Progression-free survival assessment by local investigators versus blinded independent central review in randomized clinical trials in metastatic breast cancer: A systematic review and meta-analysis.

INTRODUCTION: In randomized clinical trials (RCTs), blinded independent central review (BICR) is used to minimize heterogeneity and bias associated with radiological response evaluation by local investigators. However, BICR adds costs and complexity to the trial management. We assessed the discrepancy index between progression-free survival (PFS) assessment by local investigators and by BICR in RCTs conducted in patients with metastatic breast cancer (MBC). METHODS: A systematic search of PubMed, Embase, Cochrane databases and conference proceedings (ASCO, SABCS, ESMO) was performed up to January 4, 2023 (PROSPERO: CRD42021229865). All RCTs published from 2000 to 2022, including MBC patients treated in first- or second-line, and reporting PFS assessed by local investigators and BICR were included. A discrepancy index between BICR-assessed and investigator-assessed HR was calculated for each trial and an overall combined DI was obtained using a fixed-effects model. The agreement between hazard ratios (HR) of PFS assessed by local investigators and BICR was measured using intraclass correlation coefficient (ICC). RESULTS: We analyzed 24 studies including 13,168 patients. Among them, 19 (79%) were in first-line, 18 (75%) were phase III trials and 23 (96%) had PFS as primary endpoint. The overall combined discrepancy index was 0.97 (95%CI 0.85-1.10; ICC 0.831, p < 0.001) suggesting no statistically significant difference in PFS assessment between local investigators and BICR. This result was consistent across all analyzed subgroups. CONCLUSIONS: The good concordance between local investigator and BICR assessments supports the reliability of local investigator-assessed PFS as primary endpoint for RCTs in MBC and questions the practical utility of implementing BICR in all RCTs.

Meta-Analysis of 49 Roche Oncology Trials Comparing Blinded Independent Central Review (BICR) and Local Evaluation to Assess the Value of BICR.

BACKGROUND: Blinded independent central review (BICR) of radiographic images is frequently conducted in oncology trials to address the potential bias of local evaluation (LE) of endpoints such as progression-free survival (PFS) and objective response rate (ORR). Given that BICR is a complex and costly process, we evaluated the agreement between LE- and BICR-based treatment effect results and the impact of BICR on regulatory decision-making. MATERIALS AND METHODS: Meta-analyses were performed using hazard ratios (HRs) for PFS and odds ratios (ORs) for ORR from all randomized Roche-supported oncology clinical trials during 2006-2020 that had both LE and BICR results (49 studies with a total of over 32 000 patients). RESULTS: Overall, the evaluation bias of LE overestimating the treatment effect compared with BICR based on PFS was numerically small and not clinically meaningful, especially for double-blind studies (HR ratio between BICR and LE: 1.044). A larger bias is more likely to occur in studies with open-label design, smaller sample sizes, or an unequal randomization ratio. The majority (87%) of the PFS comparisons led to the same statistical inference by BICR and LE. For ORR, a high degree of agreement between BICR and LE results was also observed (OR ratio of 1.065), although the agreement was slightly lower than for PFS. CONCLUSION: BICR did not notably impact the study interpretation nor drive the sponsor's regulatory submission decisions. Hence, if bias can be diminished by appropriate means, LE is deemed as reliable as BICR for certain study settings.

Artificial intelligence (AI)-based decision support improves reproducibility of tumor response assessment in neuro-oncology: An international multi-reader study.

