Tumor Size Is Not Everything: Advancing Radiomics as a Precision Medicine Biomarker in Oncology Drug Development and Clinical Care. A Report of a Multidisciplinary Workshop Coordinated by the RECIST Working Group

Radiomics, the science of extracting quantifiable data from routine medical images, is a powerful tool that has many potential applications in oncology. The Response Evaluation Criteria in Solid Tumors Working Group (RWG) held a workshop in May 2022, which brought together various stakeholders to discuss the potential role of radiomics in oncology drug development and clinical trials, particularly with respect to response assessment. This article summarizes the results of that workshop, reviewing radiomics for the practicing oncologist and highlighting the work that needs to be done to move forward the incorporation of radiomics into clinical trials.

Intraoperative molecular imaging: 3rd biennial clinical trials update

Significance

This third biennial intraoperative molecular imaging (IMI) conference shows how optical contrast agents have been applied to develop clinically significant endpoints that improve precision cancer surgery.

Aim

National and international experts on IMI presented ongoing clinical trials in cancer surgery and preclinical work. Previously known dyes (with broader applications), new dyes, novel nonfluorescence-based imaging techniques, pediatric dyes, and normal tissue dyes were discussed.

Approach

Principal investigators presenting at the Perelman School of Medicine Abramson Cancer Center's third clinical trials update on IMI were selected to discuss their clinical trials and endpoints.

Results

Dyes that are FDA-approved or currently under clinical investigation in phase 1, 2, and 3 trials were discussed. Sections on how to move benchwork research to the bedside were also included. There was also a dedicated section for pediatric dyes and nonfluorescence-based dyes that have been newly developed.

Conclusions

IMI is a valuable adjunct in precision cancer surgery and has broad applications in multiple subspecialties. It has been reliably used to alter the surgical course of patients and in clinical decision making. There remain gaps in the utilization of IMI in certain subspecialties and potential for developing newer and improved dyes and imaging techniques.

Advancing Research on Medical Image Perception by Strengthening Multidisciplinary Collaboration

Medical image interpretation is central to detecting, diagnosing, and staging cancer and many other disorders. At a time when medical imaging is being transformed by digital technologies and artificial intelligence, understanding the basic perceptual and cognitive processes underlying medical image interpretation is vital for increasing diagnosticians’ accuracy and performance, improving patient outcomes, and reducing diagnostician burn-out. Medical image perception remains substantially understudied. In September of 2019, the National Cancer Institute convened a multidisciplinary panel of radiologists and pathologists together with researchers working in medical image perception and adjacent fields of cognition and perception for the “Cognition and Medical Image Perception Think Tank.” The Think Tank’s key objectives were: to identify critical unsolved problems related to visual perception in pathology and radiology from the perspective of diagnosticians; to discuss how these clinically relevant questions could be addressed through cognitive and perception research; to identify barriers and solutions for transdisciplinary collaborations; to define ways to elevate the profile of cognition and perception research within the medical image community; to determine the greatest needs to advance medical image perception; and to outline future goals and strategies to evaluate progress. The Think Tank emphasized diagnosticians’ perspectives as the crucial starting point for medical image perception research, with diagnosticians describing their interpretation process and identifying perceptual and cognitive problems that arise. This paper reports the deliberations of the Think Tank participants to address these objectives and highlight opportunities to expand research on medical image perception.

Consensus recommendations for a standardized brain tumor imaging protocol for clinical trials in brain metastases

A recent meeting was held on March 22, 2019, among the FDA, clinical scientists, pharmaceutical and biotech companies, clinical trials cooperative groups, and patient advocacy groups to discuss challenges and potential solutions for increasing development of therapeutics for central nervous system metastases. A key issue identified at this meeting was the need for consistent tumor measurement for reliable tumor response assessment, including the first step of standardized image acquisition with an MRI protocol that could be implemented in multicenter studies aimed at testing new therapeutics. This document builds upon previous consensus recommendations for a standardized brain tumor imaging protocol (BTIP) in high-grade gliomas and defines a protocol for brain metastases (BTIP-BM) that addresses unique challenges associated with assessment of CNS metastases. The "minimum standard" recommended pulse sequences include: (i) parameter matched pre- and post-contrast inversion recovery (IR)-prepared, isotropic 3D T1-weighted gradient echo (IR-GRE); (ii) axial 2D T2-weighted turbo spin echo acquired after injection of gadolinium-based contrast agent and before post-contrast 3D T1-weighted images; (iii) axial 2D or 3D T2-weighted fluid attenuated inversion recovery; (iv) axial 2D, 3-directional diffusion-weighted images; and (v) post-contrast 2D T1-weighted spin echo images for increased lesion conspicuity. Recommended sequence parameters are provided for both 1.5T and 3T MR systems. An "ideal" protocol is also provided, which replaces IR-GRE with 3D TSE T1-weighted imaging pre- and post-gadolinium, and is best performed at 3T, for which dynamic susceptibility contrast perfusion is included. Recommended perfusion parameters are given.

Molecular Features of Cancers Exhibiting Exceptional Responses to Treatment

A small fraction of cancer patients with advanced disease survive significantly longer than patients with clinically comparable tumors. Molecular mechanisms for exceptional responses to therapy have been identified by genomic analysis of tumor biopsies from individual patients. Here, we analyzed tumor biopsies from an unbiased cohort of 111 exceptional responder patients using multiple platforms to profile genetic and epigenetic aberrations as well as the tumor microenvironment. Integrative analysis uncovered plausible mechanisms for the therapeutic response in nearly a quarter of the patients. The mechanisms were assigned to four broad categories-DNA damage response, intracellular signaling, immune engagement, and genetic alterations characteristic of favorable prognosis-with many tumors falling into multiple categories. These analyses revealed synthetic lethal relationships that may be exploited therapeutically and rare genetic lesions that favor therapeutic success, while also providing a wealth of testable hypotheses regarding oncogenic mechanisms that may influence the response to cancer therapy.

