Mi-Suk Park

Perfusion CT: Noninvasive Surrogate Marker for Stratification of Pancreatic Cancer Response to Concurrent Chemo- and Radiation Therapy

PURPOSE To prospectively determine whether perfusion computed tomography (CT) parameters, such as volume transfer constant (K(trans)) between blood plasma and extracellular extravascular space (EES) and blood volume calculated from dynamic CT data, can be used to predict response of pancreatic cancer to concurrent chemotherapy and radiation therapy (CCRT). MATERIALS AND METHODS This prospective study was institutional review board approved, and written informed consent was obtained. Thirty patients with pancreatic cancer underwent perfusion CT with 64-detector row CT before gemcitabine-based CCRT. Two perfusion parameters (K(trans) and blood volume) measured before treatment were compared between patients who responded to treatment and those who did not, as determined with World Health Organization criteria from first and second posttherapeutic follow-up CT examinations, which were performed at 3- and 6-month follow-up. Statistical analysis was performed with the two-sample t test. A receiver operating characteristic curve was used to determine the best cutoff value of perfusion parameters for differentiation of responders from nonresponders. RESULTS Twenty of 30 patients examined at 3-month follow-up responded to therapy. Their pretreatment K(trans) value was significantly higher than that of nonresponders (50.8 mL/100 mL/min +/- 30.5 [standard deviation] vs 19.0 mL/100 mL/min +/- 10.8, P = .001). The best cutoff value for differentiating between responders and nonresponders was 31.8 mL/100 mL/min, which yielded 75.0% sensitivity and 90.0% specificity. Ten of 18 patients examined at 6-month follow-up responded to therapy. Their pretreatment K(trans) value was significantly higher than that of nonresponders (58.6 mL/100 mL/min +/- 43.2 vs 19.8 mL/100 mL/min +/- 10.9, P = .002). Responders also had higher blood volume values, but this difference was not significant. CONCLUSION Tumors with a high pretreatment K(trans) value tended to respond better to CCRT than did tumors with a low pretreatment K(trans) value. Perfusion CT may be used to predict tumor response to CCRT in patients with pancreatic cancer. This might aid in development of a tailored approach to therapy in these patients.

Comparison of gadoxetic acid-enhanced dynamic imaging and diffusion-weighted imaging for the preoperative evaluation of colorectal liver metastases

To retrospectively compare the diagnostic accuracy for the detection of colorectal liver metastases between gadoxetic acid‐enhanced MRI (EOB‐MRI) and diffusion‐weighted imaging (DWI) on 3.0 Tesla (T) system, and then to determine whether a combination of the two techniques may improve the diagnostic performance.

Autologous bone marrow infusion activates the progenitor cell compartment in patients with advanced liver cirrhosis.

Several clinical trials of bone marrow cell infusion in patients with liver cirrhosis (LC) have shown clinical improvement, despite conflicting results from animal models. We investigated serial pathological features and the clinical impact after autologous bone marrow infusion (ABMI) in patients with advanced LC. Ten patients with advanced LC due to chronic hepatitis B virus infection underwent ABMI. Serological tests, MRI, and liver biopsies were performed, and quality of life was assessed by a questionnaire. Median serum albumin and hemoglobin levels increased significantly after ABMI. All patients showed an improvement in quality of life, with no serious adverse events. Liver volume, measured by MRI, increased in 80% of the patients, and ascites decreased after ABMI. Child-Pugh scores were also significantly improved at 6 months after ABMI. In the serially biopsied livers, a gradually increasing activation of the hepatic progenitor cell (HPC) compartment, including HPC activation (ductular reaction) and HPC differentiation (intermediate hepatocyte), reached a peak after 3 months, with continued proliferation of hepatocytes, and returned to baseline levels after 6 months. There was no significant change in grade or stage of liver fibrosis or stellate cell activation after ABMI. ABMI is suggested to improve liver function and to activate the progenitor cell compartment. Although clinical improvement was sustained for more than 6 months, histological changes in the liver returned to baseline 6 months after ABMI. Further comparative studies are warranted.

Hepatocellular carcinoma: Detection with diffusion-weighted versus contrast-enhanced magnetic resonance imaging in pretransplant patients†

