Prediction of Efficacy for Atezolizumab/Bevacizumab in Unresectable Hepatocellular Carcinoma with Hepatobiliary-Phase Gadolinium Ethoxybenzyl-Diethylenetriaminepentaacetic Acid MRI.

BACKGROUND: This study aimed to examine whether the coefficient of variation (CV) in the hepatobiliary-phase (HBP) of Gd-EOB-DTPA-MRI could be an independent predictive factor for tumor progression. METHODS: Patients who underwent Gd-EOB-DTPA-MRI before Atezolizumab/bevacizumab therapy at six affiliated institutions between 2018 and 2022 were included. CV for each patient was calculated as the mean value for up to five tumors larger than 10 mm, and CV of the whole tumor was calculated using LIFEx software. The tumor response was evaluated within 6-10 weeks. The primary endpoint was to investigate the predictive factors, including CV, related to tumor progression using logistic regression analysis. The secondary endpoints were tumor response rate and progression-free survival (PFS) based on CV. RESULTS: Of the 46 enrolled patients, 13 (28.3%) underwent early progressive disease. Multivariate analysis revealed that a high CV (≥0.22) was an independent predictive factor for tumor progression (p = 0.043). Patients with a high CV had significantly frequent PD than those with a low CV (43.5 vs. 13.0%, p = 0.047). Patients with a high CV tended to have shorter PFS than those with a low CV (3.5 vs. 6.7 months, p = 0.071). CONCLUSION: Quantitative analysis using CV in the HBP of Gd-EOB-DTPA-MRI may be useful for predicting tumor progression for atezolizumab/bevacizumab therapy.

MR Relaxometry for Discriminating Malignant Ovarian Cystic Tumors: A Prospective Multicenter Cohort Study.

BACKGROUND: Endometriosis-associated ovarian cancer (EAOC) is a well-known type of cancer that arises from ovarian endometrioma (OE). OE contains iron-rich fluid in its cysts due to repeated hemorrhages in the ovaries. However, distinguishing between benign and malignant tumors can be challenging. We conducted a retrospective study on magnetic resonance (MR) relaxometry of cyst fluid to distinguish EAOC from OE and reported that this method showed good accuracy. The purpose of this study is to evaluate the accuracy of a non-invasive method in re-evaluating pre-surgical diagnosis of malignancy by a prospective multicenter cohort study. METHODS: After the standard diagnosis process, the R2 values were obtained using a 3T system. Data on the patients were then collected through the Case Report Form (CRF). Between December 2018 and March 2023, six hospitals enrolled 109 patients. Out of these, 81 patients met the criteria required for the study. RESULTS: The R2 values calculated using MR relaxometry showed good discriminating ability with a cut-off of 15.74 (sensitivity 80.6%, specificity 75.0%, AUC = 0.750, p < 0.001) when considering atypical or borderline tumors as EAOC. When atypical and borderline cases were grouped as OE, EAOC could be distinguished with a cut-off of 16.87 (sensitivity 87.0%, specificity 61.1%). CONCLUSIONS: MR relaxometry has proven to be an effective tool for discriminating EAOC from OE. Regular use of this method is expected to provide significant insights for clinical practice.

Effects of Short-Term Lenvatinib Administration Prior to Transarterial Chemoembolization for Hepatocellular Carcinoma.

