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Chapter 40
Doppler Ultrasonography
for Gynecologic Malignancies
Ivica Zalud
Ultrasonography has an important role in the evaluation
of patients with a suspected or palpable pelvic
mass. The origin, size, location, internal consistency,
and definition of the walls of the mass, as well as the
presence or absence of ascites or other metastatic lesions,
are the main features determined by ultrasonography.
In clinical practice pelvic tumors are most commonly
divided into three categories: cystic, solid, and
complex. Each category has a relative specificity and
should be viewed within the framework of other clinical
findings as well. Prediction of whether a mass is
benign or malignant according only to its sonographic
appearance is moderately reliable, depending on
the ultrasonographic findings of the septa, papillary
projections, and inhomogeneous solid parts of the
tumor.
The number of false-positive and false-negative sonograms
of adnexal masses has been too high. Most
errors of the sonographic evaluation of pelvic masses
can be attributed to the misinterpretation of displayed
tumor features on the ultrasound monitor.
Ovarian cancer is of particular interest to ultrasonographers
and oncologists since it is the leading
cause of gynecological malignancy mortality in the
United States, affecting 1 in 56 women and causing
about 14,500 deaths annually [1]. The natural history
of this disease remains poorly understood; thus, there
has been no reduction in mortality from this cause in
the past 60 years [1]. Ovarian cancer usually presents
late, greatly reducing the chances of curative therapy.
The 5-year survival rate for stage I disease is approximately
75%, whereas the survival rate for stage IV is
< 5% [1]. Older women are more likely to present
with advanced disease, and their relative 5-year survival
rates are less than half that for women under 65
[1]. Thus the postmenopausal woman must be the
target of any effective screening for ovarian cancer. In
the quest to diagnose ovarian cancer early, various
methods have been advocated for screening in the
asymptomatic postmenopausal woman. In 1971 Barber
and Graber [2] described the postmenopausal
palpable ovary syndrome. At the time, before the
widespread use of ultrasound, they stated that ªa pelvic
mass found during a pelvic examination is the
only practical and consistent method available to us
to detect an ovarian tumor.º
The first report of an attempt to screen women for
ovarian cancer by transabdominal ultrasonography
was by Campbell et al. [3]. The overall specificity of
such a screening procedure was high, but abdominal
ultrasonography as a predictor of malignancy in
postmenopausal women had low specificity [4]. Highfrequency
probes and the vicinity of the explored organs
provided the possibility of exploring small details.
Hence abdominal ultrasonography was abandoned
and transvaginal ultrasonography has been
used extensively. Color Doppler ultrasonography as a
method for transvaginal imaging to assess pelvic
pathology has now been described by many investigators
[5±9]. The absence of intratumoral neovascularization
and a high pulsatility index (PI) can be
used to exclude the presence of invasive carcinoma
[5]. On the other hand, a low resistance index (RI)
value was reported in the case of adnexal malignancies
[8, 9]. The authors agree that low impedance to
blood flow with high blood speed within arteriovenous
shunts is suggestive of malignancy, whereas
moderate to high impedance to blood flow is correlated
to benign tumors.
On the basis of our experience, morphology alone
is of limited value for characterizing adnexal masses.
All ovarian neoplasms should be precisely classified
according to the ultrasound appearance determined
by the shape, size, and inner cystic echoes (e.g., from
the septa, papillary projections, irregularities of the
wall) as well as the echogenicity and loculations.
Transvaginal application of color Doppler (TVCD) sonography
allows visualization of the small vessels that
feed the growing tumor. Color Doppler parameters
(vascular location as peripheral or central; vascular
quality as regular, separated vessels or randomly dispersed
vessels; and Doppler waveform type by means
of low values for the RI or PI) should be combined
with the morphologic tissue characterization to differentiate
benign from malignant pelvic tumors.
The amount and vascularity of the stroma vary
greatly among tumors. Slowly growing tumors are
less vascularized than tumors with a high growth potential.
In general, rapidly growing tumors, particu-