Original Article

Yonago Acta medica 2016;59:255-261

Contrast-Enhanced Ultrasonography in Evaluation of the Therapeutic Effect ofChemotherapy for Patients with Liver Metastases
Naoyuki Ueda,* Haruki Nagira,* Naoko Sannomiya,* Saeko Ikunishi,* Yuiko Hattori,* Akira Kamida,* Yuki
Koyanagi,* Kenta Shimabayashi,* Kengo Sato,* Hiroaki Saito† and Yasuaki Hirooka**Department of Pathobiological Science and Technology, School of Health Science, Tottori University Faculty of Medicine, Yonago 6838503, Japan and †Division of Surgical Oncology, Department of Surgery, School of Medicine, Tottori University Faculty of Medicine,
Yonago 683-8503, Japan

ABSTRACT

therapeutic effect after the fourth chemotherapy cycle.
The findings of this study suggest that
ROC of the slope of wash-in and the area under the
curve of the TIC are useful in evaluating the therapeutic
effect of chemotherapy. Furthermore, there is a possibility that TIC analysis may enable early prediction of thetherapeutic effect.

Background

Conclusion

The therapeutic effect of chemotherapy
for liver metastases is currently determined by changes intumor diameter depicted on computed tomography (CT)and magnetic resonance imaging, but it cannot accurately
determine if there is central necrosis. Furthermore, due
to the risk of radiation exposure and high cost, frequentexamination using these methods places a heavy burden
on patients. Meanwhile, real-time observation of bloodflow and vessel morphology within tumors has become
possible by contrast-enhanced ultrasonography (CEUS).
However, use of CEUS in evaluating the therapeutic
effect of anticancer chemotherapy has rarely been investigated. This study investigated whether changes in thetime-intensity curve (TIC) of CEUS are useful indicatorsof the therapeutic effect of chemotherapy.
Methods Five patients with liver metastases who had
undergone CEUS before and after chemotherapy were
included in this study. The TIC of each time point was
prepared to examine whether the following five TIC
parameters serve as indicators of the therapeutic effectof chemotherapy: peak intensity, time to wash-in, timeto peak intensity, slope of wash-in, and area under the
curve. In each parameter, rate of change (ROC) was calculated by the expression [(values before chemotherapy
minus those after chemotherapy)/those before chemotherapy × 100(%)].
Results (i) Among the five TIC parameters tested,
ROC of the slope of wash-in and the area under the
curve reflected the therapeutic effect of chemotherapy
better than the remaining three parameters. (ii) TIC parameters after one cycle of chemotherapy were examinedin two of five patients, and changes in the slope of washin and the area under the curve were in good agreementwith the computed tomography findings indicative of the

Key words liver; neoplasm metastases; Sonazoid; timeintensity curve; ultrasonography

The therapeutic effect of chemotherapy for liver metastases is currently determined by changes in tumor
diameter depicted on computed tomography (CT) andmagnetic resonance imaging, but it cannot accurately
determine if there is central necrosis. Frampas et al.
reported that it was possible to predict the therapeutic
effect by the change in tumor blood flow using dynamic
CT.1 However, due to the risk of radiation exposure andhigh cost, frequent examination using these methods
places a heavy burden on patients.
Meanwhile, real-time observation of blood flow andvessel morphology within tumors has become possible
by contrast-enhanced ultrasonography (CEUS). Lassau etal.2, 3 reported that the time-intensity curve (TIC) parameters obtained from CEUS of tumors correlated well withthe prognosis. Furthermore, Frampas et al.1 reported thatthe area under the curve (AUC), one of the TIC parameters, was useful for assessing the blood flow. However,use of CEUS in evaluating the therapeutic effect of anticancer chemotherapy has rarely been investigated. This
study investigated whether changes in the TIC of CEUS
are useful indicators of the therapeutic effect of chemotherapy. Lassau et al. reported that the TIC parameters
obtained from CEUS of tumors correlated well with theprognosis.2, 3 Furthermore, Frampas et al. reported that
AUC, one of the TIC parameters, was useful for assessing the blood flow.1 However, use of CEUS in evaluating
the therapeutic effect of anticancer chemotherapy has
rarely been investigated. This study investigated whether
changes in the TIC of CEUS are useful indicators of thetherapeutic effect of chemotherapy.

