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Neurosurgery Sep 2017Neuroimaging plays an ever evolving role in the diagnosis, treatment planning, and post-therapy assessment of brain tumors. This review provides an overview of current... (Review)
Review
Neuroimaging plays an ever evolving role in the diagnosis, treatment planning, and post-therapy assessment of brain tumors. This review provides an overview of current magnetic resonance imaging (MRI) methods routinely employed in the care of the brain tumor patient. Specifically, we focus on advanced techniques including diffusion, perfusion, spectroscopy, tractography, and functional MRI as they pertain to noninvasive characterization of brain tumors and pretreatment evaluation. The utility of both structural and physiological MRI in the post-therapeutic brain evaluation is also reviewed with special attention to the challenges presented by pseudoprogression and pseudoresponse.
Topics: Brain; Brain Neoplasms; Humans; Magnetic Resonance Imaging; Neuroimaging
PubMed: 28486641
DOI: 10.1093/neuros/nyx103 -
Frontiers in Oncology 2022In recent years, various systemic immunotherapies have been developed for cancer treatment, such as monoclonal antibodies (mABs) directed against immune checkpoints... (Review)
Review
In recent years, various systemic immunotherapies have been developed for cancer treatment, such as monoclonal antibodies (mABs) directed against immune checkpoints (immune checkpoint inhibitors, ICIs), oncolytic viruses, cytokines, cancer vaccines, and adoptive cell transfer. While being estimated to be eligible in 38.5% of patients with metastatic solid or hematological tumors, ICIs, in particular, demonstrate durable disease control across many oncologic diseases (e.g., in melanoma, lung, bladder, renal, head, and neck cancers) and overall survival benefits. Due to their unique mechanisms of action based on T-cell activation, response to immunotherapies is characterized by different patterns, such as progression prior to treatment response (pseudoprogression), hyperprogression, and dissociated responses following treatment. Because these features are not encountered in the Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1), which is the standard for response assessment in oncology, new criteria were defined for immunotherapies. The most important changes in these new morphologic criteria are, firstly, the requirement for confirmatory imaging examinations in case of progression, and secondly, the appearance of new lesions is not necessarily considered a progressive disease. Until today, five morphologic (immune-related response criteria (irRC), immune-related RECIST (irRECIST), immune RECIST (iRECIST), immune-modified RECIST (imRECIST), and intra-tumoral RECIST (itRECIST)) criteria have been developed to accurately assess changes in target lesion sizes, taking into account the specific response patterns after immunotherapy. In addition to morphologic response criteria, 2-deoxy-2-[F]fluoro-D-glucose positron emission tomography/computed tomography (F-FDG-PET/CT) is a promising option for metabolic response assessment and four metabolic criteria are used (PET/CT Criteria for Early Prediction of Response to Immune Checkpoint Inhibitor Therapy (PECRIT), PET Response Evaluation Criteria for Immunotherapy (PERCIMT), immunotherapy-modified PET Response Criteria in Solid Tumors (imPERCIST5), and immune PERCIST (iPERCIST)). Besides, there is evidence that parameters on F-FDG-PET/CT, such as the standardized uptake value (SUV)max and several radiotracers, e.g., directed against PD-L1, may be potential imaging biomarkers of response. Moreover, the emerge of human intratumoral immunotherapy (HIT-IT), characterized by the direct injection of immunostimulatory agents into a tumor lesion, has given new importance to imaging assessment. This article reviews the specific imaging patterns of tumor response and progression and available imaging response criteria following immunotherapy.
PubMed: 36387133
DOI: 10.3389/fonc.2022.982983 -
Cancer Research Feb 2022Testing peripheral blood for circulating tumor DNA (ctDNA) offers a minimally invasive opportunity to diagnose, characterize, and monitor the disease in individual... (Review)
Review
Testing peripheral blood for circulating tumor DNA (ctDNA) offers a minimally invasive opportunity to diagnose, characterize, and monitor the disease in individual cancer patients. ctDNA can reflect the actual tumor burden and specific genomic state of disease and thus might serve as a prognostic and predictive biomarker for immune checkpoint inhibitor (ICI) therapy. Recent studies in various cancer entities (e.g., melanoma, non-small cell lung cancer, colon cancer, and urothelial cancer) have shown that sequential ctDNA analyses allow for the identification of responders to ICI therapy, with a significant lead time to imaging. ctDNA assessment may also help distinguish pseudoprogression under ICI therapy from real progression. Developing dynamic changes in ctDNA concentrations as a potential surrogate endpoint of clinical efficacy in patients undergoing adjuvant immunotherapy is ongoing. Besides overall ctDNA burden, further ctDNA characterization can help uncover tumor-specific determinants (e.g., tumor mutational burden and microsatellite instability) of responses or resistance to immunotherapy. In future studies, standardized ctDNA assessments need to be included in interventional clinical trials across cancer entities to demonstrate the clinical utility of ctDNA as a biomarker for personalized cancer immunotherapy.
