Updated Response Assessment in Neuro-Oncology (RANO) for Gliomas

PURPOSE OF REVIEW

The response assessment in Neuro-Oncology (RANO) criteria and its versions were developed by expert opinion consensus to standardize response evaluation in glioma clinical trials. New patient-based data informed the development of updated response assessment criteria, RANO 2.0.

RECENT FINDINGS

In a recent study of patients with glioblastoma, the post-radiation brain MRI was a superior baseline MRI compared to the pretreatment MRI, and confirmation scans were only beneficial within the first 12 weeks of completion of radiation in newly diagnosed disease. Nonenhancing disease evaluation did not improve the correlation between progression-free survival and overall survival in newly diagnosed and recurrent settings. RANO 2.0 recommends a single common response criteria for high- and low-grade gliomas, regardless of the treatment modality being evaluated. It also provides guidance on the evaluation of nonenhancing tumors and tumors with both enhancing and nonenhancing components.

Evaluating automated longitudinal tumor measurements for glioblastoma response assessment

Automated tumor segmentation tools for glioblastoma show promising performance. To apply these tools for automated response assessment, longitudinal segmentation, and tumor measurement, consistency is critical. This study aimed to determine whether BraTumIA and HD-GLIO are suited for this task. We evaluated two segmentation tools with respect to automated response assessment on the single-center retrospective LUMIERE dataset with 80 patients and a total of 502 post-operative time points. Volumetry and automated bi-dimensional measurements were compared with expert measurements following the Response Assessment in Neuro-Oncology (RANO) guidelines. The longitudinal trend agreement between the expert and methods was evaluated, and the RANO progression thresholds were tested against the expert-derived time-to-progression (TTP). The TTP and overall survival (OS) correlation was used to check the progression thresholds. We evaluated the automated detection and influence of non-measurable lesions. The tumor volume trend agreement calculated between segmentation volumes and the expert bi-dimensional measurements was high (HD-GLIO: 81.1%, BraTumIA: 79.7%). BraTumIA achieved the closest match to the expert TTP using the recommended RANO progression threshold. HD-GLIO-derived tumor volumes reached the highest correlation between TTP and OS (0.55). Both tools failed at an accurate lesion count across time. Manual false-positive removal and restricting to a maximum number of measurable lesions had no beneficial effect. Expert supervision and manual corrections are still necessary when applying the tested automated segmentation tools for automated response assessment. The longitudinal consistency of current segmentation tools needs further improvement. Validation of volumetric and bi-dimensional progression thresholds with multi-center studies is required to move toward volumetry-based response assessment.

Radiological response of leptomeningeal metastases according to revised RANO criteria is associated with overall survival in breast cancer patients

Assessment of treatment response in patients (pts) with leptomeningeal metastases (LM) represents a significant challenge and standardized criteria are needed. In 2017, the RANO LM Working Group proposed a standardized scorecard to evaluate MRI findings (further simplified in 2019). Here, we aim to validate the prognostic impact of response to treatment assessed using this tool in a multicentric cohort of breast cancer (BC) pts. Pts with BC-related LM diagnosed at two institutions between 2005 and 2018 were identified. Baseline and follow-up MRI scans were centrally reviewed and response assessment was evaluated using 2019 revised RANO LM criteria. A total of 142 pts with BC-related LM and available baseline brain MRI imaging were identified; 60 of them had at least one follow-up MRI. In this subgroup, median overall survival (OS) was 15.2 months (95%CI 9.5-21.0). At first re-evaluation, radiological response by RANO criteria was: complete response (CR) in 2 pts (3%), partial response (PR) in 12 (20%), stable disease (SD) in 33 (55%) and progression of disease (PD) in 13 (22%). Median OS was 31.1 months (HR 0.10, 95%CI 0.01-0.78) in pts with CR, 16.1 months (HR 0.41, 95%CI 0.17-0.97) in pts with PR, 17.9 months (HR 0.45, 95%CI 0.22-0.91) in pts with SD and 9.5 months in pts with PD (P = .029). A second blinded evaluation showed a moderate interobserver agreement (K = 0.562). Radiological response according to 2019 RANO criteria is significantly associated with OS in pts with BC-related LM, thus supporting the use of this evaluation tool both in trials and clinical practice.

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).

Evolution and implementation of radiographic response criteria in neuro-oncology

Radiographic response assessment in neuro-oncology is critical in clinical practice and trials. Conventional criteria, such as the MacDonald and response assessment in neuro-oncology (RANO) criteria, rely on bidimensional (2D) measurements of a single tumor cross-section. Although RANO criteria are established for response assessment in clinical trials, there is a critical need to address the complexity of brain tumor treatment response with multiple new approaches being proposed. These include volumetric analysis of tumor compartments, structured MRI reporting systems like the Brain Tumor Reporting and Data System, and standardized approaches to advanced imaging techniques to distinguish tumor response from treatment effects. In this review, we discuss the strengths and limitations of different neuro-oncology response criteria and summarize current research findings on the role of novel response methods in neuro-oncology clinical trials and practice.

NS-HGlio: A generalizable and repeatable HGG segmentation and volumetric measurement AI algorithm for the longitudinal MRI assessment to inform RANO in trials and clinics

Background

Accurate and repeatable measurement of high-grade glioma (HGG) enhancing (Enh.) and T2/FLAIR hyperintensity/edema (Ed.) is required for monitoring treatment response. 3D measurements can be used to inform the modified Response Assessment in Neuro-oncology criteria. We aim to develop an HGG volumetric measurement and visualization AI algorithm that is generalizable and repeatable.

Methods

A single 3D-Convoluted Neural Network, NS-HGlio, to analyze HGG on MRIs using 5-fold cross validation was developed using retrospective (557 MRIs), multicentre (38 sites) and multivendor (32 scanners) dataset divided into training (70%), validation (20%), and testing (10%). Six neuroradiologists created the ground truth (GT). Additional Internal validation (IV, three institutions) using 70 MRIs, and External validation (EV, single institution) using 40 MRIs through measuring the Dice Similarity Coefficient (DSC) of Enh., Ed. ,and Enh. + Ed. (WholeLesion/WL) tumor tissue and repeatability testing on 14 subjects from the TCIA MGH-QIN-GBM dataset using volume correlations between timepoints were performed.