This study evaluates the performance of diffusion‐weighted magnetic resonance imaging (DWI) for the detection of hepatocellular carcinoma (HCC) in pre–liver transplantation patients, compared and combined with contrast‐enhanced T1‐weighted imaging (CET1WI), using liver explant as the standard of reference. We included 52 patients with cirrhosis (40 men, 12 women; mean age, 56 years) who underwent DWI and CET1WI within 90 days of liver transplantation. Magnetic resonance images were analyzed for HCC detection in three separate sessions by two independent observers: DWI images (DW‐set), CET1WI (CE‐set), and all images together (All‐set). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), per‐patient accuracy, and per‐lesion PPV were calculated for each image set. A total of 72 HCCs were present in 33 patients at explant (mean size, 1.5 cm [range, 0.3‐6.2 cm]). Per‐patient sensitivity and NPV of CE‐set were significantly higher than those of DW‐set when using pooled data between observers (P = 0.02 and 0.03, respectively), whereas specificity, PPV, and accuracy were equivalent. Per‐lesion sensitivity was significantly higher for CE‐set versus DW‐set (59.0% versus 43.8%; P = 0.008, pooled data from two observers). When stratified by lesion size, the difference was significant only for lesions with a size between 1 and 2 cm (42.0% for DW‐set versus 74.0% for CE‐set; P = 0.001). The addition of DWI to CET1WI improved sensitivity for the more experienced observer. Conclusion: DWI is outperformed by CET1WI for detection of HCC, but represents a reasonable alternative to CET1WI for detection of HCC with a size above 2 cm. The addition of DWI to CET1WI slightly increases the detection rate. (HEPATOLOGY 2012;56:140–148)

Comparison of CT and 18F-FDG pet for detecting peritoneal metastasis on the preoperative evaluation for gastric carcinoma.

Objective The aim of our study was to compare the accuracy of CT and 18F-FDG PET for detecting peritoneal metastasis in patients with gastric carcinoma. Materials and Methods One-hundred-twelve patients who underwent a histologic confirmative exam or treatment (laparotomy, n = 107; diagnostic laparoscopy, n = 4; peritoneal washing cytology, n = 1) were retrospectively enrolled. All the patients underwent CT and 18F-FDG PET scanning for their preoperative evaluation. The sensitivities, specificities and accuracies of CT and 18F-FDG PET imaging for the detection of peritoneal metastasis were calculated and then compared using Fishers exact probability test (p < 0.05), on the basis of the original preoperative reports. In addition, two board-certified radiologists and two board-certified nuclear medicine physicians independently reviewed the CT and PET scans, respectively. A receiver-operating characteristic curve analysis was performed to compare the diagnostic performance of CT and 18F-FDG PET imaging for detecting peritoneal metastasis. Results Based on the original preoperative reports, CT and 18F-FDG PET showed sensitivities of 76.5% and 35.3% (p = 0.037), specificities of 91.6% and 98.9% (p = 0.035), respectively, and equal accuracies of 89.3% (p = 1.0). The receptor operating characteristics curve analysis showed a significantly higher diagnostic performance for CT (Az = 0.878) than for PET (Az = 0.686) (p = 0.004). The interobserver agreement for detecting peritoneal metastasis was good (κ value = 0.684) for CT and moderate (κ value = 0.460) for PET. Conclusion For the detection of peritoneal metastasis, CT was more sensitive and showed a higher diagnostic performance than PET, although CT had a relatively lower specificity than did PET.

Accuracy of gadoxetic acid-enhanced magnetic resonance imaging for the diagnosis of sinusoidal obstruction syndrome in patients with chemotherapy-treated colorectal liver metastases

AbstractObjectiveTo assess whether reticular hypointensity on hepatobiliary phase images of gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) is a diagnostic finding of sinusoidal obstruction syndrome (SOS) in patients with hepatic metastases who have undergone chemotherapy.MethodsWe retrospectively analysed EOB-MRI of 42 patients who had undergone chemotherapy before hepatic resection of colorectal hepatic metastases. Two radiologists, who were unaware of whether or not the patients had SOS, reviewed the hepatobiliary phase images to determine the presence of hypointense reticulation in the liver using a 5-point scale. The sensitivity, specificity and area under the receiver operating characteristics curve (Az) were calculated for each reviewer.ResultsThe sensitivity, specificity and Az for the diagnosis of SOS were 75%, 100% and 0.957 for reader 1 and 75%, 96.2% and 0.936 for reader 2, respectively. In one patient who received a false-positive diagnosis by one reader, there was sinusoidal fibrosis on histological examination, but not diagnostic for SOS. False-negative diagnosis occurred in four patients for both readers; histology of these patients showed minimal and localised sinusoidal congestion and fibrosis.ConclusionsReticular hypointensity on hepatobiliary phase images of EOB-MRI is highly specific for the diagnosis of SOS in patients with treated colorectal hepatic metastases.Key Points• Gadoxetic acid enhanced magnetic resonance imaging (EOB-MRI) can identify the sinusoidal obstruction syndrome (SOS) • The diagnosis can be achieved with high specificity and good interobserver agreement. • SOS typically demonstrates diffuse hypointensity on hepatobiliary phase images on EOB-MRI. • EOB-MRI may be falsely negative in patients with minimal degree of SOS.

Diagnostic accuracy of multidetector row computed tomography in T- and N staging of gastric cancer with histopathologic correlation.