BACKGROUND: To assess whether artificial intelligence (AI)-based decision support allows more reproducible and standardized assessment of treatment response on MRI in neuro-oncology as compared to manual 2-dimensional measurements of tumor burden using the Response Assessment in Neuro-Oncology (RANO) criteria. METHODS: A series of 30 patients (15 lower-grade gliomas, 15 glioblastoma) with availability of consecutive MRI scans was selected. The time to progression (TTP) on MRI was separately evaluated for each patient by 15 investigators over two rounds. In the first round the TTP was evaluated based on the RANO criteria, whereas in the second round the TTP was evaluated by incorporating additional information from AI-enhanced MRI sequences depicting the longitudinal changes in tumor volumes. The agreement of the TTP measurements between investigators was evaluated using concordance correlation coefficients (CCC) with confidence intervals (CI) and P-values obtained using bootstrap resampling. RESULTS: The CCC of TTP-measurements between investigators was 0.77 (95% CI = 0.69,0.88) with RANO alone and increased to 0.91 (95% CI = 0.82,0.95) with AI-based decision support (P = .005). This effect was significantly greater (P = .008) for patients with lower-grade gliomas (CCC = 0.70 [95% CI = 0.56,0.85] without vs. 0.90 [95% CI = 0.76,0.95] with AI-based decision support) as compared to glioblastoma (CCC = 0.83 [95% CI = 0.75,0.92] without vs. 0.86 [95% CI = 0.78,0.93] with AI-based decision support). Investigators with less years of experience judged the AI-based decision as more helpful (P = .02). CONCLUSIONS: AI-based decision support has the potential to yield more reproducible and standardized assessment of treatment response in neuro-oncology as compared to manual 2-dimensional measurements of tumor burden, particularly in patients with lower-grade gliomas. A fully-functional version of this AI-based processing pipeline is provided as open-source (https://github.com/NeuroAI-HD/HD-GLIO-XNAT).

A Novel Method for Evaluating Early Tumor Response Based on Daily CBCT Images for Lung SBRT.

BACKGROUND: We aimed to develop a new tumor response assessment method for lung SBRT. METHODS: In total, 132 lung cancer patients with 134 tumors who received SBRT treatment with daily CBCT were included in this study. The information about tumor size (area), contrast (contrast-to-noise ratio (CNR)), and density/attenuation (µ) was derived from the CBCT images for the first and the last fractions. The ratios of tumor area, CNR, and µ (RA, RCNR, Rµ) between the last and first fractions were calculated for comparison. The product of the three rations was defined as a new parameter (R) for assessment. Tumor response was independently assessed by a radiologist based on a comprehensive analysis of the CBCT images. RESULTS: R ranged from 0.27 to 1.67 with a mean value of 0.95. Based on the radiologic assessment results, a receiver operation characteristic (ROC) curve with the area under the curve (AUC) of 95% was obtained and the optimal cutoff value (RC) was determined as 1.1. The results based on RC achieved a 94% accuracy, 94% specificity, and 90% sensitivity. CONCLUSION: The results show that R was correlated with early tumor response to lung SBRT and that using R for evaluating tumor response to SBRT would be viable and efficient.

Long-Term Real-World Outcomes of First-Line Pembrolizumab Monotherapy for Metastatic Non-Small Cell Lung Cancer With ≥50% Expression of Programmed Cell Death-Ligand 1.

Objectives: Immune checkpoint inhibitors (ICIs) of programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) have been rapidly adopted in US clinical practice for first-line therapy of metastatic non-small cell lung cancer (NSCLC) since regulatory approval in October 2016, and a better understanding is needed of long-term outcomes of ICI therapy administered in real-world settings outside of clinical trials. Our aim was to describe long-term outcomes of first-line pembrolizumab monotherapy at US oncology practices for patients with metastatic NSCLC, PD-L1 expression ≥50%, and good performance status. Methods: This retrospective two-cohort study used technology-enabled abstraction of deidentified electronic health records (EHR cohort) plus enhanced manual chart review (spotlight cohort) to study adult patients with stage IV NSCLC, PD-L1 expression ≥50%, no documented EGFR/ALK/ROS1 genomic aberration, and ECOG performance status 0-1 who initiated first-line pembrolizumab monotherapy from 1-November-2016 to 31-March-2020 (EHR cohort, with data cutoff 31-March-2021) or from 1-December-2016 to 30-November-2017 (spotlight cohort, with data cutoff 31-August-2020). Kaplan-Meier analysis was used to determine overall survival (OS; both cohorts) and, for the spotlight cohort, real-world progression-free survival (rwPFS) and real-world tumor response (rwTR). Results: The EHR cohort included 566 patients (298 [53%] men); the spotlight cohort included 228 (105 [46%] men); median age in both cohorts was 71. Median follow-up from pembrolizumab initiation to data cutoff was 35.1 months (range, 12.0-52.7) and 38.4 months (range, 33.1-44.9) in EHR and spotlight cohorts, respectively. Median OS was 19.6 months (95% CI, 16.6-24.3) and 21.1 months (95% CI, 16.2-28.9), respectively; 3-year OS rates were 36.2% and 38.2% in EHR and spotlight cohorts, respectively. In the spotlight cohort, median rwPFS was 7.3 months (95% CI, 5.7-9.2); 88 patients (38.6%; 95% CI, 32.2-45.2) experienced rwTR of complete or partial response. For 151/228 patients (66%) who discontinued pembrolizumab, the most common reasons were disease progression (70 [46%]) and therapy-related adverse effects (35 [23%]). Conclusions: Real-world outcomes remain consistent with outcomes observed in clinical trials, supporting long-term benefits of first-line pembrolizumab monotherapy for patients with metastatic NSCLC, PD-L1 expression ≥50%, and good performance status.

