Advances In Computed Tomography Research Articles

Advanced CT visualization improves the accuracy of orthopaedic trauma surgeons and residents in classifying proximal humeral fractures: a feasibility study.

Osteosynthesis of proximal humeral fractures remains challenging with high reported failure rates. Understanding the fracture type is mandatory in surgical treatment to achieve an optimal anatomical reduction. Therefore, a better classification ability resulting in improved understanding of the fracture pattern is important for preoperative planning. The purpose was to investigate the feasibility and added value of advanced visualization of segmented 3D computed tomography (CT) images in fracture classification. Seventeen patients treated with either plate-screw-osteosynthesis or shoulder hemi-prosthesis between 2015 and 2019 were included. All preoperative CT scans were segmented to indicate every fracture fragment in a different color. Classification ability was tested in 21 orthopaedic residents and 12 shoulder surgeons. Both groups were asked to classify fractures using three different modalities (standard CT scan, 3D reconstruction model, and 3D segmented model) into three different classification systems (Neer, AO/OTA and LEGO). All participants were able to classify the fractures more accurately into all three classification systems after evaluating the segmented three-dimensional (3D) models compared to both 2D slice-wise evaluation and 3D reconstruction model. This finding was significant (p < 0.005) with an average success rate of 94%. The participants experienced significantly more difficulties classifying fractures according to the LEGO system than the other two classifications. Segmentation of CT scans added value to the proximal humeral fracture classification, since orthopaedic surgeons were able to classify fractures significantly better into the AO/OTA, Neer, and LEGO classification systems compared to both standard 2D slice-wise evaluation and 3D reconstruction model.

Multi-energy computed tomography and material quantification: Current barriers and opportunities for advancement.

Computed tomography (CT) technology has rapidly evolved since its introduction in the 1970s. It is a highly important diagnostic tool for clinicians as demonstrated by the significant increase in utilization over several decades. However, much of the effort to develop and advance CT applications has been focused on improving visual sensitivity and reducing radiation dose. In comparison to these areas, improvements in quantitative CT have lagged behind. While this could be a consequence of the technological limitations of conventional CT, advanced dual-energy CT (DECT) and photon-counting detector CT (PCD-CT) offer new opportunities for quantitation. Routine use of DECT is becoming more widely available and PCD-CT is rapidly developing. This review covers efforts to address an unmet need for improved quantitative imaging to better characterize disease, identify biomarkers, and evaluate therapeutic response, with an emphasis on multi-energy CT applications. The review will primarily discuss applications that have utilized quantitative metrics using both conventional and DECT, such as bone mineral density measurement, evaluation of renal lesions, and diagnosis of fatty liver disease. Other topics that will be discussed include efforts to improve quantitative CT volumetry and radiomics. Finally, we will address the use of quantitative CT to enhance image-guided techniques for surgery, radiotherapy and interventions and provide unique opportunities for development of new contrast agents.

Novel Nuclear Medicine Imaging Applications in Immuno-Oncology.

The global immuno-oncology pipeline has grown progressively in recent years, leading cancer immunotherapy to become one of the main issues of the healthcare industry. Despite their success in the treatment of several malignancies, immune checkpoint inhibitors (ICIs) perform poorly in others. Again, ICIs action depends on such a multitude of clinico-pathological features, that the attempt to predict responders/long-responders with ad-hoc built immunograms revealed to be quite complex. In this landscape, the role of nuclear medicine might be crucial, with first interesting evidences coming from small case series and pre-clinical studies. Positron-emission tomography (PET) techniques provide functional information having a predictive and/or prognostic value in patients treated with ICIs or adoptive T-cell therapy. Recently, a characterization of the tumor immune microenvironment (TiME) pattern itself has been shown to be feasible through the use of different radioactive tracers or image algorithms, thus adding knowledge about tumor heterogeneity. Finally, nuclear medicine exams permit an early detection of immune-related adverse events (irAEs), with on-going clinical trials investigating their correlation with patients’ outcome. This review depicts the recent advances in molecular imaging both in terms of non-invasive diagnosis of TiME properties and benefit prediction from immunotherapeutic agents.

