Optical genome mapping identifies a novel pediatric embryonal tumor with a ZNF532::NUTM1 fusion.

The molecular characteristics of pediatric brain tumors have not only allowed for tumor subgrouping but have led to the introduction of novel treatment options for patients with specific tumor alterations. Therefore, an accurate histologic and molecular diagnosis is critical for optimized management of all pediatric patients with brain tumors, including central nervous system embryonal tumors. We present a case where optical genome mapping identified a ZNF532::NUTM1 fusion in a patient with a unique tumor best characterized histologically as a central nervous system embryonal tumor with rhabdoid features. Additional analyses including immunohistochemistry for NUT protein, methylation array, whole genome, and RNA-sequencing was done to confirm the presence of the fusion in the tumor. This is the first description of a pediatric patient with a ZNF532::NUTM1 fusion, yet the histology of this tumor is similar to that of adult cancers with ZNF::NUTM1 fusions reported in the literature. Although rare, the distinct pathology and underlying molecular characteristics of the ZNF532::NUTM1 tumor separates this from other embryonal tumors. Therefore, screening for this or similar NUTM1 rearrangements should be considered for all patients with unclassified central nervous system tumors with rhabdoid features to ensure accurate diagnosis. Ultimately, with additional cases, we may be able to better inform therapeutic management for these patients. © 2023 The Pathological Society of Great Britain and Ireland.

Cellular Therapy for Children with Central Nervous System Tumors: Mining and Mapping the Correlative Data.

PURPOSE OF REVIEW: Correlative studies should leverage clinical trial frameworks to conduct biospecimen analyses that provide insight into the bioactivity of the intervention and facilitate iteration toward future trials that further improve patient outcomes. In pediatric cellular immunotherapy trials, correlative studies enable deeper understanding of T cell mobilization, durability of immune activation, patterns of toxicity, and early detection of treatment response. Here, we review the correlative science in adoptive cell therapy (ACT) for childhood central nervous system (CNS) tumors, with a focus on existing chimeric antigen receptor (CAR) and T cell receptor (TCR)-expressing T cell therapies. RECENT FINDINGS: We highlight long-standing and more recently understood challenges for effective alignment of correlative data and offer practical considerations for current and future approaches to multi-omic analysis of serial tumor, serum, and cerebrospinal fluid (CSF) biospecimens. We highlight the preliminary success in collecting serial cytokine and proteomics from patients with CNS tumors on ACT clinical trials.

Correction to: Comparative multidimensional molecular analyses of pediatric diffuse intrinsic pontine glioma reveals distinct molecular subtypes.

The original version of this article unfortunately contained a mistake.

Social and Medical Gender Affirmation Experiences Are Inversely Associated with Mental Health Problems in a U.S. Non-Probability Sample of Transgender Adults.

A dearth of research has explored concurrently the associations between multiple forms of gender affirmation (or transitioning) and the mental health of transgender adults. In 2015, 288 U.S. transgender adults completed a cross-sectional, online survey assessing demographics, gender affirmation experiences, and mental health. Adjusting for age and discrimination experiences, we used mixed-effect logistic regression analyses to examine changes in self-reported suicidal ideation, suicide attempts, and non-suicidal self-injury (NSSI) before and after initiating the gender affirmation process, and linear regression analyses to examine associations between gender affirmation experiences and self-reported depressive, anxiety, and stress symptoms. Overall, 81.3% of participants identified along the female-to-male, trans masculine gender spectrum (of which 20.9% identified as non-binary) and 18.8% identified along the male-to-female, trans feminine gender spectrum (of which 7.4% identified as non-binary). Nearly all participants (98.6%) reported disclosing their gender identity to family or a coworker; 67.4% endorsed recently using hormones, and 31.3% endorsed a gender-affirming medical procedure. In multivariable models, participants were at greater odds of NSSI, contemplating suicide, and attempting suicide before initiating the gender affirmation process compared to after. In additional models, gender identity disclosure and medical procedure engagement were inversely associated with depressive and anxiety symptoms, whereas gender identity disclosure, hormone use, and medical procedure engagement were inversely associated with stress symptoms. Finally, the number of gender affirmation experiences endorsed was inversely associated with depressive, anxiety, and stress symptoms. Findings support the possibility that social and medical gender affirmation experiences may be protective against mental health problems in transgender adults.

