Contrast-Enhanced Computed Tomography Evaluation of Hepatic Metastases in Breast Cancer Patients Before and After Cytotoxic Chemotherapy or Targeted Therapy.

PURPOSE: To evaluate change in size vs computed tomography (CT) density of hepatic metastases in breast cancer patients before and after cytotoxic chemotherapy or targeted therapy. METHODS: A database search in a single institution identified 48 breast cancer patients who had hepatic metastases treated with either cytotoxic chemotherapy alone or targeted therapy alone, and who had contrast-enhanced CT (CECT) scans of the abdomen at baseline and within 4 months of initiation of therapy in the past 10 years. Two radiologists retrospectively evaluated CT scans and identified up to 2 index lesions in each patient. The size (centimeters) of each lesion was measured according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria, and CT density (Hounsfield units) was measured by drawing a region of interest around the margin of the entire lesion. The percent change in sum of lesion size and mean CT density on pre- and post-treatment scans was computed for each patient; results were compared within each treatment group. RESULTS: Thirty-nine patients with 68 lesions received cytotoxic chemotherapy only; 9 patients with 15 lesions received targeted therapy only. The mean percent changes in sum of lesion size and mean CT density were statistically significant within the cytotoxic chemotherapy group before and after treatment, but not significant in the targeted therapy group. The patients in the targeted therapy group tend to have better 2-year survival. The patients who survived at 2 years tend to have more decrease in tumour size in the cytotoxic chemotherapy group. CONCLUSION: Cytotoxic chemotherapy produced significant mean percent decrease in tumour size and mean CT density of hepatic metastases from breast cancer before and after treatment, whereas targeted therapy did not. Nonetheless, there is a trend that the patients in the targeted therapy group had better 2-year survival rate. This suggests that RECIST is potentially inadequate in evaluating tumour response in breast cancer liver metastases treated with targeted therapy alone, calling for an alternative marker for response evaluation in this subset of patients.

Effect of pre-enhancement set point on computed tomographic perfusion values in normal liver and metastases to the liver from neuroendocrine tumors.

OBJECTIVE: The objective of this study was to assess the effects of pre-enhancement set point (T1) positioning on computed tomographic perfusion (CTp) parameter values. METHODS: The CTp data from 16 patients with neuroendocrine liver metastases were analyzed with distributed parameter modeling to yield tissue blood flow (BF), blood volume, mean transit time, permeability, and hepatic arterial fraction for tumor and normal liver, with displacements in T1 of ±0.5, ±1.0, ±2.0 seconds, relative to the reference standard. A linear mixed-effects model was used to assess the displacement effects. RESULTS: Effects on the CTp parameter values were variable: BF was not significantly affected, but T1 positions of ≥+1.0 second and -2.0 seconds or longer significantly affected the other CTp parameters (P ≤ 0.004). Mean differences in the CTp parameter values versus the reference standard for BF, blood volume, mean transit time, permeability, and hepatic arterial fraction ranged from -5.0% to 5.2%, -12.7% to 8.9%, -12.5% to 8.1%, -5.3% to 5.7%, and -12.9% to 26.0%, respectively. CONCLUSIONS: CTp parameter values can be significantly affected by T1 positioning.

Metastases to the liver from neuroendocrine tumors: effect of duration of scan acquisition on CT perfusion values.