Results

IV Preoperative median DSC Enh. 0.89 (SD 0.11), Ed. 0.88 (0.28), WL 0.88 (0.11). EV Preoperative median DSC Enh. 0.82 (0.09), Ed. 0.83 (0.11), WL 0.86 (0.06). IV Postoperative median DSC Enh. 0.77 (SD 0.20), Ed 0.78. (SD 0.09), WL 0.78 (SD 0.11). EV Postoperative median DSC Enh. 0.75 (0.21), Ed 0.74 (0.12), WL 0.79 (0.07). Repeatability testing; Intraclass Correlation Coefficient of 0.95 Enh. and 0.92 Ed.

Conclusion

NS-HGlio is accurate, repeatable, and generalizable. The output can be used for visualization, documentation, treatment response monitoring, radiation planning, intra-operative targeting, and estimation of Residual Tumor Volume among others.

Radiographic Response Assessment Strategies for Early-Phase Brain Trials in Complex Tumor Types and Drug Combinations: from Digital "Flipbooks" to Control Systems Theory

There is an urgent need for drug development in brain tumors. While current radiographic response assessment provides instructions for identifying large treatment effects in simple high- and low-grade gliomas, there remains a void of strategies to evaluate complex or difficult to measure tumors or tumors of mixed grade with enhancing and non-enhancing components. Furthermore, most patients exhibit some period of alteration in tumor growth after starting a new therapy, but simple response categorization (e.g., stable disease, progressive disease) fails to provide any meaningful insight into the depth or degree of potential "subclinical" therapeutic response. We propose a creative solution to these issues based on a tiered strategy meant to increase confidence in identifying therapeutic effects even in the most challenging tumor types, while also providing a framework for complex evaluation of combination and sequential treatment schemes. Specifically, we demonstrate the utility of digital "flipbooks" to quickly identify subtle changes in complex tumors. We show how a modified Levin criteria can be used to quantify the degree of visual changes, while establishing estimates of the association between tumor volume and visual inspection. Lastly, we introduce the concept of quantifying therapeutic response using control systems theory. We propose measuring changes in volume (proportional), the area under the volume vs. time curve (integral) and changes in growth rates (derivative) to utilize a "PID" controller model of single or combination therapeutic activity.

Postoperative progression of brain metastasis is associated with seizures

Seizures in patients with brain metastases have an impact on morbidity and quality of life. The influence of tumor growth on the risk of seizures in these patients is not well defined. In this cohort study, we evaluated adult patients from the University Hospital of Zurich following resection of brain metastases from solid tumors, with or without preoperative seizures, at 3, 6, 9, and 12 months postoperatively. Brain magnetic resonance imaging was assessed for tumor progression using the Response Assessment in Neuro-Oncology criteria. The quarterly risk of unprovoked seizures was modeled with mixed effects logistic regression. We analyzed 444 time frames in 220 patients. Progression of brain metastases was independently associated with seizures during the respective quarterly follow-up period (odds ratio = 3.9, 95% confidence interval = 1.3-11.3, p = .014). Complete resection of brain metastases was associated with a lower risk of seizures (odds ratio = .2, 95% confidence interval = .04-.7, p = .015). Postoperative progression of brain metastases quadrupled the risk of seizures; therefore, vigorous follow-up may be useful to identify tumor progression and gauge the risk of seizures. The identification of patients at high seizure risk may have implications for treatment decisions and influence aspects of daily life. Breakthrough seizures may indicate brain metastases progression.

[18F]-fluoromisonidazole (FMISO) PET/MRI hypoxic fraction distinguishes neuroinflammatory pseudoprogression from recurrent glioblastoma in patients treated with pembrolizumab

Response assessment after immunotherapy remains a major challenge in glioblastoma due to an expected increased incidence of pseudoprogression. Gadolinium-enhanced magnetic resonance imaging (MRI) is the standard for monitoring therapeutic response, however, is markedly limited in characterizing pseudoprogression. Given that hypoxia is an important defining feature of glioblastoma regrowth, we hypothesized that [18F]-fluoromisonidazole (FMISO) positron emission tomography (PET) could provide an additional physiological measure for the diagnosis of immunotherapeutic failure. Six patients with newly diagnosed glioblastoma who had previously received maximal safe resection followed by Stupp protocol CRT concurrent with pembrolizumab immunotherapy were recruited for FMISO PET and Gd-MRI at the time of presumed progression. The hypoxic fraction was defined as the ratio of hypoxic volume to T1-weighted gadolinium-enhancing volume. Four patients diagnosed with pseudoprogression demonstrated a mean hypoxic fraction of 9.8 ± 10%. Two with recurrent tumor demonstrated a mean hypoxic fraction of 131 ± 66%. Our results, supported by histopathology, suggest that the noninvasive assessment of hypoxic fraction by FMISO PET/MRI is clinically feasible and may serve as a biologically specific metric of therapeutic failure.

Factors associated with progression and mortality among patients undergoing stereotactic radiosurgery for intracranial metastasis: results from a national real-world registry

OBJECTIVE

Stereotactic radiosurgery (SRS) has been increasingly employed in recent years to treat intracranial metastatic lesions. However, there is still a need for optimization of treatment paradigms to provide better local control and prevent progressive intracranial disease. In the current study, the authors utilized a national collaborative registry to investigate the outcomes of patients with intracranial metastatic disease who underwent SRS and to determine factors associated with lesion treatment response, overall progression, and mortality.

METHODS

The NeuroPoint Alliance SRS registry was queried for all patients with intracranial metastatic lesions undergoing single- or multifraction SRS at participating institutions between 2016 and 2020. The main outcomes of interest included lesion response (lesion-level analysis), progression using Response Assessment for Neuro-Oncology criteria, and mortality (patient-level analysis). Kaplan-Meier analysis was used to report time to progression and overall survival, and multivariable Cox proportional hazards analysis was used to investigate factors associated with lesion response, progression, and mortality.