Implementing Real-World RECIST-based Tumor Response Assessment in Patients With Metastatic Non-small Cell Lung Cancer.

BACKGROUND: To accelerate drug approvals while maintaining scientific rigor in the evaluation of a therapeutic's efficacy and safety, the United States Food and Drug Administration now considers real-world data (RWD) to support New Drug Applications and expanded indications. Response Evaluation Criteria in Solid Tumors (RECIST) are the gold standard in clinical trials, but the derivation of RECIST-based treatment response from RWD is unproven. This study investigated the feasibility of implementing RECIST criteria in RWD by comparing lung cancer response assessments from RECIST-based measurement of lesions on archived radiologic films with results from medical oncologist and radiologist narratives recorded in electronic health records (EHR). MATERIALS AND METHODS: Response to index treatment via different assessment approaches was compared among 30 metastatic non-small cell lung cancer (mNSCLC) patients receiving systemic treatment (index) after progression on a platinum or anti-PD(L)-1-containing regimen. Specifically, responses based on assessments documented in the medical oncologists' narratives were compared to a radiologist's assessments of archived images using RECIST v1.1 criteria. Each patient's best overall response was characterized as complete or partial (CR/PR), stable disease (SD), progressive disease (PD), or not evaluable (NE). RESULTS: Similar distributions of best overall response and substantial concordance (77%) between medical oncologist-reported and radiologist re-assessed responses were observed. There were no instances of CR/PR to PD or PD to CR/PR discordance. CONCLUSIONS: Results suggest that accurate treatment responses, similar to RECIST, may be derived using RWD. Further validation and improvement of real-world response assessment are needed to develop a scalable real-world approach for response assessment.

The Prognostic Value of Total Tumor Volume Response Compared With RECIST1.1 in Patients With Initially Unresectable Colorectal Liver Metastases Undergoing Systemic Treatment.

Objectives: Compare total tumor volume (TTV) response after systemic treatment to Response Evaluation Criteria in Solid Tumors (RECIST1.1) and assess the prognostic value of TTV change and RECIST1.1 for recurrence-free survival (RFS) in patients with colorectal liver-only metastases (CRLM). Background: RECIST1.1 provides unidimensional criteria to evaluate tumor response to systemic therapy. Those criteria are accepted worldwide but are limited by interobserver variability and ignore potentially valuable information about TTV. Methods: Patients with initially unresectable CRLM receiving systemic treatment from the randomized, controlled CAIRO5 trial (NCT02162563) were included. TTV response was assessed using software specifically developed together with SAS analytics. Baseline and follow-up computed tomography (CT) scans were used to calculate RECIST1.1 and TTV response to systemic therapy. Different thresholds (10%, 20%, 40%) were used to define response of TTV as no standard currently exists. RFS was assessed in a subgroup of patients with secondarily resectable CRLM after induction treatment. Results: A total of 420 CT scans comprising 7820 CRLM in 210 patients were evaluated. In 30% to 50% (depending on chosen TTV threshold) of patients, discordance was observed between RECIST1.1 and TTV change. A TTV decrease of >40% was observed in 47 (22%) patients who had stable disease according to RECIST1.1. In 118 patients with secondarily resectable CRLM, RFS was shorter for patients with less than 10% TTV decrease compared with patients with more than 10% TTV decrease (P = 0.015), while RECIST1.1 was not prognostic (P = 0.821). Conclusions: TTV response assessment shows prognostic potential in the evaluation of systemic therapy response in patients with CRLM.