AIM: Transarterial chemoembolization (TACE) combined with lenvatinib, employing a 4-day lenvatinib administration followed by TACE without an interval (short-term LEN-TACE), was performed for hepatocellular carcinoma (HCC). The aim was to assess tumor hemodynamics following the 4-day lenvatinib and to evaluate the treatment outcomes after the short-term LEN-TACE. METHODS: 25 unresectable HCC patients received this combined therapy. Lenvatinib (4-12 mg) was administrated for 4 days prior to TACE. Perfusion CT scans were obtained before and after the lenvatinib administration. Either cTACE (76%) or DEB-TACE (24%) were performed. RESULTS: intra-tumor blood flow significantly decreased after the 4-day lenvatinib (p < 0.05). The TACE procedure was successful with no severe adverse events in all patients. The overall complete response (CR) rate was 75% (cTACE 84%, DEB-TACE 40%). The lipiodol-washout ratio between 1 week and 4 months after cTACE correlated with the arterial flow reduction ratio by lenvatinib prior to TACE (r = -0.55). The 12-month progression-free survival (PFS) rate was 75.0%. CONCLUSIONS: The short-term LEN-TACE is feasible and safe, demonstrating promising outcomes with a high CR ratio, contributing to lipiodol retention in the tumor after cTACE, and extended PFS. To confirm the advantages of this treatment protocol, a prospective clinical trial is mandatory.

Multimodality Imaging of Primary Hepatic Lymphoma: A Case Report and a Literature Review.

Primary hepatic lymphoma (PHL) is a rare form of non-Hodgkin lymphoma primarily affecting the liver. We present a case of an 84-year-old man diagnosed with PHL, incidentally detected during abdominal ultrasonography. The ultrasonography showed a hypoechoic nodule. When examined by CEUS, the nodule showed hyperenhancement in the arterial phase and hypoenhancement in the portal and late phases. Conversely, CECT demonstrated hypoenhancement through all the phases. The patient declined a tumor biopsy and opted for follow-up care. Ten months later, the lobular mass had increased from 15 mm to 65 mm, presenting as hypoechogenic and demonstrating the "vessel-penetrating sign" on color Doppler imaging. CEUS revealed reticulated enhancement, indicating intratumoral vessels. The mass displayed hypoattenuation on plain CT, hypointensity in T1-weighted images, and hyperintensity in T2-weighted images and exhibited significant restriction in diffusion-weighted images. Both CECT and contrast-enhanced MRI exhibited hypoenhancement. The patient underwent a partial hepatic segmentectomy, and the mass was pathologically diagnosed as a diffuse large B-cell lymphoma. Subsequent postoperative radiological examinations revealed no other lesions, confirming the diagnosis of PHL. Our report highlights specific ultrasonographic signs of PHL observed from an early stage and presents a review of the relevant literature.

Hepatobiliary-phase gadolinium ethoxybenzyl-diethylenetriaminepentaacetic acid MRI for pretreatment prediction of efficacy-to-standard-therapies based on Barcelona Clinic Liver Cancer algorithm: an up-to-date review.

Recent advances in systemic therapy have had major impacts on treatment strategies for hepatocellular carcinoma (HCC). The 2022 Barcelona Clinic Liver Cancer (BCLC) guidelines incorporate a new section on clinical decision-making for personalized medicine, although the first treatment suggested by the BCLC guidelines is based on solid scientific evidence. More than ever before, the appropriate treatment strategy must be selected prior to the initiation of therapy for HCC. Gadolinium ethoxybenzyl-diethylenetriaminepentaacetic acid magnetic resonance imaging (Gd-EOB-DTPA-MRI) is essential for liver imaging and the hepatobiliary phase (HBP) of EOB-MRI reflects the expression of organic anion transporting polypeptide (OATP) transporters. Molecules associated with OATP expression are relevant in the molecular classification of HCC subclasses, and EOB-MRI is becoming increasingly important with advances in the molecular and genetic understanding of HCC. In this review, we describe imaging findings for the pretreatment prediction of response to standard therapies for HCC based on the BCLC algorithm using the HBP of EOB-MRI, with specific attention to the molecular background of OATPs. A more complete understanding of these findings will help radiologists suggest appropriate treatments and clinical follow-ups and could lead to the development of more personalized treatment strategies in the future. CLINICAL RELEVANCE STATEMENT: In the coming era of personalized medicine, HBP of EOB-MRI reflecting molecular and pathological factors could play a predictive role in the therapeutic efficacy of HCC and contribute to treatment selection. KEY POINTS: • Imaging features of hepatobiliary phase predict treatment efficacy prior to therapy and contribute to treatment choice. • Wnt/ß-catenin activation associated with organic anion transporting polypeptide expression is involved in the tumor immune microenvironment and chemo-responsiveness. • Peritumoral hypointensity of hepatobiliary phase reflecting microvascular invasion affects the therapeutic efficacy of locoregional to systemic therapy.

