Page 32 - textbook5chapters

122 Ultrasonography in Gynaecological Cancers
Preoperative Differentiation of Benign and
Malignant Ovarian Tumour
Transvaginal ultrasonography is the first-line and best
imaging technique for characterising adnexal masses
preoperatively. The optimal approach is the subjective
assessment of ultrasound images by experts (54, 55).
An alternative evidence-based approach to the pre-
surgical diagnosis of adnexal tumours is to use simple
ultrasound rules or logistic regression models (LR1 and
LR2) developed by the International Ovarian Tumour
Analysis (IOTA) group (http://www.iotagroup.org)
(Figure 9) (8, 10). The condition for the functioning of
predictive models is maintaining uniform ultrasound
terminology of ovarian lesion defined by IOTA group
(Figure 10) (13). Performance of predictive models
developed by IOTA group match subjective assessment
by experienced examiners and should be adopted as
the principal test to characterise masses as benign or
malignant (11). Measurements of serum CA 125 are not
necessary for the characterisation of ovarian pathology
in premenopausal women and are unlikely to improve
the performance of experienced ultrasound examiners
even in the postmenopausal group (55-57). However,
in postmenopausal patients, serum CA 125 may play a
role as a second-stage test, especially in centers with less- (60). In this study published by Tempany et al, CT and
experienced ultrasound examiners (58).
For clinical practice, it is important not only to
distinguish benign and malignant tumours, but also to
specify the type of malignant tumour. An experienced
examiner can give us a conclusive tumour-specific
diagnosis by combining ultrasound (sonomorphological
and Doppler features of an adnexal mass and tumour
characteristic spread pattern) with clinical data (history
of malignancy, age, symptoms) and tumour marker
profile (Figure 11). In addition, the IOTA group proposed
a mathematical model, the so-called ADNEX model (the
Assessment of Different NEoplasias in the Adnexa),
which is able to distinguish benign ovarian tumour,
borderline ovarian tumour, primary early ovarian
cancer, primary advanced ovarian cancer or metastatic
(secondary) ovarian tumour (59). The model developed
by Van Calster et al. was tested using the data from 6000
women with ovarian lesions and contains 9 variables:
age of the patient, serum CA 125, the maximum size of
the lesion, the proportion of solid components, number
of locules >10, the number of papillary prominences,
the presence of acoustic shadow, ascites and type of
center (tertiary hospital vs. others). The test reliably
distinguished benign and malignant lesions (AUC 0.94)
and the accuracy of the test, with different tumour types,
ranged from AUC 0.71 to 0.99 (59).
Staging
Ultrasound scanning of the pelvis and abdomen for
staging requires an experienced examiner. A detailed
review of how to scan gynaecological cancers for staging
(methodology, terminology, clinical implementation)
has been published (21). The advantages and limitations
of modern imaging methods in preoperative staging of
ovarian cancer including the ultrasound technique are
summarised in another recent review (2).
It has been shown that ultrasound can assess pelvic
and intra-abdominal spread of ovarian cancer with
satisfactory concordance with laparotomic findings
according to three available ultrasound studies on ovarian
cancer staging (60-62). These studies have shown, similar
to other imaging techniques, a limitation of ultrasound
in terms of low sensitivity especially in the assessment
of upper abdomen and retroperitoneum, which further
supported the role of comprehensive surgical staging.
Sensitivity of ultrasound in the detection of peritoneal,
lymphatic and hematogenous spread was between 69-
82.5%, 32-34.5% and 57-93%, but ultrasound revealed
an excellent specificity over 90% in detection of ovarian
cancer staging (Figure 12) (60-62).
The first report was published by the Radiological
Diagnostic Oncology Group in 2000 and included
118 malignant cases (73 patients in advanced stage)
MR imaging were more accurate than ultrasound,
particularly in the subdiaphragm and along the hepatic
surface. However, the accuracy of ultrasound was also
high and the authors advocated the use of ultrasound
to supplement CT (computed tomography) or MRI in
hepatic and lymph nodes assessment.
The second study was published by Testa et al
in 2012 assessing not only tumour spread but also
the ability of ultrasound to predict the likelihood of
suboptimal cytoreduction (61). In a study of 147 patients
enrolled between 2005 and 2008, ultrasound delivered
the best results in the assessment of pelvic and hepatic
involvement, a very reliable result in the detection of
abdominal peritoneal parietal involvement, but lower
sensitivity in the assessment of mesenterial involvement,
splenic hilum infiltration and splenic metastases. In
this study, a model for the prediction of suboptimal
cytoreduction showed sensitivity of 31% and specificity
of 92%.
The largest study on ultrasound ovarian cancer
staging published to date, included prospectively 394
patients (75% suffered from advanced stage). Ultrasound
showed high sensitivity and specificity in the assessment
of the pelvis and omentum, but in the assessment of
the upper abdomen (diaphragm), mesentery and the
retroperitoneum was less sensitive (62).
Ultrasound Guided Tru-Cut Biopsy
Ultrasound and CT enable reliable navigation of tru-
cut (core-cut) biopsy in order to achieve a histological
diagnosis using a minimally invasive approach. The