Usefulness of color Doppler and strain elastography adjunctive to B-mode ultrasonography in the diagnosis of non-mass abnormalities of the breast: results of the BC-07 multicenter study of 385 cases.

PURPOSE: The concept of non-mass abnormalities of the breast has been employed in Japan for approximately 20 years. Although B-mode findings are classified as non-mass abnormalities, the usefulness of adding color Doppler ultrasonography (US) and strain elastography to B-mode US is unclear. Therefore, we conducted a multicenter study (JABTS BC-07) to establish the diagnostic criteria for breast US, including color Doppler and elastography, for non-mass abnormalities of the breast and verify their diagnostic usefulness. METHODS: We registered US images of non-mass abnormalities of the breast and their clinical and histopathological data from 13 institutions (202 malignant and 183 benign non-mass lesions). Furthermore, we evaluated the centralized image interpretation usefulness of the diagnostic criteria for B-mode and color Doppler US, as well as the sensitivity and specificity when color Doppler US and elastography were added to B-mode US. RESULTS: Echogenic foci in the mammary gland (odds ratio 3.45, 95% confidence interval [CI] 1.92-6.19, p < 0.0001) and the configuration of internal solid components of the ducts (odds ratio 0.056, 95% CI 0.005-0.591, p < 0.0165) significantly differentiated benign and malignant non-mass abnormalities. The sensitivity of B-mode alone (83.7%) was significantly improved by adding color Doppler US (93.1%) (p = 0.0004); however, adding color Doppler US and elastography to B-mode US made no significant difference in either sensitivity or specificity. CONCLUSION: Although adding color Doppler US and elastography to B-mode US improved sensitivity, the diagnostic significance was limited. Therefore, a comprehensive diagnostic method comprising mammography and magnetic resonance imaging is warranted.

Changes in cell-free DNA after short-term palbociclib and fulvestrant treatment for advanced or metastatic hormone receptor-positive and human epidermal growth factor 2-negative breast cancer.

PURPOSE: Here, we investigated the potential predictive and elucidating efficacy of cell-free DNA (cfDNA) changes on clinical outcomes and biological effects, respectively, after short-term palbociclib and fulvestrant treatment for patients with hormone receptor (HR)-positive and human epidermal growth factor 2 (HER2)-negative advanced or metastatic breast cancer (ABC). METHODS: In this secondary analysis of the Japan Breast Cancer Research Group-M07 (FUTURE) trial, blood cfDNA was obtained before palbociclib treatment and on day 15 of cycle one (28-day cycle). Target enrichment was performed using next-generation sequencing; progression-free survival (PFS) was compared based on cfDNA changes between baseline and day 15 of cycle one after combination therapy. RESULTS: Fifty-six patients (112 paired blood samples) were examined. The median follow-up time was 8.9 months. PIK3CA (30.4%, 17/56), FOXA1 (30.4%, 17/56), and ESR1 (28.6%, 16/56) were most frequently mutated at baseline. The number of mutated genes was significantly decreased on day 15 compared with that at baseline (paired t test: P value = 0.025). No significant difference was observed in PFS (decrease group, 7.9 m vs the others, 9.3 m; log-rank P value = 0.75; hazard ratio, 1.13; 95% confidence interval, 0.53-2.41). Among patients without previous aromatase inhibitor treatment (n = 15), three (20%) had ESR1 mutations after progression to fulvestrant. CONCLUSION: No significant association was observed between changes in mutated genes after short-term palbociclib and fulvestrant treatment and disease progression; a significant reduction in cfDNA mutation level was observed on day 15 of cycle one. Clinical meanings of cfDNA should be investigated in the future trials.

Fulvestrant plus palbociclib in advanced or metastatic hormone receptor-positive/human epidermal growth factor receptor 2-negative breast cancer after fulvestrant monotherapy: Japan Breast Cancer Research Group-M07 (FUTURE trial).