Intraductal oncocytic papillary neoplasm of the pancreas: clinical and radiological features compared to those of intraductal papillary mucinous neoplasm.

PURPOSE: This study aimed to characterize the clinical and imaging findings of intraductal oncocytic papillary neoplasm of the pancreas (IOPN-P) compared to those of intraductal papillary mucinous adenoma/carcinoma (IPMA/IPMC). METHODS: This multi-institutional retrospective study reviewed the clinical, imaging, and pathological findings of 21 patients with pathologically proven IOPN-P. Twenty-one computed tomography (CT) and magnetic resonance imaging, and seven 18F-fluorodeoxyglucose (FDG)-positron emission tomography were performed before surgery. The following findings were evaluated: preoperative blood test results, lesion size and location, pancreatic duct diameter, contrast-enhancement effect, bile duct and peripancreatic invasion, maximum standardized uptake (SUVmax) value, and pathological stromal invasion. RESULTS: Serum carcinoembryonic antigen (CEA) and cancer antigen 19-9 (CA19-9) levels were significantly higher in the IPMN/IPMC group than in the IOPN-P group. Except in one patient, IOPN-P showed multifocal cystic lesions with solid components or a tumor in the main pancreatic duct (MPD) with dilatation. IOPN-P had a higher frequency of solid parts and a lower frequency of downstream MPD dilatation than IPMA. IPMC showed smaller overall cyst size, more radiological peripancreatic invasion, and worse recurrence-free and overall survival than IOPN-P. The average SUVmax value of IOPN-P was 7.5. Pathologically, 17 of the 21 IOPN-Ps had a malignant component, and six showed stromal invasion. CONCLUSION: IOPN-P shows cystic-solid lesions similar to IPMC but has lower serum CEA and CA19-9 levels, larger overall cyst size, lower frequency of peripancreatic invasion, and more favorable prognosis than IPMC. Moreover, the high FDG uptake by IOPN-Ps may be a characteristic finding of this study.

Development of liposomal contrast agent with high iodine concentration and minimal effect on renal function.

Purpose: The use of contrast media is essential to achieve high accuracy in diagnostic imaging. Iodine contrast media, one of these contrast media, has nephrotoxicity as a side effect. Therefore, the development of iodine contrast media that can reduce nephrotoxicity is expected. Since liposomes are generally adjustable in size (100-300 nm) and are not filtered by the renal glomerulus, we hypothesized that iodine contrast media could be encapsulated in liposomes and administered to avoid the nephrotoxicity of iodine contrast media. The aim of this study is to develop an iomeprol-containing liposome (IPL) agent with high iodine concentration and to investigate the effect of intravenous administration of IPL on renal function in a rat model with chronic kidney injury. Materials and methods: IPLs were prepared by encapsulating an iomeprol (400mgI/mL) solution in liposomes by a kneading method using a rotation-revolution mixer. Radiodensities of iomeprol and IPL were measured. IPL or iopamidol at normal dose (0.74 g I/kg) or high dose (3.7 g I/kg) was administered to healthy and 5/6-nephrectomized rats (n = 3-6). Serum creatinine (sCr) and histopathological change of tubular epithelial cells were evaluated after injection. Results: The iodine concentration of IPL was 220.7 mgI/mL, equivalent to 55.2% of the iodine concentration of iomeprol. The CT values of IPL was 4731.6 ± 53.2 HU, 59.04% that of iomeprol. The ratios of change in sCr in 5/6-nephrectomized rats that received high-dose iopamidol were 0.73, which were significantly higher than that in 5/6-nephrectomized rats that received high-dose IPL (-0.03) (p = 0.006). Change in foamy degeneration of tubular epithelial cells was confirmed in 5/6-nephrectomized rats that received high-dose iopamidol than that in the sham control group and healthy rats that received normal dose iopamiron (p = 0.016, p = 0.032, respectively). Foamy degeneration of tubular epitherial cells was rarely observed in the IPL injection group. Conclusions: We developed new liposomal contrast agents that have high iodine concentration and minimal effect on renal function.

