Current unmet needs in locally advanced (unresectable) or metastatic dedifferentiated liposarcoma, the relevance of progression-free survival as clinical endpoint, and expectations for future clinical trial design: an international Delphi consensus report.

BACKGROUND: Locally advanced (unresectable) or metastatic dedifferentiated liposarcoma (DDLPS) is a common presentation of liposarcoma. Despite established diagnostic and treatment guidelines for DDLPS, critical clinical gaps remain driven by diagnostic challenges, symptom burden and the lack of targeted, safe and effective treatments. The objective of this study was to gather expert opinions from Europe and the United States on the management, unmet needs and expectations for clinical trial design as well as the value of progression-free survival (PFS) in this disease. Other aims included raising awareness and educate key stakeholders across healthcare systems. MATERIALS AND METHODS: An international panel of 12 sarcoma key opinion leaders (KOLs) was recruited. The study consisted of two rounds of surveys with pre-defined statements. Experts scored each statement on a 9-point Likert scale. Consensus agreement was defined as ≥75% of experts scoring a statement with ≥7. Revised statements were discussed in a consensus meeting. RESULTS: Consensus was reached on 43 of 55 pre-defined statements across disease burden, treatment paradigm, unmet needs, value of PFS and its association with overall survival (OS), and cross-over trial design. Twelve statements were deprioritised or merged with other statements. There were no statements where experts disagreed. CONCLUSION: This study constitutes the first international Delphi panel on DDLPS. It aimed to explore KOL perception of the disease burden and unmet need in DDLPS, the value of PFS, and its potential translation to OS benefit, as well as the relevance of a cross-over trial design for DDLPS therapies. Results indicate an alignment across Europe and the United States regarding DDLPS management, unmet needs, and expectations for clinical trials. Raising awareness of critical clinical gaps in relation to DDLPS can contribute to improving patient outcomes and supporting the development of innovative treatments.

The Impact of COVID-19 on Radiotherapy Services in Scotland, UK: A Population-based Study.

AIMS: The effect of the COVID-19 pandemic on cancer radiotherapy services is largely unknown. The aim of the present study was to investigate the impact of the resultant contingency plans on radiotherapy cancer services in Scotland. MATERIALS AND METHODS: Detailed data of radiotherapy activity at our centre were collected from 1 April 2019 to 31 March 2021. Differences in mean weekly radiotherapy courses, dose and fractionation patterns and treatment intent were compared with corresponding pre-pandemic months for all treatment sites. Qualitative data were collected for a subgroup of radical radiotherapy patients. RESULTS: Total radiotherapy courses decreased from 6968 to 6240 (-10%) compared with the previous year, prior to the pandemic. Average weekly radiotherapy courses delivered were 134 (standard deviation ±13), decreasing by 10% to 120 (standard deviation 15) (Welch's t-test, P < 0.001). The greatest decrease in new start treatment courses was observed from May to August 2020 (-7.7%, -24.0%, -16.7% and -18.7%) compared with the corresponding months in 2019. A significant reduction was seen for female patients <70 years (-16%) compared with females >70 years (-8%) or their male counterparts (-7% and -6%, respectively). By diagnosis, the largest reductions between pre- and post-pandemic levels were for anal (-26%), breast (-18%) and prostate (-14%) cancer. Contrarily, a significant increase was found for bladder (28%) and oesophageal (11%) cancers. CONCLUSIONS: Over the first 12 months of the COVID-19 pandemic, radiotherapy activity significantly decreased compared with the 12 months prior. Due to issued guidance, the use of hypofractionated regimens increased, contributing to the reduction in treatments for some tumour sites. An increase in other tumour sites can probably be attributed to the reduction or cancellation of surgical interventions. These results will inform our understanding of the indirect consequences of the pandemic on radiotherapy services.

Evaluating potential of multi-parametric MRI using co-registered histology: Application to a mouse model of glioblastoma.