PURPOSE: The combination of cyclin-dependent kinase 4/6 inhibitors and endocrine therapy is a standard treatment for hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC); however, their toxicities and financial burden are major issues, especially for prolonged treatment. We investigated fulvestrant plus palbociclib in patients with HR-positive MBC resistant to fulvestrant monotherapy. METHODS: Patients who initially received fulvestrant as their first- or second-line endocrine therapy were assigned to group A. Patients with disease progression during fulvestrant monotherapy who subsequently received fulvestrant plus palbociclib were assigned to group B. The primary endpoint was progression-free survival (PFS1) in group B. We set the threshold median PFS of 5 months (null hypothesis). RESULTS: Between January 2018 and February 2020 we enrolled 167 patients in group A (January 2018-February 2020) from 55 institutions, of whom 72 subsequently received fulvestrant plus palbociclib and were enrolled in group B. The median follow-up was 23.8 and 8.9 months in groups A and B, respectively. The median PFS in group B (combination therapy) was 9.4 (90% confidence interval [CI]: 6.9-11.2) months (p < 0.001). This was 25.7 (90% CI: 21.2-30.3) months in group A (fulvestrant monotherapy). The TTF in group B was 7.2 (90% CI: 5.5-10.4) months. In the post-hoc analysis, the median PFS1 in group B among patients with longer-duration fulvestrant monotherapy (> 1 year) was longer than that of patients with shorter-duration monotherapy (≤ 1 year) (11.3 vs. 7.6 months). No new toxicities were observed. CONCLUSION: Our findings suggest that palbociclib plus fulvestrant after disease progression despite fulvestrant monotherapy is potentially safe and effective in patients with HR-positive/HER2-negative advanced MBC.

Effectiveness of eribulin as first-line or second-line chemotherapy for HER2-negative hormone-resistant advanced or metastatic breast cancer: findings from the multi-institutional, prospective, observational KBCRN A001: E-SPEC study.

BACKGROUND: The optimal positioning of eribulin treatment remains unclear. This study aimed to investigate the effectiveness of eribulin administration as first- and second-line chemotherapy in patients with endocrine-resistant advanced or metastatic breast cancer (AMBC) in the real-world clinical setting. METHODS: This multi-institutional prospective cohort study enrolled patients with triple-negative AMBC or estrogen receptor-positive AMBC refractory to at least one previous endocrine therapy. The overall survival (OS) from the start of first-line (OS1) and second-line chemotherapy (OS2) was assessed. Data analysis included real-world chemotherapy sequences of first- to third-line chemotherapy regimens. The adjusted hazard ratio (HR) with 95% confidence interval (CI) for treatment regimen comparison was calculated using a stratified proportional hazards model. RESULTS: Among 201 patients enrolled, 180 were included in the final analysis. Eribulin was administered as first- and second-line chemotherapy to 46 (26.6%) and 70 (47.9%) patients, respectively. Median OS1 and OS2 were 2.25 (95% CI 1.07-2.68) and 1.75 (95% CI, 1.28-2.45) years for first- and second-line eribulin, respectively. Oral 5-FU followed by eribulin had a numerically longer OS1 (2.84 years) than the other sequences. Among patients who proceeded to second-line or later chemotherapy, the median OS1 for those treated with anthracycline or taxane as first- or second-line (n = 98) was 2.56 years (95% CI 2.27-2.74), while it was 2.87 years (95% CI 2.20-4.32) for those who avoided anthracycline and taxane as first- and second-line (n = 48) (adjusted HR, 1.20; 95% CI 0.70-2.06). In the exploratory analysis, OS1 was 2.55 (95% CI 2.14-2.75) and 2.91 years (95% CI 2.61-4.32) for those aged < 65 and ≥ 65 years, respectively (adjusted HR of ≥ 65, 0.91; 95% CI 0.56-1.46). CONCLUSIONS: Eribulin or oral 5-FU administration in first- and second-line chemotherapy without anthracycline/taxane was acceptable in the real-world setting. TRIAL REGISTRATION: This study is registered with Clinical Trials.gov (NCT 02,551,263).

Utility of B-Mode, Color Doppler and Elastography in the Diagnosis of Breast Cancer: Results of the CD-CONFIRM Multicenter Study of 1351 Breast Solid Masses.

The usefulness of color Doppler ultrasound (CD) in distinguishing between benign and malignant breast lesions remains controversial. Our prior study, the Japan Association of Breast and Thyroid Sonology (JABTS) BC-04 study (malignant: 839, benign: 569), found CD was useful in breast cancer diagnosis, and we developed CD diagnostic criteria. The first aim of the current study (the CD-CONFIRM study) was to evaluate the usefulness of the CD diagnostic criteria. The second aim was to evaluate the relationship between CD and elastography. We evaluated ultrasound images of breast masses from 13 institutions (malignant: 639, benign: 712). While the sensitivity of B-mode alone was very high and was not significantly improved with CD, the specificity was significantly improved with CD (61.2%-69.2%, p < 0.0001). Furthermore, the specificity of the combination of B-mode and CD improved significantly with the addition of elastography (72.8%-79.0%, p < 0.0001). This study found that the CD criteria are useful, and CD and elastography are independent.

