Masakatsu Tsurusaki

Surgical and Locoregional Therapy of HCC: TACE

Transcatheter arterial chemoembolization (TACE) is performed worldwide for patients with intermediate-stage hepatocellular carcinoma (HCC). TACE has produced survival advantages in two randomized controlled trials and a meta-analysis, and is currently the mainstay of treatment for this stage of HCC. However, there are currently no global guidelines regarding the dose, choice or combination of cytotoxic agents for TACE; therefore, it is difficult to compare data from different TACE studies. In Japan, most of the TACE procedures have been based on iodized oil as conventional TACE, utilizing the microembolic and drug-carrying characteristic of iodized oil. Superselective TACE with lipiodol is the primary TACE procedure that has reported satisfactory levels of local control associated with a lower risk of complications. Conversely, TACE performed using drug-eluting beads has been widely used in western countries, and this has shown similar tumor response and median survival compared to conventional TACE. Moreover, the combination of TACE and molecular targeted agents is now ongoing to evaluate the synergistic effect. In this review, the indication, technical issues, and complications of TACE are reviewed.

Hypervascular benign and malignant liver tumors that require differentiation from hepatocellular carcinoma: key points of imaging diagnosis.

Most liver tumors are benign and hypervascular, and it is important to avoid unnecessary interventions for benign lesions. This review describes the typical and atypical imaging features of common hypervascular benign liver tumors and outlines a general approach to distinguishing between benign and malignant hepatic lesions. There are many types of benign liver tumors that need to be differentiated from hepatocellular carcinoma (HCC). Therefore, it is very important to know the imaging characteristics of benign tumors. Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging is helpful in diagnosing hypervascular pseudotumors, focal nodular hyperplasia, and nodular lesions associated with alcohol-induced hepatitis. There are also some hypervascular malignant tumors, such as cholangiocarcinoma, cholangiolocellular carcinoma, mixed type tumors, and metastatic liver tumors, which also required differentiation from HCC.

Clinical application of 18F-fluorodeoxyglucose positron emission tomography for assessment and evaluation after therapy for malignant hepatic tumor

Positron emission tomography (PET) is widely available and its application with 2-[18F] fluoro-2-deoxy-d-glucose (18F-FDG) in oncology has become one of the standard imaging modalities in diagnosing and staging of tumors, and monitoring the therapeutic efficacy in hepatic malignancies. Recently, investigators have measured glucose utilization in liver tumors using 18F-FDG and positron emission tomography/computer tomography (PET/CT) in order to establish a diagnosis of tumors, assess their biologic characteristics and predict therapeutic effects on hepatic malignancies. The PET/CT with 18F-FDG may further enhance the hepatic malignancy diagnostic algorithm by accurate diagnosis, staging, restaging and evaluating its biological characteristics, which can benefit the patients suffering from primary and metastatic hepatic tumors such as hepatocellular carcinoma (HCC), cholangiocarcinoma (CCC), and metastatic liver tumor.

Current evidence for the diagnostic value of gadoxetic acid-enhanced magnetic resonance imaging for liver metastasis

A variety of imaging techniques, including ultrasonography (US), multidetector computed tomography (MDCT), magnetic resonance imaging (MRI) and positron emission tomography combined with CT scan (PET/CT), are available for diagnosis and treatment planning in liver metastasis. Contrast‐enhanced MDCT is a relatively non‐invasive, widely available and standardized method for hepatic work‐up. Gadoxetic acid (gadolinium‐ethoxybenzyl‐diethylenetriamine pentaacetic acid; EOB Primovist®]) is a recently developed liver‐specific hepatobiliary MR contrast agent that offers both dynamic imaging as well as liver‐specific static hepatocyte imaging, referred to as the hepatobiliary phase. Following contrast injection, this technique reveals dynamic vascular phases (arterial, portal venous and delayed phases), in addition to the hepatobiliary phase upon uptake by functional hepatocytes. The overall sensitivity of gadoxetic acid‐enhanced MRI was significantly higher than that of contrast‐enhanced CT. Specifically, the higher sensitivity of gadoxetic acid‐enhanced MRI was observed in lesions smaller than 1 cm in diameter. Gadoxetic acid‐enhanced MRI is considered an extremely useful tool for the diagnosis of liver metastases. Future studies will focus on diagnostic algorithms involving combinations of modalities such as MRI, MDCT and/or 18F‐fluorodeoxyglucose PET/CT, which may impact the treatment plan for these patients.