The Exceptional Responders Initiative: Feasibility of a National Cancer Institute Pilot Study

BACKGROUND

Tumor molecular profiling from patients experiencing exceptional responses to systemic therapy may provide insights into cancer biology and improve treatment tailoring. This pilot study evaluates the feasibility of identifying exceptional responders retrospectively, obtaining pre-exceptional response treatment tumor tissues, and analyzing them with state-of-the-art molecular analysis tools to identify potential molecular explanations for responses.

METHODS

Exceptional response was defined as partial (PR) or complete (CR) response to a systemic treatment with population PR or CR rate less than 10% or an unusually long response (eg, duration >3 times published median). Cases proposed by patients' clinicians were reviewed by clinical and translational experts. Tumor and normal tissue (if possible) were profiled with whole exome sequencing and, if possible, targeted deep sequencing, RNA sequencing, methylation arrays, and immunohistochemistry. Potential germline mutations were tracked for relevance to disease.

RESULTS

Cases reflected a variety of tumors and standard and investigational treatments. Of 520 cases, 476 (91.5%) were accepted for further review, and 222 of 476 (46.6%) proposed cases met requirements as exceptional responders. Clinical data were obtained from 168 of 222 cases (75.7%). Tumor was provided from 130 of 168 cases (77.4%). Of 117 of the 130 (90.0%) cases with sufficient nucleic acids, 109 (93.2%) were successfully analyzed; 6 patients had potentially actionable germline mutations.

CONCLUSION

Exceptional responses occur with standard and investigational treatment. Retrospective identification of exceptional responders, accessioning, and sequencing of pretreatment archived tissue is feasible. Data from molecular analyses of tumors, particularly when combining results from patients who received similar treatments, may elucidate molecular bases for exceptional responses.

Consensus recommendations for a dynamic susceptibility contrast MRI protocol for use in high-grade gliomas

Despite the widespread clinical use of dynamic susceptibility contrast (DSC) MRI, DSC-MRI methodology has not been standardized, hindering its utilization for response assessment in multicenter trials. Recently, the DSC-MRI Standardization Subcommittee of the Jumpstarting Brain Tumor Drug Development Coalition issued an updated consensus DSC-MRI protocol compatible with the standardized brain tumor imaging protocol (BTIP) for high-grade gliomas that is increasingly used in the clinical setting and is the default MRI protocol for the National Clinical Trials Network. After reviewing the basis for controversy over DSC-MRI protocols, this paper provides evidence-based best practices for clinical DSC-MRI as determined by the Committee, including pulse sequence (gradient echo vs spin echo), BTIP-compliant contrast agent dosing (preload and bolus), flip angle (FA), echo time (TE), and post-processing leakage correction. In summary, full-dose preload, full-dose bolus dosing using intermediate (60°) FA and field strength-dependent TE (40-50 ms at 1.5 T, 20-35 ms at 3 T) provides overall best accuracy and precision for cerebral blood volume estimates. When single-dose contrast agent usage is desired, no-preload, full-dose bolus dosing using low FA (30°) and field strength-dependent TE provides excellent performance, with reduced contrast agent usage and elimination of potential systematic errors introduced by variations in preload dose and incubation time.

RECIST 1.1 for Response Evaluation Apply Not Only to Chemotherapy-Treated Patients But Also to Targeted Cancer Agents: A Pooled Database Analysis

PURPOSE

The mode of action of targeted cancer agents (TCAs) differs from classic chemotherapy, which leads to concerns about the role of RECIST in evaluating tumor response in trials with TCAs. We investigated the performance of RECIST using a pooled database from 50 clinical trials with at least one TCA.

METHODS

We examined the impact of the number of target lesions (TLs) on within-patient variability of tumor response. The prognostic effect of TL response (at 12 weeks or on study on the basis of a maximum five TLs) on survival was studied through landmark and time-dependent Cox models adjusted for baseline tumor load, occurrence of new lesions, or unequivocal progression of nontarget disease.

RESULTS

Data were obtained from 23,259 patients with cancer (36% lung, 28% colorectal, 11% breast, and 25% other); 15,620 received TCAs, predominantly transduction or angiogenesis inhibitors, as a single agent (37%), combined with other TCAs (7%), or as chemotherapy (56%); 28% received chemotherapy only; and 5% received best supportive care or placebo. A total of 17,222 patients contributed to the analyses. Within-patient variability decreased with increasing number of TLs, similarly for TCAs (with/without chemotherapy) and chemotherapy only. Mixed responses occurred proportionally in all treatment classes. Landmark analyses showed an ordinal relationship between percentage change from baseline to 12 weeks and overall survival, and demonstrated a clear distinction between tumor shrinkage and progressive disease according to RECIST. Time-dependent analysis showed no marked improvement in the ability to predict survival on the basis of TL tumor growth compared with nontarget progression or new lesion occurrence, regardless of treatment. Similar results were seen for major tumor types and different classes of TCAs.

CONCLUSION

This work reinforces that RECIST version 1.1 perform well for response assessment of TCAs.

Validation of RECIST 1.1 for use with cytotoxic agents and targeted cancer agents (TCA): Results of a RECIST Working Group analysis of a 50 clinical trials pooled individual patient database