Investigation of a Novel S-1 Administration Schedule for Treating Metastatic and Recurrent Breast Cancer (KBCOG13).

BACKGROUND/AIM: S-1, a 5-fluorouracil(5-FU) oral anti-cancer drug, has been traditionally used with a schedule of 4-week oral administration followed by 2-week rest for breast cancer treatment. We, herein, aimed to investigate the clinical efficacy and safety of a schedule of 2-week oral administration followed by 1-week rest for patients with metastatic breast cancer. PATIENTS AND METHODS: We enrolled patients with HER2-negative metastatic breast cancer who had not received prior chemotherapy. S-1 was administered consecutively for 2-weeks followed by a 1-week rest. RESULTS: Between September 1, 2013 and August 31, 2016, 32 patients were enrolled. The median follow-up time was 32.1 months. The median progression-free survival (PFS) was 9.4 months. Overall survival (OS) was 41.0 months, time to treatment failure (TTF) was 7.8 months, response rate (RR) was 31.3%, and disease control rate (DCR) was 78.1%. The incidence of grade 3 side-effects was not high. CONCLUSION: The 3-week schedule of S-1 can be considered useful as a treatment for patients with metastatic breast cancer, helping in maintaining a high quality of life.

Comparing the extent of breast cancer tumors through contrast-enhanced ultrasound vs B-mode, opposed with pathology: evergreen study.

BACKGROUND: To prove the efficacy of contrast-enhanced ultrasound (CEUS) in determining the extent of resection, more evidence about B-mode and CEUS as opposed to pathology is required. We compared maximum tumor width measured on B-mode/CEUS images with that determined pathologically. METHODS: In this retrospective multicenter study, 152 operable breast cancer patients who had undergone both B-mode and CEUS were analyzed. Maximum tumor width on B-mode and CEUS, and on the postoperative pathological examination (P), was measured by the participating investigators. In addition, maximum width was assessed in B-mode and CEUS image sets by independent reviewers blinded to all patient information. We analyzed differences in maximum width between CEUS, B-mode and P. RESULTS: The mean widths as measured by the participating investigators were 15 ± 7 mm (B-mode), 19 ± 8 mm (CEUS), and 17 ± 9 mm (P). The difference subtracted P from B-mode was - 3 ± 7 mm (p < 0.0001), and that from CEUS was 1 ± 6 mm (p = 0.0163). The mean widths as measured by the independent reviewers were 16 ± 7 mm (B-mode) and 18 ± 7 mm (CEUS). The difference subtracted P from B-mode was - 2 ± 8 mm (p = 0.0114), while that from CEUS was 1 ± 7 mm (p = 0.1921). CONCLUSIONS: Maximum lesion width measurement showed a tendency to increase in the order of B-mode, to P and CEUS. The difference in measurement between P and B-mode was significant, but there was no significant between CEUS and P. These results provide additional information of tendency patterns in measuring the maximum lesion width through enhancement on CEUS.

Real-World Outcomes of Treating Advanced Breast Cancer Patients With Palbociclib: A Multicenter Retrospective Cohort Study in Japan-The KBCOG-14 Study.

