Histological transformation to signet-ring cell carcinoma in a patient with clinically aggressive poorly differentiated adenocarcinoma of the ascending colon after response to chemotherapy plus cetuximab: a case report.

BACKGROUND: Alteration of chemosensitivity or tumor aggressiveness in response to chemotherapy has been reported, and liquid biopsy assessment during chemotherapy for colorectal cancers has confirmed the acquisition of mutations in various oncogenes. However, the occurrence of histological transformation seems to be extremely rare in colorectal cancers, and the few existing case reports of this transformation are from lung cancer and breast cancer. In this report, we describe the histological transformation of clinically aggressive scirrhous-type poorly differentiated adenocarcinoma of the ascending colon to signet-ring cell carcinoma in almost all recurrent tumors that were confirmed by autopsy after response to chemotherapy plus cetuximab. CASE PRESENTATION: A 59-year-old woman visited our hospital with whole abdominal pain and body weight loss and was diagnosed with scirrhous-type poorly differentiated adenocarcinoma of the ascending colon with aggressive lymph node metastases. The intrinsic chemosensitivity of the tumors was evident upon initiation of mFOLFOX6 plus cetuximab therapy, and right hemicolectomy was performed, and the tumor obviously remained in the peripancreatic area, paraaortic region, or other retroperitoneal areas. The ascending colon tumors mainly consisted of poorly differentiated adenocarcinoma and were not associated with signet-ring cell components except for minute clusters in a few lymphatic emboli in the main tumor. Chemotherapy was continued, and metastases were eliminated at 8 months after the operation; this response was maintained for an additional 4 months. Discontinuation of chemotherapy plus cetuximab resulted in immediate tumor recurrence and rapid expansion, and the patient died of the recurrent tumor 1 year and 2 months after the operation. Autopsy specimens revealed that almost all of the recurrent tumors exhibited transformation and consisted of signet-ring cell histology. CONCLUSION: This case might suggest that various oncogene mutations or epigenetic changes resulting from chemotherapy, especially regimens that include cetuximab, contribute to the transformation of non-signet-ring cell colorectal carcinoma to signet-ring cell carcinoma histology and can promote the aggressive clinical progression characteristic of signet-ring cell carcinoma.

Liver Resection for Multiple Hepatocellular Carcinomas: A Japanese Nationwide Survey.

OBJECTIVE: The aim of the study was to evaluate the survival benefits of liver resection (LR) compared with transarterial chemoembolization (TACE) for patients with multiple hepatocellular carcinomas (HCCs). BACKGROUND: Despite significant improvements in diagnostic imaging and the widespread application of screening programs, some patients with HCC continue to present with multiple tumors. The surgical indications for multiple HCCs remain controversial. METHODS: Among 77,268 patients with HCC reported in a Japanese nationwide survey, 27,164 patients had multiple HCCs. The exclusion criteria were Child-Pugh B/C, treatment other than LR and TACE, >3 tumors, and insufficient available data. Ultimately, 3246 patients (LR: n = 1944, TACE: n = 1302) were included. The survival benefit of LR for patients multiple HCCs was evaluated by using propensity score matching analysis. RESULTS: The study group of 2178 patients (LR: n = 1089, TACE: n = 1089) seemed to be well matched. The overall survival rate in the LR group was 60.0% at 5 years, which was higher than that in the TACE group (41.6%, P < 0.001). Among patients with a tumor size of 30 mm or more, LR showed a survival benefit over TACE at 5 years (53.0% vs 32.7%, P < 0.001). The multivariate analysis indicated that age, serum albumin level, serum alpha-fetoprotein (AFP) level, macrovascular invasion, tumor size, and TACE were independent predictors of poor prognosis in multiple HCCs. CONCLUSIONS: LR could offer better long-term survival than TACE for patients with multiple HCCs (up to 3 tumors). If patients have good liver function (Child-Pugh A), LR is recommended, even for those with multiple HCCs with tumor sizes of 30 mm or more.

Treatment Optimization for Hepatocellular Carcinoma in Elderly Patients in a Japanese Nationwide Cohort.