Targeting intracellular check points to unleash natural killer cell cytotoxicity

Abstract Natural killer (NK) cells are a potent weapon of the immune system against viral infections and tumor growth. The actomyosin network generates forces through the activity of actin filaments and myosin motors. This machinery is responsible for the conversion of mechanical forces into biochemical signals in a process termed mechanotransduction. However, the mechanism by which mechanotransduction controls the immune response, and specifically lymphocyte activity, is poorly understood. Here, we demonstrate that actomyosin retrograde flow (ARF) controls NK cell response through a novel interaction between beta-actin with the SH2-domain containing protein tyrosine phosphatase-1 (SHP-1), converting its conformation state, thereby regulating NK cell cytotoxicity. Actin dynamics govern SHP-1 conformational structure dictating its catalytic activity. Indeed, blocking actin dynamics results in reduced SHP-1 activity, by confining SHP-1 to its inactivated “closed” conformation. This reduced enzymatic activity of SHP-1 leads to increased phosphorylation of SHP-1 substrates, an elevation of intracellular calcium flux, and NK cell cytotoxicity. Using multidisciplinary approaches including functional and advanced molecular imaging, we followed the signaling events in individual NK cells from the moment of target cell encounter until the final outcome – target cell killing or NK cell inhibition. Our data suggest that SHP-1 plays a major role as a sensor of ARF-generated forces in the process of mechanotransduction, and reveal a novel mechanism by which regulation of SHP-1 by ARF dictates NK cell killing decisions. Our data identify ARF as a master regulator of the lymphocyte response.

Nuclear medicine and molecular imaging advances in the 21st century.

Currently, Nuclear Medicine has a clearly defined role in clinical practice due to its usefulness in many medical disciplines. It provides relevant diagnostic and therapeutic options leading to patients' healthcare and quality of life improvement. During the first two decades of the 21stt century, the number of Nuclear Medicine procedures increased considerably.Clinical and research advances in Nuclear Medicine and Molecular Imaging have been based on developments in radiopharmaceuticals and equipment, namely, the introduction of multimodality imaging. In addition, new therapeutic applications of radiopharmaceuticals, mainly in oncology, are underway.This review will focus on radiopharmaceuticals for positron emission tomography (PET), in particular, those labeled with Fluorine-18 and Gallium-68. Multimodality as a key player in clinical practice led to the development of new detector technology and combined efforts to improve resolution. The concept of dual probe (a single molecule labeled with a radionuclide for single photon emission computed tomography)/positron emission tomography and a light emitter for optical imaging) is gaining increasing acceptance, especially in minimally invasive radioguided surgery. The expansion of theranostics, using the same molecule for diagnosis (γ or positron emitter) and therapy (β minus or α emitter) is reshaping personalized medicine.Upcoming research and development efforts will lead to an even wider array of indications for Nuclear Medicine both in diagnosis and treatment.

Advanced Molecular Imaging in Histologically Verified Metanephric Adenoma

Metanephric adenoma (MA) describes a rare renal tumor and is generally considered a benign lesion. However, there are cases with regional lymphogenic and distant metastases. Noninvasive diagnosis of MA using conventional imaging remains challenging. Here, we describe a case of histologically verified MA with additional advanced molecular imaging consisting of 18F-PSMA-1007 PET/CT, 99mTc-Sestamibi SPECT and contrast-enhanced ultrasound.

Abstract P2-01-01: Evaluating the order of treatments to enhance efficacy in a murine model of triple negative breast cancer with quantitative imaging