BACKGROUND: Conventional MRI fails to detect regions of glioblastoma cell infiltration beyond the contrast-enhanced T1 solid tumor region, with infiltrating tumor cells often migrating along host blood vessels. PURPOSE: MRI is capable of generating a range of image contrasts which are commonly assessed individually by qualitative visual inspection. It has long been hypothesized that better diagnoses could be achieved by combining these multiple images, so called multi-parametric or multi-spectral MRI. However, the lack of clinical histology and the difficulties of co-registration, has meant this hypothesis has never been rigorously tested. Here we test this hypothesis, using a previously published multi-dimensional dataset consisting of registered MR images and histology. STUDY TYPE: Animal Model. SUBJECTS: Mice bearing orthotopic glioblastoma xenografts generated from a patient-derived glioblastoma cell line. FIELD STRENGTH/SEQUENCES: 7 Tesla, T1/T2 weighted, T2 mapping, contrast enhance T1, diffusion-weighted, diffusion tensor imaging. ASSESSMENT: Immunohistochemistry sections were stained for Human Leukocyte Antigen (probing human-derived tumor cells). To achieve quantitative MRI-tissue comparison, multiple histological slices cut in the MRI plane were stacked to produce tumor cell density maps acting as 'ground truth'. STATISTICAL TESTS: Sensitivity, specificity, accuracy and Dice similarity indices were calculated. ANOVA, t-test, Bonferroni correction and Pearson coefficients were used for statistical analysis. RESULTS: Correlation coefficient analysis with co-registered 'ground truth' histology showed interactive regression maps had higher correlation coefficients and sensitivity values than T2W, ADC, FA, and T2map. Further, the interaction regression maps showed statistical improved detection of tumor volume. DATA CONCLUSION: Voxel-by-voxel analysis provided quantitative evidence confirming the hypothesis that mpMRI can, potentially, better distinguish between the tumor region and normal tissue.

Stacked in-plane histology for quantitative validation of non-invasive imaging biomarkers: Application to an infiltrative brain tumour model.

BACKGROUND: While it is generally agreed that histopathology is the gold standard for assessing non-invasive imaging biomarkers, most validation has been by qualitative visual comparison. To date, the difficulties involved in accurately co-registering histology sections with imaging slices have prevented a voxel-by-voxel assessment of imaging modalities. By contrast with previous studies, which focus on improving the registration algorithms, we have taken the approach of improving the quality of the histological processing and analysis. NEW METHOD: To account for imaging slice orientation and thickness, multiple histology sections were cut in the MR imaging plane and averaged to produce stacked in-plane histology (SIH) maps. When combined with intensity sensitive staining this approach gives histopathology maps, which can be used as the gold standard to validate imaging biomarkers. RESULTS: We applied this pipeline to a patient-derived mouse model of glioblastoma multiforme (GBM). Increasing the number of stacked histology sections significantly increased SIH measured tumour volume. The SIH technique proposed here resulted in reduced variability of volume measurements and this allowed significant improvements in the quantitative volumetric assessment of multiple MRI modalities. Further, high quality registration enabled a voxel-wise comparison between MRI and histopathology maps. Previous approaches to the validation of imaging biomarkers with histology, have been either qualitative or of limited accuracy. Here we propose a pipeline that allows for a more accurate validation via co-registration with SIH maps, potentially allowing validation in a voxel-wise mode. CONCLUSION: This work demonstrates that methodically produced SIH maps facilitate the quantitative histopathologic assessment of imaging biomarkers.

Focused very high-energy electron beams as a novel radiotherapy modality for producing high-dose volumetric elements.

The increased inertia of very high-energy electrons (VHEEs) due to relativistic effects reduces scattering and enables irradiation of deep-seated tumours. However, entrance and exit doses are high for collimated or diverging beams. Here, we perform a study based on Monte Carlo simulations of focused VHEE beams in a water phantom, showing that dose can be concentrated into a small, well-defined volumetric element, which can be shaped or scanned to treat deep-seated tumours. The dose to surrounding tissue is distributed over a larger volume, which reduces peak surface and exit doses for a single beam by more than one order of magnitude compared with a collimated beam.