OBJECTIVE: We reviewed nationwide follow-up data to determine outcomes of different treatments for early-stage hepatocellular carcinoma (HCC) in elderly patients. SUMMARY BACKGROUND DATA: Outcomes of early-stage HCC treatments in elderly patients have not been prospectively compared. METHODS: We included 6490 HCC patients, aged ≥75 years at treatment, who underwent curative hepatic resection (HR, n = 2020), radiofrequency ablation (RFA, n = 1888), microwave ablation (MWA, n = 193), or transcatheter arterial chemoembolization (TACE, n = 2389), and compared their characteristics and survival. We used matching propensity score analysis (PSA) between the HR and RFA subgroups with tumors ≤3 cm to overcome baseline bias. RESULTS: The HR group had significantly longer recurrence-free survival (RFS) than the RFA, MWA, and TACE groups [RFA vs HR-hazard ratio: 1.22, 95% confidence interval (CI): 1.09-1.37, P < 0.001; MWA vs HR-hazard ratio: 1.51, 95% CI: 1.22-1.88, P < 0.001; TACE vs HR-hazard ratio: 2.70, 95% CI: 2.44-2.99, P < 0.001). HR and RFA patients had significantly longer overall survival (OS) than the TACE group (RFA vs HR-hazard ratio: 1.01, 95% CI: 0.87-1.17, P = 0.919, TACE vs HR-hazard ratio: 2.11, 95% CI: 1.86-2.40, P < 0.001). PSA successfully matched HR and RFA patients from with primary HCC tumors ≤3.0 cm and similar liver function and tumor characteristics; and showed significantly longer RFS (hazard ratio: 1.64, 95% CI: 1.29-2.10, P < 0.001) and OS (hazard ratio: 1.57, 95% CI: 1.12-2.20, P = 0.009) for HR than for RFA (including subgroup analyses). In Cox proportional hazard analysis, HR offered better prognosis than RFA. CONCLUSIONS: HR decreases recurrence risk and improves OS in patients aged ≥75 years with primary HCC tumors ≤3.0 cm.

Impact of Advanced Age on Survival in Patients Undergoing Resection of Hepatocellular Carcinoma: Report of a Japanese Nationwide Survey.

OBJECTIVE: The impact of age on survival after hepatic resection for hepatocellular carcinoma (HCC) has not been thoroughly examined. We reviewed the data of a nationwide follow-up survey to determine the outcomes of hepatectomy for HCC in elderly patients. BACKGROUND: Management of malignant diseases in elderly patients has become a global clinical issue because of the increased life expectancy worldwide. Advancements in surgical techniques and perioperative management have reduced age-related contraindications for liver surgery. METHODS: In all, 12,587 patients with HCC who underwent curative hepatic resection were included in this cohort study and classified according to age group [40-59 years (n = 2991), 60-74 years (n = 7576,), and ≥75 years (n = 2020)]. Clinicopathological features, long-term survival, and cumulative incidences of death after hepatic resection were compared among the groups. The cause-specific subdistribution hazard ratios for 3 types of death depending on age were also estimated. RESULTS: Preoperative liver function tests showed that the prothrombin activity and platelet count were higher in the ≥75-year age group than in the other age groups. The overall survival was significantly lower in the elderly than younger patients. However, recurrence-free survival was almost identical among the 3 groups. The cumulative incidence of HCC-related or liver-related death was almost identical among the 3 groups; however, the cumulative incidence of other causes of death was significantly different. The 60-year subdistribution hazard ratio for other causes of death increased remarkably with increasing age. CONCLUSIONS: Elderly patients in this nationwide survey had significantly worse overall survival after hepatectomy than middle-aged and young patients. The cumulative incidence of other causes of death in elderly patients was significantly different from that of HCC-related or liver-related death among the 3 groups.

Liver resection for hepatocellular carcinoma associated with hepatic vein invasion: A Japanese nationwide survey.