PURPOSE: To assess the effects of acquisition duration on computed tomographic (CT) perfusion parameter values in neuroendocrine liver metastases and normal liver tissue. MATERIALS AND METHODS: This retrospective study was institutional review board approved, with waiver of informed consent. CT perfusion studies in 16 patients (median age, 57.5 years; range, 42.0-69.7 years), including six men (median, 54.1 years; range, 42.0-69.7), and 10 women (median, 59.3 years; range 43.6-66.3), with neuroendocrine liver metastases were analyzed by means of distributed parametric modeling to determine tissue blood flow, blood volume, mean transit time, permeability, and hepatic arterial fraction for tumors and normal liver tissue. Analyses were undertaken with acquisition time of 12-590 seconds. Nonparameteric regression analyses were used to evaluate the functional relationships between CT perfusion parameters and acquisition duration. Evidence for time invariance was evaluated for each parameter at multiple time points by inferring the fitted derivative to assess its proximity to zero as a function of acquisition time by using equivalence tests with three levels of confidence (20%, 70%, and 90%). RESULTS: CT perfusion parameter values varied, approaching stable values with increasing acquisition duration. Acquisition duration greater than 160 seconds was required to obtain at least low confidence stability in any of the CT perfusion parameters. At 160 seconds of acquisition, all five CT perfusion parameters stabilized with low confidence in tumor and normal tissues, with the exception of hepatic arterial fraction in tumors. After 220 seconds of acquisition, there was stabilization with moderate confidence for blood flow, blood volume, and hepatic arterial fraction in tumors and normal tissue, and for mean transit time in tumors; however, permeability values did not satisfy the moderate stabilization criteria in both tumors and normal tissue until 360 seconds of acquisition. Blood flow, mean transit time, permeability, and hepatic arterial fraction were significantly different between tumor and normal tissue at 360 seconds (P < .001). CONCLUSION: CT perfusion parameter values are affected by acquisition duration and approach progressively stable values with increasing acquisition times. Online supplemental material is available for this article.

Current update on medullary thyroid carcinoma.

OBJECTIVE: This article will review the multimodality imaging spectrum of medullary thyroid carcinoma (MTC) with an emphasis on anatomic and functional imaging. Recent advances in the molecular cytogenetics of this tumor and the impact on diagnosis, prognosis, and development of novel targeted therapy will be discussed. CONCLUSION: MTC is a neuroendocrine tumor with unique clinicopathologic and radiologic features compared with other thyroid malignancies. Imaging plays an important role in the optimal management of this malignancy.

Effect of sampling frequency on perfusion values in perfusion CT of lung tumors.

OBJECTIVE: The purpose of this study was to assess as a potential means of limiting radiation exposure the effect on perfusion CT values of increasing sampling intervals in lung perfusion CT acquisition. SUBJECTS AND METHODS: Lung perfusion CT datasets in patients with lung tumors (> 2.5 cm diameter) were analyzed by distributed parameter modeling to yield tumor blood flow, blood volume, mean transit time, and permeability values. Scans were obtained 2-7 days apart with a 16-MDCT scanner without intervening therapy. Linear mixed-model analyses were used to compare perfusion CT values for the reference standard sampling interval of 0.5 second with those of datasets obtained at sampling intervals of 1, 2, and 3 seconds, which included relative shifts to account for uncertainty in preenhancement set points. Scan-rescan reproducibility was assessed by between-visit coefficient of variation. RESULTS: Twenty-four lung perfusion CT datasets in 12 patients were analyzed. With increasing sampling interval, mean and 95% CI blood flow and blood volume values were increasingly overestimated by up to 14% (95% CI, 11-18%) and 8% (95% CI, 5-11%) at the 3-second sampling interval, and mean transit time and permeability values were underestimated by up to 11% (95% CI, 9-13%) and 3% (95% CI, 1-6%) compared with the results in the standard sampling interval of 0.5 second. The differences were significant for blood flow, blood volume, and mean transit time for sampling intervals of 2 and 3 seconds (p ≤ 0.0002) but not for the 1-second sampling interval. The between-visit coefficient of variation increased with subsampling for blood flow (32.9-34.2%), blood volume (27.1-33.5%), and permeability (39.0-42.4%) compared with the values in the 0.5-second sampling interval (21.3%, 23.6%, and 32.2%). CONCLUSION: Increasing sampling intervals beyond 1 second yields significantly different perfusion CT parameter values compared with the reference standard (up to 18% for 3 seconds of sampling). Scan-rescan reproducibility is also adversely affected.

Resection of at-risk mesenteric lymph nodes is associated with improved survival in patients with small bowel neuroendocrine tumors.