Minority Stressors Associated with Sexual Risk Behaviors and HIV Testing in a U.S. Sample of Transgender Individuals.

The majority of published research on transgender health focuses on associations between external minority stressors (e.g., discrimination) and health. Little is known about how internal minority stressors (e.g., identity concealment and expecting rejection) might predict HIV disparities. The current study addresses this gap by examining the association between external and internal minority stressors and sexual risk behaviors and HIV testing history in a sample of 300 transgender adults across the U.S. Transgender-related discrimination and expecting rejection were associated with sexual risk behaviors. When controlling for covariates, none of the minority stressors were associated with HIV testing. Results illustrate how minority stress, both external and internal, may operate uniquely for transgender individuals.

Distinct Coping Profiles Are Associated With Mental Health Differences in Transgender and Gender Nonconforming Adults.

OBJECTIVE: This study assessed the unique coping strategies of transgender and gender nonconforming (TGNC) individuals in the United States used to manage gender-related stress, and examined associations between specific coping profiles and mental health. METHODS: Data were from 316 participants in the 2014-2015 Transgender Stress and Health Study, an online study of TGNC mental and sexual health. A factor analysis of the coping measure (Brief COPE) was followed by a k-means cluster analysis to evaluate distinct profiles of coping with gender-related stress. Proportional odds models and logistic regression models indicated how coping profiles related to levels of self-reported depressive symptoms and suicidality. RESULTS: A 4-factor structure was identified with three distinct profiles of coping with gender-related stress, each representative of the frequency (high or low) in which participants used functional and dysfunctional coping strategies: (a) high-functional/low-dysfunctional, (b) high-functional/high-dysfunctional, and (c) low-functional/low-dysfunctional. There were significant differences in depressive symptoms and suicidality based on distinct gender-related coping profiles. The high-functional/high-dysfunctional group reported significantly poorer mental health compared with the high-functional/low-dysfunctional group. CONCLUSION: To improve mental health outcomes in TGNC individuals, health providers and researchers should strive to not only promote functional coping strategies for managing gender-related stress but also decrease dysfunctional coping strategies.

A Proteogenomic Approach to Understanding MYC Function in Metastatic Medulloblastoma Tumors.

Brain tumors are the leading cause of cancer-related deaths in children, and medulloblastoma is the most prevalent malignant childhood/pediatric brain tumor. Providing effective treatment for these cancers, with minimal damage to the still-developing brain, remains one of the greatest challenges faced by clinicians. Understanding the diverse events driving tumor formation, maintenance, progression, and recurrence is necessary for identifying novel targeted therapeutics and improving survival of patients with this disease. Genomic copy number alteration data, together with clinical studies, identifies c-MYC amplification as an important risk factor associated with the most aggressive forms of medulloblastoma with marked metastatic potential. Yet despite this, very little is known regarding the impact of such genomic abnormalities upon the functional biology of the tumor cell. We discuss here how recent advances in quantitative proteomic techniques are now providing new insights into the functional biology of these aggressive tumors, as illustrated by the use of proteomics to bridge the gap between the genotype and phenotype in the case of c-MYC-amplified/associated medulloblastoma. These integrated proteogenomic approaches now provide a new platform for understanding cancer biology by providing a functional context to frame genomic abnormalities.

Phase I and pharmacokinetic trial of PTC299 in pediatric patients with refractory or recurrent central nervous system tumors: a PBTC study.

PTC299 is a novel, orally-bioavailable small molecule that selectively inhibits vascular endothelial growth factor receptor protein synthesis at the post-transcriptional level. Based on promising preclinical results, we conducted a pediatric phase I study to estimate the maximum tolerated dose, describe dose-limiting toxicities (DLT) and characterize the pharmacokinetic profile of PTC299 in children with recurrent CNS tumors. PTC299 was administered orally twice or three times daily, depending on the regimen. Four regimens were evaluated using the rolling 6 design, starting with 1.2 mg/kg/dose twice daily and escalating to 2 mg/kg/dose three times daily. Pharmacokinetic studies were performed during the first two courses. Twenty-seven children (14 male, median age 11.2, range 5.5-21 years) with recurrent brain tumors were treated; 21 were fully evaluable for toxicity assessment. Therapy was well-tolerated, and the only DLT was grade 3 hyponatremia. Grade three and grade four toxicities were uncommon in subsequent cycles. Median AUC0-Tlast values at the 2 mg/kg were similar to those observed in adults. The study was terminated while patients were being treated at the highest planned dose, due to hepatotoxicity encountered in the ongoing adult phase I studies. No complete or partial responses were observed. Two patients with low-grade gliomas were noted to have minor responses, and at the time of the study's closure, 5 children with low-grade gliomas had been on therapy for 8 or more courses (range 8-16). PTC299 was well-tolerated at the highest dose level tested (2 mg/kg/dose TID) in children with recurrent brain tumors and prolonged disease stabilization was seen in children with low-grade gliomas.

