Comparing confirmatory biopsy outcomes between MRI-targeted biopsy and standard systematic biopsy among men being enrolled in prostate cancer active surveillance.

OBJECTIVES: To evaluate the ability of magnetic resonance imaging (MRI)-targeted biopsy combined with systematic biopsy (MRI-biopsy) to reduce negative biopsies and detect clinically significant prostate cancer compared to systematic biopsy (SB) alone in the confirmatory biopsy setting using matched cohorts. PATIENTS AND METHODS: Patients were identified from an active surveillance database who had a previously positive transrectal ultrasonography-guided SB followed by a confirmatory biopsy at a single institution between 2006 and 2019. Patients were divided into two cohorts based on confirmatory biopsy technique: SB alone or MRI-biopsy (which included MRI-targeted and systematic biopsies). Cohorts were then matched on age, prostate-specific antigen (PSA) level, number of positive cores on initial biopsy and initial biopsy Gleason grade group (GG). Logistic regression was performed to identify associations with confirmatory biopsy upgrading. RESULTS: After matching, 514 patients were identified (257 per cohort). PSA, prostate volume and PSA density prior to initial biopsy, in addition to total number of initial biopsy positive cores and GG, were similar between the matched cohorts. After confirmatory biopsy, 118/257 patients (45.9%) in the MRI-biopsy cohort were upgraded compared to 46/257 patients (17.9%) in the SB cohort (P < 0.001). The rate of negative confirmatory biopsy was 32/257 (12.5%) compared to 97/257 (37.7%) in the MRI-biopsy and SB cohorts, respectively (P < 0.001). Confirmatory MRI-biopsy was associated with greater odds of confirmatory biopsy upgrade from GG 1 to ≥GG 2 compared to SB alone (odds ratio 3.62, 95% confidence interval 1.97-6.63; P < 0.001). CONCLUSION: The addition of MRI-targeted biopsies to SB in the confirmatory biopsy setting among men with previously detected prostate cancer resulted in fewer negative confirmatory biopsies and detection of more clinically significant prostate cancer compared to SB alone.

MRI Staging in an Evolving Management Paradigm for Rectal Cancer, From the AJR Special Series on Cancer Staging.

The treatment of rectal cancer centers around the distinct but related goals of management of distant metastases and management of local disease. Optimal local management requires attention to the primary tumor and its anatomic relationship to surrounding pelvic structures, with the goal of minimizing local recurrence (LR). High-resolution MRI is ideally suited for this purpose; application of MRI-based criteria in conjunction with optimized surgical and pathologic techniques has successfully reduced LR rates. This success has led to a shift away from using the TNM-based National Comprehensive Cancer Network (NCCN) guidelines as the sole determinant of whether a patient receives neoadjuvant chemoradiation. The new model uses a hybrid approach for assigning risk categories that combines elements of the TNM staging system with MRI-based anatomic features. These risk categories incorporate tumor proximity to the circumferential resection margin, T category, distance to the anal verge, and presence of extramural venous invasion to classify rectal tumors as low, intermediate, or high risk. This approach has been validated by accumulated data from numerous multiinstitutional studies. This article illustrates key anatomic concepts, depicts common interpretive errors and pitfalls, and discusses ongoing limitations; these insights should guide radiologists in optimal rectal MRI interpretation.

Intrahepatic Recurrence Patterns Predict Survival After Resection of Colorectal Liver Metastases.