BACKGROUND: Neuroendocrine tumors of the small intestine commonly metastasize to regional lymph nodes (LNs). Single-institution reports suggest that removal of LNs improves outcome, but comprehensive data are lacking. We hypothesized that the extent of lymphadenectomy reported in a large administrative database would be associated with overall survival for jejunal and ileal neuroendocrine tumors. METHODS: A search of the Surveillance Epidemiology and End Results database was performed for patients with jejunal and ileal neuroendocrine tumors from 1977 to 2004. Descriptive patient characteristics were collected to include age at diagnosis, sex, race, grade, primary tumor size, LN status, number of LNs resected, presence of distant metastasis, and the type of operation. Statistical analyses were limited to patients with only one primary tumor to exclude patients with other malignancies. Univariate and multivariate analyses were performed to analyze the number of LNs resected and the LN ratio (number of positive LNs/total number of LNs removed) to determine the effect on cancer-specific survival. RESULTS: Altogether, 1,364 patients were included in this analysis. Removal of any LNs was associated with improved cancer-specific survival when compared to patients with no LN removal reported (p = 0.0027) on univariate analysis. Among those who had any LNs removed, a median of eight LNs were identified in resection specimens with a median LN ratio of 0.29 (range 0-1). On multivariate analysis (adjusting for age and tumor size), patients with >7 LNs removed experienced better cancer-specific survival than those with ≤ 7 LNs removed (median survival not reached vs. 140 months): hazard ratio and 95 % confidence interval were 0.573 (0.402, 0.817) (p = 0.002). CONCLUSIONS: This review of a large number of surgical patients demonstrates that regional mesenteric lymphadenectomy in conjunction with resection of the primary tumor is associated with improved survival of patients with small bowel neuroendocrine tumors.

Vascular pancreatic lesions: spectrum of imaging findings of malignant masses and mimics with pathologic correlation.

The differential diagnosis of hypervascular pancreatic lesions is complex, and includes endocrine and exocrine tumors of the pancreas, metastases to the pancreas, and masses, or mass-like lesions, arising from the neurovascular networks traversing the pancreas. In this manuscript, we will discuss salient imaging findings of these masses, pertinent differential diagnoses, as well as review clinical symptomatology that may aid in the diagnosis of some of these lesions.

Response of borderline resectable pancreatic cancer to neoadjuvant therapy is not reflected by radiographic indicators.

BACKGROUND: Experience with preoperative therapy for other cancers has led to an assumption that borderline resectable pancreatic cancers can be converted to resectable cancers with preoperative therapy. In this study, the authors sought to determine the rate at which neoadjuvant therapy is associated with a reduction in the size or stage of borderline resectable tumors. METHODS: Patients who had borderline resectable pancreatic cancer and received neoadjuvant therapy before potentially undergoing surgery at the authors' institution between 2005 and 2010 were identified. The patients' pretreatment and post-treatment pancreatic protocol computed tomography images were rereviewed to determine changes in tumor size or stage using modified Response Evaluation Criteria in Solid Tumors (RECIST) (version 1.1) and standardized anatomic criteria. RESULTS: The authors identified 129 patients who met inclusion criteria. Of the 122 patients who had their disease restaged after receiving preoperative therapy, 84 patients (69%) had stable disease, 15 patients (12%) had a partial response to therapy, and 23 patients (19%) had progressive disease. Although only 1 patient (0.8%) had their disease downstaged to resectable status after receiving neoadjuvant therapy, 85 patients (66%) underwent pancreatectomy. The median overall survival duration for all 129 patients was 22 months (95% confidence interval, 14-30 months). The median overall survival duration for the patients who underwent pancreatectomy was 33 months (95% confidence interval, 25-41 months) and was not associated with RECIST response (P = .78). CONCLUSIONS: Radiographic downstaging was rare after neoadjuvant therapy, and RECIST response was not an effective treatment endpoint for patients with borderline resectable pancreatic cancer. The authors concluded that these patients should undergo pancreatectomy after initial therapy in the absence of metastases.

Effect of dual vascular input functions on CT perfusion parameter values and reproducibility in liver tumors and normal liver.