Corresponding author: Yasuaki Hirooka, MD, PhD
yhirooka@med.tottori-u.ac.jp
Received 2016 July 27
Accepted 2016 September 1
Abbreviations: AUC, area under the curve; CEUS, contrast-enhanced ultrasonography; CT, computed tomography; PD, progressive
disease; PR, partial response; RECIST, response evaluation criteria
in solid tumors; ROC, rate of change; TIC, time-intensity curve255

N. Ueda et al.

Fig. 1. ROI of the tumor. Circle indicates the ROI. Right image: B-mode. Left image: CEUS-mode. CEUS, contrast-enhanced ultrasonography; ROI, region of interest.

Intensity (dB)	
 SUBJECTS AND METHODSFive patients with liver metastases from digestive tract
cancer underwent CEUS before and after chemotherapy
from February 2011 to February 2015 in Tottori University Hospital and were followed up after chemotherapy.
The site of the primary tumor was the rectum in two patients, stomach in two, and esophagus in one. Histological types of all primary tumor were adenocarcinoma.
Ultrasonography was performed using a Aplio XG(Toshiba, Tokyo, Japan) and a 3.5 MHz convex probe(PVT-375BT). Before CEUS, B-mode ultrasonographyof the whole tumor was performed to determine theslice of images. Then the largest diameter slice of thetumor image was selected. A probe was fixed to obtainan image similar to the preselected image, and imaging
was recorded for 3 min immediately after bolus injection of Sonazoid (Daiichi Sankyo, Tokyo, Japan) into
the medial cubital vein. Ultrasound conditions (gain, dynamic range, mechanical index, depth, and focus) wereunaltered throughout imaging of a particular patient.
CEUS was performed before and after chemotherapy;
the number of chemotherapy cycles ranged from one to
five depending on the patient’s condition.

Time (s)	
 Fig. 2. TIC parameters. 1) Peak intensity. 2) Time to wash-in. 3)
Time to peak intensity. 4) Slope of wash-in. 5) Area under the
curve. TIC, time-intensity curve. dB, decibel.

ImageLab software ver. 2.9 (Toshiba, Tokyo, Japan)
was used for image analysis. The region of interest was
set to surround the entire region of the tumor (Fig. 1).
A TIC was prepared for each patient for 3 min immediately after Sonazoid injection. Changes in TIC parame256

CEUS in evaluation of therapeutic effectRESULTS
The therapeutic effect according to the RECIST was apartial response in two patients and progressive diseasein three (Table 1).
Figures 3 and 4 show the CEUS images and TIC
before and after chemotherapy in a patient whose CT
images indicated a good therapeutic effect (Patient 1, a
67-year-old woman with primary rectal cancer).
CEUS was performed after one cycle and CT was
performed after four cycles of XELOX therapy (capecitabine and oxaliplatin). CEUS images showed weak contrast enhancement inside the tumor in the arterial phase
before chemotherapy and reduced contrast enhancement
inside the tumor in the arterial phase after chemotherapy. CT images showed a reduction in tumor size from 57
to 38 mm (Fig. 3). ROC of the peak intensity, the slopeof wash-in and the area under the curve were decreased,
while that of the time to wash-in and time to peak intensity were increased (Fig. 4).
Figures 5 and 6 show the CEUS images and TIC
before and after chemotherapy in a patient whose CT
images did not show a therapeutic effect (Patient 3, a76-year-old man with primary stomach cancer).
CEUS was performed after one cycle and CT wasters between before and after chemotherapy were examined in relation to the CT changes in tumor diameter.
The following TIC parameters were examined: peakintensity, time to wash-in, time to peak intensity, slopeof wash-in (slope from baseline to peak), and area under the curve (Fig. 2). In each parameter, rate of change(ROC) was calculated by the expression, [(values before
chemotherapy minus those after chemotherapy)/those
before chemotherapy × 100(%)].
The therapeutic effect on the tumors was determined based on the CT changes in tumor diameter inaccordance with the response evaluation criteria in solid
tumors (RECIST) complete loss of the target lesion(complete response), > 30% decrease in the sum of thediameters of the target lesion relative to the baseline
value (partial response), > 20% increase and 5-mm increase in the sum of the diameters of the target lesion
relative to the baseline value (progressive disease), andsmall changes that do not meet the above criteria (stabledisease). 4
This study was approved by the Ethics Committee of the Tottori University Faculty of Medicine(1508A020).

Table 1. Patients’ characteristics
Case No.
Age
Sex
Primary tumor(Histological type)1
67 y
FemaleRectum(Adenoca.)2
70 yFemaleRectum(Adenoca.)

Time point

3
76 y
Male
Stomach(Adenoca.)

4
80 y
Male
Esophagus(Adenoca.)