BACKGROUND: After resection of colorectal liver metastases (CLM), up to 40% of patients will develop intrahepatic recurrence. This study aims to identify patterns of intrahepatic recurrence and their impact on survival after preoperative chemotherapy and CLM resection. METHODS: A retrospective review was performed of patients developing intrahepatic recurrence after CLM resection following preoperative chemotherapy. Prechemotherapy, preoperative, and postoperative computed tomography scans were reviewed. Recurrences were classified as in situ, de novo, or both in situ and de novo. Median follow-up was 42 months (range 2-144 months). RESULTS: Among 223 patients meeting study criteria, intrahepatic recurrence was identified a median of 9 months after hepatectomy. Isolated de novo or in situ recurrence developed in 105 (47%) and 86 (39%) patients, respectively. Thirty-two patients (14%) developed both in situ and de novo recurrence, which was associated with significantly lower median overall survival of 33 months compared with 49 and 45 months with isolated in situ or de novo recurrence, respectively (p = 0.048). Among 118 patients (53%) who developed in situ recurrence as a component of disease relapse, recurrences resulted from disappearing or missed liver metastases in 47 patients (40%). CONCLUSIONS: An intrahepatic recurrence pattern of both in situ and de novo metastases after CLM resection following preoperative chemotherapy predicts significantly worse overall survival compared with isolated in situ or de novo recurrence.

Total Transthoracic Approach Facilitates Laparoscopic Hepatic Resection in Patients with Significant Prior Abdominal Surgery.

BACKGROUND: While the oncologic safety of minimally invasive hepatectomy for colorectal liver metastases (CLM) has been demonstrated, lesions in the postero-superior segments may be challenging.1 - 3 For these lesions, a transthoracic approach may be particularly helpful, especially in patients with a hostile/reoperative abdomen or morbid obesity.4 , 5 PATIENT: A 43-year-old man with a body mass index of 36.0 who had undergone rectosigmoid resection for primary cancer 5 years ago recurred with a solitary liver metastasis in SVIII. He had previously undergone the following resections for metachronous CLM: (i) partial resections of SV/VIII and SII/III; (ii) ablation for SVII; and (iii) left hepatectomy, common bile duct resection, and choledochojejunostomy. Following four cycles of FOLFIRI/panitumumab with good response, the patient was considered for his fourth abdominal cancer intervention via a thoracoscopic approach. TECHNIQUE: In a modified French position with left-lung ventilation, access to the right thoracic cavity was gained. Following thoracic adhesiolysis, transdiaphragmatic intraoperative ultrasonography (IOUS) was performed. To ensure optimal margins, IOUS-guided transthoracic hepatic resection with partial resection of the diaphragm was conducted. The diaphragm was reconstructed and a chest tube placed. Operative time was 247 min, with an estimated blood loss of 100 mL. Postoperative recovery was uneventful; pathology demonstrated no viable tumor, with the closest margin 5 mm from the necrotic area. CONCLUSION: Transthoracic hepatic resection of SVIII can optimize the port-target axis while minimizing morbidity. A systematic approach that includes precise port positioning, non-traumatic intrathoracic adhesiolysis, and meticulous transdiaphragmatic IOUS-guided parenchymal transection can optimize outcomes.

Alternative Response Criteria and Clinical Risk Factors for Assessing Tumor Response in Patients With Metastatic Renal Cell Carcinoma Who Are Receiving Salvage Therapy.

OBJECTIVE: The purpose of this study is to compare the prognostic value of various solid tumor response criteria as well as the additive value of clinical risk factors in patients with advanced renal cell carcinoma (RCC). MATERIALS AND METHODS: Two sets of CT scans (pretreatment scans and scans obtained 1-3.5 months after treatment) were reviewed for 57 patients with metastatic RCC treated with pazopanib in the salvage setting. Tumor response on the posttherapy scan was evaluated using Response Evaluation Criteria in Solid Tumors (RECIST) and Choi, modified Choi (mChoi), MASS (Morphology, Attenuation, Size, and Structure), and 10% threshold criteria. In addition, combined Memorial Sloan-Kettering Cancer Center (MSKCC) risk factors plus imaging criteria were used to define response groups. Response evaluations using these criteria were correlated with overall survival (OS) and progression-free survival (PFS), with use of the log-rank test. RESULTS: Patients classified as having progressive disease (PD) on the basis of RECIST, mChoi, and MASS criteria had a significantly worse OS than patients with stable disease (SD) and partial response (PR). With the addition of MSKCC risk factors, all groups with PD defined by combined criteria had significantly worse OS. For 37 patients with no or one MSKCC risk factor, response groups defined by Choi, mChoi, MASS, and 10% threshold criteria did not differ in PFS or OS. However, among 20 patients with two to three MSKCC risk factors, those classified as having PR had longer PFS than did those with SD and had longer OS than did those with PD. CONCLUSION: For patients with advanced RCC for which prior therapies have failed, the prognostic value of various imaging-based tumor response criteria differs on the basis of the MSKCC clinical risk status.