2534

Background: The Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 were derived from an international collaborative effort supported by data from clinical trials (16 studies, 9147 patients) on cytotoxic chemotherapy (CT), providing a standard tool for response assessment. RECIST’s role has been questioned for TCA. Using a pooled individual patient database (IPD) from clinical trials performed by industry and cooperative groups, we assessed whether modifications to RECIST are required to evaluate antitumor activity of TCA. Methods: Data were collected from phase 2 and 3 clinical trials testing TCA in solid tumors. To study the occurrence of mixed responses, the variability of response of lesions within patients was studied. Furthermore, response was correlated with survival through landmark analyses and time dependent Cox models. Results: Clinical data were obtained from 23,259 patients, mainly with lung (36%), colorectal (28%) or breast cancer (11%). 15,620 patients (67%) received a TCA, mainly transduction or angiogenesis inhibitors, either as single agent (37%) or combined with other TCAs (7%) or CT (56%); 28% received CT only and 5% best supportive care or placebo. Within-patient variability reduced as the number of lesions used for response assessment increased, and did so similarly for TCAs (+/- CT) and CT. Mixed responses seemed to occur similarly across these treatment categories as well. Landmark analyses showed improving overall survival by % tumor shrinkage and a clear distinction between the effect of tumor shrinkage and progressive disease (PD) according to RECIST 1.1. This was confirmed by time dependent analysis. In addition target lesion growth showed no marked improvement in overall survival prediction over and above the other components of RECIST 1.1 PD (new lesions, non-target PD), regardless of treatment (TCA, CT or both) received. Similar results were seen focusing on major tumor types and classes of TCA. Conclusions: Using a large IPD dataset we demonstrated that RECIST 1.1 performs equally well for response assessment of TCA as for CT. No modifications are required.

Regulatory Aspects of Optical Methods and Exogenous Targets for Cancer Detection

Considerable advances in cancer-specific optical imaging have improved the precision of tumor resection. In comparison to traditional imaging modalities, this technology is unique in its ability to provide real-time feedback to the operating surgeon. Given the significant clinical implications of optical imaging, there is an urgent need to standardize surgical navigation tools and contrast agents to facilitate swift regulatory approval. Because fluorescence-enhanced surgery requires a combination of both device and drug, each may be developed in conjunction, or separately, which are important considerations in the approval process. This report is the result of a one-day meeting held on May 4, 2016 with officials from the National Cancer Institute, the FDA, members of the American Society of Image-Guided Surgery, and members of the World Molecular Imaging Society, which discussed consensus methods for FDA-directed human testing and approval of investigational optical imaging devices as well as contrast agents for surgical applications. The goal of this workshop was to discuss FDA approval requirements and the expectations for approval of these novel drugs and devices, packaged separately or in combination, within the context of optical surgical navigation. In addition, the workshop acted to provide clarity to the research community on data collection and trial design. Reported here are the specific discussion items and recommendations from this critical and timely meeting. Cancer Res; 77(9); 2197-206. ©2017 AACR.

Performance Observations of Scanner Qualification of NCI-Designated Cancer Centers: Results From the Centers of Quantitative Imaging Excellence (CQIE) Program

We present an overview of the Centers for Quantitative Imaging Excellence (CQIE) program, which was initiated in 2010 to establish a resource of clinical trial-ready sites within the National Cancer Institute (NCI)-designated Cancer Centers (NCI-CCs) network. The intent was to enable imaging centers in the NCI-CCs network capable of conducting treatment trials with advanced quantitative imaging end points. We describe the motivations for establishing the CQIE, the process used to initiate the network, the methods of site qualification for positron emission tomography, computed tomography, and magnetic resonance imaging, and the results of the evaluations over the subsequent 3 years.

RECIST 1.1-Update and clarification: From the RECIST committee

The Response Evaluation Criteria in Solid Tumours (RECIST) were developed and published in 2000, based on the original World Health Organisation guidelines first published in 1981. In 2009, revisions were made (RECIST 1.1) incorporating major changes, including a reduction in the number of lesions to be assessed, a new measurement method to classify lymph nodes as pathologic or normal, the clarification of the requirement to confirm a complete response or partial response and new methodologies for more appropriate measurement of disease progression. The purpose of this paper was to summarise the questions posed and the clarifications provided as an update to the 2009 publication.

Consensus recommendations for a standardized Brain Tumor Imaging Protocol in clinical trials

A recent joint meeting was held on January 30, 2014, with the US Food and Drug Administration (FDA), National Cancer Institute (NCI), clinical scientists, imaging experts, pharmaceutical and biotech companies, clinical trials cooperative groups, and patient advocate groups to discuss imaging endpoints for clinical trials in glioblastoma. This workshop developed a set of priorities and action items including the creation of a standardized MRI protocol for multicenter studies. The current document outlines consensus recommendations for a standardized Brain Tumor Imaging Protocol (BTIP), along with the scientific and practical justifications for these recommendations, resulting from a series of discussions between various experts involved in aspects of neuro-oncology neuroimaging for clinical trials. The minimum recommended sequences include: (i) parameter-matched precontrast and postcontrast inversion recovery-prepared, isotropic 3D T1-weighted gradient-recalled echo; (ii) axial 2D T2-weighted turbo spin-echo acquired after contrast injection and before postcontrast 3D T1-weighted images to control timing of images after contrast administration; (iii) precontrast, axial 2D T2-weighted fluid-attenuated inversion recovery; and (iv) precontrast, axial 2D, 3-directional diffusion-weighted images. Recommended ranges of sequence parameters are provided for both 1.5 T and 3 T MR systems.

The components of progression as explanatory variables for overall survival in the Response Evaluation Criteria in Solid Tumours 1.1 database

PURPOSE

Progressive disease (PD) per Response Evaluation Criteria in Solid Tumours (RECIST) 1.1 is defined as growth of measurable target lesions, presence of new lesions or unequivocal progression of non-target disease. In this manuscript we explored whether a more refined categorisation of tumour response and/or these components of progression, varying over time, can improve prediction of overall survival (OS) in the RECIST database.

METHODS

Data were randomly selected from 13 randomised clinical trials (3758 patients with breast, lung or colorectal cancer). A maximum of five target lesions contributed to the sum of longest diameters. At each measurement time we determined: best target response as best % improvement from baseline; tumour growth of target lesions as worst % change and worst rate of increase (mm/week) from nadir; presence of new lesions and occurrence of non-target PD. OS was analysed by tumour type using Cox regression, adjusting for baseline sum and including these parameters as time-dependent covariates.

RESULTS

36% of patients had new lesions, 28% non-target PD and 49% experienced target lesion growth (median strongest growth 1.5mm/week). Regardless of tumour type, presence of new lesions (hazard ratio (HR) ranging 1.5-2.3) and non-target PD (HR 1.5-2.0) were strongly associated with worse OS. The explanatory value of tumour growth for OS was low compared to the other components.