5
76 y
Male
Stomach(Adenoca.)

4 cycles3 cycles4 cycles7 cycles5 cycles
57
mm
54
mm
27
mm
26
mm
35
mm
Change in tumor diameter→38 mm→23 mm→43mm→39 mm→56 mmTherapeutic effect
PR
PR
PD
PD
PD
Time point
1 cycle3 cycles1 cycle3 cycles5 cyclesbefore–37.25–23.16–35.24–40.27–27.24
Peak intensity
after–53.24–24.40–36.79–17.55–18.45
ROC
–43.9
–5.3
–4.4
56.4
32.2
before
19
9
17
32
19
Time to wash in after
21
9
18
19
25
ROC
5.3
0.0
5.8
–40.6
31.6
before
23
19
38
46
29
Evaluationof the CEUS Time to peak
after
30
14
22
30
44
intensity
ROC
30.4
–26.3
–42.1
–34.8
51.7
before
5.69
4.14
1.18
0.81
1.58
Slope of wash-in after
0.75
2.21
5.80
2.14
2.18
ROC
–86.8
–46.6
391.5
164.2
38.0
before
19.30
17.51
5.65
14.42
22.77
Area under the
after
1.73
10.03
12.09
23.29
29.31
curve
ROC
–91.0
–42.7
114.0
61.5
28.7
Adenoca., adenocarcinoma; after, after chemotherapy; before, before chemotherapy; CEUS, contrast-enhanced ultrasonography; CT,
computed tomography; No., number; PD, progressive disease; PR, partial response; ROC, rate of change; y, years old.
Evaluationof the CT257

N. Ueda et al.

A

B

C

D

Fig. 3. Several images of a case of partial response to chemotherapy. Arrows indicate the tumor. A: CEUS image before chemotherapy.
Right image: B-mode. Left image: CEUS mode. Weak contrast enhancement was observed inside the tumor in the arterial phase. B:
CEUS image after chemotherapy. Right image: B-mode. Left image: CEUS mode. Contrast enhancement was reduced inside the tumor in
the arterial phase. C: CT image before chemotherapy. Right image: Contrast enhanced CT. Left image: Plain CT. The largest tumor was
57 mm in diameter. D: CT image after chemotherapy. Right image: Contrast enhanced CT. Left image: Plain CT. The largest tumor was
decreased to 38 mm in diameter. CEUS, contrast-enhanced ultrasonography; CT, computed tomography.

performed after four cycles of FP therapy (cisplatin andfluorouracil). CEUS images showed contrast enhancement of the tumor margins in the arterial phase before
chemotherapy and increased contrast enhancement inside the tumor in the arterial phase after chemotherapy.
CT images showed an increase in tumor size from 27 to
43 mm (Fig. 5). ROC of the time to wash-in, the slopeof wash-in and the area under the curve were increased,
while ROC of the peak intensity and the time to peakintensity were decreased (Fig. 6). Two patients of case 2
and 5 underwent CEUS and CT at the same time point(3 and 5 cycle). CT images of case 2 patient showed areduction in tumor size, and ROC of the peak intensity,
the slope of wash-in and the area under the curve weredecreased based on CEUS findings. As a patient of case5, CT images showed an increase in tumor size, and
ROC of all parameters of TIC were increased (Table 1).

Fig. 4. Graph showing the TIC. Dotted line: TIC before chemotherapy. Solid line: TIC after chemotherapy. The peak intensity,
slope of wash-in, and area under the curve were decreased, while
the time to wash-in and time to peak identity were unchanged. dB,
decibel; TIC, time-intensity curve.

258

CEUS in evaluation of therapeutic effect

A

B

C

D

Fig. 5. Several images of a case of progressive disease after chemotherapy. Arrows indicate the tumor. A: CEUS image before chemotherapy. Right image: B-mode. Left image: CEUS mode. Contrast enhancement was observed in the tumor margins in the arterial phase. B:
CEUS image after chemotherapy. Right image: B-mode. Left image: CEUS mode. Contrast enhancement was observed inside the tumor
in the arterial phase. C: CT image before chemotherapy. Right image: Contrast enhanced CT. Left image: Plain CT. The largest tumor
was 27 mm in diameter. D: CT image after chemotherapy. Right image: Contrast enhanced CT. Left image: Plain CT. The largest tumor
was increased to 43 mm in diameter. CEUS, contrast-enhanced ultrasonography; CT, computed tomography.