The ABCs of BHD: An In-Depth Review of Birt-Hogg-Dubé Syndrome.

OBJECTIVE: Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant inherited syndrome involving multiple organs. In young patients, renal neoplasms that are multiple, bilateral, or both, such as oncocytomas, chromophobe renal cell carcinoma (RCC), hybrid chromophobe RCC-oncocytomas, clear cell RCC, and papillary RCC, can suggest BHD syndrome. Extrarenal findings, including dermal lesions, pulmonary cysts, and spontaneous pneumothoraces, also aid in diagnosis. CONCLUSION: Radiologists may be one of the first medical specialists to suggest the diagnosis of BHD syndrome. Knowledge of pathogenesis and management, including the importance of the types of renal neoplasms in a given patient, is needed to properly recognize this rare condition.

Biliary cancer: Utility of next-generation sequencing for clinical management.

BACKGROUND: Biliary tract cancers (BTCs) typically present at an advanced stage, and systemic chemotherapy is often of limited benefit. METHODS: Hybrid capture-based comprehensive genomic profiling (CGP) was performed for 412 intrahepatic cholangiocarcinomas (IHCCAs), 57 extrahepatic cholangiocarcinomas (EHCCAs), and 85 gallbladder carcinomas (GBCAs). The mutational profile was correlated with the clinical outcome of standard and experimental therapies for 321 patients. Clinical variables, detected mutations, and administered therapies were correlated with overall survival (OS) in a Cox regression model. RESULTS: The most frequent genetic aberrations (GAs) observed were tumor protein 53 (TP53; 27%), cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B; 27%), KRAS (22%), AT-rich interactive domain-containing protein 1A (ARID1A; 18%), and isocitrate dehydrogenase 1 (IDH1; 16%) in IHCCA; KRAS (42%), TP53 (40%), CDKN2A/B (17%), and SMAD4 (21%) in EHCCA; and TP53 (59%), CDKN2A/B (19%), ARID1A (13%), and ERBB2 (16%) in GBCA. Fibroblast growth factor receptor (FGFR; 11%) and IDH mutations (20%) were mostly limited to IHCCA but appeared to be mutually exclusive. In the IHCCA group, TP53 and KRAS mutations were associated significantly with poor OS, whereas FGFR2 mutations were associated with improved OS (P = .001), a younger age at onset, and female sex. IDH1/2 mutations were not prognostic. In a multivariate model, the effects of TP53 and FGFR GAs remained significant (P < .05). Patients with FGFR GAs had superior OS with FGFR-targeted therapy versus standard regimens (P = .006). Targeted therapy in IHCCA was associated with a numerical OS improvement (P = .07). CONCLUSIONS: This is the largest clinically annotated data set of BTC cases with CGP and indicates the potential of CGP for improving outcomes. CGP should be strongly considered in the management of BTC patients. Cancer 2016;122:3838-3847. © 2016 American Cancer Society.

Diagnostic approach to hereditary renal cell carcinoma.

OBJECTIVE: The purpose of this article is to discuss the histopathologic features, genetics, clinical presentation, and imaging of hereditary renal cancer syndromes. CONCLUSION: Hereditary renal cell carcinoma syndromes can be diagnosed with a pattern-based approach focused on the predominant histologic renal cell carcinoma subtype and associated renal and extrarenal features of each syndrome.

Phase 1 and pharmacodynamic trial of everolimus in combination with cetuximab in patients with advanced cancer.