Because of the rarity of hepatic vein tumor thrombus (HVTT) compared with portal vein tumor thrombus (PVTT) in patients with hepatocellular carcinoma, little is known about this disease entity. The aim of this study was to evaluate the prognosis of each treatment modality for HVTT through an analysis of data collected in a Japanese nationwide survey. We analyzed data for 1,021 Child-Pugh A hepatocellular carcinoma patients with HVTT without inferior vena cava invasion registered between 2000 and 2007. Of these patients, 540 who underwent liver resection (LR) and 481 who received other treatments were compared. Propensity scores were calculated, and we successfully matched 223 patients (49.0% of the LR group). The median survival time in the LR group was 2.89 years longer than that in the non-LR group (4.47 versus 1.58 years, P < 0.001) and 1.61 years longer than that in the non-LR group (3.42 versus 1.81 years, P = 0.023) in a propensity score-matched cohort. After curative resection, median survival times were similar between patients with HVTT in the peripheral hepatic vein and those with HVTT in the major hepatic vein (4.85 versus 4.67 years, P = 0.974). In the LR group, the postoperative 90-day mortality rate was 3.4% (16 patients). In patients without PVTT, the median survival time was significantly better than that in patients with PVTT (5.67 versus 1.88 years, P < 0.001). CONCLUSION: LR is associated with a good prognosis in hepatocellular carcinoma patients with HVTT, especially in patients without PVTT. (Hepatology 2017;66:510-517).

Impact of resection and ablation for single hypovascular hepatocellular carcinoma ≤2 cm analysed with propensity score weighting.

BACKGROUND AND AIMS: Small hypovascular hepatocellular carcinoma (HCC) ≤2 cm is biologically less aggressive than hypervascular one, however, the optimal treatment is still undetermined. The efficacy of surgical resection (SR), radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI) was evaluated. METHODS: The 853 (SR, 176; RFA, 491; PEI, 186) patients were enrolled who met Child-Pugh A/B, single hypovascular HCC ≤2 cm pathologically proven, available tumour differentiation and absence of macrovascular invasion and extrahepatic metastasis. Overall and recurrence-free survivals were compared in original and a propensity score weighted pseudo-population with 732 patients. RESULTS: The median follow-up time and tumour size were 2.8 years and 1.47 cm respectively. In original population, multivariate Cox regression showed no significant difference for overall survival among three groups. In pseudo-population, Cox regression also revealed no significant difference for overall survival among them, although SR (HR, 0.56; 95% CI, 0.36-0.86) and RFA (HR, 0.75; 95% CI, 0.57-1.00) groups had significantly lower recurrence than PEI group. The overall survival rates at 3 and 5 years for the SR, RFA and PEI groups were 94%/70%, 90%/75% and 94%/73% respectively. Corresponding recurrence-free survival rates were 64%/54%, 59%/41% 48%/33% respectively. Subgroup analysis revealed no significant survival benefit of SR compared with non-SR. No treatment-related death occurred. CONCLUSIONS: For patients with single hypovascular HCC ≤2 cm, no significant difference for overall survival was first identified among 3 treatment groups. The SR or RFA could be recommended, and PEI would be alternative to RFA.

Compartment model analysis of intravenous contrast-enhanced dynamic computed tomography in hepatic hemodynamics: A validation study using intra-arterial contrast-enhanced computed tomography.

AIM: To verify the utility of the 2-in-1-out-compartment model analysis (CMA) of intravenous contrast-enhanced dynamic computed tomography (IV-CT) for evaluating hepatic arterial and portal venous flow using intra-arterial contrast-enhanced CT (IA-CT). METHODS: We retrospectively evaluated 49 consecutive patients who underwent IV-CT and were radiologically or histologically diagnosed as having hepatic malignant lesion (51 classical hepatocellular carcinomas [HCC], 4 early HCC, 3 cholangiolocellular carcinomas, 1 mixed HCC, 3 cholangiocellular carcinomas). As a gold standard for hepatic arterial and portal blood flows, we defined the normalized enhancement in CT values on CTAP (nCTAP) and CTHA (nCTHA). The hepatic arterial (k1a ) and portal venous inflow velocity (k1p ) constants in hepatic lesions and surrounding liver parenchyma were obtained from the CMA of IV-CT with various outflow velocity constant (k2 ) limits using the nonlinear least square method. The correlation coefficient between the normalized enhancement in IA-CT and CMA of IV-CT was statistically evaluated according to various k2 limits. RESULTS: The highest mean correlation coefficient between k1a and nCTHA (r = 0.65, P < 0.0001) was observed when k2 ≦0.035. The highest mean correlation coefficient between k1p and nCTAP (r = 0.69, P < 0.0001) was observed when k2 ≦0.045. The decrease in correlation coefficient was significant when the upper k2 limit was lower than 0.03 or higher than 0.07 compared to the best mean correlation coefficient (P < 0.05). CONCLUSION: Hepatic arterial and portal venous flows can be evaluated quantitatively to some extent with appropriate outflow velocity constant limits using the CMA of IV-CT.