RESULTS

A total of 501 patients (1447 intracranial metastatic lesions) who underwent SRS and had available follow-up were included in the current analyses. The most common primary tumor was lung cancer (49.5%, n = 248), followed by breast (15.4%, n = 77) and melanoma (12.2%, n = 61). Most patients had a single lesion (44.9%, n = 225), 29.3% (n = 147) had 2 or 3 lesions, and 25.7% (n = 129) had > 3 lesions. The mean sum of baseline measurements of the lesions according to Response Evaluation Criteria in Solid Tumors (RECIST) was 35.54 mm (SD 25.94). At follow-up, 671 lesions (46.4%) had a complete response, 631 (43.6%) had a partial response (≥ 30% decrease in longest diameter) or were stable (< 30% decrease but < 20% increase), and 145 (10%) showed progression (> 20% increase in longest diameter). On multivariable Cox proportional hazards analysis, melanoma-associated lesions (HR 0.48, 95% CI 0.34-0.67; p < 0.001) and larger lesion size (HR 0.94, 95% CI 0.93-0.96; p < 0.001) showed lower odds of lesion regression, while a higher biologically effective dose was associated with higher odds (HR 1.001, 95% CI 1.0001-1.00023; p < 0.001). A total of 237 patients (47.3%) had overall progression (local failure or intracranial progressive disease), with a median time to progression of 10.03 months after the index SRS. Factors found to be associated with increased hazards of progression included male sex (HR 1.48, 95% CI 1.108-1.99; p = 0.008), while administration of immunotherapy (before or after SRS) was found to be associated with lower hazards of overall progression (HR 0.62, 95% CI 0.460-0.85; p = 0.003). A total of 121 patients (23.95%) died during the follow-up period, with a median survival of 19.4 months from the time of initial SRS. A higher recursive partitioning analysis score (HR 21.3485, 95% CI 1.53202-3.6285; p < 0.001) was found to be associated with higher hazards of mortality, while single-fraction treatment compared with hypofractionated treatment (HR 0.082, 95% CI 0.011-0.61; p = 0.015), administration of immunotherapy (HR 0.385, 95% CI 0.233-0.64; p < 0.001), and presence of single compared with > 3 lesions (HR 0.427, 95% CI 0.187-0.98; p = 0.044) were found to be associated with lower risk of mortality.

CONCLUSIONS

The comparability of results between this study and those of previously published clinical trials affirms the value of multicenter databases with real-world data collected without predetermined research purpose.

Glioblastoma radiotherapy using Intensity modulated Radiotherapy (IMRT) or proton Radiotherapy-GRIPS Trial (Glioblastoma Radiotherapy via IMRT or Proton BeamS): a study protocol for a multicenter, prospective, open-label, randomized, two-arm, phase III study

Background

Radiation therapy is an integral part of the multimodal primary therapy of glioblastomas. As the overall prognosis in this tumor entity remains unfavorable, current research is focused on additional drug therapies, which are often accompanied by increases in toxicity. By using proton beams instead of photon beams, it is possible to protect large parts of the brain which are not affected by the tumor more effectively. An initial retrospective matched-pair analysis showed that this theoretical physical benefit is also clinically associated with a reduction in toxicity during therapy and in the first few months thereafter.

Methods/design

The GRIPS trial is a multicenter, prospective, open-label, randomized, two-arm, phase III study using either intensity modulated photon radiation techniques (standard arm) or proton beam radiotherapy (experimental arm). Additionally, patients are stratified according to "fractionation scheme" (normofractionated/hypofractionated), "subventricular zone involvement" (yes/no) and concurrent chemotherapy (yes/no) and the planned case number is 326 patients.

Radiation therapy is performed with a dose of 30 × 2 Gy(RBE) or 33 × 1.8 Gy(RBE), or for patients treated according to the hypofractionation protocol with 15 × 2.67 Gy(RBE). A possible administration of additional chemotherapy (concurrent or adjuvant) or tumor treating fields is applied in dosage and frequency according to the therapy standard outside of this study. The primary endpoint is the cumulative rate of toxicity CTC grade 2 and higher in the first 4 months. Secondary endpoints include overall survival, progression-free survival, quality of life, and neurocognition.

Discussion

Aim of the GRIPS study is to prospectively assess whether the theoretical physical advantage of proton beam radiotherapy will translate into a clinical reduction of toxicity during and in the first months after therapy.

Trial registration

ClinicalTrials (NCT): NCT04752280.

Malignant Meningitis Associated with Hydrocephalus

Malignant meningitis (MM) is the diffuse involvement of the leptomeninges by infiltrating cancer cells, most frequently from lung and breast cancers. This review is aimed to discuss the current advances in the diagnosis and management of MM, along with management of MM-associated hydrocephalus. We reviewed the literature using PubMed and Google Scholar search engines, focusing on various recent randomized controlled trials and clinical trials on MM. Given the hallmark multifocal involvement, the clinical symptoms and signs are also random and asymmetric. There are three important pillars for establishing a diagnosis of MM: clinical examination, neuroimaging, and CSF cytological findings. Several factors should be considered in decision-making, including performance status, neurological findings (clinical, MRI, and CSF flow dynamic), and evaluation of the primary tumor (nature and systemic dissemination). Response Assessment in Neuro-Oncology (RANO) working group recommended the objective assessment of disease for evaluating the progression and response to therapy. Pillars of current management are mainly focal irradiation and intrathecal or systemic chemotherapy. Symptomatic hydrocephalus is managed with a ventriculoperitoneal shunt, lumboperitoneal shunt, or endoscopic third ventriculostomy as palliative procedures, providing significant improvement in performance scores in the limited survival time of patients with MM. Studies using novel therapeutic approaches, such as new biological or cytotoxic compounds, are ongoing. Despite the use of all the combinations, the overall prognosis remains grim; therefore, decision-making for treatment should predominantly be based on attaining an optimal quality of life.

Phase II trial of proton therapy versus photon IMRT for GBM: secondary analysis comparison of progression-free survival between RANO versus clinical assessment

Background

This secondary image analysis of a randomized trial of proton radiotherapy (PT) versus photon intensity-modulated radiotherapy (IMRT) compares tumor progression based on clinical radiological assessment versus Response Assessment in Neuro-Oncology (RANO).

Methods

Eligible patients were enrolled in the randomized trial and had MR imaging at baseline and follow-up beyond 12 weeks from completion of radiotherapy. “Clinical progression” was based on a clinical radiology report of progression and/or change in treatment for progression.