BACKGROUND: Preclinical and clinical studies suggest mTOR (mammalian target of rapamycin) inhibitors may have metabolic and antiangiogenic effects, and synergize with epidermal growth factor pathway inhibitors. Therefore, a phase 1/pharmacodynamic trial of everolimus with cetuximab was performed. METHODS: A total of 29 patients were randomized to a run-in of oral everolimus (30, 50, or 70 mg) or cetuximab (400 mg/m(2) loading, 250 mg/m(2) maintenance) weekly, followed by the combination in this dose-escalation study. Primary endpoints were phase 2 dose and toxicity characterization. [(18)F]Fluorodeoxyglucose positron emission tomography (FDG-PET) was performed as a pharmacodynamic marker of mTOR inhibition, and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was performed as an indicator of tumor perfusion changes, at 3 time points. RESULTS: Everolimus and cetuximab were tolerable at full doses, with an expected toxicity profile. Dose-limiting toxicities in the everolimus 70 mg group included grade 3 skin toxicity in 2 patients, and mucositis in 1 patient. Of 16 patients evaluable for response, 5 had stable disease lasting 4 to 19 months. Mean change in maximum standardized uptake value (SUV(max)) for those treated initially with everolimus was -24% (2% to -54%), and with cetuximab was -5% (-23 to 36%). The K(trans) measured by DCE-MRI did not decrease, regardless of run-in drug. CONCLUSIONS: Everolimus and cetuximab can be safely administered at standard doses, and are associated with prolonged disease control. The recommended phase 2 dose of oral weekly everolimus is 70 mg in combination with standard cetuximab. Imaging studies reveal that metabolic inhibition by everolimus alone and in combination with cetuximab predominates over changes in tumor perfusion in this patient population.

Beyond the GIST: mesenchymal tumors of the stomach.

Intramural gastric masses arise in the wall of the stomach (generally within the submucosa or muscularis propria), often with intact overlying mucosa. These tumors are typically mesenchymal in origin and have overlapping radiologic appearances. A combination of features such as location, attenuation, enhancement, and growth pattern may suggest one diagnosis over another. Gastrointestinal stromal tumors (GISTs) account for the majority of intramural tumors and can vary widely in appearance, from small intraluminal lesions to exophytic masses that protrude into the peritoneal cavity, commonly with areas of hemorrhage or necrosis. A well-circumscribed mass measuring -70 to -120 HU is a lipoma. Leiomyomas usually manifest as low-attenuation masses at the gastric cardia. Homogeneous attenuation is a noteworthy characteristic of schwannomas, particularly for larger lesions that might otherwise be mistaken for GISTs. A hypervascular mass in the antrum is a common manifestation of glomus tumors. Hemangiomas are also hypervascular but often manifest in childhood. Inflammatory fibroid polyps usually arise as a polypoid mass in the antrum. Inflammatory myofibroblastic tumors are infiltrative neoplasms with a propensity for local recurrence. Plexiform fibromyxomas are rare, usually antral tumors. Carcinoid tumors are epithelial in origin, but often submucosal in location, and therefore should be distinguished from other intramural lesions. Multiple carcinoid tumors are associated with hypergastrinemia, either in the setting of chronic atrophic gastritis or Zollinger-Ellison syndrome. Sporadic solitary carcinoid tumors not associated with hypergastrinemia have a higher rate of metastasis. Histopathologic analysis, including immunohistochemistry, is usually required for diagnosis of intramural masses.

Tuberous Sclerosis Complex (TSC): Renal and Extrarenal Imaging.

Tuberous sclerosis complex is a multiorgan syndrome manifesting with several benign and malignant tumors. Complications arising from renal abnormalities are a leading cause of death in patients with tuberous sclerosis complex. Renal cell carcinoma is relatively uncommon, occurring in 2%-4% of patients with tuberous sclerosis complex syndrome, but nonetheless can significantly contribute to morbidity and mortality. Extrarenal manifestations of tuberous sclerosis complex, including within the chest, abdomen and central nervous system, aid in diagnosis. Pathogenesis and management are also discussed, including the importance of the types of renal masses found in these patients.