Predictive Factors of Complete Response to Transarterial Chemoembolization in Intermediate Stage Hepatocellular Carcinoma beyond Up-To-7 Criteria.

AIM: To clarify the prognosis and identify predictors for obtaining a complete response (CR) by transarterial chemoembolization (TACE) in intermediate stage HCC beyond up-to-7 criteria. METHODS: Of the 120 patients with intermediate stage HCC who were treated by TACE as the initial treatment from February 2007 to January 2016, 72 finally matched the following inclusion criteria: beyond up-to-7 criteria; Child-Pugh score under 7; and no combined therapy within 4 weeks after the initial TACE. The CR rate and overall survival (OS) were evaluated. Logistic regression analysis was performed to identify predictors of CR. The deterioration of liver function after TACE was also evaluated. RESULTS: The CR rate was 56.9%, and the overall median survival time (MST) was 37.7 months. The MST was 38.7 months in the CR group and 28.0 months in the non-CR group (p = 0.018). HCC within up-to-11 criteria was the only predictor of CR. The CR rate and MST were 70.7% and 37.7 months, respectively, in patients with HCC within up-to-11 criteria and 38.7% and 32.7 months, respectively, in the patients beyond up-to-11 criteria. Deterioration of the Child-Pugh score after the initial TACE and the 2nd TACE occurred in 24.2% and 12.0%, respectively, and deterioration of the modified albumin-bilirubin (mALBI) grade occurred in 17.6% and 7.4%, respectively. CONCLUSION: TACE can achieve high CR rates with prolonged overall survival for intermediate stage HCC beyond up-to-7 criteria. The predictor of CR was within up-to-11 criteria. Deterioration of liver function was not severe, but requires caution. Multidisciplinary approach as additional treatment after TACE is important.

Vascular Normalization Caused by Short-Term Lenvatinib Could Enhance Transarterial Chemoembolization in Hepatocellular Carcinoma.

We describe the clinical effects of short-term lenvatinib administration prior to conventional transarterial chemoembolization (cTACE) on tumor vasculature. Two patients with unresectable hepatocellular carcinoma underwent high-resolution digital subtraction angiography (DSA) and perfusion four-dimensional computed tomography during hepatic arteriography (4D-CTHA) before and after administration of lenvatinib treatment. The doses and periods of lenvatinib administration were, respectively, 12 mg/day for 7 days and 8 mg/day for 4 days. In both cases, high-resolution DSA revealed a decrease in dilatation and tortuosity of the tumor vessels. Furthermore, the tumor staining became more refined, and newly formed tiny tumor vessels were observed. Perfusion 4D-CTHA revealed a decrease in arterial blood flow to the tumor by 28.6% (from 487.9 to 139.5 mL/min/100 mg) and 42.5% (from 288.2 to 122.6 mL/min/100 mg) in the two cases, respectively. The cTACE procedure resulted in good lipiodol accumulation and complete response. Patients have remained recurrence-free for 12 and 11 months after the cTACE procedure, respectively. The administration of short-term lenvatinib in these two cases resulted in the normalization of tumor vessels, which likely led to improved lipiodol accumulation and a favorable antitumor effect.

Leydig cell tumor of the testis with characteristic contrast patterns of tumor and non-tumorous testicular parenchyma on MRI: a case report.