BACKGROUND: Clinical studies have shown that palbociclib improves progression-free survival in hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) patients with advanced breast cancer (ABC). However, there are insufficient data on its use in a real-world setting in Japan. The aim of this study was to investigate the effectiveness, predictive factors, and safety of palbociclib among Japanese patients in routine clinical practice. METHODS: Between December 1, 2017, and April 30, 2019, we recruited patients from 9 hospitals and retrospectively evaluated the data on HR+/HER2- patients with ABC who received palbociclib for at least 1 week. The correlation between time-to-treatment discontinuation (TTD) and clinical background was investigated via univariate and multivariate analyses using Cox hazards models. RESULTS: A total of 177 women were available for analysis. Of these patients, 58 (33%) patients were treated with palbociclib with an aromatase inhibitor and 117 (66%) patients were treated with palbociclib and a selective estrogen receptor degrader. Approximately three-fourths of the patients (n = 130, 73%) received palbociclib as third- or later-line therapy. One-third of the patients had 3 or more metastatic sites (n = 59, 33%), and one-third of the patients had liver metastasis (n = 59, 33%). The median follow-up duration at the time of data cutoff was 8.9 months, the median TTD was 6.3 months, and the median overall survival was not reached. Liver metastasis (hazard ratio [HR]: 1.54 [95% confidence interval {CI}: 1.03-2.27]), high serum lactate dehydrogenase (LDH) level (>300 U/L) (HR: 2.58 [95% CI: 1.49-4.26]), and high neutrophil-to-lymphocyte ratio (NLR) (⩾3.0) (HR: 1.76 [95% CI: 1.13-2.69]) were significantly associated with shorter TTD. The most common hematologic adverse event was neutropenia, which occurred in 93% of the patients. CONCLUSION: Based on the results of the pivotal phase 3 trials, the median TTD recorded in this study was shorter than expected. Our results suggest that liver metastasis, serum LDH level, and NLR may be predictive factors for HR+/HER2- ABC treatment outcomes.

Effectiveness and safety of surgical glove compression therapy as a prophylactic method against nanoparticle albumin-bound-paclitaxel-induced peripheral neuropathy.

BACKGROUND: We have developed a surgical glove (SG)-compression therapy and reported that this method significantly reduced the overall occurrence of grade 2 or higher nanoparticle albumin-bound-paclitaxel (nab-PTX)-induced peripheral neuropathy (PN) from 76.1% to 21.4%. In this multicenter single-arm confirmatory study, we investigated the efficacy and safety of SG-compression therapy for the prevention of nab-PTX-induced PN, compared with the incidence of grade 2 or higher PN in published literature as controls. PATIENTS AND METHODS: Primary breast cancer patients who received 260 mg/m2 of nab-PTX were eligible for this study. Patients wore two SGs (one size smaller than the tight-fitting size) in each hand for 90 min. PN was evaluated at each treatment cycle using the Common Terminology Criteria for Adverse Events (CTCAE) version 4.0 and the Patient Neurotoxicity Questionnaire (PNQ). The temperature of each fingertip was measured using thermography. RESULTS: Between October 2016 and June 2017, 58 patients were evaluated. The incidence of CTCAE grade 2 or higher PN was as low as 13.8% following SG-compression therapy. A goodness-of-fit test proved that the overall incidence of 13.8% grade 2 or higher PN in this study was comparable to the hypothesis-predicted value (13%). No adverse events, including compression intolerance or skin disorders caused by use of SG, were observed. SG-compression therapy significantly reduced the temperature of each fingertip by 1.3°C-2.3 °C compared to pre-chemotherapy level. CONCLUSIONS: This study suggested the safety and efficacy of SG-compression therapy for the amelioration of CIPN. CLINICAL TRIAL NUMBER: UMIN 000024836.

Multicenter Prospective Study of Color Doppler Ultrasound for Breast Masses: Utility of Our Color Doppler Method.

The use of color Doppler ultrasound (CD) for distinguishing between benign and malignant breast lesions remains controversial. This study (JABTS BC-04 study) was aimed at confirming the usefulness of our CD diagnostic criteria. We evaluated ultrasound images of 1408 solid breast masses from 16 institutions in Japan (malignant: 839, benign: 569). Multivariate analysis indicated that vascularity (amount of blood flow), vascular flow pattern ("surrounding marginal flow" or "penetrating flow") and the incident angle of penetrating flow were significant findings for distinguishing between benign and malignant lesions. However, the sensitivity and specificity of B-mode alone did not improve significantly with CD addition (97.6% → 97.9%, 38.3% → 41.5%, respectively). We explored the causes of these negative results and found that age should have been considered when evaluating vascularity. Simulation experiments suggested that specificity is significantly improved when age is taken into consideration (38.3% → 46.0%, p < 0.001) and we thereby improved our diagnostic criteria.

Ultrasound Image Classification of Ductal Carcinoma In Situ (DCIS) of the Breast: Analysis of 705 DCIS Lesions.