OBJECTIVE: To assess the impact on absolute values and reproducibility of adding portal venous (PV) to arterial input functions in computed tomographic perfusion (CTp) evaluations of liver tumors and normal liver. METHODS: Institutional review board approval and written informed consent were obtained; the study complied with Health Insurance Portability and Accountability Act regulations. Computed tomographic perfusion source data sets, obtained from 7 patients (containing 9 liver tumors) on 2 occasions, 2 to 7 days apart, were analyzed by deconvolution modeling using dual ("Liver" protocol: PV and aorta) and single ("Body" protocol: aorta only) vascular inputs. Identical tumor, normal liver, aortic and, where applicable, PV regions of interest were used in corresponding analyses to generate tissue blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability (PS) values. Test-retest variability was assessed by within-patient coefficients of variation. RESULTS: For liver tumor and normal liver, median BF, BV, and PS were significantly higher for the Liver protocol than for the Body protocol: 171.3 to 177.8 vs 39.4 to 42.0 mL/min per 100 g, 17.2 to 18.7 vs 3.1 to 4.2 mL/100 g, and 65.1 to 78.9 vs 50.4 to 66.1 mL/min per 100 g, respectively (P < 0.01 for all). There were no differences in MTT between protocols. Within-patient coefficients of variation were lower for all parameters with the Liver protocol than with the Body protocol: BF, 7.5% to 11.2% vs 11.7% to 20.8%; BV, 10.1% to 14.4% vs 16.6% to 30.1%; MTT, 4.2% to 5.5% vs 10.4% to 12.9%; and PS, 7.3% to 12.1% vs 12.6% to 20.3%, respectively. CONCLUSION: Utilization of dual vascular input CTp liver analyses has substantial impact on absolute CTp parameter values and test-retest variability. Incorporation of the PV inputs may yield more precise results; however, it imposes substantial practical constraints on acquiring the necessary data.

Reproducibility of CT perfusion parameters in liver tumors and normal liver.

PURPOSE: To assess the reproducibility of computed tomographic (CT) perfusion measurements in liver tumors and normal liver and effects of motion and data acquisition time on parameters. MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained for this prospective study. The study complied with HIPAA regulations. Two CT perfusion scans were obtained 2-7 days apart in seven patients with liver tumors with two scanning phases (phase 1: 30-second breath-hold cine; phase 2: six intermittent free-breathing cines) spanning 135 seconds. Blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability-surface area product (PS) for tumors and normal liver were calculated from phase 1 with and without rigid registration and, for combined phases 1 and 2, with manually and rigid-registered phase 2 images, by using deconvolution modeling. Variability was assessed with within-patient coefficients of variation (CVs) and Bland-Altman analyses. RESULTS: For tumors, BF, BV, MTT, and PS values and reproducibility varied by analytical method, the former by up to 11%, 23%, 21%, and 138%, respectively. Median PS values doubled with the addition of phase 2 data to phase 1 data. The best overall reproducibility was obtained with rigidly registered phase 1 and phase 2 images, with within-patient CVs for BF, BV, MTT, and PS of 11.2%, 14.4%, 5.5% and 12.1%, respectively. Normal liver evaluations were similar, except with marginally lower variability. CONCLUSION: Absolute values and reproducibility of CT perfusion parameters were markedly influenced by motion and data acquisition time. PS, in particular, probably requires data acquisition beyond a single breath hold, for which motion-correction techniques are likely necessary.

Reproducibility of perfusion parameters obtained from perfusion CT in lung tumors.

