Current Status and Future Directions of Image-Guided Adaptive Brachytherapy for Locally Advanced Cervical Cancer.

PURPOSE: The standard of care for patients with locally advanced cervical cancer is definitive chemoradiation followed by a brachytherapy boost. This review describes the current status and future directions of image-guided adaptive brachytherapy for locally advanced cervical cancer. METHODS: A systematic search of the PubMed and Clinicaltrials.gov databases was performed, focusing on studies published within the last 10 years. The search queried "cervical cancer [AND] image-guided brachytherapy [OR] magnetic resonance imaging (MRI) [OR] adaptive brachytherapy". DISCUSSION: The retroEMBRACE and EMBRACE-I trials have established the use of MRI as the standard imaging modality for brachytherapy application and planning. Quantitative imaging and radiomics have the potential to improve outcomes, with three ongoing prospective studies examining the use of radiomics to further risk-stratify patients and personalize brachytherapy. Another active area of investigation includes utilizing the superior soft tissue contrast provided by MRI to increase the dose per fraction and decrease the number of fractions needed for brachytherapy, with several retrospective studies demonstrating the safety and feasibility of three-fraction courses. For developing countries with limited access to MRI, trans-rectal ultrasound (TRUS) appears to be an effective alternative, with several retrospective studies demonstrating improved target delineation with the use of TRUS in conjunction with CT guidance. CONCLUSIONS: Further investigation is needed to continue improving outcomes for patients with locally advanced cervical cancer treated with image-guided brachytherapy.

Explainable artificial intelligence analysis of brachytherapy boost receipt in cervical cancer during the COVID-19 era.

PURPOSE: Brachytherapy is a critical component of the standard-of-care curative radiotherapy regimen for women with locally advanced cervical cancer (LACC). However, existing literature suggests that many patients will not receive the brachytherapy boost. We used machine learning (ML) and explainable artificial intelligence to characterize this disparity. MATERIALS AND METHODS: Patients with LACC diagnosed from 2004 to 2020 who received definitive radiation were identified in the National Cancer Database. Five ML models were trained to predict if a patient received a brachytherapy boost. The best-performing model was explained using SHapley Additive exPlanation (SHAP) values. To identify trends that may be attributable to the coronavirus disease 2019 (COVID-19) pandemic, the previous analysis was repeated and limited to 2019 to 2020. RESULTS: A total of 37,564 patients with LACC were identified; 5799 were diagnosed from 2019 to 2020 (COVID cohort). Of these patients, 59.3% received a brachytherapy boost, with 76.4% of patients diagnosed in 2019 to 2020 receiving a boost. The random forest model achieved the best performance for both the overall and COVID cohorts. In the overall cohort, the most important predictive features were the year of diagnosis, stage, age, and insurance status. In the COVID cohort, the most important predictive features were FIGO stage, age, insurance status, and hospital type. Of the 26 patients who tested positive for COVID-19 during their course of radiotherapy, 19 (73.1%) received a brachytherapy boost. CONCLUSIONS: A gradual increase in brachytherapy boost utilization has been noted, which did not seem to be significantly impacted by the onset of the COVID-19 pandemic. ML could be considered to identify patient populations where brachytherapy is underutilized, which can provide actionable feedback for improving access.

Biology-Guided Radiation Therapy: An Evolving Treatment Paradigm.

Biology-guided radiation therapy is an emerging field whereby delivery of external beam radiotherapy incorporates biological/molecular imaging to inform radiation treatment. At present, there is evidence for the use of functional imaging such as PET to evaluate treatment response in patients both during and after radiation treatment as well as to provide a method of adapting or selecting patient-specific treatments. Examples in thoracic, gastrointestinal, and hematologic malignancies are provided. Improvements in PET metrics, thresholds, and novel radiotracers will further move this novel field forward.

The Emerging Role of Radiotherapy in Oligoprogressive Non-Small Cell Lung Cancer.

Oligoprogressive disease (OPD) is an emerging concept that describes patients who have progression of disease in a limited number of metastatic sites while on systemic therapy. Growing evidence has suggested the integration of local ablative therapy with systemic agents in patients with OPD further improves survival. In oligoprogressive non-small cell lung cancer, stereotactic body radiotherapy may have an important role in the effective local control of selective progressing metastases, which may translate to better patient outcomes. This review explores the treatment paradigm of this subset of patients and provides an update on the current existing literature on this topic.

Stereotactic radiosurgery for ruptured versus unruptured intracranial arteriovenous malformations.