Impact of MRI/US fusion-guided prostate biopsy on biopsy-naïve patients: A single urologist's experience.

Objectives: To report our experience with imaging-guided targeted prostate biopsy (IGTpBx) for patients undergoing initial prostate biopsy in a clinical setting. Materials and methods: From July 2014 to February 2020, 305 men who had IGTpBx performed as their first prostate biopsy were enrolled. Two dedicated magnetic resonance imaging (MRI) radiologists segmented at least 1 region of interest (ROI) for each of these men using screening 1.5T MRI images. A single urologist employed the robotic-assisted Artemis MRI/ultrasonography (US) fusion platform to obtain 2-3 targeted samples from each ROI and additional random samples from the zones of the prostate outside the ROIs (a total of 12 zonal samples). Biopsy outcomes were categorized based on the Gleason score (GS) grade group (GG) as no cancer, favorable (GG < 3 or GS < 4 + 3), or clinically significant (GG ≥ 3 or GS ≥ 4 + 3) cancer. Results: The overall cancer detection rate was 75%:31% clinically significant, 44% favorable, and 25% no cancer. These findings triggered active interventions in 176 (58%) patients. A prostate-specific antigen (PSA) level of 0-4 ng/mL was detected in 39 (66%) of 59 patients (32 favorable, 7 significant), 4-10 ng/mL in 147 (77%) of 190 patients (85 favorable, 62 significant), and 10 ng/mL and over in 44 (80%) of 55 patients (17 favorable, 27 significant). Conclusions: The tumor detection rate was 75% with IGTpBx in patients without a previous biopsy. In addition, about 42% of detected cancers were deemed clinically significant and led to active interventions. IGTpBx as a patient's first prostate biopsy improves the detection of clinically significant prostate cancer when compared with historical data for random systematic prostate biopsy.

Accuracy of Prostate Magnetic Resonance Imaging: Reader Experience Matters.

BACKGROUND: Prostate magnetic resonance imaging (MRI) is increasingly used in the detection, image-guided biopsy, and active surveillance of prostate cancer. The accuracy of prostate MRI may differ based on factors including imaging technique, patient population, and reader experience. OBJECTIVE: To determine whether the accuracy of prostate MRI varies with reader experience. DESIGN SETTING AND PARTICIPANTS: We rescored regions of interest from 194 consecutive patients who had undergone MRI/ultrasonography fusion biopsy. Original prostate MRI scans had been interpreted by one of 33 abdominal radiologists (AR group). More than 14 mo later, rescoring was performed by two blinded, prostate MRI radiologists (PR group). Likert scoring was used for both original MRI reports and rescoring. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Test performance (sensitivity, specificity, positive predictive value [PPV], and negative predictive value [NPV]) of prostate MRI was defined for the AR and PR groups. A Likert score of 4-5 was considered test positive and clinically significant prostate carcinoma (csPCa; Gleason grade group [GGG] ≥2) was considered outcome positive. RESULTS AND LIMITATIONS: MRI-positive lesions (Likert 4-5) scored by the PR group resulted in csPCa more frequently than those scored by the AR group (64.9% vs 39.3%). MRI-negative lesions (Likert 2-3) were more likely to result in a clinically insignificant biopsy (benign pathology or GGG 1) when scored by the PR versus the AR group (91.8% vs 76.6%). Sensitivity and specificity of MRI to detect csPCa were higher for the PR group than for the AR group (sensitivity 85.9% vs 70.7%; specificity 77.3% vs 46.8%). Overall diagnostic accuracy was higher for the PR group than for the AR group (80.1% vs 54.6%). CONCLUSIONS: Sensitivity, specificity, PPV, and NPV of prostate MRI were higher for the PR group than for the AR group. PATIENT SUMMARY: We examined the accuracy of prostate magnetic resonance imaging (MRI) in two groups of radiologists. Experienced radiologists were more likely to detect clinically significant prostate cancer on MRI.

A core system for the implementation of task sets.