Can low-dose CT with iterative reconstruction reduce both the radiation dose and the amount of iodine contrast medium in a dynamic CT study of the liver?

PURPOSE To investigate whether low-dose dynamic CT of the liver with iterative reconstruction can reduce both the radiation dose and the amount of contrast medium. MATERIALS AND METHODS This study was approved by our institutional review board. 113 patients were randomly assigned to one of two groups. Group A/group B (fifty-eight/fifty-five patients) underwent liver dynamic CT at 120/100 kV, with 0/40% adaptive statistical iterative reconstruction (ASIR), with a contrast dose of 600/480 mg I/kg, respectively. Radiation exposure was estimated based on the manufacturers phantom data. The enhancement value of the hepatic parenchyma, vessels and the tumor-to-liver contrast of hepatocellular carcinomas (HCCs) were compared between two groups. Two readers independently assessed the CT images of the hepatic parenchyma and HCCs. RESULTS The mean CT dose indices: 6.38/4.04 mGy, the dose-length products: 194.54/124.57 mGy cm, for group A/group B. The mean enhancement value of the hepatic parenchyma and the tumor-to-liver contrast of HCCs with diameters greater than 1cm in the post-contrast all phases did not differ significantly between two groups (P>0.05). The enhancement values of vessels in group B were significantly higher than that in group A in the delayed phases (P<0.05). Two readers confidence levels for the hepatic parenchyma in the delayed phases and HCCs did not differ significantly between the groups (P>0.05). CONCLUSIONS Low-dose dynamic CT with ASIR can reduce both the radiation dose and the amount of contrast medium without image quality degradation, compared to conventional dynamic CT without ASIR.

Recent Advances in Bioinformatics Reveal the Molecular Heterogeneity of Hepatocellular Carcinoma

Bioinformatics is an academic field that manages information about materials and substances essential for the biological activities of genes, proteins, and RNA. Bioinformatics enables vast amounts of biological data to be made available for statistical analysis to improve our understanding, diagnosis, and treatment of diseases. In recent years, genome-wide association studies (GWAS) and next-generation DNA sequencing technology have made it possible to generate large amounts of data very quickly. Consequently, the biggest challenge today is to extract clinically useful data from overwhelmingly large datasets, and this challenge has become a major research objective in the field of bioinformatics. A key example is that these techniques made it possible to achieve the long-held goal of molecular classification of hepatocellular carcinoma (HCC) [1, 2](fig. 1). In 2011, the National Cancer Center of Japan achieved a world first by the whole-genome sequencing of HCC using next-generation sequencers [3], and this was successively followed by reports of whole-genome and exome sequencing of HCC by both Japanese and overseas research groups [4–8]. However, in contrast to the well-known high-frequency mutations of epidermal growth factor receptor genes and the anaplastic-lymphoma-kinase fusion gene in lung adenocarcinoma, the whole-genome sequence of HCC revealed the presence of lowfrequency mutations in various genes but no single driver mutation, thereby practically ruling out the possibility that HCC is caused by a single driver mutation. However, since such vast amounts of bioinformatic data are now readily available to clinicians, we believe that if the correct approaches are taken, it is only a matter of time before a paradigm-shattering concept buried deep in bioinformatic data will be found that will revolutionize medical care. In the field of bioinformatics, a very wide range of applications is possible; for example, it can be used to predict tumor malignancy, optimal treatments, and prognosis. Also, GWAS data are useful for predicting drug sensitivity and adverse effects. This is truly the dawn of the era of individualized medicine, and the application of bioinformatics in the field of oncology is already forging a path to this goal.