The Japan Association of Breast and Thyroid Sonology (JABTS) proposed, in 2003, a conceptual classification system for non-mass abnormalities to be applied in addition to the conventional concept of masses, to facilitate detecting ductal carcinoma in situ (DCIS) lesions. The aim of this study was to confirm the utility of this system and to clarify the distribution of these findings in DCIS lesions. Data on 705 surgically treated DCIS lesions from 16 institutions in Japan were retrospectively reviewed. All 705 DCIS lesions could be classified according to the JABTS classification system. The most frequent findings were hypo-echoic areas in the mammary gland (48.6%), followed by solid masses (28.0%) and duct abnormalities (10.2%) or mixed masses (8.1%). Distortion (1.3%), clustered microcysts (1.4%) and echogenic foci without a hypo-echoic area (2.5%) were uncommon. These results suggest that the concept of non-mass abnormalities is useful in detecting DCIS lesions.

Body mass index and menopausal disorders during menopause affect vasomotor symptoms of postmenopausal Japanese breast cancer patients treated with anastrozole: a prospective multicenter cohort study of patient-reported outcomes.

BACKGROUND: Adverse events related to endocrine therapies have a major impact not only on patients' quality of life but also on treatment discontinuation. Although vasomotor symptoms induced by aromatase inhibitors are frequently recognized, risk factors, especially for Japanese women, are not well reported. To identify risk factors for vasomotor symptoms of Japanese breast cancer patients treated with adjuvant anastrozole, we conducted a prospective cohort study based on patient-reported outcomes (PROs). PATIENTS AND METHODS: For this prospective cohort study (SAVS-JP, UMIN000002455), 391 postmenopausal Japanese estrogen receptor-positive breast cancer patients who were treated with adjuvant anastrozole were recruited from 28 centers. The PRO assessment was obtained from a self-reported questionnaire at baseline, 3, 6, 9 and 12 months between August 2009 and April 2012. Vasomotor symptoms, comprising hot flashes, night sweats, and cold sweats, were categorized into four grades (none, Grade 1: mild, Grade 2: moderate, Grade 3: severe). Pre-existing symptoms were only included if they had become worse than at baseline. RESULTS: Hot flashes, night sweats, and cold sweats at baseline were reported by 20.5, 15.1, and 8.2 % of the patients, respectively, and new appearance or worsening of symptoms in comparison with baseline by 38.4, 29.3, and 28.7 %, respectively. About 80 % of newly occurring symptoms were Grade 1, and less than 5 % were Grade 3. Vasomotor symptoms were reported by 201 out of 362 patients (55.5 %) during the first year and the mean time to onset was 5.6 months. Patients with vasomotor symptoms were significantly younger (mean 62.8 years, range 38-86 vs 64.7 years, range 37-84; p = 0.02), had higher body mass index (BMI) (23.4 kg/m2, range 15.8-39.9 vs 22.4 kg/m2, range 15.8-34.9; p = 0.01), had vasomotor symptoms sooner after menopause (12.4 years, range 0-51 vs 15.1 years, range 1-37; p = 0.002), and had more menopausal disorders during menopause (63.3 vs 36.7 %; p = 0.002). Multivariate analysis showed that BMI [odds ratio (OR) 1.09 per unit of increase, 95 % confidence interval (CI) 1.02-1.16; p = 0.009] and experiencing menopausal disorders (OR 2.11, 95 % CI 1.35-3.30; p = 0.001) were significantly associated with vasomotor symptoms. CONCLUSION: High BMI and experiencing menopausal disorders at menopause were found to be significantly associated with the occurrence of vasomotor symptoms. These findings are expected to prove useful for the management of postmenopausal Japanese women treated with aromatase inhibitors.

Evaluation of the effect of compression therapy using surgical gloves on nanoparticle albumin-bound paclitaxel-induced peripheral neuropathy: a phase II multicenter study by the Kamigata Breast Cancer Study Group.