Current concepts in radiologic assessment of pediatric brain tumors during treatment, part 1.

Pediatric brain tumors differ from those in adults by location, phenotype and genotype. In addition, they show dissimilar imaging characteristics before and after treatment. While adult brain tumor treatment effects are primarily assessed on MRI by measuring the contrast-enhancing components in addition to abnormalities on T2-weighted and fluid-attenuated inversion recovery images, these methods cannot be simply extrapolated to pediatric central nervous system tumors. A number of researchers have attempted to solve the problem of tumor assessment during treatment in pediatric neuro-oncology; specifically, the Response Assessment in Pediatric Neuro-Oncology (RAPNO) working group was recently established to deal with the distinct challenges in evaluating treatment-related changes on imaging, but no established criteria are available. In this article we review the current methods to evaluate brain tumor therapy and the numerous challenges that remain. In part 1, we examine the role of T2-weighted imaging and fluid-attenuated inversion recovery sequences, contrast enhancement, volumetrics and diffusion imaging techniques. We pay particular attention to several specific pediatric brain tumors, such as optic pathway glioma, diffuse midline glioma and medulloblastoma. Finally, we review the best means to assess leptomeningeal seeding.

Revised Modified Response Evaluation Criteria in Solid Tumors for Assessment of Response in Malignant Pleural Mesothelioma (Version 1.1).

INTRODUCTION: Malignant pleural mesothelioma poses unique difficulties in tumor measurement and response assessment; however, robust and reproducible assessment of response is critically important in the conduct, interpretation, and reporting of clinical trials. METHODS: The current de facto standard for the assessment of mesothelioma tumor response, "modified RECIST" (Response Evaluation Criteria in Solid Tumors), was published in 2004 as a research paper. Practical application of the modified RECIST guidelines has suffered from varied interpretations, resulting in inaccuracies and inconsistencies in tumor response assessment across and within mesothelioma clinical trials. The presented "modified RECIST 1.1 for mesothelioma" response assessment guidelines provide a much-needed update that incorporates recommendations from RECIST 1.1 and approaches to other practical issues, including: (1) definition of minimally measurable disease; (2) definition of measurable lesions; (3) acceptable measurement location; (4) non-pleural disease considerations; (5) characterization of non-measurable pleural disease; (6) assessment of pathological lymph nodes; (7) establishing progressive disease; and (8) accommodations for bilateral pleural disease. RESULTS: These modified RECIST 1.1 guidelines for mesothelioma tumor response collate and apply research published since the development of modified RECIST, align modified RECIST with RECIST 1.1, address those aspects of tumor measurement that were neglected or not well characterized in the modified RECIST paper, and clarify ambiguous or difficult measurement issues that have been highlighted through the subsequent decade of clinical trials research. CONCLUSION: Adoption of the modified RECIST 1.1 guidelines for mesothelioma is recommended to harmonize the application of tumor measurement and response assessment across the next generation of clinical trials in this disease.

Tumor response assessment: comparison between unstructured free text reporting in routine clinical workflow and computer-aided evaluation based on RECIST 1.1 criteria.

PURPOSE: Standardized computer-aided tumor response assessment is common in clinical trials. In contrast, unstructured free text reporting (UFTR) is common in daily routine. Therefore, this study aimed to discern and quantify differences between UFTR and computer-aided standardized tumor response evaluation based on RECIST 1.1 criteria (RECIST), serving as gold standard, in clinical workflow. METHODS: One-hundred consecutive patients with cancer eligible for RECIST 1.1 evaluation, who received five follow-up CTs of the trunk, were retrospectively included. All UFTRs were assigned to RECIST response categories [complete response, partial response (PR), stable disease (SD), progressive disease (PD)]. All CTs were re-evaluated using dedicated software (mint lesion™) applying RECIST 1.1. The accordance in tumor response ratings was analyzed using Cohen's kappa. RESULTS: At the first follow-up, 47 cases were rated differently with an SD underrepresentation and a PR and PD overrepresentation in UFTR. In the subsequent follow-ups, categorical differences were seen in 38, 44, 37, and 44%. Accordance between UFTR and RECIST was fair to moderate (Cohen's kappa: 0.356, 0.477, 0.390, 0.475, 0.376; always p < 0.001). Differences were mainly caused by the rating of even small tumor burden changes as PD or PR in UFTR or by comparison to the most recent prior CT scan in UFTR instead of comparison to nadir or baseline. CONCLUSIONS: Significant differences in tumor response ratings were detected comparing UFTR and computer-aided standardized evaluation based on RECIST 1.1. Thus, standardized reporting should be implemented in daily routine workflow.