CONCLUSION

Modelling target lesion tumour growth did not show a marked improvement in OS prediction over and above the other components. These analyses enable a better understanding of the role of each component in PD evaluation. Work is ongoing to incorporate this information into an updated version of RECIST with enhanced prediction of subsequent survival.

The role of response evaluation criteria in solid tumour in anticancer treatment evaluation: results of a survey in the oncology community

PURPOSE

With the increasing use of novel targeted agents and the development of high imaging techniques, response evaluation criteria in solid tumour (RECIST) 1.1 developed primarily for cytotoxic agents and anatomic imaging, has demonstrated limitations. A survey was conducted of RECIST users to identify concerns and their suggestions for future RECIST criteria.

METHODS

140 key partners of the RECIST collaboration were asked to complete a questionnaire. The 49 questions concerned (a) satisfaction and concerns with RECIST 1.1; (b) use of modified RECIST criteria and (c) suggestions for the next RECIST Version.

RESULTS

Sixty-five replies were received. 52.3% responders were satisfied with RECIST 1.1, while 10.8% indicated dissatisfaction. Areas of potential weakness included: (a) lack of incorporation of potential early indicators of response such as functional imaging, (b) lack of validation in rarer tumour types and (c) lack of validation for novel (targeted) agents. Suggestions were multiple, with highest numbers on two points: developing sub-criteria for certain disease types and including advanced imaging techniques for the evaluation.

CONCLUSIONS

Constructive suggestions were received for optimising the next version. Ongoing data collection will make it possible to investigate the possible utilisation of fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging in tumour assessment, to verify whether RECIST is/can still be applicable in novel targeted therapy and to consider the need for criteria for specific disease types.

The components of progression as explanatory variables for overall survival in the RECIST database

10602

Background: Progressive disease (PD) according to RECIST 1.1 (Eisenhauer et al, 2009) is defined as one or more of (1) PD of measurable target lesions, (2) the presence of a new lesion (NL) or (3) the unequivocal PD of non-target disease (NT-PD). We explored the impact of these components, varying over time, on predicting overall survival (OS) in the RECIST database residing at EORTC (Bogaerts et al, 2009). Methods: Data was selected from 12 randomized clinical trials (3530 patients with breast, lung or colorectal cancer). A maximum of 5 target lesions was used to determine the sum of diameters. The following were calculated or assigned at each measurement time t: best response (BR) was best % improvement from baseline up to t (0% if no improvement - 100% if complete response (CR)); tumor growth (TG) was the weekly rate of increase from nadir to t (0 if no increase; irrespective of prior shrinkage), presence of NL (yes/no), and occurrence of NT-PD (yes/no); categories were not mutually exclusive. OS was analyzed by tumor type using a Cox regression model, adjusting for baseline sum, and including BR, TG, presence of NL and NT-PD as time dependent covariates. Results: Thirty-six percent of patients had NL, 26% had NT-PD, 11% achieved CR and 14% did not have shrinkage of target lesions, while 46% experienced TG (median strongest growth per patient of 0.5 mm/week). Regardless of tumor type, the presence of NL (Hazard Ratio (HR) ranging 1.4-2.5), NT-PD (HR 1.2-2.5) and TG (per 1mm/week increase; HR 1.1-1.4) were associated with worse OS, while achieving CR was associated with a longer OS (HR 0.2-0.8). Further analyses exploring the functional shape of the association between BR and TG, and OS are ongoing. This includes putting TG in contrast with the more usual % cutoff defining target PD. Conclusions: All three components of PD according to RECIST are independently strongly associated with OS. Quantification such as this will enable a better understanding of the role of each component (e.g. clinical aspect of NT-PD assessment) in PD evaluation. Work is ongoing to incorporate this information into an updated RECIST with enhanced prediction of subsequent survival.

OT2-05-03: ACRIN 6688 Phase II Study of Fluorine-18 3′-Deoxy-3′ Fluorothymidine (FLT) in Invasive Breast Cancer

Background

Neoadjuvant chemotherapy (NAC) prior to surgery provides enhanced options for locoregional management and has become an integral component of primary breast cancer management. Initial tumor response in patients receiving NAC is generally determined at therapy completion. This evaluation is determined by either the presence/absence of palpable tumor as a clinical response and/or presence/absence of invasive tumor cells in the breast and nodes as a pathological response. The ability to evaluate the effectiveness of neoadjuvant therapy early during treatment would be of significant importance. FDG PET imaging has been shown to be predictive of subsequent tumor response, but the tendency of FDG to accumulate in inflammatory tissues can complicate image interpretation. MRI changes have also been touted as predictors of response. Preliminary data suggest that early FLT PET is better able to predict response to therapy, as FLT uptake has been shown to correlate with cellular proliferation, and does not significantly accumulate in inflammatory tissue (Kenny et al, Eur J Nucl Med Mol Imaging 2007:1339–1347). The analysis of these data may provide a better understanding of early treatment response and improve the clinical management of breast cancer in the future.

Trial design and eligibility: In this phase II multi-institutional study, breast cancer patients with locally advanced disease with a tumor size ≥2cm (measured on imaging or estimated by physical exam) are eligible. Participants will receive standard of care NAC at their respective institutions. Participants will have 3 FLT imaging sessions to evaluate therapy response: at baseline, early-treatment (5-10 days after initiating treatment), and post-treatment prior to surgery.

Specific aims: The primary objective is to correlate the percentage change in the standardized uptake value between baseline and early therapy FLT in the primary tumor with pathologic response. Correlatively, FLT PET parameters will be compared with proliferative indices from the initial biopsy and residual tumor surgical samples using Ki-67 staining, mitotic index, and residual cancer burden. Potential safety issues and the physiologic effects associated with FLT administration will also be evaluated.