PURPOSE: To investigate the efficacy of using surgical glove (SG) compression therapy to prevent nanoparticle albumin-bound paclitaxel (nab-PTX)-induced peripheral neuropathy. PATIENTS AND METHODS: Patients with primary and recurrent breast cancer who received 260 mg/m2 of nab-PTX were eligible for this case-control study. Patients wore two SGs of the same size, i.e., one size smaller than the size that fit their dominant hand, for only 90 min. They did not wear two SGs on the non-dominant hand, which served as the control hand. Peripheral neuropathy was evaluated at each treatment cycle using common terminology criteria for adverse events (CTCAE) version 4.0 and the Patient Neurotoxicity Questionnaire. The temperature of each fingertip of the compression SG-protected hand and control hand was measured using thermography. RESULTS: Between August 2013 and January 2016, 43 patients were enrolled and 42 were evaluated. The occurrence rates of CTCAE grade 2 or higher sensory and motor peripheral neuropathies were significantly lower for SG-protected hands than for control hands (sensory neuropathy 21.4 vs. 76.1 %; motor neuropathy 26.2 vs. 57.1 %). No patients withdrew from this study because they could not tolerate the compression from the SGs. SG compression therapy significantly decreased the temperature of each fingertip by 1.6-2.2 °C as compared with the temperature before chemotherapy (p < 0.0001). CONCLUSIONS: SG compression therapy is effective for reducing nab-PTX-induced peripheral neuropathy. The nab-PTX exposure to the peripheral nerve may be decreased because the SG decreases microvascular flow to the fingertip.

Risk factors for joint symptoms in postmenopausal Japanese breast cancer patients treated with anastrozole: a prospective multicenter cohort study of patient-reported outcomes.

BACKGROUND: Endocrine treatment-related adverse events have a strong impact on patients' quality of life and sometimes result in treatment discontinuation. Since joint symptoms are the most frequently recognized side effect of aromatase inhibitors, evaluation of associated risk factors may yield significant findings. PATIENTS AND METHODS: A total of 391 postmenopausal Japanese women with estrogen receptor-positive breast cancer and treated with adjuvant anastrozole were enrolled from 28 centers for assessment of patient-reported outcomes (PROs) in this prospective cohort study (SAVS-JP, UMIN000002455). Patients completed the self-report questionnaire at baseline and after 3, 6, 9, and 12 months of treatment for evaluation of frequency of treatment-related joint symptoms (arthralgia, decrease in range of joint motion, and joint stiffness). RESULTS: We obtained PROs from 362 patients (92.6 %) at baseline and at one or more subsequent points. New or worsening from baseline of joint symptoms were reported by 260 patients (71.8 %). More than 90 % of the symptoms were mild or moderate and nearly 80 % had occurred by 6 months. Multivariate analysis showed that a short time span after menopause [odds ratio (OR) 0.95, 95 % confidence interval (CI) 0.90-0.99; P = 0.02] and adjuvant chemotherapy (OR 2.29, 95 % CI 1.06-4.95; P = 0.03) were significant independent risk factors for joint symptoms. No significant relationships between body mass index (BMI) and joint symptoms were identified. Eighteen patients discontinued treatment during the 1st year and eight of them reported joint symptoms. CONCLUSION: Taking into consideration that PROs may yield higher prevalence rates than physician ratings for symptoms published in pivotal clinical trials, we found that a short time span after menopause and use of adjuvant chemotherapy, but not high BMI, were significantly associated with joint symptoms. These findings might prove useful for counseling before initiating treatment with adjuvant aromatase inhibitors in postmenopausal Japanese women.

Phase II clinical study of DD-723 (perflubutane): dose-response study in patients with breast tumors.

PURPOSE: We compared the contrast effect of three doses of DD-723 in subjects with breast tumors to determine the recommended dose. We then evaluated differential diagnosis results using plain ultrasonography, contrast-enhanced ultrasonography (plain + enhanced), and contrast-enhanced magnetic resonance imaging (MRI) compared to the pathological diagnosis. METHODS: To evaluate the contrast effect, contrast-enhanced ultrasonic images were independently evaluated in a randomized sequence by three blinded reviewers trained in the evaluation method beforehand. Multiple evaluation results from the three reviewers were used to assess the overall contrast effect. The differential diagnosis was evaluated independently by three blinded reviewers using contrast-enhanced ultrasonic images and contrast-enhanced magnetic resonance images in a randomized sequence; reviewers were also blinded to subject characteristics. Multiple evaluation results from the three reviewers were used to assess the overall differential diagnosis. RESULTS: The recommended dose of DD-723 is an intermediate dose of 0.12 µL MB/kg. Accuracy, sensitivity, and specificity were improved more in the differential diagnosis by contrast-enhanced ultrasonography than in plain ultrasonography. Accuracy and specificity were better and sensitivity similar compared to contrast-enhanced MRI. CONCLUSIONS: An intermediate dose showed the highest efficacy in terms of overall contrast effect. Contrast-enhanced ultrasonography is safe and useful when used in differential diagnosis.