PURPOSE: Testicular Leydig cell tumor (LCT) is a rare subtype of testicular neoplasms that occurs in the interstitial tissue of testes, accounting for 1-3% of total testicular masses removed annually. We report a case of 70-year-old man diagnosed as testicular LCT. This report demonstrates a testicular LCT with intratumoral and non-tumorous testicular parenchymal enhancement in the affected testis, which should be considered characteristic findings of LCT. METHODS: Ultrasonography showed a hypoechoic mass. On magnetic resonance imaging, the tumor showed low signal intensity comparable to the surrounding testicular tissue on T1-weighted images (T1WI) and low signal intensity on T2-weighted images (T2WI). On gadolinium contrast-enhanced T1WI (CE-T1WI), the tumor showed a rapid and marked wash-in and subsequent prolonged washout. The spared, non-tumorous testicular parenchyma showed slow and progressive enhancement in the early phase, which was as strong as or stronger than that of the mass in the delayed phase. The patient underwent right orchiectomy. RESULTS: Pathologically, the tumor was diagnosed as a testicular Leydig cell tumor (LCT). Leydig cell proliferation was observed with well-developed microvessels, atrophy of the seminiferous tubules, and stromal edema in the non-tumorous testicular parenchyma. Leydig cells in the non-tumorous parenchyma were positive for estrogen receptors. CONCLUSION: Since the contrast findings in the non-tumorous testicular parenchymal region on CE-T1WI likely match the histopathological features of LCT, our case suggests that the presence of non-tumorous testicular parenchymal enhancement on imaging might indicate a diagnosis of LCT.

[Feasibility Study of the Prediction of Radiologist's Instructions with the Bi-LSTM Model Trained with Descriptions of MR Imaging Order-statement].

PURPOSE: Magnetic resonance (MR) images provide essential diagnostic information; however, it is also a very burdensome examination for patients. At our hospital, radiologists make imaging instructions for all MR examination orders, but this is a time-consuming task. If a natural language processing model can predict the imaging instructions, it will be possible to reduce the burden on radiologists and the instruction quality can be assured. The purpose of this study was to investigate the feasibility of using natural language processing to predict MR imaging instructions with the aim of assisting radiologists. METHODS: Considering the uniqueness of the MR imaging protocols at each facility and the particularity of the test order text, we considered that the use of large datasets and pre-training models would be unsuitable. We focused on LSTM, which has been used for natural language processing, and built a 4-layer bi-LSTM model in combination with our own morphological preprocessing to predict MR imaging instructions. RESULTS: The proposed method achieved macro-average precision, recall, and F1-score of 70.6%, 69.5%, and 68.9%, respectively. Compared to the previous studies, the proposed method achieved satisfactory performance in the natural language analysis task for Japanese. It is considered that the proposed method improved the prediction accuracy of the minority class through direct and indirect effects of vocabulary reduction, optimization, and similarity learning. CONCLUSION: It is suggested that the proposed method is effective and that the prediction of MR imaging instructions using natural language analysis in combination with the proposed method is feasible.

Quantitative Analysis of Signal Heterogeneity in the Hepatobiliary Phase of Pretreatment Gadoxetic Acid-Enhanced MRI as a Prognostic Imaging Biomarker in Transarterial Chemoembolization for Intermediate-Stage Hepatocellular Carcinoma.

BACKGROUND: In the era of local and systemic therapies for intermediate-stage hepatocellular carcinoma (HCC), personalized therapy has become available. The aim of our study was to evaluate the usefulness of quantitative analysis of pretreatment gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) to predict prognosis following transarterial chemoembolization (TACE). METHODS: This retrospective study included patients with treatment-naïve intermediate-stage HCC who underwent EOB-MRI before the initial TACE and were treated by initial TACE between February 2007 and January 2016. Signal heterogeneity in the hepatobiliary phase (HBP) of EOB-MRI was quantitatively evaluated by the coefficient of variation (CV). The cutoff CV value was determined using the Classification and Regression Tree algorithm. RESULTS: A total of 64 patients were enrolled. In multivariate analysis, High CV (≥0.16) was significantly associated with poor prognosis (p = 0.038). In a subgroup analysis of patients within up-to-7 criteria, MST was significantly shorter in the High CV group than in the Low CV group (37.7 vs. 82.9 months, p = 0.024). In patients beyond up-to-7 criteria, MST was 18.0 and 38.3 months in the High CV and Low CV groups, respectively (p = 0.182). In both groups scanned at 1.5 T or 3.0 T, High CV was significantly associated with poor prognosis (p = 0.001 and 0.003, respectively). CONCLUSION: CV of the tumor in the HBP of EOB-MRI is a valuable prognostic factor of TACE.