Abstract Introduction: The purpose of this study is to determine if order of dosing of combination chemotherapies (paclitaxel, doxorubicin) alters response in triple negative breast cancers (TNBCs). TNBC has limited treatment options and primarily relies on chemotherapy in both primary and metastatic disease. There are a number of clinically utilized regimens of combination chemotherapies and the optimal treatment strategy is still unknown. Thus, there is a need to explore how the order of regimens effects tumor response and optimize treatment efficacy in breast cancer population. Currently, one of the most commonly used regimens for locally advanced TNBCs is administration of doxorubicin (DRB) followed by paclitaxel (PTX). DRB, as a topoisomerase inhibitor, targets both cell cycle stage G1 and S, while PTX only targets cell cycle stage S. Our goal is to evaluate and compare tumor response of the order of dosing of PTX and DRB with quantitative molecular imaging. Advanced molecular imaging provides a noninvasive and highly sensitive approach to identify changes in quantify the early signal of drug response prior tumor size changes. Experimental Design: MDA-MB-231-FUCCI (Green fluorescence during S, G2, M phase; Red fluorescence during G1 phase) TNBC cells (2 × 106) were subcutaneously injected into nude mice (n = 12) and randomly assigned into three treatment groups: PTX (10 mg/kg)→DRB (10 mg/kg), DRB→PTX (same drug dosage), and saline control. 3’-Deoxy-3’-[18F]fluorothymidine ([18F]-FLT) positron emission tomography (PET)/computed tomography (CT) (SOFIE preclinical PET/CT) was performed before treatment (day 0), and on days 3 and 6. Treatment occurred on days 0 and 3 post imaging. GFP and RFP fluorescence were measured through in vivo imaging system (IVIS) on baseline and on day 6. In vivo cell proliferation was quantifying the percent change from baseline of normalized [18F]-FLT standard uptake value (SUV) (tumor mean/muscle mean) and normalized GFP signal (tumor/muscle). In vivo cell viability was determined by RFP signal percentage change. Statistical significance was evaluated with a t-test. Results: Cell proliferation and viability assessed through [18F]-FLT PET and fluorescence imaging showed that PTX prior to DRB treatment significantly decreased cancer cell proliferation and viability. From day 0 to 6, overall RFP signal of control increased 14%, while DRB → PTX decreased 36%, and PTX→DRB decreased 50% (p=0.060). Fluorescence imaging showed DRB→PTX treatment GFP signal increase by 3-fold (p=0.029) compared to control, while PTX→DRB treatment is similar to control (p&amp;gt;0.05). 18F-FLT PET SUV revealed from day 0 to 6, control had a 110% increase, DRB→PTX showed 60% increase, while PTX→DRB showed about 10% increase (p=0.010). Conclusion: PTX prior to DRB significantly improved tumor response to chemotherapy in this TNBC model by decreasing tumor cell viability and proliferation. Molecular imaging allows us to visualize and quantitate these cellular changes prior tumor size changes and may help guide clinical decision making for the treatment for TNBC patients. We acknowledge the support of ACS RSG-18-006-01-CCE Citation Format: Yun Lu, Adriana Massicano, Rachel David, Anna Sorace. Evaluating the order of treatments to enhance efficacy in a murine model of triple negative breast cancer with quantitative imaging [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-01-01.

Bioconjugates of Chelators with Peptides and Proteins in Nuclear Medicine: Historical Importance, Current Innovations, and Future Challenges.

Molecular radiopharmaceuticals based on bioconjugates of chelators with peptides and proteins have had significant clinical impact in the diagnosis and treatment of several types of cancers. In the 1990s, indium-111 and yttrium-90 labeled chelator-peptide/protein conjugates established the clinical utility of these radiopharmaceuticals for receptor-targeted γ-scintigraphy imaging and systemic radiotherapy. Second-generation bioconjugates based on peptides targeting the somatostatin II receptor and the prostate-specific membrane antigen are now widely used for management of neuroendocrine and prostate cancer, respectively. These bioconjugates are typically radiolabeled with gallium-68 for imaging of target receptor expression with positron emission tomography, and the β--emitter, lutetium-177, for targeted radiotherapy. Innovations in radioisotope technology and biomolecular therapies are likely to drive the future clinical development of radiopharmaceuticals based on radiometals. New chelator-peptide and chelator-protein bioconjugates will underpin nuclear medicine advances in molecular imaging and radiotherapy.

Recent advances in molecular imaging of atherosclerotic plaques and thrombosis.