Imaging in pleural mesothelioma: A review of the 13th International Conference of the International Mesothelioma Interest Group.

Imaging plays an important role in the detection, diagnosis, staging, response assessment, and surveillance of malignant pleural mesothelioma. The etiology, biology, and growth pattern of mesothelioma present unique challenges for each modality used to capture various aspects of this disease. Clinical implementation of imaging techniques and information derived from images continue to evolve based on active research in this field worldwide. This paper summarizes the imaging-based research presented orally at the 2016 International Conference of the International Mesothelioma Interest Group (iMig) in Birmingham, United Kingdom, held May 1-4, 2016. Presented topics included intraoperative near-infrared imaging of mesothelioma to aid the assessment of resection completeness, an evaluation of tumor enhancement improvement with increased time delay between contrast injection and image acquisition in standard clinical magnetic resonance imaging (MRI) scans, the potential of early contrast enhancement analysis to provide MRI with a role in mesothelioma detection, the differentiation of short- and long-term survivors based on MRI tumor volume and histogram analysis, the response-assessment potential of hemodynamic parameters derived from dynamic contrast-enhanced computed tomography (DCE-CT) scans, the correlation of CT-based tumor volume with post-surgical tumor specimen weight, and consideration of the need to update the mesothelioma tumor response assessment paradigm.

Quantitative ultrasound assessment of breast tumor response to chemotherapy using a multi-parameter approach.

PURPOSE: This study demonstrated the ability of quantitative ultrasound (QUS) parameters in providing an early prediction of tumor response to neoadjuvant chemotherapy (NAC) in patients with locally advanced breast cancer (LABC). METHODS: Using a 6-MHz array transducer, ultrasound radiofrequency (RF) data were collected from 58 LABC patients prior to NAC treatment and at weeks 1, 4, and 8 of their treatment, and prior to surgery. QUS parameters including midband fit (MBF), spectral slope (SS), spectral intercept (SI), spacing among scatterers (SAS), attenuation coefficient estimate (ACE), average scatterer diameter (ASD), and average acoustic concentration (AAC) were determined from the tumor region of interest. Ultrasound data were compared with the ultimate clinical and pathological response of the patient's tumor to treatment and patient recurrence-free survival. RESULTS: Multi-parameter discriminant analysis using the κ-nearest-neighbor classifier demonstrated that the best response classification could be achieved using the combination of MBF, SS, and SAS, with an accuracy of 60 ± 10% at week 1, 77 ± 8% at week 4 and 75 ± 6% at week 8. Furthermore, when the QUS measurements at each time (week) were combined with pre-treatment (week 0) QUS values, the classification accuracies improved (70 ± 9% at week 1, 80 ± 5% at week 4, and 81 ± 6% at week 8). Finally, the multi-parameter QUS model demonstrated a significant difference in survival rates of responding and non-responding patients at weeks 1 and 4 (p=0.035, and 0.027, respectively). CONCLUSION: This study demonstrated for the first time, using new parameters tested on relatively large patient cohort and leave-one-out classifier evaluation, that a hybrid QUS biomarker including MBF, SS, and SAS could, with relatively high sensitivity and specificity, detect the response of LABC tumors to NAC as early as after 4 weeks of therapy. The findings of this study also suggested that incorporating pre-treatment QUS parameters of a tumor improved the classification results. This work demonstrated the potential of QUS and machine learning methods for the early assessment of breast tumor response to NAC and providing personalized medicine with regards to the treatment planning of refractory patients.