The diagnostic challenge of non-traumatic bladder rupture: a pictorial essay.

Non-traumatic bladder rupture (NTBR) is relative rare pathology including spontaneous rupture and iatrogenic injury. As increasing the medical intervention for the pelvic malignancy or elderly population, NTBR will be encountered more frequently. There are few previous studies summarizing the imaging features of NTBR. We reviewed imaging characteristics of 18 previous cases of NTBR experienced. In addition, 3 presentative cases that can be a pitfall to differentiate from NTBR. The aim of this article is to clarify the key CT findings of NTBR and its pitfalls.

Imaging features of ß-catenin-activated hepatocellular adenoma with weak ß-catenin activation: A rare case report.

We report valuable imaging findings in a case of ß-catenin-activated hepatocellular adenoma (ß-HCA) with weak ß-catenin activation. A 40 year-old female presented with a liver tumor in S8 that was incidentally detected on ultrasonography. The tumor showed marked enhancement and early venous drainage into the middle hepatic vein in the arterial phase of contrast-enhanced computed tomography (CT). The tumor revealed slight hypointensity in the hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI). Six months after detection, the tumor had increased in size and a biopsy indicated hepatocellular carcinoma. The tumor was resected and pathologically diagnosed as ß-HCA with weak ß-catenin activation such as exon 3 S45 mutation and exon 7/8 mutation. Marked enhancement in the arterial phase of CT and MRI is a characteristic finding of ß-HCA with weak ß-catenin activation. Furthermore, the degree of ß-catenin activation might determine the signal intensity of ß-HCA in the hepatobiliary phase of EOB-MRI.

Clinical Significance of the Highest Regional Bone Scan Index in Patients with Metastatic Castration-Resistant Prostate Cancer.

Purpose: This study evaluated the clinical utility of the highest bone scan index (BSI), among other BSIs, for each bone metastatic site in patients with bone metastatic castration-resistant prostate cancer (bmCRPC). Methods: Thirty patients, diagnosed with bmCRPC by bone scintigraphy, were included. Total BSI, the number of hot spots, and regional BSI on each hot spot from bone scintigraphy at diagnosis with bmCRPC were evaluated by VSBONE BSI®. Highest regional BSI was defined as the highest value among regional BSIs on each hot spot in each patient. Related factors to overall survival and skeletal-related events (SREs) were evaluated using the Cox proportional-hazards model. Results: The median follow-up time from diagnosis with bmCRPC was 29.0 months. During this time, 24 patients died, of which 22 patients died from prostate cancer. On univariate analysis, alkaline phosphatase (ALP) [Hazard ratio (HR): 5.96, 95% confidence interval (CI): 2.05-17.3] and highest regional BSI (HR: 2.01, 95% CI: 1.17-7.05) had significant correlation with overall survival. On multivariate analysis, ALP (HR: 4.79, 95% CI: 1.61-14.2) had significant correlation with overall survival. SREs were found in eight patients. Only the highest regional BSI (HR: 9.99, 95% CI: 2.46-40.6) significantly correlated with SREs on univariate analysis. Conclusion: Highest regional BSI may provide important information regarding prognosis and SREs in patients with bmCRPC.

Long-term chronological changes in renal function and functional renal volume after nephron-sparing surgery: A prospective observational study.