Statistical methods: To evaluate the relationship between an uptake parameter and pathologic complete response, a ROC curve will be estimated and the area under the curve, along with its 95% confidence interval, will be determined.

Accrual: Currently, 45/67 patients have accrued to the study.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT2-05-03.

Improving cancer outcomes through international collaboration in academic cancer treatment trials

PURPOSE

The need for international collaboration in cancer clinical trials has grown stronger as we have made progress both in cancer treatment and screening. We sought to identify those efforts already underway which facilitate such collaboration, as well as barriers to greater collaboration.

METHODS

We reviewed the collective experiences of many cooperative groups, governmental organizations, nongovernmental organizations, and academic investigators in their work to build international collaboration in cancer clinical trials across multiple disease sites.

RESULTS

More than a decade of work has led to effective global harmonization for many of the elements critical to cancer clinical trials. Many barriers remain, but effective international collaboration in academic cancer treatment trials should become the norm, rather than the exception.

CONCLUSION

Our ability to strengthen international collaborations will result in maximization of our resources and patients, permitting us to change practice by establishing more effective therapeutic strategies. Regulatory, logistical, and financial hurdles, however, often hamper the conduct of joint trials. We must work together as a global community to overcome these barriers so that we may continue to improve cancer treatment for patients around the world.

The uterine compression suture - a valuable approach to control major haemorrhage at lower segment caesarean section

The aim of this article is to review the efficacy of a modified uterine compression suture in controlling major haemorrhage at lower segment caesarean section. This is a descriptive study of patients who had major obstetric haemorrhage where a compression suture was used to control bleeding at the two obstetrics unit in Cardiff between January 1998 and December 2003 (n = 11).

Lessons learned from independent central review

Independent central review (ICR) is advocated by regulatory authorities as a means of independent verification of clinical trial end-points dependent on medical imaging, when the data from the trials may be submitted for licensing applications [Food and Drug Administration. United States food and drug administration guidance for industry: clinical trial endpoints for the approval of cancer drugs and biologics. Rockville, MD: US Department of Health and Human Services; 2007; Committee for Medicinal Products for Human Use. European Medicines Agency Committee for Medicinal Products for Human Use (CHMP) guideline on the evaluation of anticancer medicinal products in man. London, UK: European Medicines Agency; 2006; United States Food and Drug Administration Center for Drug Evaluation and Research. Approval package for application number NDA 21-492 (oxaliplatin). Rockville, MD: US Department of Health and Human Services; 2002; United States Food and Drug Administration Center for Drug Evaluation and Research. Approval package for application number NDA 21-923 (sorafenib tosylate). Rockville, MD: US Department of Health and Human Services; 2005; United States Food and Drug Administration Center for Drug Evaluation and Research. Approval package for application number NDA 22-065 (ixabepilone). Rockville, MD: US Department of Health and Human Services; 2007; United States Food and Drug Administration Center for Drug Evaluation and Research. Approval package for application number NDA 22-059 (lapatinib ditosylate). Rockville, MD: US Department of Health and Human Services; 2007; United States Food and Drug Administration Center for Biologics Evaluation and Research. Approval package for BLA numbers 97-0260 and BLA Number 97-0244 (rituximab). Rockville, MD: US Department of Health and Human Services; 1997; United States Food and Drug Administration. FDA clinical review of BLA 98-0369 (Herceptin((R)) trastuzumab (rhuMAb HER2)). FDA Center for Biologics Evaluation and Research; 1998; United States Food and Drug Administration. FDA Briefing Document Oncology Drugs Advisory Committee meeting NDA 21801 (satraplatin). Rockville, MD: US Department of Health and Human Services; 2007; Thomas ES, Gomez HL, Li RK, et al. Ixabepilone plus capecitabine for metastatic breast cancer progressing after anthracycline and taxane treatment. JCO 2007(November):5210-7]. In addition, clinical trial sponsors have used ICR in Phase I-II studies to assist in critical pathway decisions including in-licensing of compounds [Cannistra SA, Matulonis UA, Penson RT, et al. Phase II study of bevacizumab in patients with platinum-resistant ovarian cancer or peritoneal serous cancer. JCO 2007(November):5180-6; Perez EA, Lerzo G, Pivot X, et al. Efficacy and safety of ixabepilone (BMS-247550) in a phase II study of patients with advanced breast cancer resistant to an anthracycline, a taxane, and capecitabine. JCO 2007(August):3407-14; Vermorken JB, Trigo J, Hitt R, et al. Open-label, uncontrolled, multicenter phase II study to evaluate the efficacy and toxicity of cetuximab as a single agent in patients with recurrent and/or metastatic squamous cell carcinoma of the head and neck who failed to respond to platinum-based therapy. JCO 2007(June):2171-7; Ghassan KA, Schwartz L, Ricci S, et al. Phase II study of sorafenib in patients with advanced hepatocellular carcinoma. JCO 2006(September):4293-300; Boué F, Gabarre J, GaBarre J, et al. Phase II trial of CHOP plus rituximab in patients with HIV-associated non-Hodgkin's lymphoma. JCO 2006(September):4123-8; Chen HX, Mooney M, Boron M, et al. Phase II multicenter trial of bevacizumab plus fluorouracil and leucovorin in patients with advanced refractory colorectal cancer: an NCI Treatment Referral Center Trial TRC-0301. JCO 2006(July):3354-60; Ratain MJ, Eisen T, Stadler WM, et al. Phase II placebo-controlled randomized discontinuation trial of sorafenib in patients with metastatic renal cell carcinoma. JCO 2006(June):2502-12; Jaffer AA, Lee FC, Singh DA, et al. Multicenter phase II trial of S-1 plus cisplatin in patients with untreated advanced gastric or gastroesophageal junction adenocarcinoma. JCO 2006(February):663-7; Bouché O, Raoul JL, Bonnetain F, et al. Randomized multicenter phase II trial of a biweekly regimen of fluorouracil and leucovorin (LV5FU2), LV5FU2 plus cisplatin, or LV5FU2 plus irinotecan in patients with previously untreated metastatic gastric cancer: a Fédération Francophone de Cancérologie Digestive Group Study-FFCD 9803. JCO 2004(November):4319-28]. This article will focus on the definition and purpose of ICR and the issues and lessons learned in the ICR setting primarily in Phase II and III oncology studies. This will include a discussion on discordance between local and central interpretations, consequences of ICR, reader discordance during the ICR, operational considerations and the need for specific imaging requirements as part of the study protocol.