The findings for all five patients are summarized inTable 1. ROC of the slope of wash-in and the area under
the curve, but not in the other TIC parameters, reflected
the therapeutic effects based on CT findings.
DISCUSSION
The RECIST, which are based on changes in tumor
diameter on CT images, are commonly used to evaluate the therapeutic effect of chemotherapy for liver
metastases.5 However, the presence of necrosis in thetumor complicates the evaluation, and a more accurate
approach would be visualization of tumor hemodynamics. CEUS is a highly sensitive and specific method for
detecting liver metastases and provides valuable information about tumor hemodynamics and morphology.6–11
When a tumor grows or shrinks, feeding vessels
are created or damaged, respectively, and morphological changes then become prominent. CEUS reportedly
allows for visualization of changes in feeding vessels
before tumor morphology changes, enabling early evalu-

Fig. 6. Graph showing the TIC. Dotted line: TIC before chemotherapy. Solid line: TIC after chemotherapy. The slope of wash-in
and area under the curve were increased, while the time to peakintensity was decreased; the peak intensity and time to wash-in
were unchanged. dB, decibel; TIC, time-intensity curve.

259

N. Ueda et al.

ation of the therapeutic effect.12–14 This early predictionof the therapeutic effect allows alteration of the method
or schedule of treatment, thereby avoiding unnecessary
administration of anticancer agents. In this study, we
performed CEUS prior to CT in three patients and foundthat CEUS was able to know the therapeutic effect ofanticancer agents at an earlier stage than CT in all cases. Furthermore, this study showed that the findings of
CEUS performed at the earliest stage of therapy (after
one cycle) reflected the results of the CT evaluation, suggesting that CEUS may have a possibility to predict thetherapeutic effect at the earliest stage of chemotherapy.
Conversely, patients whose CT images indicated a complete response or stable disease were not examined by
CEUS, and the timing of CEUS and CT examinations
were not controlled in this study. Further studies withmore patients and controlled timing of CEUS and CT
examinations are needed. Additionally, this study examined liver metastases from digestive tract cancer, but
the type of primary organ was not controlled because
there were only five patients included in this study. Livermetastases from digestive tract cancer reportedly show
contrast enhancement in the arterial phase.15 Without
well-enhanced contrast in the arterial phase, the peakintensity, time to wash-in and slope of wash-in cannot be
accurately calculated. This study indicated that changes
in the TIC would be useful in the evaluation of the therapeutic effect when contrast enhancement was present in
the arterial phase.
Lassau et al. prepared TICs of CEUS in patientswith liver metastases from renal cell carcinoma andfound significant differences in the peak intensity, slopeof wash-in, time to peak intensity, and area under the
curve between groups with and without a therapeutic effect.16 In this study, ROC of the slope of wash-in and thearea under the curve reflected the therapeutic effect, butthat of the peak intensity and the time to peak intensity
showed no relationship with the therapeutic effect. Thismay be explained by differences in the locations of primary tumors and by the use of angiogenic inhibitors as
anticancer agents in the previous study. Schirin-Sokhan
et al. prepared TICs for liver metastases of rectal cancer
treated with an angiogenic inhibitor and found that increases in the time to peak intensity were observed whentherapy was effective.14 This suggests that ROC of thetime to peak intensity might vary depending on the anticancer agents used. Based on the previous and present
studies, it was thought that the angiogenesis of the tumor
may reflected the two parameters of TIC (slope of wash
in and area under curve). Furthermore, Schirin-Sokhan
et al.14 reported that there were no significant differencesin the peak intensity, which is in good agreement withthis study.
In conclusion, the results of this study indicate thatin tumors with contrast enhancement in the arterial
phase, differences in the TIC between before and after
chemotherapy may serve as useful indicators of therapeutic effect for patients with liver metastases. In particular, ROC of the slope of wash-in and the area under the
curve appear to specifically reflect the therapeutic effect.
Furthermore, there is a possibility that TIC analysis may
enable early prediction of the therapeutic effect.
The authors declare no conflict of interest.