Purpose: To evaluate the diagnostic accuracy of multidetector row computed tomography (MDCT) for the preoperative T- and N staging of gastric cancer. Materials and Methods: Eighty-four consecutive patients with gastric cancer underwent preoperative MDCT. Except for 15 patients who did not undergo surgery, 69 patients were included in our study. Two radiologists independently evaluated the T- and N staging on the axial CT images alone and in combination with the MPR images. For N staging, the new TNM and Japanese classifications were independently used. Differences in staging accuracy for T- and N staging were assessed using the McNemar test. Results: The overall T staging accuracy of the axial and combined axial and MPR images was as follows: 67% (47 of 70 cancers) versus 77% (54 of 70 cancers) (P = 0.039). The overall N staging accuracy of the axial and combined axial and MPR images was as follows: 59% (41 of 69 cancers) versus 67% (46 of 69 cancers) (P = 0.180, Japanese classification) and 54% (37 of 69 cancers) versus 59% (41 of 69 cancers) (P = 0.109, TNM classification). Conclusions: Using MPR images enables more accurate preoperative T staging of gastric cancer, but not for N staging in either classification system.

Hepatocellular carcinoma in patients with chronic liver disease: a comparison of gadoxetic acid-enhanced MRI and multiphasic MDCT.

AIM To compare the diagnostic performances of gadoxetic acid-enhanced magnetic resonance imaging (MRI) and multiphasic multidetector computed tomography (MDCT) in the detection of hepatocellular carcinoma (HCC) in patients with chronic liver disease. MATERIALS AND METHODS Institutional review board approval was obtained for this study and informed consent was obtained from all patients. Fifty-one patients (43 men, eight women; age range 32-80 years) with 73 HCCs underwent gadoxetic acid-enhanced MRI and multiphasic MDCT. Two readers independently analysed each image in three separate reading sessions. The alternative free-response receiver operating characteristic (AFROC) method was used to analyse the diagnostic accuracy. Positive and negative predictive values and sensitivity were evaluated. RESULTS A total of 73 HCCs were detected in 51 patients. Although not significant (p>0.05), the areas under the receiver operating characteristic curves were 0.877 and 0.850 for MDCT, 0.918 and 0.911 for dynamic MRI, and 0.905 and 0.918 for combined interpretation of dynamic and hepatobiliary phase MR images. Differences in sensitivity, specificity, and positive and negative predictive values between the readers were not statistically significant (p>0.05). Combined interpretation of dynamic and hepatobiliary phase MRI images was more useful than MDCT in the detection of HCC lesions ≤1cm in diameter for one reader (p=0.043). CONCLUSION Gadoxetic acid-enhanced MRI and MDCT show similar diagnostic performances for the detection of HCC in patients with chronic liver disease. However, the combined interpretation of dynamic and hepatobiliary phase MRI images may improve diagnostic accuracy in the detection of HCC lesions ≤1cm in diameter.

Can microvessel invasion of hepatocellular carcinoma be predicted by pre-operative MRI?

Microvessel invasion is a major prognostic factor in hepatocellular carcinoma (HCC) that influences the suitability of surgery, but rarely can be evaluated preoperatively. This study was performed to identify preoperative MRI findings that reflect histopathological microvessel invasion in hepatocellular carcinoma. Gadobenate dimeglumine-enhanced four-arterial phase dynamic study and hepatobiliary phase images of preoperative MRI of 70 HCC lesions were retrospectively reviewed. Tumor size (cm), peritumoral enhancement, tumor margins, and radiological capsule were analyzed as radiological parameters reflecting microvessel invasion and were compared with histopathological references. The chi-square test and the independent t-test were used for univariate analysis, and a logistic regression analysis was performed for multivariate analysis. In univariate analysis, tumor size (p = 0.030), peritumoral enhancement (p < 0.001), and tumor margins (p = 0.007) were associated with microvessel tumor invasion. However, in multivariate analysis irregular circumferential peritumoral enhancement only showed statistical significance (odds ratio 13.0), suggesting a high probability of microvessel invasion of HCC. Irregular circumferential peritumoral enhancement on contrast-enhanced multi-arterial phase dynamic MRI could be a preoperative surrogate marker for microvessel tumor invasion.

Predisposing factors of bile duct injury after transcatheter arterial chemoembolization (TACE) for hepatic malignancy.

AbstractThe purpose of this study was to investigate the predisposing factors of bile duct injury after transcatheter arterial chemoembolization (TACE) for treatment of hepatic malignancy. For patients (n = 31) with TACE-related bile duct injuries during a 36-month period, final diagnoses of the tumor, the liver profile, presence of portal vein thrombosis, total number and mode of the TACE just before the development of bile duct injury were compared, respectively with those of patients without bile duct injury n = 234) after TACE. The incidence of bile duct injury was higher in the patients with non-hepatocellular tumors than in patients with hepatocellular carcinoma (p <0.01), and higher in Child-Pugh class A patients than in B or C patients (p <0.01). Segmental or subsegmental TACE tended to induce bile duct injury more frequently than the proximal TACE (p = 0.01). Portal vein thrombosis, the total number of TACEs, total amount of iodized oil, and the usage of gelatin sponge were not closely related to bile duct injuries after TACE (p >0.05). It was concluded that the chance of bile duct injury after TACE is increased in non-cirrhotic livers with good liver profile and to the more selective embolization of distal arterial branches.