New response evaluation criteria in solid tumours: revised RECIST guideline (version 1.1)

BACKGROUND

Assessment of the change in tumour burden is an important feature of the clinical evaluation of cancer therapeutics: both tumour shrinkage (objective response) and disease progression are useful endpoints in clinical trials. Since RECIST was published in 2000, many investigators, cooperative groups, industry and government authorities have adopted these criteria in the assessment of treatment outcomes. However, a number of questions and issues have arisen which have led to the development of a revised RECIST guideline (version 1.1). Evidence for changes, summarised in separate papers in this special issue, has come from assessment of a large data warehouse (>6500 patients), simulation studies and literature reviews. HIGHLIGHTS OF REVISED RECIST 1.1: Major changes include: Number of lesions to be assessed: based on evidence from numerous trial databases merged into a data warehouse for analysis purposes, the number of lesions required to assess tumour burden for response determination has been reduced from a maximum of 10 to a maximum of five total (and from five to two per organ, maximum). Assessment of pathological lymph nodes is now incorporated: nodes with a short axis of 15 mm are considered measurable and assessable as target lesions. The short axis measurement should be included in the sum of lesions in calculation of tumour response. Nodes that shrink to <10mm short axis are considered normal. Confirmation of response is required for trials with response primary endpoint but is no longer required in randomised studies since the control arm serves as appropriate means of interpretation of data. Disease progression is clarified in several aspects: in addition to the previous definition of progression in target disease of 20% increase in sum, a 5mm absolute increase is now required as well to guard against over calling PD when the total sum is very small. Furthermore, there is guidance offered on what constitutes 'unequivocal progression' of non-measurable/non-target disease, a source of confusion in the original RECIST guideline. Finally, a section on detection of new lesions, including the interpretation of FDG-PET scan assessment is included. Imaging guidance: the revised RECIST includes a new imaging appendix with updated recommendations on the optimal anatomical assessment of lesions.

FUTURE WORK

A key question considered by the RECIST Working Group in developing RECIST 1.1 was whether it was appropriate to move from anatomic unidimensional assessment of tumour burden to either volumetric anatomical assessment or to functional assessment with PET or MRI. It was concluded that, at present, there is not sufficient standardisation or evidence to abandon anatomical assessment of tumour burden. The only exception to this is in the use of FDG-PET imaging as an adjunct to determination of progression. As is detailed in the final paper in this special issue, the use of these promising newer approaches requires appropriate clinical validation studies.

Evaluation of lymph nodes with RECIST 1.1

Lymph nodes are common sites of metastatic disease in many solid tumours. Unlike most metastases, lymph nodes are normal anatomic structures and as such, normal lymph nodes will have a measurable size. Additionally, the imaging literature recommends that lymph nodes be measured in the short axis, since the short axis measurement is a more reproducible measurement and predictive of malignancy. Therefore, the RECIST committee recommends that lymph nodes be measured in their short axis and proposes measurement values and rules for categorising lymph nodes as normal or pathologic; either target or non-target lesions. Data for the RECIST warehouse are presented to demonstrate the potential change in response assessment following these rules. These standardised lymph node guidelines are designed to be easy to implement, focus target lesion measurements on lesions that are likely to be metastatic and prevent false progressions due to minimal change in size.

Maxillary sinus hypoplasia, embryology, and radiology

Maxillary sinus hypoplasia has been observed in up to 10% of radiological studies of the face or head. Although this may be a coincidental finding, it has been associated with chronic sinusitis and facial pain. Associated abnormalities of the lateral nasal wall, orbit, and ostiomeatal complex are common. The importance of this condition is, first, in the differential diagnosis of an "opaque" maxillary sinus and, second, as a potential hazard to the orbit of such patients, should they undergo functional endoscopic sinus surgery.

Progress and promise of FDG-PET imaging for cancer patient management and oncologic drug development

2-[(18)F]Fluoro-2-deoxyglucose positron emission tomography (FDG-PET) assesses a fundamental property of neoplasia, the Warburg effect. This molecular imaging technique offers a complementary approach to anatomic imaging that is more sensitive and specific in certain cancers. FDG-PET has been widely applied in oncology primarily as a staging and restaging tool that can guide patient care. However, because it accurately detects recurrent or residual disease, FDG-PET also has significant potential for assessing therapy response. In this regard, it can improve patient management by identifying responders early, before tumor size is reduced; nonresponders could discontinue futile therapy. Moreover, a reduction in the FDG-PET signal within days or weeks of initiating therapy (e.g., in lymphoma, non-small cell lung, and esophageal cancer) significantly correlates with prolonged survival and other clinical end points now used in drug approvals. These findings suggest that FDG-PET could facilitate drug development as an early surrogate of clinical benefit. This article reviews the scientific basis of FDG-PET and its development and application as a valuable oncology imaging tool. Its potential to facilitate drug development in seven oncologic settings (lung, lymphoma, breast, prostate, sarcoma, colorectal, and ovary) is addressed. Recommendations include initial validation against approved therapies, retrospective analyses to define the magnitude of change indicative of response, further prospective validation as a surrogate of clinical benefit, and application as a phase II/III trial end point to accelerate evaluation and approval of novel regimens and therapies.