Preclinical magnetic resonance imaging and systems biology in cancer research: current applications and challenges.

Biologically accurate mouse models of human cancer have become important tools for the study of human disease. The anatomical location of various target organs, such as brain, pancreas, and prostate, makes determination of disease status difficult. Imaging modalities, such as magnetic resonance imaging, can greatly enhance diagnosis, and longitudinal imaging of tumor progression is an important source of experimental data. Even in models where the tumors arise in areas that permit visual determination of tumorigenesis, longitudinal anatomical and functional imaging can enhance the scope of studies by facilitating the assessment of biological alterations, (such as changes in angiogenesis, metabolism, cellular invasion) as well as tissue perfusion and diffusion. One of the challenges in preclinical imaging is the development of infrastructural platforms required for integrating in vivo imaging and therapeutic response data with ex vivo pathological and molecular data using a more systems-based multiscale modeling approach. Further challenges exist in integrating these data for computational modeling to better understand the pathobiology of cancer and to better affect its cure. We review the current applications of preclinical imaging and discuss the implications of applying functional imaging to visualize cancer progression and treatment. Finally, we provide new data from an ongoing preclinical drug study demonstrating how multiscale modeling can lead to a more comprehensive understanding of cancer biology and therapy.

Comparative multidimensional molecular analyses of pediatric diffuse intrinsic pontine glioma reveals distinct molecular subtypes.

Diffuse intrinsic pontine glioma (DIPG) is a highly morbid form of pediatric brainstem glioma. Here, we present the first comprehensive protein, mRNA, and methylation profiles of fresh-frozen DIPG specimens (n = 14), normal brain tissue (n = 10), and other pediatric brain tumors (n = 17). Protein profiling identified 2,305 unique proteins indicating distinct DIPG protein expression patterns compared to other pediatric brain tumors. Western blot and immunohistochemistry validated upregulation of Clusterin (CLU), Elongation Factor 2 (EF2), and Talin-1 (TLN1) in DIPGs studied. Comparisons to mRNA expression profiles generated from tumor and adjacent normal brain tissue indicated two DIPG subgroups, characterized by upregulation of Myc (N-Myc) or Hedgehog (Hh) signaling. We validated upregulation of PTCH, a membrane receptor in the Hh signaling pathway, in a subgroup of DIPG specimens. DNA methylation analysis indicated global hypomethylation of DIPG compared to adjacent normal tissue specimens, with differential methylation of 24 genes involved in Hh and Myc pathways, correlating with protein and mRNA expression patterns. Sequencing analysis showed c.83A>T mutations in the H3F3A or HIST1H3B gene in 77 % of our DIPG cohort. Supervised analysis revealed a unique methylation pattern in mutated specimens compared to the wild-type DIPG samples. This study presents the first comprehensive multidimensional protein, mRNA, and methylation profiling of pediatric brain tumor specimens, detecting the presence of two subgroups within our DIPG cohort. This multidimensional analysis of DIPG provides increased analytical power to more fully explore molecular signatures of DIPGs, with implications for evaluating potential molecular subtypes and biomarker discovery for assessing response to therapy.

The Open Pediatric Cancer Project.