When performing tasks, humans are thought to adopt task sets that configure moment-to-moment data processing. Recently developed mixed blocked/event-related designs allow task set-related signals to be extracted in fMRI experiments, including activity related to cues that signal the beginning of a task block, "set-maintenance" activity sustained for the duration of a task block, and event-related signals for different trial types. Data were conjointly analyzed from mixed design experiments using ten different tasks and 183 subjects. Dorsal anterior cingulate cortex/medial superior frontal cortex (dACC/msFC) and bilateral anterior insula/frontal operculum (aI/fO) showed reliable start-cue and sustained activations across all or nearly all tasks. These regions also carried the most reliable error-related signals in a subset of tasks, suggesting that the regions form a "core" task-set system. Prefrontal regions commonly related to task control carried task-set signals in a smaller subset of tasks and lacked convergence across signal types.

Tumor response criteria for assessing pazopanib first-line therapy in patients with metastatic renal cell carcinoma (mRCC).

PURPOSE: To identify the optimum response criteria for first-line targeted pazopanib therapy in patients with mRCC using solid tumor response criteria and clinical risk factors. METHODS: Pre- and post-treatment CTs of patients (n = 43) with mRCC treated with first-line pazopanib therapy were analyzed retrospectively. Treatment response was evaluated with Response Evaluation Criteria in Solid Tumors (RECIST) v1.1, Choi, modified Choi (mChoi), revised Choi (rChoi), MASS (Morphology, Attenuation, Size, and Structure), 10% threshold criteria, and subjective assessment. Memorial Sloan-Kettering Cancer Center and International Metastatic Renal Cell Carcinoma Database Consortium clinical risk factors were also used to define response groups. Response evaluations were correlated with overall survival (OS) and progression-free survival (PFS) using log-rank test. RESULTS: Patients with partial response (PR) by mChoi and rChoi had longer OS than those with stable disease (SD) (P < 0.001). Responders by 10% threshold criteria also had better OS, without or combined with clinical criteria. Patients with PR by rChoi, mChoi, RECIST v1.1, MASS criteria, and by subjective assessment had longer PFS than those with SD. rChoi and mChoi criteria best delineated the difference in PFS for patients with PR versus SD, without or combined with clinical criteria. CONCLUSION: For mRCC patients treated with pazopanib, OS and PFS for PR and SD groups were best predicted by rChoi and mChoi criteria, without or combined with clinical risk factors. 10% threshold criteria also predicted OS and PFS, whereas RECIST did so only in a limited number of patients.

Comparison of virtual to true unenhanced abdominal computed tomography images acquired using rapid kV-switching dual energy imaging.

OBJECTIVE: To compare "virtual" unenhanced (VUE) computed tomography (CT) images, reconstructed from rapid kVp-switching dual-energy computed tomography (DECT), to "true" unenhanced CT images (TUE), in clinical abdominal imaging. The ability to replace TUE with VUE images would have many clinical and operational advantages. METHODS: VUE and TUE images of 60 DECT datasets acquired for standard-of-care CT of pancreatic cancer were retrospectively reviewed and compared, both quantitatively and qualitatively. Comparisons included quantitative evaluation of CT numbers (Hounsfield Units, HU) measured in 8 different tissues, and 6 qualitative image characteristics relevant to abdominal imaging, rated by 3 experienced radiologists. The observed quantitative and qualitative VUE and TUE differences were compared against boundaries of clinically relevant equivalent thresholds to assess their equivalency, using modified paired t-tests and Bayesian hierarchical modeling. RESULTS: Quantitatively, in tissues containing high concentrations of calcium or iodine, CT numbers measured in VUE images were significantly different from those in TUE images. CT numbers in VUE images were significantly lower than TUE images when calcium was present (e.g. in the spine, 73.1 HU lower, p < 0.0001); and significantly higher when iodine was present (e.g. in renal cortex, 12.9 HU higher, p < 0.0001). Qualitatively, VUE image ratings showed significantly inferior depiction of liver parenchyma compared to TUE images, and significantly more cortico-medullary differentiation in the kidney. CONCLUSIONS: Significant differences in VUE images compared to TUE images may limit their application and ability to replace TUE images in diagnostic abdominal CT imaging.