Evaluation of splenic perfusion and spleen size using dynamic computed tomography: Usefulness in assessing degree of liver fibrosis.

AIM: To enhance the usefulness of splenic perfusion evaluated by means of dynamic computed tomography (CT) and spleen size in assessing the degree of liver fibrosis. METHODS: We retrospectively studied 133 patients who had undergone dynamic CT before hepatectomy. Fibrosis was histologically established in all. First we calculated splenic perfusion parameters K1 (inflow rate constant), 1/k2 (mean transit time; MTT), and K1 /k2 (distribution volume; Vd ), using compartment model analysis. Then we compared the stage of fibrosis with splenic perfusion and spleen size (long axis, R), using the Kruskal-Wallis test and multiple comparisons. After that, we assessed the diagnostic accuracy of the combination of splenic perfusion, spleen size, age, gender, and the presence or absence of hepatitis B and hepatitis C viral infection in detecting liver fibrosis, using stepwise regression and receiver operating characteristic analysis. RESULTS: Significant differences (P < 0.05) in MTT were observed in comparisons between fibrosis stages F0 and F4, between F1 and F4, and between F2 and F4. Significant differences (P < 0.05) in R were observed in comparisons between F0 and F4, and between F1 and F4. Considering the presence or absence of hepatitis B and C viral infection along with MTT and R, the areas under the receiver operating characteristic curves were 0.89 for ≥F1, 0.83 for ≥F2, 0.82 for ≥F3, and 0.82 for F4. CONCLUSION: Splenic MTT and spleen size are helpful in assessing liver fibrosis.

Quantitative estimation of progression of chronic liver disease using gadoxetate disodium-enhanced magnetic resonance imaging.

AIM: The purpose of this study was to determine whether the liver stiffness (LS) measured on magnetic resonance (MR) elastography can be estimated by a combination of gadoxetate disodium-enhanced MR imaging (EOB-MRI) and ordinary blood tests. METHODS: We evaluated 33 consecutive patients with suspected liver disease who underwent EOB-MRI using a Differential Subsampling with Cartesian Ordering MR sequence and MR elastography using a 1.5-T MR system in this prospective study. A stepwise multiple linear regression model analysis of LS was performed using various predictive values obtained from two-in-one-uptake, two-compartment model analysis of EOB-MRI (velocity constants of arterial inflow [K1a ], portal venous inflow [K1p ], hepatocellular uptake [Ki ]), and ordinary blood test results (blood platelet count, serum albumin level [ALB], total serum bilirubin level [T-BIL], and prothrombin time [PT%]). RESULTS: Multiple linear regression model analysis revealed that hepatic perfusion-uptake index (HPUI = -K1a + K1p + Ki ) (P < 0.0001), albumin-bilirubin linear predictor (ALBI-LP = 0.66 × log10 T-BIL - 0.085 × ALB) (P = 0.034), and blood platelet count (P = 0.046) were significant independent predictors of LS (r = 0.863). The area under receiver operator characteristics curve of multiple linear regression model in prediction of the liver stiffness corresponding to higher (LS > 5.0 kPa) and lower (LS < 4.2 kPa) risk for developing hepatocellular carcinoma were 0.956 and 0.938, respectively. CONCLUSION: LS can be estimated quantitatively with the use of HPUI obtained from compartment model analysis of EOB-MRI combined with ALBI-LP and blood platelet count.

Uterine cervical adenocarcinoma associated with lobular endocervical glandular hyperplasia: Radiologic-pathologic correlation.