Topics: Biomarkers, Tumor; Circulating Tumor DNA; Humans; Immunotherapy
PubMed: 34815256
DOI: 10.1158/0008-5472.CAN-21-1718 -
Cancer Cell Sep 2020Even though the immuno-oncology (IO) era has achieved many successes, some signs of research development deceleration are arising. Recently, the number of FDA... (Review)
Review
Even though the immuno-oncology (IO) era has achieved many successes, some signs of research development deceleration are arising. Recently, the number of FDA immunotherapy approvals has decreased concurrently with a decline in the relative number of patients recruited to these trials. Identifying the unique features of IO treatments and taking them into consideration on clinical research will lead to a better evaluation of these agents and patient outcomes. In this review, we discuss current challenges and new potential approaches to implement rationally designed clinical trials of IO drugs, particularly those targeting immune checkpoints.
Topics: Antineoplastic Agents, Immunological; B7-H1 Antigen; CTLA-4 Antigen; Humans; Immune Checkpoint Inhibitors; Immunotherapy; Neoplasms; Programmed Cell Death 1 Receptor; Signal Transduction; Treatment Outcome
PubMed: 32750319
DOI: 10.1016/j.ccell.2020.07.004 -
Therapeutic Advances in Neurological... 2018Imaging plays several key roles in managing brain tumors, including diagnosis, prognosis, and treatment response assessment. Ongoing challenges remain as new therapies... (Review)
Review
Imaging plays several key roles in managing brain tumors, including diagnosis, prognosis, and treatment response assessment. Ongoing challenges remain as new therapies emerge and there are urgent needs to find accurate and clinically feasible methods to noninvasively evaluate brain tumors before and after treatment. This review aims to provide an overview of several advanced imaging modalities including magnetic resonance imaging and positron emission tomography (PET), including advances in new PET agents, and summarize several key areas of their applications, including improving the accuracy of diagnosis and addressing the challenging clinical problems such as evaluation of pseudoprogression and anti-angiogenic therapy, and rising challenges of imaging with immunotherapy.
PubMed: 29511385
DOI: 10.1177/1756286418759865 -
The Journal of Clinical Investigation Aug 2022Accurately identifying patients who respond to immunotherapy remains clinically challenging. A noninvasive method that can longitudinally capture information about...
Accurately identifying patients who respond to immunotherapy remains clinically challenging. A noninvasive method that can longitudinally capture information about immune cell function and assist in the early assessment of tumor responses is highly desirable for precision immunotherapy. Here, we show that PET imaging using a granzyme B-targeted radiotracer named 68Ga-grazytracer, could noninvasively and effectively predict tumor responses to immune checkpoint inhibitors and adoptive T cell transfer therapy in multiple tumor models. 68Ga-grazytracer was designed and selected from several radiotracers based on non-aldehyde peptidomimetics, and exhibited excellent in vivo metabolic stability and favorable targeting efficiency to granzyme B secreted by effector CD8+ T cells during immune responses. 68Ga-grazytracer permitted more sensitive discrimination of responders and nonresponders than did 18F-fluorodeoxyglucose, distinguishing between tumor pseudoprogression and true progression upon immune checkpoint blockade therapy in mouse models with varying immunogenicity. In a preliminary clinical trial with 5 patients, no adverse events were observed after 68Ga-grazytracer injection, and clinical responses in cancer patients undergoing immunotherapy were favorably correlated with 68Ga-grazytracer PET results. These results highlight the potential of 68Ga-grazytracer PET to enhance the clinical effectiveness of granzyme B secretion-related immunotherapies by supporting early response assessment and precise patient stratification in a noninvasive and longitudinal manner.
Topics: Animals; CD8-Positive T-Lymphocytes; Granzymes; Immunologic Factors; Immunotherapy; Mice; Neoplasms; Positron-Emission Tomography
PubMed: 35788116
DOI: 10.1172/JCI161065 -
Blood Nov 2016Uniformly adopted response criteria are essential for assessment of therapies incorporating conventional chemotherapy and chemoimmunotherapy regimens. Recently,... (Review)
Review
Uniformly adopted response criteria are essential for assessment of therapies incorporating conventional chemotherapy and chemoimmunotherapy regimens. Recently, immunomodulatory agents, such as immune checkpoint inhibitors, have demonstrated impressive activity in a broad range of lymphoma histologies. However, these agents may be associated with clinical and imaging findings during treatment suggestive of progressive disease (PD) despite evidence of clinical benefit (eg, tumor flare or pseudo-progression). Considering this finding as PD could lead to patients being prematurely removed from a treatment from which they actually stand to benefit. This phenomenon has been well described with checkpoint blockade therapy in solid tumors and anecdotally seen in lymphoma as well. To address this issue in the context of lymphoma immunomodulatory therapy, a workshop was convened to provide provisional recommendations to modify current response criteria in patients receiving these and future agents in clinical trials. The term "indeterminate response" was introduced to identify such lesions until confirmed as flare/pseudo-progression or true PD by either biopsy or subsequent imaging.