OBJECTIVE: The purpose of this article is to assess the variability of perfusion CT measurements in lung tumors and the effects of motion and duration of data acquisition on perfusion CT parameter values. SUBJECTS AND METHODS: Two perfusion CT scans were obtained in 11 patients with lung tumors, 2-7 days apart, using phase 1 scans (30-second breath-hold cine) followed by phase 2 scans (six intermittent helical breath-holds), spanning 125 seconds. Tumor blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability were calculated for phase 1 using all-cine and motion-corrected (rigidly registered) images, both with and without matching phase 2 images (manually or rigidly registered). Variability was assessed by the within-patient coefficient of variation (CV) and Bland-Altman analyses. RESULTS: BF, BV, MTT, and permeability values varied widely by method of analysis (median BF, 45.3-65.1 mL/min/100 g; median BV, 2.6-3.8 mL/100 g; median MTT, 3.6-4.1 seconds, and median permeability, 13.7-39.3 mL/min/100 g), as did within-patient CVs (10.9-114.4%, 25.3-117.6%, 22.3-51.5%, and 29.6-134.9%, respectively). Parameter values and variability were affected by motion and duration of data analyzed: permeability values doubled when phase 2 images were added to phase 1 data. Overall, the best reproducibility was obtained with registered phase 1 and 2 data, with within-patient CVs of 11.6%, 26.5%, 45.4%, and 30.2%, respectively. CONCLUSION: The absolute values and reproducibility of perfusion parameters in lung tumors are markedly influenced by motion and duration of data acquisition. Permeability, in particular, probably requires data acquisition beyond a single breath-hold. The smallest variability in parameter values was obtained with motion correction and extended acquisition durations.

Pathways of extrapelvic spread of pelvic disease: imaging findings.

The complex extraperitoneal anatomy of the pelvis includes various outlets for the transit of organs and neurovascular structures to the rest of the body. These outlets include the greater sciatic foramen, lesser sciatic foramen, inguinal canal, femoral triangle, obturator canal, anal and genitourinary hiatuses of the pelvic floor, prevesical space, and iliopsoas compartment. All of these structures serve as conduits for the dissemination of malignant and benign inflammatory diseases from the pelvic cavity and into the soft-tissue structures of the abdominal wall, buttocks, and upper thigh. Knowledge of the pelvic anatomy is crucial to understand these patterns of disease spread. Cross-sectional imaging provides important anatomic information and depicts the extent of disease and its involvement of surrounding extrapelvic structures, information that is important for planning surgery and radiation therapy.

Extramural venous invasion by gastrointestinal malignancies: CT appearances.

The purpose of this article is to describe and demonstrate the appearances of extramural vascular invasion on computed tomography in gastrointestinal malignancies as one of the pathways of disease spread. In this article, we demonstrate the imaging features with pathologically proven examples, along with a brief description of relevant vascular anatomy. We shall also discuss the clinical significance and prognostic implications of extramural vascular invasion in gastrointestinal malignancies.

Gastric cancer: Patterns of disease spread via the perigastric ligaments shown by CT.

OBJECTIVE: The stomach is suspended in the abdominal cavity by perigastric ligaments, which are derived from the dorsal and ventral mesogastrium. These ligaments provide a direct contiguous pathway for the peritoneal spread of gastric cancer. In this article, we discuss the embryology and anatomy of the stomach and describe the specific ligamentous routes along which gastric cancers may spread by direct invasion. CONCLUSION: Extragastric disease alters the prognosis and treatment options available to patients with gastric cancer. Familiarity with the stomach's embryology will help the radiologist understand its anatomy and, therefore, the patterns of regional spread of gastric cancer. The location of the primary tumor can predict involvement of specific perigastric ligaments because locoregional spread of gastric cancer occurs along the arteries, veins, nerves, and lymphatic channels within those ligaments. Thus, identifying the location of the primary tumor can potentially improve patient outcomes.

Perfusion CT in patients with metastatic renal cell carcinoma treated with interferon.