AIM: We aimed to identify the radiologic features of uterine cervical adenocarcinoma associated with lobular endocervical glandular hyperplasia (LEGH). METHODS: We retrospectively analyzed magnetic resonance (MR) images and pathologic findings of eight patients who underwent preoperative MR imaging followed by surgical resection and who were pathologically diagnosed with adenocarcinoma (except for adenocarcinoma in situ) associated with LEGH. We assessed the following MR findings: multicystic component (MC), solid component (SC), signal intensity of SC on diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) map, and radiological stage (r-stage) based on the FIGO classification. A pathologist reevaluated the pathological stage (p-stage) according to the FIGO classification. We correlated the MR findings with the pathologic features. RESULTS: Eight patients were classified into the following three types based on the MR findings: type A, MC and SC; type B, only SC; and type C, only MC. In the five patients with type A, diffusion restriction (DR) was seen on DWI and the ADC map. In 80% of type A cases, the r-stage matched the p-stage. In the one patient with type B, DR was not seen on DWI or the ADC map, and the r-stage matched the p-stage. In the remaining type C cases, DR was not seen on DWI or the ADC map, and the r-stage was underestimated compared with the p-stage. CONCLUSION: On MR imaging, the most common type of adenocarcinoma with LEGH is type A; type C is difficult to diagnose as carcinoma.

Usefulness of three-dimensional magnetic resonance cholangiopancreatography with partial maximum intensity projection for diagnosing autoimmune pancreatitis.

PURPOSE: To compare three-dimensional magnetic resonance cholangiopancreatography (MRCP) with/without partial maximum intensity projection (MIP) and endoscopic retrograde cholangiopancreatography (ERCP) in patients with autoimmune pancreatitis (AIP). MATERIALS AND METHODS: Three-dimensional MRCP and ERCP images were retrospectively analyzed in 24 patients with AIP. We evaluated the narrowing length of the main pancreatic duct (NR-MPD), multiple skipped MPD narrowing (SK-MPD), and side branches arising from the narrowed portion of the MPD (SB-MPD) using four MRCP datasets: 5 original images (MIP5), 10 original images (MIP10), all original images (full-MIP), and a combination of these three datasets (a-MIP). The images were scored using a 3- or 5-point scale. The scores of the four MRCP datasets were statistically analyzed, and the positive rate of each finding was compared between MRCP and ERCP. RESULTS: The median scores for SB-MPD on MIP5 and a-MIP were significantly higher than those on MIP10 and full-MIP. In other words, partial MIP is superior to full-MIP for visualization of detailed structures. The positive rate for SB-MPD on full-MIP was significantly lower than that on ERCP, whereas the positive rate on MIP5, MIP10, and a-MIP was not significantly different from that on ERCP. Moreover, the positive rate for NR-MPD and SK-MPD on the MRCP images was significantly higher than that on the ERCP images. CONCLUSION: Partial MIP is useful for evaluating the MPD and is comparable with ERCP for diagnosing AIP.

Epithelioid trophoblastic tumor of the uterus: A case report with radiologic-pathologic correlation.

Herein, we report a rare case of an epithelioid trophoblastic tumor of the uterus with radiologic-pathologic correlation in a 56-year-old postmenopausal woman. On T2-weighted magnetic resonance (MR) imaging, the tumor appeared as a hypointense irregular mass compared with the surrounding myometrium of the uterine corpus and encircled the cavity of the lower uterine segment. On dynamic contrast-enhanced MR images, the tumor appeared as a hypovascular mass and an inhomogeneously hyperintense mass in the delayed phase. In addition, non-contrast computed tomography images showed some spotty areas of very high density within the tumor. These radiologic findings were well correlated with the histological features, such as abundant hyalinization and calcification within the tumor. Accurate interpretation of MR and computed tomography findings was helpful to differentiate epithelioid trophoblastic tumor from other gestational trophoblastic diseases and uterine carcinomas.

Outcomes of uterine cervical cancer patients with pelvic lymph node metastases after radiotherapy without boost irradiation of metastases.