As the complications of atherosclerosis such as myocardial infarction and stroke are still one of the leading causes of mortality worldwide, the development of new diagnostic tools for the early detection of plaque instability and thrombosis is urgently needed. Advanced molecular imaging probes based on functional nanomaterials in combination with cutting edge imaging techniques are now paving the way for novel and unique approaches to monitor the inflammatory progress in atherosclerosis. This review focuses on the development of various molecular probes for the diagnosis of plaques and thrombosis in atherosclerosis, along with perspectives of their diagnostic applications in cardiovascular diseases. Specifically, we summarize the biological targets that can be used for atherosclerosis and thrombosis imaging. Then we describe the emerging molecular imaging techniques based on the utilization of engineered nanoprobes together with their challenges in clinical translation.

Technical Note: Impact on central frequency and noise magnitude ratios by advanced CT image reconstruction techniques.

We use central frequency ratio and noise magnitude ratio from noise power spectrum (NPS) to evaluate the noise reduction techniques of ASiR and ASiR-V of GE, SAFIRE and ADMIRE of Siemens, and PixelShine of AlgoMedica. ASiR, ASiR-V, SAFIRE and ADMIRE use a combination of image and projection data whereas PixelShine uses artificial intelligence neural network for noise reduction. The homogeneous module of the ACR computed tomography (CT) phantom was scanned on a GE Revolution HD 64-slice CT for ASiR and ASiR-V, a Siemens Somatom Force for ADMIRE, and a Siemens Definition AS 64-slice for SAFIRE for NPS calculation. The baseline filtered back-projection (FBP) reconstructions were derived from the standard kernel on Revolution HD, Hr44f on Force and D40s on Definition AS. The central frequency ratio (CFR) indicates the degree of shift in the central frequency of NPS after noise reduction. A smaller CFR means a larger shift of the NPS curve, or a larger degree of image blurring. The noise magnitude ratio (NMR) indicates the amount of noise removed. A smaller NMR means a larger degree of noise reduction. An ideal noise reduction shall maintain a CFR close to 1 and a NMR close to 0. The ideal noise reduction by increasing radiation exposure did not shift the central frequency when the image noise was reduced. PixelShine was the closest to the ideal noise reduction in CFR, and was followed by SAFIRE, ASiR-V, ADMIRE and ASiR, in sequence. Similarly, PixelShine had the smallest NMR, and was followed by SAFIRE, ASiR-V, ADMIRE and ASiR in sequence. Overall, PixelShine had the least central frequency shift for the same amount of noise reduction or the most noise reduction for the same amount of central frequency shift. For the same CFR, ASiR-V reduced more noise than ASiR; and SAFIRE reduced more noise than ADMIRE. We introduced two new parameters of CFR and NMR from NPS to compare the reconstructions from different manufacturers. PixelShine had the least central frequency shift for the same amount of noise reduction or the most noise reduction for the same amount of central frequency shift. For the same central frequency shift, ASiR-V reduced more noise than ASiR, and SAFIRE reduced more noise than ADMIRE.

Proceedings of the Comprehensive Oncology Network Evaluating Rare CNS Tumors (NCI-CONNECT) Oligodendroglioma Workshop.

Oligodendroglioma is a rare primary central nervous system (CNS) tumor with highly variable outcome and for which therapy is usually not curative. At present, little is known regarding the pathways involved with progression of oligodendrogliomas or optimal biomarkers for stratifying risk. Developing new therapies for this rare cancer is especially challenging. To overcome these challenges, the neuro-oncology community must be particularly innovative, seeking multi-institutional and international collaborations, and establishing partnerships with patients and advocacy groups thereby ensuring that each patient enrolled in a study is as informative as possible. The mission of the National Cancer Institute's NCI-CONNECT program is to address the challenges and unmet needs in rare CNS cancer research and treatment by connecting patients, health care providers, researchers, and advocacy organizations to work in partnership. On November 19, 2018, the program convened a workshop on oligodendroglioma, one of the 12 rare CNS cancers included in its initial portfolio. The purpose of this workshop was to discuss scientific progress and regulatory challenges in oligodendroglioma research and develop a call to action to advance research and treatment for this cancer. The recommendations of the workshop include a multifaceted and interrelated approach covering: biology and preclinical models, data sharing and advanced molecular diagnosis and imaging; clinical trial design; and patient outreach and engagement. The NCI-CONNECT program is well positioned to address challenges in oligodendroglioma care and research in collaboration with other stakeholders and is developing a list of action items for future initiatives.