Audio-Visual-Olfactory Resource Allocation for Tri-modal Virtual Environments.

Virtual Environments (VEs) provide the opportunity to simulate a wide range of applications, from training to entertainment, in a safe and controlled manner. For applications which require realistic representations of real world environments, the VEs need to provide multiple, physically accurate sensory stimuli. However, simulating all the senses that comprise the human sensory system (HSS) is a task that requires significant computational resources. Since it is intractable to deliver all senses at the highest quality, we propose a resource distribution scheme in order to achieve an optimal perceptual experience within the given computational budgets. This paper investigates resource balancing for multi-modal scenarios composed of aural, visual and olfactory stimuli. Three experimental studies were conducted. The first experiment identified perceptual boundaries for olfactory computation. In the second experiment, participants ( N=25) were asked, across a fixed number of budgets ( M=5), to identify what they perceived to be the best visual, acoustic and olfactory stimulus quality for a given computational budget. Results demonstrate that participants tend to prioritize visual quality compared to other sensory stimuli. However, as the budget size is increased, users prefer a balanced distribution of resources with an increased preference for having smell impulses in the VE. Based on the collected data, a quality prediction model is proposed and its accuracy is validated against previously unused budgets and an untested scenario in a third and final experiment.

Quantitative histopathologic assessment of perfusion MRI as a marker of glioblastoma cell infiltration in and beyond the peritumoral edema region.

BACKGROUND: Conventional MRI fails to detect regions of glioblastoma cell infiltration beyond the contrast-enhanced T1 solid tumor region, with infiltrating tumor cells often migrating along host blood vessels. PURPOSE: To quantitatively and qualitatively analyze the correlation between perfusion MRI signal and tumor cell density in order to assess whether local perfusion perturbation could provide a useful biomarker of glioblastoma cell infiltration. STUDY TYPE: Animal model. SUBJECTS: Mice bearing orthotopic glioblastoma xenografts generated from a patient-derived glioblastoma cell line. FIELD STRENGTH/SEQUENCES: 7T perfusion images acquired using a high signal-to-noise ratio (SNR) multiple boli arterial spin labeling sequence were compared with conventional MRI (T1 /T2 weighted, contrast-enhanced T1 , diffusion-weighted, and apparent diffusion coefficient). ASSESSMENT: Immunohistochemistry sections were stained for human leukocyte antigen (probing human-derived tumor cells). To achieve quantitative MRI-tissue comparison, multiple histological slices cut in the MRI plane were stacked to produce tumor cell density maps acting as a "ground truth." STATISTICAL TESTS: Sensitivity, specificity, accuracy, and Dice similarity indices were calculated and a two-tailed, paired t-test used for statistical analysis. RESULTS: High comparison test results (Dice 0.62-0.72, Accuracy 0.86-0.88, Sensitivity 0.51-0.7, and Specificity 0.92-0.97) indicate a good segmentation for all imaging modalities and highlight the quality of the MRI tissue assessment protocol. Perfusion imaging exhibits higher sensitivity (0.7) than conventional MRI (0.51-0.61). MRI/histology voxel-to-voxel comparison revealed a negative correlation between tumor cell infiltration and perfusion at the tumor margins (P = 0.0004). DATA CONCLUSION: These results demonstrate the ability of perfusion imaging to probe regions of low tumor cell infiltration while confirming the sensitivity limitations of conventional imaging modalities. The quantitative relationship between tumor cell density and perfusion identified in and beyond the edematous T2 hyperintensity region surrounding macroscopic tumor could be used to detect marginal tumor cell infiltration with greater accuracy. LEVEL OF EVIDENCE: 1 Technical stage: 2 J. Magn. Reson. Imaging 2019;50:529-540.

SYSTEMS-2: A randomised phase II study of radiotherapy dose escalation for pain control in malignant pleural mesothelioma.