OBJECTIVE: The objective of our study was to assess the potential value of tumor perfusion parameters measured by perfusion CT as possible biomarkers of prognosis and early indicator of treatment efficacy in patients with metastatic conventional renal cell carcinoma (RCC) treated with interferon. MATERIALS AND METHODS: This study comprised 37 patients with metastatic RCC who were enrolled in a larger (n=118) randomized clinical trial of intermediate- versus low-dose interferon. Tumor perfusion parameters-that is, tumor blood flow, blood volume, mean transit time (MTT), and permeability-surface area product-of index metastatic lesions were obtained at baseline and at 8-week follow-up. Baseline perfusion parameters and changes at follow-up were compared, and their associations with patient progression-free survival were estimated. Univariate and multivariate analyses were performed. RESULTS: Twenty-eight patients were assessable. Median progression-free survival was 5.3 months (95% CI, 2.4-7.4 months), with one partial response. Tumor blood flow at baseline was inversely associated with patient progression-free survival in both univariate (hazard ratio [HR]=1.006, p=0.025) and multivariate (HR=1.007, p=0.012) analyses. There were significant increases in tumor blood flow and reductions in MTT on follow-up scans compared with baseline scans (both, p=0.04), but no association between changes in perfusion parameters and progression-free survival was detected. CONCLUSION: Patients with highly vascularized metastatic RCC as shown by high baseline tumor blood flow appear to have a worse prognosis than those who do not. Tumor perfusion may be a useful biomarker of prognosis and additionally, in the future, may assist in treatment stratification. The potential utility of perfusion CT as an early response indicator was probably inadequately assessed in this study because of the limited antiangiogenic activity of interferon in metastatic RCC.

Portal hypertension associated with oxaliplatin administration: clinical manifestations of hepatic sinusoidal injury.

Oxaliplatin-based chemotherapy regimens are currently a standard of care for the treatment of colorectal cancer (CRC) in both the adjuvant treatment and metastatic disease settings. Significant improvements in outcomes have been achieved with oxaliplatin-based combinations in these settings when compared with administration of 5-fluorouracil alone. Pathologic evaluation of normal liver from patients undergoing neoadjuvant oxaliplatin treatment has identified histologic evidence of sinusoidal injury, although the effect of this finding on patient outcomes after hepatic resection appears to be minimal. This article describes the use of oxaliplatin-based chemotherapy in 6 patients with stage III or IV CRC who developed evidence of noncirrhotic portal hypertension. These patients developed complications of portal hypertension including esophageal or hemorrhoidal varices with bleeding, splenomegaly with associated thrombocytopenia, and ascites. In each case, oxaliplatin-induced hepatic sinusoidal injury was identified as the most likely factor contributing to the development of noncirrhotic portal hypertension. The literature on hepatic sinusoidal injury after oxaliplatin is reviewed and the proposed pathophysiology is discussed.

Pancreas: peritoneal reflections, ligamentous connections, and pathways of disease spread.

The pancreas is a retroperitoneal organ with a close anatomic relationship to the peritoneal reflections in the abdomen, including the transverse mesocolon and the small bowel mesentery, and is directly contiguous to peritoneal ligaments such as the hepatoduodenal ligament, gastrohepatic ligament, splenorenal ligament, gastrocolic ligament, and the greater omentum. Understanding of these anatomic relationships of the pancreas is aided by knowledge of its embryologic development. These reflections and ligaments are potential pathways for spread of disease processes such as pancreatitis and pancreatic carcinoma. One can recognize these ligaments and reflections by identifying the blood vessels that traverse them.

Tumor blood flow measured by perfusion computed tomography and 15O-labeled water positron emission tomography: a comparison study.

OBJECTIVES: To compare blood flow measurements of tumors assessed by perfusion computed tomography (pCT) and the clinical gold standard of 15O-labeled water positron emission tomography (15O-PET). METHODS: Blood flows were estimated by pCT (4-row multidetector, CT Perfusion 3.1) and 15O-PET (Posicam, first-pass model) in 14 patients with solid tumors, totaling 22 index tumors and 57 matched pairs of examinations. Blood flow estimates were compared using t test, Bland-Altman, and linear mixed regression analyses. RESULTS: There was no significant difference between the mean (SD) blood flow values measured by pCT and 15O-PET: 25.9 +/- 15.4 and 27.8 +/- 14.0 mL/min per 100 g, respectively. CONCLUSIONS: The demonstration of a good correlation between pCT and 15O-PET potentially enables the use of pCT, which is more widely available than 15O-PET, when tumor blood flow estimates are required, particularly in the context of clinical studies.