OBJECTIVES: To investigate long-term chronological changes in functional renal volume and renal function after nephron-sparing surgery, and factors that contribute to the progression of postoperative chronic kidney disease. METHODS: A total of 80 patients who underwent nephron-sparing surgery were enrolled in this prospective observational study. The renal function deterioration group was defined as patients whose estimated glomerular filtration rate at 5 postoperative years decreased by ≥20% relative to that before surgery. RESULTS: The predicted estimated glomerular filtration rate, calculated based on the functional renal volume at 5 postoperative years, was strongly correlated with the postoperative estimated glomerular filtration rate (Spearman's ρ = 0.89, P < 0.001). The rate of new-onset stage IIIb chronic kidney disease was significantly higher in the renal function deterioration group than in the stable renal function group (P < 0.001). Multivariate analysis identified proteinuria (P = 0.017), small preoperative total functional renal volume (≤250 mL, P = 0.046) and large tumor volume (≥4.5 mL, P = 0.036) as independent factors associated with renal function deterioration. CONCLUSIONS: Our findings show that the functional renal volume is significantly associated with renal function, even in the long-term postoperative period. Additionally, for patients with preoperative proteinuria, large tumor volume and small total preoperative functional renal volume, both oncological follow ups and medical interventions, including prevention of lifestyle-related diseases, might prevent the progression of chronic kidney disease.

Useful Parameters in Dynamic Contrast-enhanced Ultrasonography for Identifying Early Response to Chemotherapy in a Rat Liver Tumor Model.

OBJECTIVES: The objective of the study is to determine a parameter on the time-intensity curve (TIC) of dynamic contrast-enhanced ultrasonography (DCE-US) that best correlates with tumor growth and to evaluate whether the parameter could correlate with the early response to irinotecan in a rat liver tumor model. MATERIAL AND METHODS: Twenty rats with tumors were evaluated (control: Saline, n = 6; treatment: Irinotecan, n = 14) regarding four parameters from TIC: Peak intensity (PI), k value, slope (PI × k), and time to peak (TTP). Relative changes in maximum tumor diameter between day 0 and 10, and parameters in the first 3 days were evaluated. The Mann-Whitney U-test was used to compare differences in tumor size and other parameters. Pearson's correlation coefficients (r) between tumor size and parameters in the control group were calculated. In the treatment group, relative changes of parameters in the first 3 days were compared between responder and non-responder (<20% and ≥20% increase in size on day 10, respectively). RESULTS: PI, k value, PI × k, and TTP significantly correlated with tumor growth (r = 0.513, 0.911, 0.665, and 0.741, respectively). The mean RC in k value among responders (n = 6) was significantly lower than non-responders (n = 8) (mean k value, 4.96 vs. 72.5; P = 0.003). CONCLUSION: Parameters of DCE-US could be a useful parameter for identifying early response to irinotecan.

Feasibility and Techniques of Securing 3D-Safety Margin in Superselective Transarterial Chemoembolization to Improve Local Tumor Control for Small Hepatocellular Carcinoma: An Intend-to-Treat Analysis.

INTRODUCTION: The aim of this study was to investigate the technical success rate of obtaining 3D-safety margin in superselective conventional transarterial chemoembolization (cTACE) using 3D images for small hepatocellular carcinoma (HCC). METHODS: Consecutive 48 HCC nodules (diameter, 1-3 cm) in 44 patients were intentionally treated by superselective cTACE in an attempt to achieve 3D-safety margin. Superselective CT during hepatic arteriography (CTHA) was obtained before cTACE. When negative 3D-safety margin was found, branches supplied into the margin area were detected by using a 3D workstation. The technical success rate to obtain 3D-safety margin was investigated by intend-to-treat analysis. Local tumor recurrence rate and adverse events were also evaluated. RESULT: Nine of 48 tumors (18.8%) had 3D-safety margin in the initial superselective CTHA. After pulling back of the catheter and/or selection of another branch based on 3D images, 3D-safety margin was finally achieved in 45 (93.8%). There were 8 of 46 tumors (17.4%) with local recurrence after 5-year follow-up. Grade 3-4 of aspartate aminotransferase, alanine aminotransferase, and total bilirubin were found in 38.6, 36.4, and 2.3%, respectively. One portal vein thrombus and 3 biliary dilation or biloma were developed. CONCLUSION: Superselective cTACE obtaining 3D-safety margin in small HCC was feasible with a high success rate by using 3D images, which could be tolerable and prevent local tumor recurrence.