Background: In 2019, the Open Pediatric Brain Tumor Atlas (OpenPBTA) was created as a global, collaborative open-science initiative to genomically characterize 1,074 pediatric brain tumors and 22 patient-derived cell lines. Here, we extend the OpenPBTA to create the Open Pediatric Cancer (OpenPedCan) Project, a harmonized open-source multi-omic dataset from 6,112 pediatric cancer patients with 7,096 tumor events across more than 100 histologies. Combined with RNA-Seq from the Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA), OpenPedCan contains nearly 48,000 total biospecimens (24,002 tumor and 23,893 normal specimens). Findings: We utilized Gabriella Miller Kids First (GMKF) workflows to harmonize WGS, WXS, RNA-seq, and Targeted Sequencing datasets to include somatic SNVs, InDels, CNVs, SVs, RNA expression, fusions, and splice variants. We integrated summarized CPTAC whole cell proteomics and phospho-proteomics data, miRNA-Seq data, and have developed a methylation array harmonization workflow to include m-values, beta-vales, and copy number calls. OpenPedCan contains reproducible, dockerized workflows in GitHub, CAVATICA, and Amazon Web Services (AWS) to deliver harmonized and processed data from over 60 scalable modules which can be leveraged both locally and on AWS. The processed data are released in a versioned manner and accessible through CAVATICA or AWS S3 download (from GitHub), and queryable through PedcBioPortal and the NCI's pediatric Molecular Targets Platform. Notably, we have expanded PBTA molecular subtyping to include methylation information to align with the WHO 2021 Central Nervous System Tumor classifications, allowing us to create research-grade integrated diagnoses for these tumors. Conclusions: OpenPedCan data and its reproducible analysis module framework are openly available and can be utilized and/or adapted by researchers to accelerate discovery, validation, and clinical translation.

The receptor tyrosine kinase EphA2 is a direct target gene of hypermethylated in cancer 1 (HIC1).

The tumor suppressor gene hypermethylated in cancer 1 (HIC1), which encodes a transcriptional repressor, is epigenetically silenced in many human tumors. Here, we show that ectopic expression of HIC1 in the highly malignant MDA-MB-231 breast cancer cell line severely impairs cell proliferation, migration, and invasion in vitro. In parallel, infection of breast cancer cell lines with a retrovirus expressing HIC1 also induces decreased mRNA and protein expression of the tyrosine kinase receptor EphA2. Moreover, chromatin immunoprecipitation (ChIP) and sequential ChIP experiments demonstrate that endogenous HIC1 proteins are bound, together with the MTA1 corepressor, to the EphA2 promoter in WI38 cells. Taken together, our results identify EphA2 as a new direct target gene of HIC1. Finally, we observe that inactivation of endogenous HIC1 through RNA interference in normal breast epithelial cells results in the up-regulation of EphA2 and is correlated with increased cellular migration. To conclude, our results involve the tumor suppressor HIC1 in the transcriptional regulation of the tyrosine kinase receptor EphA2, whose ligand ephrin-A1 is also a HIC1 target gene. Thus, loss of the regulation of this Eph pathway through HIC1 epigenetic silencing could be an important mechanism in the pathogenesis of epithelial cancers.

Loss of Hypermethylated in Cancer 1 (HIC1) in breast cancer cells contributes to stress-induced migration and invasion through ß-2 adrenergic receptor (ADRB2) misregulation.

The transcriptional repressor HIC1 (Hypermethylated in Cancer 1) is a tumor suppressor gene inactivated in many human cancers including breast carcinomas. In this study, we show that HIC1 is a direct transcriptional repressor of ß-2 adrenergic receptor (ADRB2). Through promoter luciferase activity, chromatin immunoprecipitation (ChIP) and sequential ChIP experiments, we demonstrate that ADRB2 is a direct target gene of HIC1, endogenously in WI-38 cells and following HIC1 re-expression in breast cancer cells. Agonist-mediated stimulation of ADRB2 increases the migration and invasion of highly malignant MDA-MB-231 breast cancer cells but these effects are abolished following HIC1 re-expression or specific down-regulation of ADRB2 by siRNA treatment. Our results suggest that early inactivation of HIC1 in breast carcinomas could predispose to stress-induced metastasis through up-regulation of the ß-2 adrenergic receptor.

The Reelin receptors ApoER2 and VLDLR are direct target genes of HIC1 (Hypermethylated In Cancer 1).