Noninvasive in vivo fluorescence measurement of airway-surface liquid depth, salt concentration, and pH

The concentration of salt in the thin layer of fluid at the surface of large airways, the airway-surface liquid (ASL), is believed to be of central importance in airway physiology and in the pathophysiology of cystic fibrosis. Invasive sampling methods have yielded a wide range of ASL [NaCl] from 40 to 180 mM. We have developed novel fluorescent probes and microscopy methods to measure ASL thickness, salt concentration, and pH quantitatively in cell-culture models and in the trachea in vivo. By rapid z-scanning confocal microscopy, ASL thickness was 21 +/- 4 microm in well-differentiated cultures of bovine tracheal epithelial cells grown on porous supports at an air-liquid interface. By ratio imaging fluorescence microscopy using sodium, chloride, and pH-sensitive fluorescent indicators, ASL [Na+] was 97 +/- 5 mM, [Cl-] was 118 +/- 3 mM, and pH was 6.94 +/- 0.03. In anesthetized mice in which a transparent window was created in the trachea, ASL thickness was 45 +/- 5 microm, [Na+] was 115 +/- 4 mM, [Cl-] was 140 +/- 5 mM, and pH was 6.95 +/- 0.05. Similar ASL tonicity and pH were found in cystic fibrosis (CFTR-null) mice. In freshly harvested human bronchi, ASL thickness was 55 +/- 5 microm, [Na+] was 103 +/- 3 mM, [Cl-] was 92 +/- 4 mM, and pH was 6.78 +/- 0.2. These results establish by a noninvasive approach the key properties of the ASL and provide direct evidence that the ASL is approximately isotonic and not saltier in cystic fibrosis.

Pathology of Madras type of motor neuron disease (MMND)--a histological and immunohistochemical study

A neuropathological report of Madras type of motor neuron disease (MMND) is presented and the differences from other forms of MND are discussed. An 18-year-old girl presented with nerve deafness and slowly progressive bulbo-spinal muscular atrophy, characteristic of MMND. Post-mortem examination of the spinal cord showed a severe loss of anterior horn cells, prominent dilatation of vessels, diffuse, but sparse sprinkling of microglial cells and lymphocytes, and demyelination and sclerosis of the ventrolateral columns. Neuronal depletion and marked gliosis was noted in the cochlear nucleus on both sides, while other bulbar motor nuclei were also involved. The cochlear nerve showed demyelination and axonal loss. Trigeminal and vestibular ganglia revealed features of ganglionitis. The possibility of an inflammatory aetiology for MMND needs to be considered.

Monitoring glutamate and ascorbate in the extracellular space of brain tissue with electrochemical microsensors

This paper describes electrochemical microsensors for the in vivo measurement of glutamate and ascorbate in the extracellular space of brain tissue. To prepare glutamate microsensors, carbon fiber microelectrodes (10 microns in diameter and 300-400 microns long) were modified with a cross-linked redox polymer film containing enzymes. The microsensors were coated with a thin Nafion film before use. The glutamate microsensors were both selective and sensitive toward glutamate, with detection limits in the low micromolar range. Physiologically relevant concentrations of several electroactive compounds found in brain tissue produced no response at the glutamate microsensors and also did not affect their glutamate response, the only exception being glutamine, for which a small response was observed in the absence, but not in the presence, of glutamate. The ascorbate microsensors were used in conjunction with cyclic voltammetry. They were sensitive and selective toward ascorbate, but did exhibit a small sensitivity toward the dopamine metabolite, dihydroxyphenylacetic acid. The in vivo measurements performed establish the ability of the glutamate microsensors to monitor the component of the basal extracellular glutamate level that is derived from the neuronal activity of brain tissue.

The mysterious case of persistent malocclusion

We report an unusual case of malocclusion following a history of apparently blunt trauma. No maxillary or mandibular fractures were identified. The malocclusion persisted for several days. Finally computed tomography was performed, which revealed a foreign body in the infratemporal fossa. A 4-cm pencil was extracted from the patient's right temporomandibular joint.

Histopathological & immunohistochemical evaluation of ageing changes in normal human brain

As age related changes in the brain have not been systematically studied in the Indian population though there is an impression that they are less frequent, we studied 52 brains collected at autopsy from individuals above the age of 60 yr. The incidence of senile plaques (SPs) and neurofibrillary tangles (NFTs) together were found to increase with age from 21 per cent in the seventh decade to 33 per cent in the eighth decade and 54 per cent in the ninth decade, the increasing incidence of NFTs being statistically significant. The SPs were found both in the hippocampus and frontal cortex while NFTs were seen only in the hippocampus in non-demented aged individuals. In contrast, in the three cases of Alzheimer's disease (symbol: see text) AD studied, the NFTs and SPs were found in high density in both hippocampus and frontal cortex. By immunohistochemistry, various morphological forms of SPs were found to have beta amyloid protein consistently, while ubiquitin and phosphorylated neurofilament occurred variably. More number of SPs could be labelled by amyloid immunostaining than by conventional silver stains. The NFTs contained ubiquitin and phosphorylated neurofilament protein as the antigenic components, both in AD and normal ageing. The incidence of age related changes and their antigenic character in the limited sample studied from south India appears to be comparable to findings from the West. Multicentric studies on a large sample derived from different ethnic groups in India are needed to further evaluate these features.

Renal dysfunction detected by beta-2 microglobulinuria in sick neonates

OBJECTIVE

To assess renal involvement in sick neonates referred to Neonatal Intensive Care Unit (NICU) using standard renal parameters and urinary beta 2 microglobulin (B2M) excretion.

DESIGN

Descriptive study.

SETTING

Level II NICU and Nephrology Division of Pediatric Tertiary hospital.

SUBJECTS

Forty six term sick neonates transferred for neonatal care and forty healthy term neonates who served as normal controls for urinary B2M excretion.

METHODS

Standard tests including estimation of BUN, serum creatinine, blood pH, serum bicarbonate, serum and urinary electrolytes, urine output, and urinalysis. Urinary B2M levels were estimated from urine collected on day 1 (D1) and day 3 (D3) in all and 18 neonates were tested on day 7 (D7) by radio-immunoassay method.

