and specificity are only around 80% (Chung et al., 2006; Han et al., 2010; Hsieh et al., 2002; Sood et al., 1997). This means that 1 in 5 patients will be over-treated and 1 in 5

Most patients with endometrial cancer will have a transvaginal ultrasound (TVS) as it is the imaging procedure of choice to assess post-menopausal bleeding, the most common presenting symptom. TVS is a non-invasive, readily available and inexpensive test that has a very high sensitivity of 96% for raising suspicion about the presence of endometrial cancer

≥70 years + 1 RF ≥50 years + 2 RF any age with 3 RF

Low others 3-5 10-15

uterine cancers >30 >25

Risk of metastatic LN (%)

Risk of recurrence at 5 years (%)

10-30 20-25

Kadar et al., 1992; Keys et al., 2004; Morrow et al., 1991).

High

High Stage II-IV, non-endometrioid

**3. Pre-operative assessment of the spread of disease** 

Table 1. Classification of endometrial cancers adjusted to FIGO 2009.

Risk group

Intermediate Risk factors (RF): age, grade III, LVSI present, deep myometrial invasion (>50%)

spread of disease.

**3.1 CA 125** 

undertreated.

**3.2 Imaging 3.2.1 Ultrasound**  CT scan is considered inferior to TVS in determining the depth of myometrial invasion (accuracy around 60%). The ability of CT scan to identify cervical involvement has not been properly investigated. The value of multidetector CT in the staging of endometrial cancer has yet to be explored (Lee et al., 2011; Loubeyre et al., 2011). Using a 1cm cut-off to evaluate pelvic and para-aortic lymph nodes, the sensitivity of CT is only 50% (range 44% to 66%) no better than flipping a coin; its specificity is 95% (range 73% to 98%) (Lee et al., 2011). This poor correlation is due to the fact that only 39% of metastatic lymph nodes are enlarged and 37% are smaller than 2mm (Creasman et al., 1987; Mariani et al., 2000). For the same reason, MRI and PET-CT have similar results in detecting metastatic lymph nodes.

#### **3.2.3 MRI**

The imaging procedure of choice to assess patients with endometrial cancer is MRI, but it is an expensive test and, as mentioned before, is ineffective in detecting metastatic lymph nodes. However, MRI is superior to TVS and CT in evaluating the depth of myometrial invasion as well as cervical involvement (Loubreyre et al., 2011; Lee et al., 2011, on behalf of the American College of Radiology). Loubeyre et al. (2011) reviewed the correlation between depth of myometrial invasion on MRI and final pathology in nine studies with a total of 1,115 patients with endometrial cancer. Sensitivity ranged from 56% to 88% and specificity from 74% to 100%. This group also reviewed the correlation between cervical involvement on MRI and final pathology in five studies with a total of 623 patients with endometrial cancer. Sensitivity ranged from 47% to 72% and specificity from 83% to 100%. In its pretreatment evaluation of endometrial cancer, the American College of Radiology indicates that the accuracy of MRI in predicting myometrial involvement ranges from 85% to 92%, cervical involvement from 86% to 95% and overall staging from 85% to 93% (Lee et al., 2011).

#### **3.2.4 PET**

The role of PET in endometrial cancer is more in the detection of disease recurrence than in the pre-operative evaluation of extra-uterine disease (Lee et al., 2011).