Topics: Humans; Immunologic Factors; Immunotherapy; Lymphoma
PubMed: 27574190
DOI: 10.1182/blood-2016-05-718528 -
Journal of the Advanced Practitioner in... 2020Traditionally, treatment responses to chemotherapy had been based on Response Evaluation Criteria in Solid Tumours (RECIST) criteria evaluating tumor shrinkage,...
Traditionally, treatment responses to chemotherapy had been based on Response Evaluation Criteria in Solid Tumours (RECIST) criteria evaluating tumor shrinkage, stabilization of disease, growth, or development of new metastatic lesions. Using the same criteria to determine response in patients on immunotherapy has proven difficult, as some patients have initial growth of disease or develop new small metastatic lesions. The phenomenon of pseudoprogression is the initial growth of a primary lesion followed by latent or delayed response. Advanced practitioners need to be aware of the possibility of pseudoprogression in order to educate patients and help them stay on effective treatment.
PubMed: 33575068
DOI: 10.6004/jadpro.2020.11.7.6 -
International Journal of Molecular... May 2019Immunotherapy is now widely prescribed in oncology, leading to the observation of new types of responses, including rapid disease progression sometimes reported as... (Review)
Review
Immunotherapy is now widely prescribed in oncology, leading to the observation of new types of responses, including rapid disease progression sometimes reported as hyperprogression. However, only a few studies have assessed the question of hyperprogression and there is no consensual definition of this phenomenon. We reviewed existing data on hyperprogression in published studies, focusing on reported definitions, predictive factors, and potential biological mechanisms. Seven studies retrospectively assessed hyperprogression incidence, using various definitions, some based on the tumoral burden variation across time with repeated computed-tomography (CT) scan, others based on an association of radiological and clinical criteria. Reported hyperprogression incidence varied between 4% and 29% of all responses, mostly in multi-tumor cohorts and with patients receiving immune checkpoint inhibitors. Hyperprogression correlated with worse chances of survival than standard progression in two studies. However, no strong predictive factors of hyperprogression were identified, and none were consistent across studies. In total, hyperprogression is a frequent pattern of response under immunotherapy, with a strong impact on patient outcome. There is a need for a consensual definition of hyperprogression. Immunotherapy should be stopped early in cases where there is suspicion of hyperprogression.
Topics: Disease Management; Disease Progression; Humans; Immunotherapy; Incidence; Neoplasms; Prognosis
PubMed: 31151303
DOI: 10.3390/ijms20112674 -
Acta Neuropathologica Communications Dec 2023Post-resection radiologic monitoring to identify areas of new or progressive enhancement concerning for cancer recurrence is critical during patients with glioblastoma...
Post-resection radiologic monitoring to identify areas of new or progressive enhancement concerning for cancer recurrence is critical during patients with glioblastoma follow-up. However, treatment-related pseudoprogression presents with similar imaging features but requires different clinical management. While pathologic diagnosis is the gold standard to differentiate true progression and pseudoprogression, the lack of objective clinical standards and admixed histologic presentation creates the needs to (1) validate the accuracy of current approaches and (2) characterize differences between these entities to objectively differentiate true disease. We demonstrated using an online RNAseq repository of recurrent glioblastoma samples that cancer-immune cell activity levels correlate with heterogenous clinical outcomes in patients. Furthermore, nCounter RNA expression analysis of 48 clinical samples taken from second neurosurgical resection supports that pseudoprogression gene expression pathways are dominated with immune activation, whereas progression is predominated with cell cycle activity. Automated image processing and spatial expression analysis however highlight a failure to apply these broad expressional differences in a subset of cases with clinically challenging admixed histology. Encouragingly, applying unsupervised clustering approaches over our segmented histologic images provides novel understanding of morphologically derived differences between progression and pseudoprogression. Spatially derived data further highlighted polarization of myeloid populations that may underscore the tumorgenicity of novel lesions. These findings not only help provide further clarity of potential targets for pathologists to better assist stratification of progression and pseudoprogression, but also highlight the evolution of tumor-immune microenvironment changes which promote tumor recurrence.
Topics: Humans; Glioblastoma; Disease Progression; Brain Neoplasms; Chemoradiotherapy; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Tumor Microenvironment
PubMed: 38049893
DOI: 10.1186/s40478-023-01587-w