AIM: The aim of this study was to evaluate the outcomes of uterine cervical cancer patients with pelvic lymph node (PLN) metastases after radiotherapy without boost irradiation of the metastases and to clarify the necessity of the boost irradiation of metastatic lesions. METHODS: Thirty-two patients with uterine cervical cancer metastasizing only to the PLN were treated with definitive radiotherapy without boost irradiation of the metastases between 2008 and 2012 at our institution and were selected for this study. The pattern of progression, overall survival, and progression-free survival were analyzed. RESULTS: Ninety percent of the PLN metastases were controlled by radiotherapy. Twenty-two of 32 patients (69%) experienced progression. Distant metastases as initial progression were observed in 21 of these 22 patients (95%). Only two patients experienced failures in pre-treatment metastatic PLN as initial progression, along with other failures. Severe late lower gastrointestinal toxicities were not observed in any patients. Two-year cumulative overall survival and progression-free survival were 74% and 31%, respectively. CONCLUSION: Boost irradiation of PLN metastases is not necessarily indispensable. Further studies to examine the necessity of boost irradiation of PLN metastases in radiotherapy for uterine cervical cancer patients with metastases are required.

Proposal of a new staging system for intrahepatic cholangiocarcinoma: Analysis of surgical patients from a nationwide survey of the Liver Cancer Study Group of Japan.

BACKGROUND: In the current American Joint Committee on Cancer/International Union Against Cancer staging system (seventh edition) for intrahepatic cholangiocarcinoma (ICC), tumor size was excluded, and periductal invasion was added as a new tumor classification-defining factor. The objective of the current report was to propose a new staging system for ICC that would be better for stratifying the survival of patients based on data from the nationwide Liver Cancer Study Group of Japan database. METHODS: Of 756 patients who underwent surgical resection for ICC between 2000 and 2005, multivariate analyses of the clinicopathologic factors of 419 patients who had complete data sets were performed to elucidate relevant factors for inclusion in a new tumor classification and staging system. RESULTS: Overall survival data were best stratified using a cutoff value of 2 cm using a minimal P value approach to discriminate patient survival. The 5-year survival rate of 15 patients who had ICC measuring ≤ 2 cm in greatest dimension without lymph node metastasis or vascular invasion was 100%, and this cohort was defined as T1. Multivariate analysis of prognostic factors for 267 patients with lymph node-negative and metastasis-negative (N0M0) disease indicated that the number of tumors, the presence arterial invasion, and the presence major biliary invasion were independent and significant prognostic factors. The proposed new system, which included tumor number, tumor size, arterial invasion, and major biliary invasion for tumor classification, provided good stratification of overall patient survival according to disease stage. Macroscopic periductal invasion was associated with major biliary invasion and an inferior prognosis. CONCLUSIONS: The proposed new staging system, which includes a tumor cutoff size of 2 cm and major biliary invasion, may be useful for assigning patients to surgery.

Survival benefit of liver resection for hepatocellular carcinoma associated with portal vein invasion.

BACKGROUND & AIMS: The presence of portal vein tumor thrombosis (PVTT) in patients with hepatocellular carcinoma (HCC) is regarded as indicating an advanced stage, and liver resection (LR) is not recommended. The aim of this study was to evaluate the survival benefit of LR for HCC patients with PVTT through the analysis of the data from a Japanese nationwide survey. METHODS: We analyzed data for 6474 HCC patients with PVTT registered between 2000 and 2007. Of these patients, 2093 patients who underwent LR and 4381 patients who received other treatments were compared. The propensity scores were calculated and we successfully matched 1058 patients (66.1% of the LR group). RESULTS: In the Child-Pugh A patients, the median survival time (MST) in the LR group was 1.77years longer than that in the non-LR group (2.87years vs. 1.10years; p<0.001) and 0.88years longer than that in the non-LR group (2.45years vs. 1.57years; p<0.001) in a propensity score-matched cohort. A subgroup analysis revealed that LR provides a survival benefit regardless of age, etiology of HCC, tumor marker elevation, and tumor number. The survival benefit was not statistically significant only in patients with PVTT invading the main trunk or contralateral branch. In the LR group, the postoperative 90-day mortality rate was 3.7% (68 patients). CONCLUSIONS: As long as the PVTT is limited to the first-order branch, LR is associated with a longer survival outcome than non-surgical treatment. LAY SUMMARY: The presence of portal vein tumor thrombosis in patients with hepatocellular carcinoma is regarded as indicating an advanced stage, and liver resection is not recommended. We performed a multicenter, nationwide study to assess the survival benefit of liver resection in hepatocellular carcinoma patients with portal vein tumor thrombosis using propensity score-based matching. As long as the portal vein tumor thrombosis is limited to the first-order branch, liver resection is associated with a longer survival outcome than non-surgical treatment.