Recent Advances in Molecular Imaging with Gold Nanoparticles.

Gold nanoparticles (AuNP) have been extensively developed as contrast agents, theranostic platforms, and probes for molecular imaging. This popularity has yielded a large number of AuNP designs that vary in size, shape, surface functionalization, and assembly, to match very closely the requirements for various imaging applications. Hence, AuNP based probes for molecular imaging allow the use of computed tomography (CT), fluorescence, and other forms of optical imaging, photoacoustic imaging (PAI), and magnetic resonance imaging (MRI), and other newer techniques. The unique physicochemical properties, biocompatibility, and highly developed chemistry of AuNP have facilitated breakthroughs in molecular imaging that allow the detection and imaging of physiological processes with high sensitivity and spatial resolution. In this Review, we summarize the recent advances in molecular imaging achieved using novel AuNP structures, cell tracking using AuNP, targeted AuNP for cancer imaging, and activatable AuNP probes. Finally, the perspectives and current limitations for the clinical translation of AuNP based probes are discussed.

High-Performance Molecular Imaging with MALDI Trapped Ion-Mobility Time-of-Flight (timsTOF) Mass Spectrometry.

Imaging mass spectrometry (IMS) enables the spatially targeted molecular assessment of biological tissues at cellular resolutions. New developments and technologies are essential for uncovering the molecular drivers of native physiological function and disease. Instrumentation must maximize spatial resolution, throughput, sensitivity, and specificity, because tissue imaging experiments consist of thousands to millions of pixels. Here, we report the development and application of a matrix-assisted laser desorption/ionization (MALDI) trapped ion-mobility spectrometry (TIMS) imaging platform. This prototype MALDI timsTOF instrument is capable of 10 μm spatial resolutions and 20 pixels/s throughput molecular imaging. The MALDI source utilizes a Bruker SmartBeam 3-D laser system that can generate a square burn pattern of <10 × 10 μm at the sample surface. General image performance was assessed using murine kidney and brain tissues and demonstrate that high-spatial-resolution imaging data can be generated rapidly with mass measurement errors <5 ppm and ∼40 000 resolving power. Initial TIMS-based imaging experiments were performed on whole-body mouse pup tissue demonstrating the separation of closely isobaric [PC(32:0) + Na]+ and [PC(34:3) + H]+ (3 mDa mass difference) in the gas phase. We have shown that the MALDI timsTOF platform can maintain reasonable data acquisition rates (>2 pixels/s) while providing the specificity necessary to differentiate components in complex mixtures of lipid adducts. The combination of high-spatial-resolution and throughput imaging capabilities with high-performance TIMS separations provides a uniquely tunable platform to address many challenges associated with advanced molecular imaging applications.

Nanoparticles-mediated Brain Imaging and Disease Prognosis by Conventional as well as Modern Modal Imaging Techniques: a Comparison.

Multimodal imaging plays an important role in the diagnosis of brain disorders. Neurological disorders need to be diagnosed at an early stage for their effective treatment as later, it is very difficult to treat them. If possible, diagnosing at an early stage can be much helpful in curing the disease with less harm to the body. There is a need for advanced and multimodal imaging techniques for the same. This paper provides an overview of conventional as well as modern imaging techniques for brain diseases, specifically for tumor imaging. In this paper, different imaging modalities are discussed for tumor detection in the brain along with their advantages and disadvantages. Conjugation of two and more than two modalities provides more accurate information rather than a single modality. They can monitor and differentiate the cellular processes of normal and diseased condition with more clarity. The advent of molecular imaging, including reporter gene imaging, has opened the door of more advanced noninvasive detection of brain tumors. Due to specific optical properties, semiconducting polymer-based nanoparticles also play a pivotal role in imaging tumors. The objective of this paper is to review nanoparticles-mediated brain imaging and disease prognosis by conventional as well as modern modal imaging techniques. We reviewed in detail various medical imaging techniques. This paper covers recent developments in detail and elaborates a possible research aspect for the readers in the field.