Results

Of 90 enrolled patients, 66 were evaluable. Median clinical progression-free survival (PFS) was 10.8 (range: 9.4–14.7) months; 10.8 months IMRT versus 11.2 months PT (P = .14). Median RANO-PFS was 8.2 (range: 6.9, 12): 8.9 months IMRT versus 6.6 months PT (P = .24). RANO-PFS was significantly shorter than clinical PFS overall (P = .001) and for both the IMRT (P = .01) and PT (P = .04) groups. There were 31 (46.3%) discrepant cases of which 17 had RANO progression more than a month prior to clinical progression, and 14 had progression by RANO but not clinical criteria.

Conclusions

Based on this secondary analysis of a trial of PT versus IMRT for glioblastoma, while no difference in PFS was noted relative to treatment technique, RANO criteria identified progression more often and earlier than clinical assessment. This highlights the disconnect between measures of tumor response in clinical trials versus clinical practice. With growing efforts to utilize real-world data and personalized treatment with timely adaptation, there is a growing need to improve the consistency of determining tumor progression within clinical trials and clinical practice.

Imaging Surveillance of Gliomas: Role of Basic and Advanced Imaging Techniques

It is essential to be aware of widely accepted criteria for grading of treatment response in both high-grade and low-grade gliomas. These criteria primarily take into account responses of measurable and nonmeasurable lesions on T2-weighted, fluid-attenuated inversion recovery, and postcontrast images to determine a final category of response for the patient. The additional role that other advanced imaging techniques, such as diffusion and perfusion imaging, can play in the surveillance of these tumors is discussed in this article.

Radiographic read paradigms and the roles of the central imaging laboratory in neuro-oncology clinical trials

Determination of therapeutic benefit in intracranial tumors is intimately dependent on serial assessment of radiographic images. The Response Assessment in Neuro-Oncology (RANO) criteria were established in 2010 to provide an updated framework to better characterize tumor response to contemporary treatments. Since this initial update a number of RANO criteria have provided some basic principles for the interpretation of changes on MR images; however, the details of how to operationalize RANO and other criteria for use in clinical trials are ambiguous and not standardized. In this review article designed for the neuro-oncologist or treating clinician, we outline essential steps for performing radiographic assessments by highlighting primary features of the Imaging Charter (referred to as the Charter for the remainder of this article), a document that describes the clinical trial imaging methodology and methods to ensure operationalization of the Charter into the workings of a clinical trial. Lastly, we provide recommendations for specific changes to optimize this methodology for neuro-oncology, including image registration, requirement of growing tumor for eligibility in trials of recurrent tumor, standardized image acquisition guidelines, and hybrid reader paradigms that allow for both unbiased measurements and more comprehensive interpretation.

Combined iron oxide nanoparticle ferumoxytol and gadolinium contrast enhanced MRI define glioblastoma pseudoprogression

BACKGROUND

Noninvasively differentiating therapy-induced pseudoprogression from recurrent disease in patients with glioblastoma is prospectively difficult due to the current lack of a biologically specific imaging metric. Ferumoxytol iron oxide nanoparticle MRI contrast characterizes innate immunity mediated neuroinflammation; therefore, we hypothesized that combined ferumoxytol and gadolinium enhanced MRI could serve as a biomarker of glioblastoma pseudoprogression.

METHODS

In this institutional review board-approved, retrospective study, we analyzed ferumoxytol and gadolinium contrast enhanced T1-weighted 3T MRI in 45 patients with glioblastoma over multiple clinical timepoints. Isocitrate dehydrogenase 1 (IDH-1) mutational status was characterized by exome sequencing. Sum of products diameter measurements were calculated according to Response Assessment in Neuro-Oncology criteria from both gadolinium and ferumoxytol enhanced sequences. Enhancement mismatch was calculated as the natural log of the ferumoxytol to gadolinium sum of products diameter ratio. Analysis of variance and Student's t-test assessed differences in mismatch ratios. P-value <0.05 indicated statistical significance.

RESULTS

With the development of pseudoprogression we observed a significantly elevated mismatch ratio compared with disease recurrence (P < 0.01) within IDH-1 wild type patients. Patients with IDH-1 mutation demonstrated significantly reduced mismatch ratio with the development of pseudoprogression compared with disease recurrence (P < 0.01). Receiver operator curve analysis demonstrated 100% sensitivity and specificity for the use of mismatch ratios as a diagnostic biomarker of pseudoprogression.

CONCLUSION

Our study suggests that ferumoxytol to gadolinium contrast mismatch ratios are an MRI biomarker for the diagnosis of pseudoprogression in patients with glioblastoma. This may be due to the unique characterization of therapy-induced neuroinflammation.

Automatic assessment of glioma burden: a deep learning algorithm for fully automated volumetric and bidimensional measurement

BACKGROUND

Longitudinal measurement of glioma burden with MRI is the basis for treatment response assessment. In this study, we developed a deep learning algorithm that automatically segments abnormal fluid attenuated inversion recovery (FLAIR) hyperintensity and contrast-enhancing tumor, quantitating tumor volumes as well as the product of maximum bidimensional diameters according to the Response Assessment in Neuro-Oncology (RANO) criteria (AutoRANO).

METHODS

Two cohorts of patients were used for this study. One consisted of 843 preoperative MRIs from 843 patients with low- or high-grade gliomas from 4 institutions and the second consisted of 713 longitudinal postoperative MRI visits from 54 patients with newly diagnosed glioblastomas (each with 2 pretreatment "baseline" MRIs) from 1 institution.

RESULTS

The automatically generated FLAIR hyperintensity volume, contrast-enhancing tumor volume, and AutoRANO were highly repeatable for the double-baseline visits, with an intraclass correlation coefficient (ICC) of 0.986, 0.991, and 0.977, respectively, on the cohort of postoperative GBM patients. Furthermore, there was high agreement between manually and automatically measured tumor volumes, with ICC values of 0.915, 0.924, and 0.965 for preoperative FLAIR hyperintensity, postoperative FLAIR hyperintensity, and postoperative contrast-enhancing tumor volumes, respectively. Lastly, the ICCs for comparing manually and automatically derived longitudinal changes in tumor burden were 0.917, 0.966, and 0.850 for FLAIR hyperintensity volume, contrast-enhancing tumor volume, and RANO measures, respectively.

CONCLUSIONS

Our automated algorithm demonstrates potential utility for evaluating tumor burden in complex posttreatment settings, although further validation in multicenter clinical trials will be needed prior to widespread implementation.