Contrast-enhancement ratio on multiphase enhanced computed tomography predicts recurrence of pancreatic neuroendocrine tumor after curative resection.

BACKGROUND/OBJECTIVE: No previous study has quantitatively investigated the degree of enhancement of pancreatic neuroendocrine tumors (pNETs) using a routine preoperative modality. The aim of this study was to evaluate the contrast-enhancement ratio (CER) of pNETs using multiphase enhanced CT and to assess the impact of the CER on disease recurrence after surgery. METHODS: A retrospective study was performed using data from 47 consecutive patients with pNETs who had undergone curative surgery. The CER of the tumor was calculated by dividing the CT attenuation value obtained during the maximum-enhanced phase by that obtained during the pre-enhanced phase. A region of interest was placed in the largest tumor dimension plane so as to cover as much surface of the tumor as possible while avoiding adjacent normal structures, calcification, and necrotic areas of the tumor. RESULTS: During a median follow-up period of 51 months (range, 1-132 months), a total of 4 patients (8.5%) developed disease recurrence. The median CER value was significantly lower for the patients with recurrence than for the patients without recurrence (2.9 vs. 4.3, P = 0.013). Univariate analyses showed that a CER ≤3.2 was significantly associated with disease recurrence (P < 0.001). All the patients with disease recurrence had tumors that were both large (>20 mm) and weakly enhanced (CER ≤ 3.2), whereas no recurrences were observed even in patients with tumors >20 mm when the CER was greater than 3.2. CONCLUSIONS: CER might be a useful predictor of disease recurrence in patients with pNETs.

Advantages of radial volumetric breath-hold examination (VIBE) with k-space weighted image contrast reconstruction (KWIC) over Cartesian VIBE in liver imaging of volunteers simulating inadequate or no breath-holding ability.

OBJECTIVES: To investigate the superiority of radial volumetric breath-hold examination (r-VIBE) with k-space weighted image contrast reconstruction (KWIC) over Cartesian VIBE (c-VIBE) for reducing motion artefacts. METHODS: We acquired r-VIBE-KWIC and c-VIBE images in 10 healthy volunteers. Each acquisition lasted 24 seconds. The volunteers held their breath for decreasing lengths of time during the acquisitions, from 24 to 0 seconds (protocols A-E). Magnetic resonance images at the level of the right portal vein and confluence of hepatic veins were assessed by two readers using a five-point scale with a higher number indicating a better study. RESULTS: The mean scores for the complete r-VIBE-KWIC series (r-VIBEfull) and first r-VIBE-KWIC series (r-VIBE1) were not significantly lower than those for c-VIBE in any protocols. The mean scores for c-VIBE were lower than those for r-VIBEfull and r-VIBE1 in protocols C and D. The mean score for c-VIBE was lower than that for r-VIBEfull in protocol E. The mean score for the eighth r-VIBE-KWIC series (r-VIBE8) was lower than that for c-VIBE only in protocol B. CONCLUSION: r-VIBE-KWIC minimised artefacts relative to c-VIBE at any slice location. The r-VIBE-KWIC's sub-frame images during the breath-holding period were hardly affected by another failed breath-holding period. KEY POINTS: • A two-reader study revealed r-VIBE-KWIC's advantages over c-VIBE • The image quality of r-VIBE-KWIC's sub-frame images was maintained during breath holding • Full-frame r-VIBE-KWIC images minimized motion artefacts caused by breathing • A complete breath holding over half the acquisition time is recommended for c-VIBE • c-VIBE was susceptible to respiratory motion especially in the subphrenic region.

Response Evaluation Criteria in Cancer of the Liver (RECICL) (2015 Revised version).