A Response Assessment Platform for Development and Validation of Imaging Biomarkers in Oncology.

Quantitative imaging biomarkers are increasingly used in both oncology clinical trials and clinical practice aid evaluation of tumor response to novel therapies. To obtain these biomarkers, and to ensure smooth clinical adoption once they have been validated, it is critical to develop reliable computer-aided methods and a workflow-efficient imaging platform for integration in research and clinical settings. Here, we present a volumetric response assessment system developed based on an open-source image-viewing platform (WEASIS). Our response assessment system is designed using the Model-View-Controller concept, and it offers standard image-viewing and -manipulation functions, efficient tumor segmentation and quantification algorithms, and a reliable database containing tumor segmentation and measurement results. This prototype system is currently used in our research laboratory to foster the development and validation of new quantitative imaging biomarkers including the volumetric computed tomography technique as a more accurate and early assessment method of solid tumor response to targeted therapy and immunotherapy.

Imaging in pleural mesothelioma: A review of the 12th International Conference of the International Mesothelioma Interest Group.

Imaging of malignant pleural mesothelioma is essential to patient management, prognostication, and response assessment. From animal models to clinical trials, the gamut of research activities and clinical standards relies on imaging to provide information on lesion morphology and the growing number of physiologic characteristics amenable to capture through imaging techniques. The complex morphology, growth pattern, and biological mechanisms of mesothelioma, however, present challenges for image acquisition and interpretation. Nevertheless, novel approaches to image acquisition and subsequent image analysis have expanded the opportunities for (as well as the need for) imaging in this disease. This paper summarizes the imaging-based research presented orally at the 2014 International Conference of the International Mesothelioma Interest Group (iMig) in Cape Town, South Africa, October 2014. Presented topics include the imaging of hypoxia in a murine model through positron emission tomography (PET), the use of diffusion-weighted magnetic resonance imaging (MRI) to assess the histologic composition of biphasic mesothelioma and to assess early response to chemotherapy, the correlation of CT-based tumor volume with the volume of the post-surgical tumor specimen, the development of volumetric tumor response criteria, and pre-treatment tumor volume growth considerations for tumor response assessment.

Cancer immunotherapy and immune-related response assessment: The role of radiologists in the new arena of cancer treatment.

The recent advances in the clinical application of anti-cancer immunotherapeutic agents have opened a new arena for the treatment of advanced cancers. Cancer immunotherapy is associated with a variety of important radiographic features in the assessments of tumor response and immune-related adverse events, which calls for radiologists' awareness and in-depth knowledge on the topic. This article will provide the state-of-the art review and perspectives of cancer immunotherapy, including its molecular mechanisms, the strategies for immune-related response assessment on imaging and their pitfalls, and the emerging knowledge of radiologic manifestations of immune-related adverse events. The cutting edge clinical and radiologic investigations are presented to provide future directions.

Pitfalls in RECIST Data Extraction for Clinical Trials: Beyond the Basics.

Response Evaluation Criteria in Solid Tumors (RECIST) is a standardized methodology for determining therapeutic response to anticancer therapy using changes in lesion appearance on imaging studies. Many radiologists are now using RECIST in their routine clinical workflow, as part of consultative arrangements, or within dedicated imaging core laboratories. Although basic RECIST methodology is well described in published articles and online resources, inexperienced readers may encounter difficulties with certain nuances and subtleties of RECIST. This article illustrates a set of pitfalls in RECIST assessment considered to be "beyond the basics." These pitfalls were uncovered during a quality improvement review of a recently established cancer imaging core laboratory staffed by radiologists with limited prior RECIST experience. Pitfalls are presented in four categories: (1) baseline selection of lesions, (2) reassessment of target lesions, (3) reassessment of nontarget lesions, and (4) identification of new lesions. Educational and operational strategies for addressing these pitfalls are suggested. Attention to these pitfalls and strategies may improve the overall quality of RECIST assessments performed by radiologists.

RECIST 1.1 compared with RECIST 1.0 in patients with advanced renal cell carcinoma receiving vascular endothelial growth factor-targeted therapy.