REFERENCES
1 Frampas E, Lassau N, Zappa M, Vullierme MP, Koscielny S,
Vilgrain V. Advanced Hepatocellular Carcinoma: early evaluation of response to targeted therapy and prognostic value of
Perfusion CT and Dynamic Contrast Enhanced-Ultrasound.
Preliminary results. Eur J Radiol. 2013;82:e205-11. PMID:
23273822.
2 Lassau N, Bonastre J, Kind M, Vilgrain V, Lacroix J, Cuinet M,
et al. Validation of dynamic contrast-enhanced ultrasoundin predicting outcomes of antiangiogenic therapy for solid
tumors: the French multicenter support for innovative andexpensive techniques study. Invest Radiol. 2014;49:794-800.
PMID: 24570378.
3 Lassau N, Chebil M, Chami L, Bidault S, Girard E, Roche A.
Dynamic contrast-enhanced ultrasonography (DCE-US): a
new tool for the early evaluation of antiangiogenic treatment.
Target Oncol. 2010;5:53-8. PMID: 20379790.
4 Eisenhauer EA, Therasse P, Bogaerts J, Schwartz LH, Sargent D,
Ford R, et al. New response evaluation criteria in solid tumours: revised RECIST guideline (version 1.1). Eur J Cancer.
2009;45:228-47. PMID: 19097774.
5 Tirumani SH, Kim KW, Nishino M, Howard SA, Krajewski KM,
Jagannathan JP, et al. Update on the role of imaging in management of metastatic colorectal cancer. Radiographics.
2014;34:1908-28. PMID: 25384292.
6 Arita J, Ono Y, Takahashi M, Inoue Y, Takahashi Y, Saiura A.
Usefulness of contrast-enhanced intraoperative ultrasound in
identifying disappearing liver metastases from colorectal carcinoma after chemotherapy. Ann Surg Oncol. 2014;21 Suppl
3:S390-7. PMID: 24570378.
7 Mishima M, Toh U, Iwakuma N, Takenaka M, Furukawa M,
Akagi Y. Evaluation of contrast Sonazoid-enhanced ultrasonography for the detection of hepatic metastases in breast
cancer. Breast Cancer. 2016;23:231-41. PMID: 25143060.
8 Cantisani V, Grazhdani H, Fioravanti C, Rosignuolo M,
Calliada F, Messineo D, et al. Liver metastases: Contrast-enhanced ultrasound compared with computed tomography andmagnetic resonance. World J Gastroenterol. 2014;20:999810007. PMID: 25110428.
9 Shiozawa K, Watanabe M, Sumino Y. Evaluation of the hemodynamic status of focal hepatic lesions 20 mm or less in diameter by contrast-enhanced ultrasonography using Sonazoid.
Intervirology. 2009;52:213-22. PMID: 19556803.
10 Yoshida K, Hirokawa T, Moriyasu F, Liu L, Liu GJ, Yamada M,
et al. Arterial-phase contrast-enhanced ultrasonography forevaluating anti-angiogenesis treatment: a pilot study. World J
Gastroenterol. 2011;17:1045-50. PMID: 21448357.

260

CEUS in evaluation of therapeutic effectchemotherapy in metastatic colorectal cancer by contrast
enhanced ultrasound. World J Gastroenterol. 2012;18:541-5.
PMID: 22363120.
15 Claudon M, Dietrich CF, Choi BI, Cosgrove DO, Kudo M,
Nolsøe CP, et al. Guidelines and good clinical practice recommendations for Contrast Enhanced Ultrasound (CEUS) in theliver - update 2012: A WFUMB-EFSUMB initiative in cooperation with representatives of AFSUMB, AIUM, ASUM,
FLAUS and ICUS. Ultrasound Med Biol. 2013;39:187-210.
PMID: 23137926.
16 Lassau N, Koscielny S, Albiges L, Chami L, Benatsou B,
Chebil M, et al. Metastatic renal cell carcinoma treated withsunitinib: early evaluation of treatment response using dynamic contrast-enhanced ultrasonography. Clin Cancer Res.
2010;16:1216-25. PMID: 20145174.

11 Lassau N, Paturel-Asselin C, Guinebretiere JM, Leclère J,
Koscielny S, Roche A, et al. New hemodynamic approach toangiogenesis: color and pulsed Doppler ultrasonography. Invest Radiol. 1999;34:194-8. PMID: 10084663.
12 Moschouris H, Malagari K, Marinis A, Kornezos I, Stamatiou K,
Nikas G, et al. Hepatocellular carcinoma treated with transarterial chemoembolization: Evaluation with parametric contrast-enhanced ultrasonography. World J Radiol. 2012;4:37986. PMID: 22937217.
13 Lassau N, Koscielny S, Chami L, Chebil M, Benatsou B,
Roche A, et al. Advanced hepatocellular carcinoma: early
evaluation of response to bevacizumab therapy at dynamic
contrast-enhanced US with quantification--preliminary results. Radiology. 2011;258:291-300. PMID: 20980447.
14 Schirin-Sokhan R, Winograd R, Roderburg C, Bubenzer J,
do Ó NC, Guggenberger D, et al. Response evaluation of261