In silico study of pseudoprogression in glioblastoma: collaboration of radiologists and radiation oncologists in the estimation of extent of high dose RT region

BACKGROUND AND AIM

Oncologists play a vital role in the interpretation of radiographic results in glioblastoma patients. Molecular pathology and information on radiation treatment protocols among others are all important for accurate interpretation of radiology images. One important issue that may arise in interpreting such images is the phenomenon of tumor "pseudoprogression"; oncologists need to be able to distinguish this effect from true disease progression.Exact knowledge about the location of high-dose radiotherapy region is needed for valid determination of pseudoprogression according to RANO (Response Assessment in Neuro-Oncology) criteria in neurooncology. The aim of the present study was to evaluate the radiologists' understanding of a radiotherapy high-dose region in routine clinical practice since radiation oncologists do not always report 3-dimensional isodoses when ordering follow up imaging.

METHODS

Eight glioblastoma patients who underwent postresection radiotherapy were included in this study. Four radiologists worked with their pre-radiotherapy planning MR, however, they were blinded to RT target volumes which were defined by radiation oncologists according to current guidelines. The aim was to draw target volume for high dose RT fields (that is the region, where they would consider that there may be a pseudoprogression in future MRI scans). Many different indices describing structure differences were analyzed in comparison with original per-protocol RT target volumes.

RESULTS

The median volume for RT high dose field was 277 ccm (range 218 to 401 ccm) as defined per protocol by radiation oncologist and 87 ccm (range 32-338) as defined by radiologists (median difference of paired difference 31%, range 15-112%). The Median Dice index of similarity was 0.46 (range 0.14 - 0.78), the median Hausdorff distance 25 mm.

CONCLUSION

Continuing effort to improve education on specific procedures in RT and in radiology as well as automatic tools for exporting RT targets is needed in order to increase specificity and sensitivity in response evaluation.

Imaging-guided precision medicine in glioblastoma patients treated with immune checkpoint modulators: research trend and future directions in the field of imaging biomarkers and artificial intelligence

Immunotherapies that employ immune checkpoint modulators (ICMs) have emerged as an effective treatment for a variety of solid cancers, as well as a paradigm shift in the treatment of cancers. Despite this breakthrough, the median survival time of glioblastoma patients has remained at about 2 years. Therefore, the safety and anti-cancer efficacy of combination therapies that include ICMs are being actively investigated. Because of the distinct mechanisms of ICMs, which restore the immune system’s anti-tumor capacity, unconventional immune-related phenomena are increasingly being reported in terms of tumor response and progression, as well as adverse events. Indeed, immunotherapy response assessments for neuro-oncology (iRANO) play a central role in guiding cancer patient management and define a “wait and see strategy” for patients treated with ICMs in monotherapy with progressive disease on MRI. This article deciphers emerging research trends to ameliorate four challenges unaddressed by the iRANO criteria: (1) patient selection, (2) identification of immune-related phenomena other than pseudoprogression (i.e., hyperprogression, the abscopal effect, immune-related adverse events), (3) response assessment in combination therapies including ICM, and (4) alternatives to MRI. To this end, our article provides a structured approach for standardized selection and reporting of imaging modalities to enable the use of precision medicine by deciphering the characteristics of the tumor and its immune environment. Emerging preclinical or clinical innovations are also discussed as future directions such as immune-specific targeting and implementation of artificial intelligence algorithms.

Predicting disease progression in high-grade glioma with neuropsychological parameters: the value of personalized longitudinal assessment

PURPOSE

Progressive disease in patients with high-grade glioma may be reflected in cognitive decline. However, the cognitive functions most sensitive to progression may differ between patients. We investigated whether decline on a personalized selection of tests predicted progressive disease according to RANO criteria in high-grade glioma patients.

METHODS

Starting one day before surgery, patients underwent neuropsychological assessment every three months during standard treatment and clinical follow-up. We first made a personalized selection of three tests that showed the highest Reliable Change Index (RCI) values, i.e., most positive change, at the first post-surgical assessment for each patient. In subsequent follow up, a decline of RCI ≤ - 1 on at least two of the three tests in the selection was considered cognitive decline. We performed a discrete Cox proportional hazards model including a time-dependent coefficient cognitive decline (vs. stability) and covariate age to predict progressive disease.

RESULTS

Twenty five patients were included. Cognitive decline on the personalized test selection preceded or had occurred by the time progression was established in 9/15 patients with RANO confirmed progressive disease (60%). Decline was absent in 8/10 patients (80%) with stable disease during participation. The independent hazard ratio for progression in case of cognitive decline was 5.05 (p < 0.01) compared to stable performance.

CONCLUSIONS

Using only three patient-specific neuropsychological tests, we found a fivefold increased chance of disease progression in case of cognitive decline as compared to stable performance. Brief, patient-tailored cognitive assessment may be a noninvasive addition to disease monitoring without overburdening patients and clinical care.

Comparison of Radiographic Approaches to Assess Treatment Response in Pituitary Adenomas: Is RECIST or RANO Good Enough?

Context

Pituitary adenomas (PA) are often irregularly shaped, particularly posttreatment. There are no standardized radiographic criteria for assessing treatment response, substantially complicating interpretation of prospective outcome data. Existing imaging frameworks for intracranial tumors assume perfectly spherical targets and may be suboptimal.

Objective

To compare a three-dimensional (3D) volumetric approach against accepted surrogate measurements to assess PA posttreatment response (PTR).

Design

Retrospective review of patients with available pre- and postradiotherapy (RT) imaging. A neuroradiologist determined tumor sizes in one dimensional (1D) per Response Evaluation in Solid Tumors (RECIST) criteria, two dimensional (2D) per Response Assessment in Neuro-Oncology (RANO) criteria, and 3D estimates assuming a perfect sphere or perfect ellipsoid. Each tumor was manually segmented for 3D volumetric measurements. The Hakon Wadell method was used to calculate sphericity.

Setting

Tertiary cancer center.

Patients or Other Participants

Patients (n = 34, median age = 50 years; 50% male) with PA and MRI scans before and after sellar RT.

Interventions

Patients received sellar RT for intact or surgically resected lesions.

Main Outcome Measures

Radiographic PTR, defined as percent tumor size change.