Association of computed tomography morphologic criteria with pathologic response and survival in patients treated with bevacizumab for colorectal liver metastases.

CONTEXT: The standard criteria used to evaluate tumor response, the Response Evaluation Criteria in Solid Tumors (RECIST), were developed to assess tumor shrinkage after cytotoxic chemotherapy and may be limited in assessing response to biologic agents, which have a cytostatic mechanism of action. OBJECTIVE: To validate novel tumor response criteria based on morphologic changes observed on computed tomography (CT) in patients with colorectal liver metastases treated with bevacizumab-containing chemotherapy regimens. DESIGN, SETTING, AND PATIENTS: A total of 234 colorectal liver metastases were analyzed from 50 patients who underwent hepatic resection after preoperative chemotherapy that included bevacizumab at a comprehensive US cancer center from 2004 to 2007; date of last follow-up was March 2008. All patients underwent routine contrast-enhanced CT at the start and end of preoperative therapy. Three blinded, independent radiologists evaluated images for morphologic response, based on metastases changing from heterogeneous masses with ill-defined margins into homogeneous hypoattenuating lesions with sharp borders. These criteria were validated with a separate cohort of 82 patients with unresectable colorectal liver metastases treated with bevacizumab-containing chemotherapy. MAIN OUTCOME MEASURES: Response determined using morphologic criteria and RECIST was correlated with pathologic response in resected liver specimens and with patient survival. RESULTS: Interobserver agreement for scoring morphologic changes was good among 3 radiologists (kappa, 0.68-0.78; 95% confidence interval [CI], 0.51-0.93). In resected tumor specimens, the median (interquartile range [IQR]) percentages of residual tumor cells for optimal morphologic response was 20% (10%-30%); for incomplete response, 50% (30%-60%); and no response, 70% (60%-70%; P < .001). With RECIST, the median (IQR) percentages of residual tumor cells were for partial response 30% (10%-60%); for stable disease, 50% (20%-70%); and for progressive disease, 70% (65%-70%; P = .04). Among patients who underwent hepatic resection, median overall survival was not yet reached with optimal morphologic response and 25 months (95% CI, 20.2-29.8 months) with incomplete or no morphologic response (P = .03). In the validation cohort, patients with optimal morphologic response had median overall survival of 31 months (95% CI, 26.8-35.2 months) compared with 19 months (95% CI, 14.6-23.4 months) with incomplete or no morphologic response (P = .009). RECIST did not correlate with survival in either the surgical or validation cohort. CONCLUSION: Among patients with colorectal liver metastases treated with bevacizumab-containing chemotherapy, CT-based morphologic criteria had a statistically significant association with pathologic response and overall survival.

Early hepatocellular carcinoma: pathology, imaging, and therapy.

BACKGROUND: In 1987, Japanese researchers proposed to define the pathological concept of early hepatocellular carcinoma (HCC). However, there are some conceptual differences between the East and the West in the diagnosis and treatment of early HCC. METHODS: To provide up-to-date data for making a worldwide consensus, this article has collected six papers focused on the management of early HCC, which were presented in the Fifth International Meeting of "Hepatocellular Carcinoma: Eastern and Western Experiences" in Houston in January 2007. RESULTS: In the pathological perspective, the common criteria to discriminate early HCC from dysplastic nodule included hepatocytic invasion of portal triads and septa (stromal invasion). The current imaging modalities such as contrast-enhanced ultrasound (CEUS), computed tomography (CT), and magnetic resonance imaging (MRI) with the use of intravenous contrast material with multiphasic imaging could enhance their ability to accurately characterize early HCC. From the treatment perspective, a single early HCC had a high chance for cure by resection, ablation, or transplantation, which proved to be the earliest clinical entity (Stage 0 HCC). CONCLUSIONS: Early HCC is characterized by its incipient malignant nature and by an extremely favorable clinical outcome, thereby justifying its definition.