The tumor suppressor gene HIC1 (Hypermethylated In Cancer 1) is located in 17p13.3 a region frequently hypermethylated or deleted in tumors and in a contiguous-gene syndrome, the Miller-Dieker syndrome which includes classical lissencephaly (smooth brain) and severe developmental defects. HIC1 encodes a transcriptional repressor involved in the regulation of growth control, DNA damage response and cell migration properties. We previously demonstrated that the membrane-associated G-protein-coupled receptors CXCR7, ADRB2 and the tyrosine kinase receptor EphA2 are direct target genes of HIC1. Here we show that ectopic expression of HIC1 in U2OS and MDA-MB-231 cell lines decreases expression of the ApoER2 and VLDLR genes, encoding two canonical tyrosine kinase receptors for Reelin. Conversely, knock-down of endogenous HIC1 in BJ-Tert normal human fibroblasts through RNA interference results in the up-regulation of these two Reelin receptors. Finally, through chromatin immunoprecipitation (ChIP) in BJ-Tert fibroblasts, we demonstrate that HIC1 is a direct transcriptional repressor of ApoER2 and VLDLR. These data provide evidence that HIC1 is a new regulator of the Reelin pathway which is essential for the proper migration of neuronal precursors during the normal development of the cerebral cortex, of Purkinje cells in the cerebellum and of mammary epithelial cells. Deregulation of this pathway through HIC1 inactivation or deletion may contribute to its role in tumor promotion. Moreover, HIC1, through the direct transcriptional repression of ATOH1 and the Reelin receptors ApoER2 and VLDLR, could play an essential role in normal cerebellar development.

A feasibility and efficacy study of rapamycin and erlotinib for recurrent pediatric low-grade glioma (LGG).

BACKGROUND: To determine the toxicity and efficacy of rapamycin and erlotinib for the treatment of recurrent pediatric low-grade gliomas (LGGs). METHODS: Patients <21 years of age with recurrent LGGs who had failed conventional treatment were eligible, including those with NF1. The treatment consisted of two phases, a feasibility portion which assessed the toxicity of erlotinib at 65 mg/m(2) /day once daily and rapamycin at 0.8 mg/m(2) /dose twice daily for 28 consecutive days. RESULTS: Nineteen (19) patients, median age of 8 years, with recurrent LGGs received the two-drug regimen. Eight (8) of the patients had NF1. The combination of erlotinib and rapamycin was well tolerated and no patient was removed from study due to toxicity. All 19 patients were evaluable for response and one child, with NF1, had a partial response to treatment. Six (6) patients received the planned 12 courses of treatment. The reasons for stoppage of therapy before 1 year of treatment were poor compliance (1), parental desire for withdrawal (1), persistent vomiting which pre-dated initiation of therapy (1), and radiographic progression (10). In those patients with stabilization of disease for 12 months or greater, 3 stayed on therapy and ultimately developed progressive disease, and one patient stopped therapy at 12 months and progressed. Two (2) patients, both with NF1, have had >1 year disease control. CONCLUSIONS: The combination of rapamycin and erlotinib is well tolerated in children with LGGs. Objective responses were infrequent, although there was prolonged disease stabilization in some patients with LGGs, especially in two children with NF1.

Long-term efficacy and toxicity of bevacizumab-based therapy in children with recurrent low-grade gliomas.

BACKGROUND: Because definitive resection or radiotherapy for pediatric low-grade gliomas (LGGs) may be associated with severe and permanent adverse effects, medical management has taken a significant role. Bevacizumab-based therapy has demonstrated encouraging responses; however, longer-term toxicity, response durability and alternative dosing regimens have not been evaluated. PROCEDURE: This was a retrospective review of children with multiply recurrent, progressive LGGs treated with bevacizumab-based therapy and followed for at least 12 months after treatment completion. Toxicity was uniformly graded and imaging was centrally reviewed. RESULTS: All fourteen patients had failed at least two prior treatment regimens; six had dissemination. Patients received initial bevacizumab-based therapy at a median age of 5.3 years (range, 1-12 years). Median treatment duration was 12 months (range, 1-24 months). 12 patients had an objective response; 2 had stable disease. Median time to maximum response was 9 weeks (range, 7-17 weeks). No patients progressed on therapy, although 13/14 progressed after stopping bevacizumab at a median of 5 months. Four patients were re-treated with bevacizumab and all again responded or stabilized. Alternative dosing strategies were effective, including bevacizumab monotherapy and prolonging the dosing interval to 3 weeks. High-grade bevacizumab-related toxicities consisted of grade 3 proteinuria (n = 2), primary inflammatory arthritis (n = 1), and somnolence (n = 1). Toxicities resolved within 6 months of treatment cessation except one case of hypertension. CONCLUSIONS: Bevacizumab-based therapy is successful at inducing rapid LGG response. Patients progressing off-therapy may be successfully re-treated with bevacizumab. Nearly all tumors progress once treatment is discontinued. Toxicities are not insignificant but usually reversible.