Results

Using 3D volumetrics, mean sphericity = 0.63 pre-RT and 0.60 post-RT. With all approaches, most patients had stable disease on post-RT scan. PTR for 1D, 2D, and 3D spherical measurements were moderately well correlated with 3D volumetrics (e.g., for 1D: 0.66, P < 0.0001) and were superior to 3D ellipsoid. Intraclass correlation coefficient demonstrated moderate to good reliability for 1D, 2D, and 3D sphere (P < 0.001); 3D ellipsoid was inferior (P = 0.009). 3D volumetrics identified more potential partially responding and progressive lesions.

Conclusions

Although PAs are irregularly shaped, 1D and 2D approaches are adequately correlated with volumetric assessment.

Response assessment in medulloblastoma and leptomeningeal seeding tumors: recommendations from the Response Assessment in Pediatric Neuro-Oncology committee

Lack of standard response criteria in clinical trials for medulloblastoma and other seeding tumors complicates assessment of therapeutic efficacy and comparisons across studies. An international working group was established to develop consensus recommendations for response assessment. The aim is that these recommendations be prospectively evaluated in clinical trials, with the goal of achieving more reliable risk stratification and uniformity across clinical trials. Current practices and literature review were performed to identify major confounding issues and justify subsequently developed recommendations; in areas lacking scientific investigations, recommendations were based on experience of committee members and consensus was reached after discussion. Recommendations apply to both adult and pediatric patients with medulloblastoma and other seeding tumors. Response should be assessed using MR imaging (brain and spine), CSF cytology, and neurologic examination. Clinical imaging standards with minimum mandatory sequence acquisition that optimizes detection of leptomeningeal metastases are defined. We recommend central review prior to inclusion in treatment cohorts to ensure appropriate risk stratification and cohort inclusion. Consensus recommendations and response definitions for patients with medulloblastomas and other seeding tumors have been established; as with other Response Assessment in Neuro-Oncology recommendations, these need to now be prospectively validated in clinical trials.

Institutional review of glial tumors treated with chemotherapy: the first description of PCV-related pseudoprogression

BACKGROUND

Pseudoprogression refers to areas of enhancement on MRI postadjuvant chemoradiation that arise as a result of treatment-related effects. Pseudoprogression has been well described with temozolomide-based chemoradiation but has not been studied in the setting of procarbazine, lomustine, and vincristine (PCV) chemotherapy. We reviewed patients treated with PCV to investigate the occurrence of pseudoprogression.

METHODS

Adults diagnosed with World Health Organization grade II or III gliomas between 2010 and 2015 and treated with PCV or temozolomide were identified. Patient, tumor, treatment, and MRI data were retrospectively collected and analyzed. Pseudoprogression was defined as new enhancement seen on MRI within 6 months of completion of adjuvant radiotherapy or concurrent chemoradiation, which improved or remained stable on subsequent scans without therapeutic intervention. If MRI showed areas of new enhancement outside the 6-month post-treatment window, which resolved or remained stable without treatment, or in patients who did not receive adjuvant treatment, it was referred to as "atypical pseudoprogression."

RESULTS

Fifty-seven patients were identified. Nine (16%) patients were identified as having pseudoprogression on MRI. Two (4%) of these patients were treated with PCV and 7 (12%) were treated with temozolomide. Seventeen (30%) patients had atypical pseudoprogression: 8 (14%) treated with temozolomide, 8 (14%) treated with PCV, and 1 (2%) treated with both types of chemotherapy.

CONCLUSIONS

We describe the first 2 cases of PCV-related pseudoprogression and 17 cases of atypical pseudoprogression. As the re-emergence of adjuvant PCV occurs in clinical practice, the occurrence of classical and atypical pseudoprogression could have a significant impact on clinical decision making.

Earliest radiological progression in glioblastoma by multidisciplinary consensus review

BACKGROUND

Detection of glioblastoma progression is important for clinical decision-making on cessation or initiation of therapy, for enrollment in clinical trials, and for response measurement in time and location. The RANO-criteria are considered standard for the timing of progression. To evaluate local treatment, we aim to find the most accurate progression location. We determined the differences in progression free survival (PFS) and in tumor volumes at progression (Vprog) by three definitions of progression.

METHODS

In a consecutive cohort of 73 patients with newly-diagnosed glioblastoma between 1/1/2012 and 31/12/2013, progression was established according to three definitions. We determined (1) earliest radiological progression (ERP) by retrospective multidisciplinary consensus review using all available imaging and follow-up, (2) clinical practice progression (CPP) from multidisciplinary tumor board conclusions, and (3) progression by the RANO-criteria.

RESULTS

ERP was established in 63 (86%), CPP in 64 (88%), RANO progression in 42 (58%). Of the 63 patients who had died, 37 (59%) did with prior RANO-progression, compared to 57 (90%) for both ERP and CPP. The median overall survival was 15.3 months. The median PFS was 8.8 months for ERP, 9.5 months for CPP, and 11.8 months for RANO. The PFS by ERP was shorter than CPP (HR 0.57, 95% CI 0.38-0.84, p = 0.004) and RANO-progression (HR 0.29, 95% CI 0.19-0.43, p < 0.001). The Vprog were significantly smaller for ERP (median 8.8 mL), than for CPP (17 mL) and RANO (22 mL).

CONCLUSION

PFS and Vprog vary considerably between progression definitions. Earliest radiological progression by retrospective consensus review should be considered to accurately localize progression and to address confounding of lead time bias in clinical trial enrollment.

Recurrent pseudoprogression in isocitrate dehydrogenase 1 mutant glioblastoma

In a subset of glioblastoma (GBM) patients, the differentiation between tumor progression and tumor pseudoprogression (PsP) is challenging. This case describes a male patient suffering from isocitrate dehydrogenase 1 (IDH1) mutant GBM who demonstrated an increasing contrast-enhancing (CE) lesion on a cranial magnetic resonance imaging (cMRI) scan 8 months after radiochemotherapy. In accordance with the response assessment in neuro-oncology (RANO) criteria, the cMRI lesion was classified as recurrent tumor, although ¹⁸F-fluoroethyl-L-tyrosine positron emission tomography (¹⁸F-FET-PET) did not indicate vital tumor tissue. The patient underwent re-surgery but histopathology only revealed reactive and necrotic tissue, consistent with PsP. Nine weeks after complete resection of the CE lesion, a new lesion emerged that later regressed in the follow-up cMRI scans, thereby retrospectively establishing the diagnosis of recurrent PsP.