OBJECTIVE. Response Evaluation Criteria in Solid Tumors (RECIST) is the most widely accepted method to objectively assess response to therapy in renal cell carcinoma (RCC) treated with vascular endothelial growth factor (VEGF)-targeted therapy. Both RECIST 1.0 and 1.1 have been used to assess response to VEGF-targeted therapies; however, systematic comparisons are lacking. MATERIALS AND METHODS. Sixty-two patients with metastatic RCC treated with VEGF-targeted therapies were retrospectively studied. Tumor measurements and response assessment according to RECIST 1.1 and RECIST 1.0 were compared, including the number of target lesions, baseline measurements, response at each follow-up, best overall response, and time to progression (TTP). Morphologic changes and new enhancement were also assessed over the course of treatment, and TTP was evaluated using morphologic change criteria in combination with RECIST 1.1. RESULTS. The number of target lesions according to RECIST 1.1 was significantly fewer than by RECIST 1.0 (median, 2 vs 4; p < 0.0001). At first imaging follow-up, the percentage change of the sums of the diameter measurements by RECIST 1.1 and RECIST 1.0 were highly concordant (R = 0.857; mean shrinkage, 12.1% by RECIST 1.1 vs 10.8% by RECIST 1.0). Best response assessment was highly concordant between the two criteria (weighted κ = 0.819). There was no evidence of a difference in TTP by the two criteria, with a median TTP of 8.9 months (95% CI for the median, 5.5-13.9) by RECIST 1.1 and 8.9 months (95% CI for the median, 5.8-13.6) by RECIST 1.0. The median TTP by RECIST 1.1 alone was 8.9 months compared with 5.6 months for RECIST 1.1 and morphologic changes combined. CONCLUSION. RECIST 1.1 and RECIST 1.0 response assessments were overall highly concordant in patients with RCC treated with VEGF-targeted therapy, with fewer target lesions according to RECIST 1.1 but no difference in TTP.

Functional MR imaging of the abdomen.

In this article, functional magnetic resonance (MR) imaging techniques in the abdomen are discussed. Diffusion-weighted imaging (DWI) increases the confidence in detecting and characterizing focal hepatic lesions. The potential uses of DWI in kidneys, adrenal glands, bowel, and pancreas are outlined. Studies have shown potential use of quantitative dynamic contrast-enhanced MR imaging parameters, such as K(trans), in predicting outcomes in cancer therapy. MR elastography is considered to be a useful tool in staging liver fibrosis. A major issue with all functional MR imaging techniques is the lack of standardization of the protocol.

Imaging in pleural mesothelioma: a review of the 11th International Conference of the International Mesothelioma Interest Group.

Imaging of malignant pleural mesothelioma (MPM) is essential to the diagnosis, assessment, and monitoring of this disease. The complex morphology and growth pattern of MPM, however, create unique challenges for image acquisition and interpretation. These challenges have captured the attention of investigators around the world, some of whom presented their work at the 2012 International Conference of the International Mesothelioma Interest Group (iMig 2012) in Boston, Massachusetts, USA, September 2012. The measurement of tumor thickness on computed tomography (CT) scans is the current standard of care in the assessment of MPM tumor response to therapy; in this context, variability among observers in the measurement task and in the tumor response classification categories derived from such measurements was reported. Alternate CT-based tumor response criteria, specifically direct measurement of tumor volume change and change in lung volume as a surrogate for tumor response, were presented. Dynamic contrast-enhanced CT has a role in other settings, but investigation into its potential use for imaging mesothelioma tumor perfusion only recently has been initiated. Magnetic resonance imaging (MRI) and positron-emission tomography (PET) are important imaging modalities in MPM and complement the information provided by CT. The pointillism sign in diffusion-weighted MRI was reported as a potential parameter for the classification of pleural lesions as benign or malignant, and PET parameters that measure tumor activity and functional tumor volume were presented as indicators of patient prognosis. Also reported was the use of PET/CT in the management of patients who undergo high-dose radiation therapy. Imaging for MPM impacts everything from initial patient diagnosis to the outcomes of clinical trials; iMig 2012 captured this broad range of imaging applications as investigators exploit technology and implement multidisciplinary approaches toward the benefit of MPM patients.