Background: There are a limited data examining the effects of prior hemorrhage on outcomes after stereotactic radiosurgery (SRS). The goal of this study was to identify risk factors for arteriovenous malformation (AVM) rupture and compare outcomes, including post-SRS hemorrhage, between patients presenting with ruptured and unruptured AVMs. Methods: A retrospective review of consecutive patients undergoing SRS for intracranial AVMs between 2009 and 2019 at our institution was conducted. Chi-square and multivariable logistic regression analyses were utilized to identify patient and AVM factors associated with AVM rupture at presentation and outcomes after SRS including the development of recurrent hemorrhage in both ruptured and unruptured groups. Results: Of 210 consecutive patients with intracranial AVMs treated with SRS, 73 patients (34.8%) presented with AVM rupture. Factors associated with AVM rupture included smaller AVM diameter, deep venous drainage, cerebellar location, and the presence of intranidal aneurysms (P < 0.05). In 188 patients with adequate follow-up time (mean 42.7 months), the overall post-SRS hemorrhage rate was 8.5% and was not significantly different between ruptured and unruptured groups (10.3 vs. 7.5%, P = 0.51). There were no significant differences in obliteration rate, time to obliteration, or adverse effects requiring surgery or steroids between unruptured and ruptured groups. Conclusion: Smaller AVM size, deep venous drainage, and associated intranidal aneurysms were associated with rupture at presentation. AVM rupture at presentation was not associated with an increased risk of recurrent hemorrhage or other complication after SRS when compared to unruptured AVM presentation. Obliteration rates were similar between ruptured and unruptured groups.

Seizure Rates After Stereotactic Radiosurgery for Cerebral AVMs: A Single Center Study.

OBJECTIVES: Seizure control after stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMs) is an area of growing interest, with previous studies reporting up to 70% seizure freedom after treatment. The goals of this study were to identify specific patient and AVM characteristics associated with seizure presentation and seizure outcomes after SRS treatment. METHODS: A retrospective review of consecutive patients undergoing SRS for brain AVMs between 2009 and 2019 at our institution was conducted. Chi-squared and logistic regression analyses were utilized to identify patient and AVM factors associated with preoperative seizure presentation and development of new onset seizures after SRS. RESULTS: Two hundred ten consecutive patients presenting with AVMs treated with SRS were reviewed. Factors associated with seizure presentation included larger AVM size (P = 0.02), superficial venous drainage (P < 0.05), and parietal location (P = 0.04). Of 188 patients with follow-up (90%), 30 patients presented with seizures and 14 (47%) were seizure-free post-SRS. Of 158 patients presenting without seizure, 29 (18%) developed de novo seizures during follow-up. De novo post-SRS seizures were associated with prior craniotomy for resection of AVM (P = 0.04), post-treatment hemorrhage (P = 0.02), parietal location (P = 0.05), adverse effect requiring steroids (P < 0.01), and adverse effect requiring surgery (P < 0.01). CONCLUSIONS: Seizures are a common presentation of brain AVMs and can be treated effectively with SRS. However, seizures can also be a complication of SRS and are associated with post-treatment hemorrhage, edema, and need for future open surgery.

An in vivo model of glioblastoma radiation resistance identifies long noncoding RNAs and targetable kinases.

Key molecular regulators of acquired radiation resistance in recurrent glioblastoma (GBM) are largely unknown, with a dearth of accurate preclinical models. To address this, we generated 8 GBM patient-derived xenograft (PDX) models of acquired radiation therapy-selected (RTS) resistance compared with same-patient, treatment-naive (radiation-sensitive, unselected; RTU) PDXs. These likely unique models mimic the longitudinal evolution of patient recurrent tumors following serial radiation therapy. Indeed, while whole-exome sequencing showed retention of major genomic alterations in the RTS lines, we did detect a chromosome 12q14 amplification that was associated with clinical GBM recurrence in 2 RTS models. A potentially novel bioinformatics pipeline was applied to analyze phenotypic, transcriptomic, and kinomic alterations, which identified long noncoding RNAs (lncRNAs) and targetable, PDX-specific kinases. We observed differential transcriptional enrichment of DNA damage repair pathways in our RTS models, which correlated with several lncRNAs. Global kinomic profiling separated RTU and RTS models, but pairwise analyses indicated that there are multiple molecular routes to acquired radiation resistance. RTS model-specific kinases were identified and targeted with clinically relevant small molecule inhibitors. This cohort of in vivo RTS patient-derived models will enable future preclinical therapeutic testing to help overcome the treatment resistance seen in patients with GBM.

A single institution experience with papillary thyroid cancer: Are outcomes better at comprehensive cancer centers?