Evaluation of the apparent diffusion coefficient in patients with recurrent glioblastoma under treatment with bevacizumab with radiographic pseudoresponse

BACKGROUND

Response Assessment in Neuro-Oncology Criteria (RANO), are used to asses response to first-line treatment of glioblastoma (GBM). Differentiation between response and pseudoresponse under treatment with Bevacizumab (BVZ) remains challenging. This study evaluates ADC changes in patients with radiographic pseudoresponse under treatment with (BVZ).

METHODS

Patients (n=40) with recurrent GBM under-treatment with BVZ underwent MRI before, two and four months after treatment with BVZ. In patients with radiological pseudoresponse (n=11), ADC analyses were performed. Areas with decreasing T1 contrast enhancement (CE) and FLAIR signal decrease were manually selected and compared to size and position matched healthy contralateral brain parenchyma.

RESULTS

Histogram based ADC (10^-6×mm²/s) of these patients decreased significantly (P<0.005) from baseline MRI (T1-CE, FLAIR: 1124.9±160.3, 1098.4±226.2, respectively) to 2months (781.3±110.7, 783.3±103.3) and remained stable during 4months (777.0±138.5, 784.4±155.4, all mean±1 SD), despite progressive disease. Mean ADC values of the healthy contralateral brain tissue remained stable (P>0.05) (ADC values: baseline: 786.2±110.7, 2months: 781.1±76.2, 4months: 804.1±86.2).

CONCLUSION

Treatment of GBM with BVZ leads to a decrease of ADC values in areas of pre-treatment T1-CE/FLAIR signal hyperintensity to levels of comparable with normal brain tissue. ADC values remained stable, even when progressive tumor growth was reported.

Comparison of 2D (RANO) and volumetric methods for assessment of recurrent glioblastoma treated with bevacizumab-a report from the BELOB trial

Background

The current method for assessing progressive disease (PD) in glioblastoma is according to the Response Assessment in Neuro-Oncology (RANO) criteria. Bevacizumab-treated patients may show pseudo-response on postcontrast T1-weighted (T1w) MRI, and a more infiltrative non-enhancing growth pattern on T2w/fluid attenuated inversion recovery (FLAIR) images. We investigated whether the RANO criteria remain the method of choice for assessing bevacizumab-treated recurrent glioblastoma when compared with various volumetric methods.

Methods

Patients with assessable MRI data from the BELOB trial (n = 148) were included. Patients were treated with bevacizumab, lomustine, or both. At first and second radiological follow-up (6 and 12 wk), PD was determined using the 2D RANO criteria and various volumetric methods based on enhancing tumor only and enhancing plus non-enhancing tumor. Differences in overall survival (OS) between PD and non-PD patients were assessed with the log-rank test and a Cox model. Hazard ratios (HRs) and their 95% CIs were determined.

Results

For all patients together, all methods (except subtraction of non-enhancing from enhancing volume at first follow-up) showed significant differences in OS between PD and non-PD patients (P < .001). The largest risk increase for death in case of PD at both first and second follow-up was found with the RANO criteria: HR = 2.81 (95% CI, 1.92-4.10) and HR = 2.80 (95% CI, 1.75-4.49), respectively. In the bevacizumab-treated patients, all methods assessed showed significant differences in OS between PD and non-PD patients. There were no significant differences between methods.

Conclusions

In the first 12 weeks, volumetric methods did not provide significant improvement over the RANO criteria as a posttreatment prognostic marker.

Reviewing RECIST in the Era of Prolonged and Targeted Therapy

Accurate assessment of disease response is the foundation of therapeutic trails, which is why the Response Evaluation Criteria in Solid Tumors (RECIST) serve as an international standard that investigators can utilize when examining patient outcomes. Nine years after the initial RECIST criteria were released, an update, RECIST 1.1, was published to improve on the initial criteria and address technologic advancements in imaging. Since then, advancements in both standard clinical and trial practices, combined with improvements in our understanding of cancer biology, have resulted in the identification of a number of limitations of the current RECIST 1.1, either in lack of clear guidance with regard to its best application or in potential benefit of capturing imaging-related data beyond standard categorical response details. As several of these situations reflect the consequences of prolonged control of metastatic disease by using targeted therapies, thoracic oncology has generated many of the key scenarios requiring elucidation and/or improvements. This article specifically examines current controversies in the interpretation and/or optimal utilization of RECIST 1.1, focusing on examples from thoracic oncology, and makes proposals, where possible, on how best to address these issues. These situations include addressing central nervous system versus extra-central nervous system response and progression, depth of response, oligoprogression versus polyprogression, continuation of systemic therapy after use of a local ablative therapy, and the impact of fluctuations in measurements bridging partial response and stable disease categories during prolonged therapy.

Modified Criteria for Radiographic Response Assessment in Glioblastoma Clinical Trials

Radiographic endpoints including response and progression are important for the evaluation of new glioblastoma therapies. The current RANO criteria was developed to overcome many of the challenges identified with previous guidelines for response assessment, however, significant challenges and limitations remain. The current recommendations build on the strengths of the current RANO criteria, while addressing many of these limitations. Modifications to the current RANO criteria include suggestions for volumetric response evaluation, use contrast enhanced T1 subtraction maps to increase lesion conspicuity, removal of qualitative non-enhancing tumor assessment requirements, use of the post-radiation time point as the baseline for newly diagnosed glioblastoma response assessment, and "treatment-agnostic" response assessment rubrics for identifying pseudoprogression, pseudoresponse, and a confirmed durable response in newly diagnosed and recurrent glioblastoma trials.

Early tumour shrinkage as a survival predictor in patients with recurrent glioblastoma treated with bevacizumab in the AVAREG randomized phase II study

BACKGROUND

Disease assessment for recurrent glioblastoma (GBM) represents a challenge, especially with the use of antiangiogenic agents. Moreover, validated neuroradiological predictors of outcome are lacking. Recently, the concept of early tumor shrinkage (ETS) has been developed to better assess the ability of treatments in determining a rapid and remarkable tumor response.