Metastatic-directed therapy using PSMA-PET/CT at PSA relapse

The side effects of androgen deprivation therapy (ADT) as general treatment against prostate cancer are known to impair quality of life. However, the optimal onset of ADT at PSA relapse is unknown, especially in patients with normal testosterone. In our case a limited PSMA avid lymph node was detected on PET/CT. Our case highlights the importance of metastasis-directed therapy balancing general versus tailored treatment in the decision making in the era of advanced molecular imaging. By using PSMA-PET/CT and radiation we were able to pinpoint the metastasis prolonging the ADT-free survival, thus sparing the patient the side-effects of continuous ADT.

Tumor acidic microenvironment and targeted pH molecular imaging

The tumor acidosis or low extracellular pH (pHe) is a consequence of the anaerobic glycolysis and hypoxia. Tumor acidosis plays a crucial role in tumor progression, metastasis, and resistance to therapy. Recent advances in molecular imaging targeted to tumor acidic microenvironment, including the acido chemical exchange saturation transfer magnetic resonance imaging (AcidoCEST MRI), pH-sensitive nanoparticle and pH-low insertion peptide (pHLIP), offer the opportunity to facilitate the mechanism research in this field and to promote the diagnosis and treatment. This review summarizes the effects of tumor microenvironment on tumor cells and the underlying mechanisms. In addition, this article concentrates more on the application of molecular imaging targeted tumor acidic microenvironment. Key words: Tumor microenvironment; Hydrogen-ion concentration; Molecular imaging; Trends

Nanoparticle Therapy for Vascular Diseases.

Nanoparticles promise to advance strategies to treat vascular disease. Since being harnessed by the cancer field to deliver safer and more effective chemotherapeutics, nanoparticles have been translated into applications for cardiovascular disease. Systemic exposure and drug-drug interactions remain a concern for nearly all cardiovascular therapies, including statins, antithrombotic, and thrombolytic agents. Moreover, off-target effects and poor bioavailability have limited the development of completely new approaches to treat vascular disease. Through the rational design of nanoparticles, nano-based delivery systems enable more efficient delivery of a drug to its therapeutic target or even directly to the diseased site, overcoming biological barriers and enhancing a drug's therapeutic index. In addition, advances in molecular imaging have led to the development of theranostic nanoparticles that may simultaneously act as carriers of both therapeutic and imaging payloads. The following is a summary of nanoparticle therapy for atherosclerosis, thrombosis, and restenosis and an overview of recent major advances in the targeted treatment of vascular disease.

Optimizing the use of androgen deprivation therapy in men with localized intermediate-risk prostate cancer in the era of modern dose-escalated radiation therapy.

109 Background: While level one evidence has shown an overall survival (OS) advantage with the addition of androgen deprivation therapy (ADT) to radiotherapy (RT) for intermediate risk prostate cancer (PCa), the benefit in the era of modern dose escalation is controversial, especially given the heterogeneity within this risk group. We assessed the impact of adding ADT to high dose RT on OS for intermediate risk PCa stratified by number of intermediate risk factors (IRF). Methods: We identified 114,339 men with intermediate risk PCa (Gleason 7, clinical stage T1-2, PSA &lt; 20 ng/mL) using the National Cancer Database. Men were stratified into the following subgroups based on the number of IRFs (Gleason 7, cT2b-c, PSA &gt; 10-20 ng/mL): A) Gleason 3+4 and no other IRF, B) Gleason 4+3 and no other IRF, C) two IRFs, and D) three IRFs. The addition of ADT to dose-escalated external beam RT (DE-EBRT, ≥ 75.6 Gy), brachytherapy (BT), or combination EBRT+BT on OS was assessed within each subgroup using Kaplan-Meier and log-rank tests in propensity score-matched cohorts in all men and subsequently only in those with Charlson-Deyo comorbidity index (CDI) of zero. Results: There was no OS benefit with the addition of ADT to DE-EBRT, BT, or EBRT+BT in groups A, B, and C, even after limiting the cohort to men with CDI = 0. However, in group D, the addition of ADT to DE-EBRT was associated with a trend for OS improvement in patients with CDI = 0 only (8-year OS with and without ADT 68.3% and 62.4%, respectively, log-rank P= .07). Conversely, there was a trend for OS decrement with the addition of ADT to DE-EBRT in men with CDI ≥ 1 (8-year OS with and without ADT 61.8% and 67.5%, respectively, log-rank P= .06). There was no OS benefit of ADT in group D treated with BT or EBRT+BT, regardless of comorbidity status. Conclusions: The OS benefit of ADT in men with intermediate risk PCa may be limited to those with 3 IRFs and minimal comorbidities treated with DE-EBRT. If prospectively validated, extreme dose escalation achieved with BT (alone or in combination with EBRT) may obviate the addition of ADT in all men with intermediate risk disease, especially in an era of advanced molecular imaging.