Balloon-Occluded Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma: A Single-Center Experience

Objective: To investigate whether balloon-occluded transcatheter arterial chemoembolization (b-TACE) can produce a more dense accumulation of iodized oil in various stages of hepatocellular carcinoma (HCC), from single to uncountable, to overcome inferior local control. Materials and Methods: We studied 27 patients with HCC, including single to uncountable multiple lesions, who underwent b-TACE between August 2013 and April 2015. Dynamic CT was performed at baseline and 1-3 months after b-TACE. The treatment effect (TE) after b-TACE was evaluated using the Response Evaluation Criteria in Cancer of the Liver (RECICL) proposed by the Liver Cancer Study Group of Japan. Results: In the countable HCC group, contrast-enhanced CT demonstrated RECICL TE4 in 43.8% (14/32), TE3 in 12.5% (4/32), TE2 in 37.5% (12/32), and TE1 in 6.3% (2/32) of patients. For the TACE-naïve cohort, the objective response rate was 52.9%. The objective response rate was 60% for the previously TACE-treated cohort. In the uncountable multiple HCC group, the objective response rate was 0% (0/10), with progressive disease in 90% (9/10) of patients. Conclusion: Our observations suggested that b-TACE did not reduce the efficacy of retreatment for HCC with an insufficient outcome from conventional TACE, but it could not improve the efficacy of treatment for uncountable multiple HCCs.

Role of diffusion weighted imaging and contrast-enhanced MRI in the evaluation of intrapelvic recurrence of gynecological malignant tumor.

Background and Purpose To investigate the diagnostic performance of diffusion-weighted imaging (DWI) and contrast-enhanced imaging in combination with T2-weighted imaging (T2WI) for magnetic resonance imaging (MRI) evaluation of intrapelvic recurrence of gynecological malignancies. Materials and Methods Sixty-two patients with suspected intrapelvic recurrence of gynecological malignancies underwent pelvic MRI including T2WI DWI, and contrast-enhanced imaging. Diagnostic performance for detection of local recurrence, pelvic lymph node and bone metastases, and peritoneal lesions was evaluated by consensus reading of two experienced radiologists using a 5-point scoring system, and compared among T2WI with unenhanced T1-weighted imaging (T1WI) (protocol A), a combination of protocol A and DWI (protocol B), and a combination of protocol B and contrast-enhanced imaging (protocol C). Final diagnoses were obtained by histopathological examinations, radiological imaging and clinical follow-up for at least 6 months. Receiver operating characteristic (ROC) analysis and McNemar test were employed for statistical analysis. Results Locally recurrent disease, lymph node recurrence, peritoneal dissemination and bone metastases were present in 48.4%, 29.0%, 16.1%, and 6.5% of the patients, respectively. The patient-based sensitivity, specificity, accuracy, and area under the ROC curve (AUC) for detection of intrapelvic recurrence were 55.0, 81.8, 64.5% and 0.753 for protocol A, 80.0, 77.3, 79.0% and 0.838 for protocol B, and 80.0, 90.9, 83.9% and 0.862 for protocol C, respectively. The sensitivity, accuracy, and AUC were significantly better for protocols B and C than for protocol A (p<0.001). There was no significant difference between protocols B and C. Conclusion MRI using a combination of DWI and T2WI gives comparatively acceptable results for assessment of intrapelvic recurrence of gynecological malignancies.

Interventional radiology for critical hemorrhage in obstetrics: Japanese Society of Interventional Radiology (JSIR) procedural guidelines

AbstractThere has been an increasing demand for interventional radiology (IR) procedures for the treatment of severe postpartum hemorrhage (PPH) (also called critical hemorrhage in obstetrics). The Japanese Society of Interventional Radiology Guideline Committee developed the practical guidelines for IR procedures for severe PPH using evidence-based methodology. This article aimed to describe the rationale for developing these guidelines and to provide the answers for clinical questions about IR procedures consisting of current available evidence and the consensus among experts.

Imaging of metastases from breast cancer to uncommon sites: a pictorial review

There are three types of breast cancer recurrence which can occur after initial treatment: local, regional, and distant. Distant metastases are more frequent than local and regional recurrences. It usually occurs several years after the primary breast cancer, although it is sometimes diagnosed at the same time as the primary breast cancer. Although the common distant metastases are bone, lung and liver, breast cancer has the potential to metastasize to almost any region of the body. Early detection and treatment of distant metastases improves the prognosis, therefore radiologists and clinicians should recognize the possibility of metastasis from breast cancer and grasp the imaging characteristics. In this report, we demonstrate the imaging characteristics of metastases from breast cancer to uncommon sites.