A multi-institutional pediatric dataset of clinical radiology MRIs by the Children's Brain Tumor Network.

Pediatric brain and spinal cancers remain the leading cause of cancer-related death in children. Advancements in clinical decision-support in pediatric neuro-oncology utilizing the wealth of radiology imaging data collected through standard care, however, has significantly lagged other domains. Such data is ripe for use with predictive analytics such as artificial intelligence (AI) methods, which require large datasets. To address this unmet need, we provide a multi-institutional, large-scale pediatric dataset of 23,101 multi-parametric MRI exams acquired through routine care for 1,526 brain tumor patients, as part of the Children's Brain Tumor Network. This includes longitudinal MRIs across various cancer diagnoses, with associated patient-level clinical information, digital pathology slides, as well as tissue genotype and omics data. To facilitate downstream analysis, treatment-naïve images for 370 subjects were processed and released through the NCI Childhood Cancer Data Initiative via the Cancer Data Service. Through ongoing efforts to continuously build these imaging repositories, our aim is to accelerate discovery and translational AI models with real-world data, to ultimately empower precision medicine for children.

OpenPBTA: The Open Pediatric Brain Tumor Atlas.

Pediatric brain and spinal cancers are collectively the leading disease-related cause of death in children; thus, we urgently need curative therapeutic strategies for these tumors. To accelerate such discoveries, the Children's Brain Tumor Network (CBTN) and Pacific Pediatric Neuro-Oncology Consortium (PNOC) created a systematic process for tumor biobanking, model generation, and sequencing with immediate access to harmonized data. We leverage these data to establish OpenPBTA, an open collaborative project with over 40 scalable analysis modules that genomically characterize 1,074 pediatric brain tumors. Transcriptomic classification reveals universal TP53 dysregulation in mismatch repair-deficient hypermutant high-grade gliomas and TP53 loss as a significant marker for poor overall survival in ependymomas and H3 K28-mutant diffuse midline gliomas. Already being actively applied to other pediatric cancers and PNOC molecular tumor board decision-making, OpenPBTA is an invaluable resource to the pediatric oncology community.

Targeted gene expression profiling predicts meningioma outcomes and radiotherapy responses.

Background: Surgery is the mainstay of treatment for meningioma, the most common primary intracranial tumor, but improvements in meningioma risk stratification are needed and current indications for postoperative radiotherapy are controversial. Recent studies have proposed prognostic meningioma classification systems using DNA methylation profiling, copy number variants, DNA sequencing, RNA sequencing, histology, or integrated models based on multiple combined features. Targeted gene expression profiling has generated robust biomarkers integrating multiple molecular features for other cancers, but is understudied for meningiomas. Methods: Targeted gene expression profiling was performed on 173 meningiomas and an optimized gene expression biomarker (34 genes) and risk score (0 to 1) was developed to predict clinical outcomes. Clinical and analytical validation was performed on independent meningiomas from 12 institutions across 3 continents (N = 1856), including 103 meningiomas from a prospective clinical trial. Gene expression biomarker performance was compared to 9 other classification systems. Results: The gene expression biomarker improved discrimination of postoperative meningioma outcomes compared to all other classification systems tested in the independent clinical validation cohort for local recurrence (5-year area under the curve [AUC] 0.81) and overall survival (5-year AUC 0.80). The increase in area under the curve compared to the current standard of care, World Health Organization 2021 grade, was 0.11 for local recurrence (95% confidence interval [CI] 0.07-0.17, P < 0.001). The gene expression biomarker identified meningiomas benefiting from postoperative radiotherapy (hazard ratio 0.54, 95% CI 0.37-0.78, P = 0.0001) and re-classified up to 52.0% meningiomas compared to conventional clinical criteria, suggesting postoperative management could be refined for 29.8% of patients. Conclusions: A targeted gene expression biomarker improves discrimination of meningioma outcomes compared to recent classification systems and predicts postoperative radiotherapy responses.