The middle rectal artery detected by contrast-enhanced magnetic resonance imaging predicts lateral lymph node metastasis in lower rectal cancer.

PURPOSE: Lateral lymph node (LLN) metastasis is one of the leading causes of local recurrence in patients with lower rectal cancer. Unfortunately, no diagnostic biomarkers are currently available that can predict LLN metastasis preoperatively. Accordingly, we investigated the relationship between the middle rectal artery (MRA) identified by contrast-enhanced magnetic resonance imaging (ceMRI) and LLN metastases. METHODS: Data from 102 patients with lower rectal cancer who underwent surgery, and were evaluated by preoperative ceMRI, between 2008 and 2016 were reviewed retrospectively. Two expert radiologists evaluated the MRA findings. The diagnostic performance of MRA for LLN metastasis was evaluated by a multivariate analysis with conventional clinicopathological factors. RESULTS: The MRA was detected in 67 patients (65.7%), including 32 (31.4%) with bilateral MRA and 35 (34.3%) with unilateral MRA. The tumor size, presence of the MRA, and clinical LLN status were significantly correlated with LLN metastasis. A multivariate analysis demonstrated that the presence of MRA (P = 0.045) and clinical LLN status (P = 0.001) were independent predictive factors for LLN metastasis. Furthermore, the sensitivity and negative predictive value of MRA for LLN metastasis were 95% and 97.1%, respectively. CONCLUSION: We successfully demonstrated that MRAs could be clearly detected by ceMRI, and the presence of MRA robustly predicted LLN metastasis in patients with lower rectal cancer, highlighting its clinical significance in the selection of more appropriate treatment strategies. TRIAL REGISTRATION: Trial registration number: retrospectively registered 2126 Trial registration date of registration: August 23, 2019.

Evaluation of background parenchymal enhancement in breast contrast-enhanced ultrasound with Sonazoid®.

PURPOSE: The objective of this study was to retrospectively evaluate the association between background parenchymal enhancement (BPE) on contrast-enhanced ultrasound (CEUS) with Sonazoid® and patient characteristics. Additionally, background parenchymal tissues with the high-contrast effect were pathologically observed compared to those showing the low-contrast effect. METHODS: A total of 65 patients who underwent breast CEUS with Sonazoid® between January 2010 and November 2013 were enrolled. Regions of interest (ROIs) were put on the tumor and on the background parenchymal tissue. The dB values during the nonenhanced time and at peak contrast enhancement were measured based on the time intensity curve (TIC) drawn by the ROI. The differences in the dB values of pre- and post-enhanced time were obtained separately for ROIs on the tumor and ROIs on the parenchymal tissue. The patient characteristics studied were age, menstrual status, mammographic density, BPE on magnetic resonance imaging (MRI), and pathological diagnoses of breast tumors. RESULTS: There was a weak negative correlation between BPE on CEUS and age. As for the contrast effect of parenchymal tissue, there was a significant difference between the menstruating and menopausal groups. There was no significant difference among the levels of mammographic density, and among the degrees of contrast effect on MRI. BPE on CEUS was the same between those with a malignant tumor and those with a benign tumor in each menstrual status. The parenchymal tissue with the low-contrast effect showed pathological atrophy. CONCLUSION: The degree of BPE on CEUS appeared related to age, menstruating or menopausal, and atrophy of breast tissue. BPE on CEUS was the same between those with a malignant tumor and those with a benign tumor in each menstrual status.