RESULTS

Statistically significant elevation of mean values of urinary B2M were noted when sick neonates were compared with normal controls irrespective of primary disease, indicating tubular dysfunction (41/46 = 90%), whilst only 7 of these (17%) had abnormalities indicating renal involvement when judged by standard tests. Very high levels of urinary B2M were noted with birth asphyxia (n = 9), sepsis (n = 8) and renal disease (n = 7). Transient elevation of urinary B2M was noted in meconium aspiration syndrome (n = 4). Ten surgical cases with non renal congenital malformations showed high urinary B2M and 12/18 tested on D7 had persistently high urinary B2M due to multiple factors.

CONCLUSIONS

Elevated urinary B2M in 90% sick neonates with apparently normal renal parameters in majority (34/41) indicates subclinical proximal tubular dysfunction especially in neonates with asphyxia, sepsis and congenital malformations. Persistent elevation of urinary B2M appear to be a sensitive diagnostic indicator for defining a group of neonates with subtle renal tubular dysfunction, the clinical relevance of which on long term basis is a subject for future study.

Histological, histochemical and autoradiographic evidence of in vitro neurotoxic effects of the novel antitumor agent, 9-methoxy-N2-methylellipticinium acetate

9-Methoxy-N2-methylellipticinium acetate (MMEA) exhibits selective cytotoxicity towards glial-derived human brain tumor cell lines comprising the U.S. National Cancer Institute preclinical drug screen. Neurotoxic potential of MMEA has been demonstrated in an in vitro model employing sagittal slices of rat brain. Histochemical staining of rat brain slices for lactate dehydrogenase (LDH) activity revealed decreased staining intensity following incubation with increasing concentrations of MMEA (0.1-100 microM). Cytological evaluation of paraffin sections stained with Cresyl Fast Violet revealed neuronal damage delineated by cytoplasmic vacuolation, and distention and fraying of the plasma membrane. No glial or vascular pathology could be discerned. Autoradiography, following exposure to 14C-MMEA, revealed distinct labelling of the large neurons of the brain stem, neurons in the thalamus and pyramidal neurons of the hippocampus, indicating neuronal uptake of the drug.

Petrous carotid canal stenosis in malignant osteopetrosis: CT documentation with MR angiographic correlation

PURPOSE

To study the association between petrous carotid canal (PCC) and internal carotid artery (ICA) stenoses in patients with malignant osteopetrosis.

MATERIALS AND METHODS

Mean and minimum PCC diameters obtained from cranial computed tomographic (CT) scans in 20 patients were compared with similar measurements in 52 control subjects. ICA caliber, evaluated with magnetic resonance (MR) arteriography, was correlated with age and PCC dimensions.

RESULTS

There was a statistically significant difference between patient and control PCC diameters. There was a strong positive correlation between age and PCC diameter in the control subjects, but only a weakly positive correlation in the patients. One or both ICAs were stenotic on all patient MR arteriograms. MR angiographic stenosis grade correlated positively with age but not with PCC diameters.

CONCLUSION

PCC and ICA stenoses occur frequently in patients with malignant osteopetrosis. Bony overgrowth or a "persistent fetal state" may produce the PPC stenoses. The findings do not support progressive PCC narrowing in these patients.

Diagnostic imaging of fungal sinusitis: eleven new cases and literature review

Fungal sinusitis should always be considered in the differential diagnosis of chronic or recurring sinusitis resistant to adequate medical treatment. A high index of suspicion is necessary for the diagnosis, and the clinical examination is rarely conclusive. The definitive diagnosis depends on the pathologist in most cases. We reviewed retrospectively the imaging findings, specifically computed tomography (CT) and magnetic resonance (MR), in a series of fungal sinusitis patients. Non-enhanced CT scan is more sensitive than conventional X-ray in detecting the classical focal areas of hyper-attenuation and calcification seen in soft-tissue masses of fungal sinusitis. MR findings of hypo-intense signals on T1-weighted sequences which progress to signal-void area on T2-weighted sequences, are characteristic features of fungal sinusitis; however, it is reserved for cases where intracranial invasion is suspected or CT findings are inconclusive.

CT imaging in the diagnosis and treatment of sinus disease: a partnership between the radiologist and the otolaryngologist

We consider that the nasal cavity and the paranasal sinuses cannot be declared completely normal without a normal CT scan. While CT scans are clearly useful in the evaluation of patients with recurrent sinusitis, it is important to emphasize that they should not be employed exclusively for diagnosis. Nasal endoscopy and clinical evaluation still form the basis for the diagnosis of chronic and recurring sinusitis. The CT technique described should be used only to supplement the clinical data obtained during history-taking and the rhinoscopic/endoscopic examination and is essential before functional endoscopic sinus surgery. The complexity of the diagnostic process is simplified to patient benefit when the radiologist and the otolaryngologist form a functional interactive partnership.

CT scanning for functional endoscopic sinus surgery: analysis of 200 cases with reporting scheme

An analysis of the computed tomograms of the paranasal sinuses from 200 patients with sinonasal complaints is presented. The results of our study are similar to those of other reported series despite a different patient selection. We have developed a simple systematic reporting scheme which includes all of the relevant abnormalities, and which allows a much more detailed picture of the disease pattern to be generated for both clinical use and for analytical studies.

A family exhibiting carotid body tumours

The authors describe the surgery carried out for 11 carotid body tumours (CBTs) that were found in three generations of a Greek family. Eight patients with CBTs were operated upon at St. Joseph's Health Centre, Toronto, within 1 year. Three patients had bilateral CBTs, which were removed in two stages. Only one of the CBTs occurred in a female. Seven CBTs were excised by meticulous subadventitial dissection. In the eighth, a previous attempt at removal in another hospital had proved unsuccessful, and excision of the tumour required ligation of the external carotid artery and partial excision of the carotid bulb. The authors conclude that most CBTs can be excised directly without ligation, shunts or bypasses. In eight operations carried out on five patients, the only complication was a transient neuropraxia of the hypoglossal nerve that resolved within 2 weeks.