The aim of the study was to evaluate the role of ETS in predicting survival of GBM patients treated with BEV

METHODS

We examined the radiological data of patients with recurrent GBM treated with bevacizumab (BEV) or fotemustine (FTM) in the randomized phase II AVAREG trial (EudraCT: 2011-001363-46).

Radiologic assessments at first disease assessment (day 46) were used to calculate the relative change in the sum of the products of perpendicular diameters of all measurable lesions determined by either T1 contrast and T2/FLAIR.

RESULTS

In patients treated with BEV, the best ETS cut-off was reduction of 15% with T1 contrast and of 40% with T2/FLAIR. Adopting this cut-off for T1 contrast radiological changes, ETS was a significant predictor of OS for patients treated with BEV (HR = 0.511, 95%CI:0.269-0.971, p = 0.040). The cut-off obtained for T2/FLAIR was not significantly correlated with OS (p = 0.102), but we found a trend for correlation with survival when considering the variable as continuous (p = 0.058).

CONCLUSIONS

ETS evaluating T1 contrast reduction is a helpful predictor of survival in patients with recurrent GBM treated with BEV, and if validated in a larger prospective trial could be a helpful surrogate endpoint.

Response Assessment in Neuro-Oncology Criteria and Clinical Endpoints

The Response Assessment in Neuro-Oncology (RANO) Working Group is an international multidisciplinary group whose goal is to improve response criteria and define endpoints for neuro-oncology trials. The RANO criteria for high-grade gliomas attempt to address the issues of pseudoprogression, pseudoresponse, and nonenhancing tumor progression. Incorporation of advanced MR imaging may eventually help improve the ability of these criteria to define enhancing and nonenhancing disease better. The RANO group has also developed criteria for neurologic response and evaluation of patients receiving immunologic therapies. RANO criteria have been developed for brain metastases and are in progress for meningiomas, leptomeningeal disease, spinal tumors, and pediatric tumors.

Small increases in enhancement on MRI may predict survival post radiotherapy in patients with glioblastoma

To assess impact of volumetric changes in tumour volume post chemoradiotherapy in glioblastoma. Patients managed with chemoradiotherapy between 2008 and 2011 were included. Patients with incomplete MRI sets were excluded. Analyses were performed on post-operative MRI, and MRIs at 1 month (M+1), 3 months (M+3), 5 months (M+5), 7 months (M+7), and 12 months (M+12) post completion of RT. RANO definitions of response were used for all techniques. Modified RANO criteria and two volumetric analysis techniques were used. The two volumetric analysis techniques involved utility of the Eclipse treatment planning software to calculate the volume of delineated tissue: surgical cavity plus all surrounding enhancement (Volumetric) versus surrounding enhancement only (Rim). Retrospective analysis of 49 patients with median survival of 18.4 months. Using Volumetric analysis the difference in MS for patients who had a <5 % increase versus ≥5 % at M+3 was 23.1 versus 15.1 months (p = 0.006), and M+5 was 26.3 versus 15.1 months (p = 0.006). For patients who were classified as progressive disease using modified RANO criteria at M+1 and M+3 there was a difference in MS compared with those who were not (M+1: 13.1 vs. 19.4 months, p = 0.017, M+3: 13.2 vs. 20.1 months, p = 0.096). An increase in the volume of cavity and enhancement of ≥5 % at M+3 and M+5 post RT was associated with reduced survival, suggesting that increases in radiological abnormality of <25 % may predict survival.

Pros and cons of current brain tumor imaging

Over the past 20 years, very few agents have been approved for the treatment of brain tumors. Recent studies have highlighted some of the challenges in assessing activity in novel agents for the treatment of brain tumors. This paper reviews some of the key challenges related to assessment of tumor response to therapy in adult high-grade gliomas and discusses the strengths and limitations of imaging-based endpoints. Although overall survival is considered the "gold standard" endpoint in the field of oncology, progression-free survival and response rate are endpoints that hold great value in neuro-oncology. Particular focus is given to advancements made since the January 2006 Brain Tumor Endpoints Workshop, including the development of Response Assessment in Neuro-Oncology criteria, the value of T2/fluid-attenuated inversion recovery, use of objective response rates and progression-free survival in clinical trials, and the evaluation of pseudoprogression, pseudoresponse, and inflammatory response in radiographic images.

Report of the Jumpstarting Brain Tumor Drug Development Coalition and FDA clinical trials neuroimaging endpoint workshop (January 30, 2014, Bethesda MD)

On January 30, 2014, a workshop was held on neuroimaging endpoints in high-grade glioma. This workshop was sponsored by the Jumpstarting Brain Tumor Drug Development Coalition, consisting of the National Brain Tumor Society, the Society for Neuro-Oncology, Accelerate Brain Cancer Cure, and the Musella Foundation for Research and Information, and conducted in collaboration with the Food and Drug Administration. The workshop included neuro-oncologists, neuroradiologists, radiation oncologists, neurosurgeons, biostatisticians, patient advocates, and representatives from industry, clinical research organizations, and the National Cancer Institute. This report summarizes the presentations and discussions of that workshop and the proposals that emerged to improve the Response Assessment in Neuro-Oncology (RANO) criteria and standardize neuroimaging parameters.

The imaging core lab perspective on glioblastoma imaging and response assessment in clinical trials

Multicenter clinical trials that include medical images as a key component of response assessment often involve an imaging service provider (a core laboratory or contract research organization) to collect images and often to provide independent assessments of treatment response. The brief discussion and recommendations provided here are not intended as a rigorous academic analysis but reflect the practical experience accumulated at one such institution, which has conducted the image collection and review for numerous glioblastoma trials, in every phase of drug development, encompassing over 4000 patients scanned at over 900 sites.

Challenges with defining response to antitumor agents in pediatric neuro-oncology: a report from the response assessment in pediatric neuro-oncology (RAPNO) working group

Criteria for new drug approval include demonstration of efficacy. In neuro-oncology, this is determined radiographically utilizing tumor measurements on MRI scans. Limitations of this method have been identified where drug activity is not reflected in decreased tumor size. The RANO (Response Assessment in Neuro-Oncology) working group was established to address limitations in defining endpoints for clinical trials in adult neuro-oncology and to develop standardized response criteria. RAPNO was subsequently established to address unique issues in pediatric neuro-oncology. The aim of this paper is to delineate response criteria issues in pediatric clinical trials as a basis for subsequent recommendations.