Consultation and citation rates for prior imaging studies and documents in radiology.

Frequently, the consensus conclusion after quality assurance conferences in radiology is that whatever mistake was made could have been avoided if more prior images or documents had been consulted. It is generally assumed that anything that was not specifically cited in the report had not been consulted. Is it actually safe to assume that an image or document that is not cited was also not consulted? It is this question that this investigation addresses. In this Institutional Review Board-approved study, one observer watched the board-certified radiologists while they interpreted imaging studies and issued reports. He recorded what type of study was being interpreted [either computed tomography, magnetic resonance imaging, or conventional radiography (x-ray)]. He also recorded the number and type of prior imaging studies and documents that were consulted during the interpretation. These observations were then compared with the signed report to determine how many of the consulted imaging studies and documents were cited. Of the 198 previous imaging studies that the radiologists consulted, 116 (58.6%) were cited in a report. Of the 285 documents consulted, 3 (1.1%) were cited in a report. This difference in citation rate was statistically significant ([Formula: see text]). It cannot be safely assumed that an older radiologic image or medical document was not consulted during radiologic interpretation merely because it is not cited in the report. Radiologists often consult more old studies than they cite, and they do not cite the majority of prior documents that they consult.

Imaging features of rare mesenychmal liver tumours: beyond haemangiomas.

Tumours arising from mesenchymal tissue components such as vascular, fibrous and adipose tissue can manifest in the liver. Although histopathology is often necessary for definitive diagnosis, many of these lesions exhibit characteristic imaging features. The radiologist plays an important role in suggesting the diagnosis, which can direct appropriate immunohistochemical staining at histology. The aim of this review is to present clinical and imaging findings of a spectrum of mesenchymal liver tumours such as haemangioma, epithelioid haemangioendothelioma, lipoma, PEComa, angiosarcoma, inflammatory myofibroblastic tumour, solitary fibrous tumour, leiomyoma, leiomyosarcoma, Kaposi sarcoma, mesenchymal hamartoma, undifferentiated embryonal sarcoma, rhabdomyosarcoma and hepatic metastases. Knowledge of the characteristic features of these tumours will aid in guiding the radiologic diagnosis and appropriate patient management.

Comparative Effectiveness of Tumor Response Assessment Methods: Standard of Care Versus Computer-Assisted Response Evaluation.

PURPOSE: To compare the effectiveness of metastatic tumor response evaluation with computed tomography using computer-assisted versus manual methods. MATERIALS AND METHODS: In this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study, 11 readers from 10 different institutions independently categorized tumor response according to three different therapeutic response criteria by using paired baseline and initial post-therapy computed tomography studies from 20 randomly selected patients with metastatic renal cell carcinoma who were treated with sunitinib as part of a completed phase III multi-institutional study. Images were evaluated with a manual tumor response evaluation method (standard of care) and with computer-assisted response evaluation (CARE) that included stepwise guidance, interactive error identification and correction methods, automated tumor metric extraction, calculations, response categorization, and data and image archiving. A crossover design, patient randomization, and 2-week washout period were used to reduce recall bias. Comparative effectiveness metrics included error rate and mean patient evaluation time. RESULTS: The standard-of-care method, on average, was associated with one or more errors in 30.5% (6.1 of 20) of patients, whereas CARE had a 0.0% (0.0 of 20) error rate ( P < .001). The most common errors were related to data transfer and arithmetic calculation. In patients with errors, the median number of error types was 1 (range, 1 to 3). Mean patient evaluation time with CARE was twice as fast as the standard-of-care method (6.4 minutes v 13.1 minutes; P < .001). CONCLUSION: CARE reduced errors and time of evaluation, which indicated better overall effectiveness than manual tumor response evaluation methods that are the current standard of care.