SYSTEMS-2 is a randomised study of radiotherapy dose escalation for pain control in 112 patients with malignant pleural mesothelioma (MPM). Standard palliative (20 Gy/5#) or dose escalated treatment (36 Gy/6#) will be delivered using advanced radiotherapy techniques and pain responses will be compared at week 5. Data will guide optimal palliative radiotherapy in MPM.

Challenges to Treating Older Glioblastoma Patients: the Influence of Clinical and Tumour Characteristics on Survival Outcomes.

AIMS: There is now evidence to support giving single-agent chemotherapy, radiotherapy or hypofractionated concurrent chemoradiotherapy to older patients with glioblastoma (GBM). However, the clinical basis on which treatment decisions are made is under-researched and not standardised. This retrospective, multicentre study assessed whether pre-morbid characteristics or tumour imaging features could predict for overall survival in a cohort of older patients with GBM. MATERIALS AND METHODS: Patients aged > 70 years, diagnosed with GBM at three neuro-oncology centres from 2010 to 2015 were retrospectively analysed. Demographic, clinical, radiological and treatment details were included in a multivariate model to examine for predictors of overall survival. RESULTS: In total, 339 patients were included with a median overall survival of 3.8 months. One and 2 year overall survival rates were 13% and 4%, respectively. The median age at diagnosis was 75 years. Pre-treatment characteristics predicting for overall survival included Eastern Cooperative Oncology Group performance status over 0 (performance status 1, hazard ratio 1.66, P = 0.042; performance status 2, hazard ratio 1.78, P = 0.031; performance status 3, hazard ratio 2.20, P = 0.008; performance status 4, hazard ratio 2.40, P = 0.021), radiological evidence of mass effect (hazard ratio 1.31, P = 0.049), multifocal tumours (hazard ratio 3.419, P = 0.013), presenting with seizures (hazard ratio 0.63, P = 0.008) and tumours confined to the cerebral hemisphere (hazard ratio 0.59, P = 0.048). Subtotal resection decreased risk of death by 37% (P = 0.019) and total tumour resection by 44% (P = 0.019). Palliative radiotherapy decreased risk of death by 41% (P = 0.005), temozolomide alone by 60% (P = 0.004) and radical chemoradiotherapy by 81% (P < 0.001). CONCLUSION: Clinical presentation, performance status and imaging characteristics are independent prognostic indicators of overall survival in older GBM patients, irrespective of age or treatment received.

Study of diffusion weighted MRI as a predictive biomarker of response during radiotherapy for high and intermediate risk squamous cell cancer of the oropharynx: The MeRInO study.

INTRODUCTION AND BACKGROUND: A significant proportion of patients with intermediate and high risk squamous cell cancer of the oropharynx (OPSCC) continue to relapse locally despite radical chemoradiotherapy (CRT). The toxicity of the current combination of intensified dose per fraction radiotherapy and platinum based chemotherapy limits further uniform intensification. If a predictive biomarker for outcomes from CRT can be identified during treatment then individualised and adaptive treatment strategies may be employed. METHODS/DESIGN: The MeRInO study is a prospective observational imaging study of patients with intermediate and high risk, locally advanced OPSCC receiving radical RT or concurrent CRT Patients undergo diffusion weighted MRI prior to treatment (MRI_1) and during the third week of RT (MRI_2). Apparent diffusion coefficient (ADC) measurements will be made on each scan for previously specified target lesions (primary and lymph nodes) and change in ADC calculated. Patients will be followed up and disease status for each target lesion noted. The primary aim of the MeRInO study is to determine the threshold change in ADC from baseline to week 3 of RT that may identify the sub-group of non-responders during treatment. DISCUSSION: The use of DW-MRI as a predictive biomarker during RT for SCC H&N is in its infancy but studies to date have found that response to treatment may indeed be predicted by comparison of DW-MRI carried out before and during treatment. However, previous studies have included all sub-sites and biological sub-types. Establishing ADC thresholds that predict for local failure is an essential step towards using DW-MRI to improve the therapeutic ratio in treating SCC H&N. This would be done most robustly in a specific H&N sub-site and in sub-types with similar biological behaviour. The MeRInO study will help establish these thresholds in OPSCC.