In the future, emission‐guided radiation therapy will play a critical role in clinical radiation oncology

Emission‐guided radiation therapy entails the use of radiation emitted by molecular imaging probes (SPECT for PET) to guide delivery directly, thus avoiding the need to wait for long acquisition times to collect sufficient count statistics. The potential of biological targeting in radiation treatment planning, taking advantage of advanced molecular imaging techniques in the form of hybrid SPECT/CT, PET/CT, or PET/MRI systems, is well established. The last three decades have witnessed abundant contributions indicative of the advantages of multiparametric molecular imaging in this framework. Ultimately, molecular imaging‐guided radiation therapy planning holds the promise of improved delineation of target volumes even in the presence of significant motion. Yet, despite significant advances to date, challenges remain limiting exploitation of the potential of this technology in the clinic to academic facilities with advanced technical support. Fortunately, these limitations are not preventing novel exciting developments to emerge with the aim to further boost the incorporation of multimodality imaging in the process of radiation therapy planning for various indications. In this regard, the conceptual basis of using on‐board PET to guide the radiation treatment process has been around since 2010. A small company based in the US (RefleXion Medical, Hayward, CA) pioneered the development of a device enabling commercial implementation of one approach to biologically guided radiation therapy. The product was displayed for the first time at the last ASTRO 2018 annual meeting. While some think that this is relevant technology that should soon be adopted for use in the clinic, others think that the concept is still in its infancy and not mature enough for clinical adoption. This is the topic addressed in this month's Point/Counterpoint debate.

Samidorphan attenuates the effects of buprenorphine in rat models evaluating abuse potential

Over the past decade rapid advancements in molecular imaging (MI) and artificial intelligence (AI) have revolutionized traditional musculoskeletal radiology. Molecular imaging refers to the ability of various methods to in vivo characterize and quantify biological processes, at a molecular level. The extracted information provides the tools to understand the pathophysiology of diseases and thus to early detect, to accurately evaluate the extend and to apply and evaluate targeted treatments. At present, molecular imaging mainly involves CT, MRI, radionuclide, US, and optical imaging and has been reported in many clinical and preclinical studies. Although originally MI techniques targeted at central nervous system disorders, later on their value on musculoskeletal disorders was also studied in depth. Meaningful exploitation of the large volume of imaging data generated by molecular and conventional imaging techniques, requires state-of-the-art computational methods that enable rapid handling of large volumes of information. AI allows end-to-end training of computer algorithms to perform tasks encountered in everyday clinical practice including diagnosis, disease severity classification and image optimization. Notably, the development of deep learning algorithms has offered novel methods that enable intelligent processing of large imaging datasets in an attempt to automate decision-making in a wide variety of settings related to musculoskeletal trauma. Current applications of AI include the diagnosis of bone and soft tissue injuries, monitoring of the healing process and prediction of injuries in the professional sports setting. This review presents the current applications of novel MI techniques and methods and the emerging role of AI regarding the diagnosis and evaluation of musculoskeletal trauma.