The Response Evaluation Criteria in Solid Tumors (RECIST) is inappropriate to assess the direct effects of treatment on hepatocellular carcinoma (HCC) by locoregional therapies such as radiofrequency ablation (RFA) and transarterial chemoembolization (TACE). Therefore, establishment of response evaluation criteria solely devoted to HCC is needed urgently in clinical practice as well as in clinical trials of HCC treatment, such as molecular-targeted therapies, which cause necrosis of the tumor. The Response Evaluation Criteria in Cancer of the Liver (RECICL) was revised in 2015 by the Liver Cancer Study Group of Japan based on the 2009 version of RECICL, which was commonly used in Japan. Major revised points of the RECICL 2015 is to define the target lesions of two lesions per organ or three lesions per liver, up to a maximum of five lesions. The second revised point is that setting the timing at which the overall treatment response has been changed. The third point is that the definition of treatment effect 1 has been changed to more than 50% tumor enlargement, excluding the area of necrosis after treatment. Overall evaluation of treatment response has been amended to make it possible to evaluate the overall response including extrahepatic lesions by systemic therapy, which is similar to RECIST or modified RECIST. We hope this new treatment response criteria, RECICL, proposed by the Liver Cancer Study Group of Japan will benefit HCC treatment response evaluation in the setting of daily clinical practice and clinical trials, not only in Japan, but also internationally.

Features of acute liver congestion on gadoxetate disodium-enhanced MRI in a rat model: Role of organic anion-transporting polypeptide 1A1.

PURPOSE: To evaluate the features of hepatic congestion on gadoxetate disodium (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and the mechanisms responsible for the radiological findings in a rat model of partial liver congestion. MATERIALS AND METHODS: A conventional T1 -weighted spin-echo sequence of the liver was performed using a 1.5T magnetic resonance imager with an 80-mm magnetic aperture for animal studies. We induced regional congestion using partial left lateral hepatic vein ligation (n = 5) and evaluated the following in both congestive liver (CL) and noncongestive liver (non-CL): 1) chronological changes in the relative enhancement (RE) up to 60 minutes after Gd-EOB-DTPA administration, and 2) mRNA and protein expression of rat organic anion transporting protein 1a1 (Oatp1a1). RESULTS: The RE in the CL reached a small peak (18%) at 5 minutes, corresponding to approximately half of the value observed in the non-CL, then slowly decreased in a linear manner thereafter. The degree of RE in the CL was significantly lower than that in the non-CL for up to 30 minutes (P < 0.05). An immunohistological examination showed that Oatp1a1 protein expression was downregulated in the CL. The mRNA level of Oatp1a1 in the CL was significantly upregulated, compared with that in control rat liver (P = 0.046), whereas no significant difference was observed between the CL and the non-CL (P = 0.698). CONCLUSION: The reduced signal intensity in the CL on Gd-EOB-DTPA-enhanced MRI could be explained by the decreased uptake of Gd-EOB-DTPA via Oatp1a1 protein in the congestive area.

Signal intensity of the pancreas on magnetic resonance imaging: Prediction of postoperative pancreatic fistula after a distal pancreatectomy using a triple-row stapler.

BACKGROUND/OBJECTIVES: The aim of this study was to evaluate the impact of the pancreatic signal intensity (SI) on magnetic resonance imaging (MRI) findings for predicting the development of pancreatic fistula (PF) after a distal pancreatectomy (DP) involving a triple-row stapler closure. METHODS: A multivariate logistic regression analysis was used to identify risk factors for clinical PF, as defined by the International Study Group on Pancreatic Fistula grade B or C. The pancreas-to-muscle SI ratio was evaluated using fat-suppressed T1-weighted MRI. RESULTS: Of the 41 enrolled patients, 8 (19.5%) developed clinical PF. The pancreatic thickness (≥15 mm) and SI ratio (≥1.3) were identified as independent predictors of clinical PF in a multivariate analysis. Clinical PF was observed in one patient with a thick pancreas and a low SI ratio (14.3%), whereas it was observed in 60% of the patients with a thick pancreas and a high SI ratio. The area under the receiver operating characteristic curve for a predictive model consisting of the two factors was 0.87 (95% confidence interval, 0.75 to 0.99), the level of which tended to be greater than that for pancreatic thickness alone (0.81, p = 0.09). CONCLUSIONS: The SI ratio as evaluated using MRI might be useful for predicting clinical PF in patients with the pancreatic thickness ≥15 mm after DP involving a stapler closure.