The Challenges Faced in Developing Novel Drug Radiation Combinations in Non-small Cell Lung Cancer.

Lung cancer is the most common cancer diagnosed in the UK. Outcomes for patients with this disease remain poor and new strategies to treat this disease require investigation. One potential option is to combine novel agents with radiotherapy in clinical studies. Here we discuss some of the important issues to consider when combining novel agents with radiotherapy, together with potential solutions as discussed at a recent Clinical Translational Radiotherapy Group (CTRad) workshop.

IL10 receptor is a novel therapeutic target in DLBCLs.

Diffuse large B-cell lymphoma (DLBCL) is a biologically and clinically heterogeneous disease with marked genomic instability and variable response to conventional R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) chemotherapy. More clinically aggressive cases of DLBCLs have high level of circulating interleukin 10 (IL10) cytokine and evidence of activated intracellular STAT3 (signal transducer and activator of transcription 3) signaling. We investigated the role of IL10 and its surface receptor in supporting the neoplastic phenotype of DLBCLs. We determined that IL10RA gene is amplified in 21% and IL10RB gene in 10% of primary DLBCLs. Gene expression of IL10, IL10RA and IL10RB was markedly elevated in DLBCLs. We hypothesized that DLBCLs depend for their proliferation and survival on IL10-STAT3 signaling and that blocking the IL10 receptor (IL10R) would induce cell death. We used anti-IL10R blocking antibody, which resulted in a dose-dependent cell death in all tested activated B-cell-like subtype of DLBCL cell lines and primary DLBCLs. Response of germinal center B-cell-like subtype of DLBCL cell lines to anti-IL10R antibody varied from sensitive to resistant. Cells underwent cell cycle arrest, followed by induction of apoptosis. Cell death depended on inhibition of STAT3 and, to a lesser extent, STAT1 signaling. Anti-IL10R treatment resulted in interruption of IL10-IL10R autostimulatory loop. We thus propose that IL10R is a novel therapeutic target in DLBCLs.

Concentrations of hormones, pharmaceuticals and other micropollutants in groundwater affected by septic systems in New England and New York.

Septic-system discharges can be an important source of micropollutants (including pharmaceuticals and endocrine active compounds) to adjacent groundwater and surface water systems. Groundwater samples were collected from well networks tapping glacial till in New England (NE) and sandy surficial aquifer New York (NY) during one sampling round in 2011. The NE network assesses the effect of a single large septic system that receives discharge from an extended health care facility for the elderly. The NY network assesses the effect of many small septic systems used seasonally on a densely populated portion of Fire Island. The data collected from these two networks indicate that hydrogeologic and demographic factors affect micropollutant concentrations in these systems. The highest micropollutant concentrations from the NE network were present in samples collected from below the leach beds and in a well downgradient of the leach beds. Total concentrations for personal care/domestic use compounds, pharmaceutical compounds and plasticizer compounds generally ranged from 1 to over 20 µg/L in the NE network samples. High tris(2-butoxyethyl phosphate) plasticizer concentrations in wells beneath and downgradient of the leach beds (>20 µg/L) may reflect the presence of this compound in cleaning agents at the extended health-care facility. The highest micropollutant concentrations for the NY network were present in the shoreline wells and reflect groundwater that is most affected by septic system discharges. One of the shoreline wells had personal care/domestic use, pharmaceutical, and plasticizer concentrations ranging from 0.4 to 5.7 µg/L. Estradiol equivalency quotient concentrations were also highest in a shoreline well sample (3.1 ng/L). Most micropollutant concentrations increase with increasing specific conductance and total nitrogen concentrations for shoreline well samples. These findings suggest that septic systems serving institutional settings and densely populated areas in coastal settings may be locally important sources of micropollutants to adjacent aquifer and marine systems.