INTRODUCTION: Papillary thyroid cancer (PTC) is the most common form of thyroid cancer. Although the survival rate is excellent, recurrence is as high as 20%. The mainstay of therapy is thyroidectomy and lymph node dissection based on risk factors. Data from other cancers suggest that surgical outcomes are most optimal at comprehensive cancer centers. We hypothesize that patients with PTC who had their initial operation at a comprehensive cancer center would have a better oncologic outcome. METHODS: We utilized an IRB-approved cancer care registry database of patients with thyroid cancer who were seen at our institution between 2000 and 2018. Patient records were updated with cancer-specific outcomes including recurrence and need for re-intervention. Clinical and surgical outcomes were then compared between patients who had their initial operation at a comprehensive cancer center (CCC group, n = 503) versus those who did not (non-CCC group, n = 72). RESULTS: Mean patient age was 49 ± 16 years and 70% were female. Average tumor size was 1.6 ± 1.6 cm. There was no difference in tumor size, age, gender or race between groups. Pre-operative ultrasound was more frequently performed at the CCC (89%) than at non-CCC's (51%, p < 0.001). CCC patients were more likely to undergo initial total thyroidectomies compared to non-CCC patients (76% vs. 21%, p < 0.001). Positive surgical margins were more frequently found in patients at non-CCC's (19%) than at the CCC (9.7%, p = 0.016). Finally, CCC patients had a significantly lower cancer recurrence rate (5.0% vs. 37.5%, p < 0.001). Therefore, the need for additional cancer operations was much greater in patients who had initial thyroid surgery at non-CCC (31.9% vs. 1.4%, p < 0.001). CONCLUSIONS: Patients with PTC who have their initial thyroidectomy at non-CCC have higher recurrence rates, higher rates of positive tumor margins on pathology, and increased need for additional operations. These data suggest that patients who have their initial procedure at a CCC for PTC have better long-term outcomes.

Sternoplasty and rib distraction in neonatal Jeune syndrome.

BACKGROUND: A 12-week-old boy with Jeune syndrome (asphyxiating thoracic dystrophy) was referred to the orthopaedic unit with progressive respiratory failure, recurrent respiratory tract infections, and recurrent admissions to the intensive care unit for ventilatory support. His chest x-ray revealed a small and narrow thoracic cage with short broad ribs and abnormal costal cartilages. His chest expansion was impaired by the short, horizontally positioned ribs resulting in alveolar hypoventilation. Without surgical intervention to expand his thoracic cage, he would die of respiratory failure. METHODS: Using the technique of distraction osteogenesis, we split his sternum and slowly expanded this split to a total of 3 cm using a Leibinger mid-face distractor allowing adequate wound healing and bone formation between the 2 sternal edges. He returned to the theater 4 weeks after his initial surgery to have the distractor removed and 2 Leibinger plates inserted to hold the sternum out to length. Sternal distraction was repeated and the sternum was then supplemented with a Leibinger mesh. At 8 months, he had successful expansion of his ribs bilaterally using this technique of distraction osteogenesis. RESULTS: Presently, the patient is 30 months old and is living at home, is not oxygen dependent, and continues to thrive. CONCLUSIONS: Jeune syndrome presenting with respiratory failure in the neonate is fatal without surgical intervention to expand the thoracic cage. No successful surgical techniques have been described in the literature for neonates. This is the first case in which distraction osteogenesis has been used to distract both sternum and ribs in an infant with Jeune syndrome. Hence, distraction osteogenesis in thoracic dystrophy is a novel approach in the neonate. LEVEL OF EVIDENCE: Case report.

A cell-penetrating MARCKS mimetic selectively triggers cytolytic death in glioblastoma.

Glioblastoma (GBM) is an aggressive malignancy with limited effectiveness of standard of care therapies including surgery, radiation, and temozolomide chemotherapy necessitating novel therapeutics. Unfortunately, GBMs also harbor several signaling alterations that protect them from traditional therapies that rely on apoptotic programmed cell death. Because almost all GBM tumors have dysregulated phosphoinositide signaling as part of that process, we hypothesized that peptide mimetics derived from the phospholipid binding domain of Myristoylated alanine-rich C-kinase substrate (MARCKS) could serve as a novel GBM therapeutic. Using molecularly classified patient-derived xenograft (PDX) lines, cultured in stem-cell conditions, we demonstrate that cell permeable MARCKS effector domain (ED) peptides potently target all GBM molecular classes while sparing normal human astrocytes. Cell death mechanistic testing revealed that these peptides produce rapid cytotoxicity in GBM that overcomes caspase inhibition. Moreover, we identify a GBM-selective cytolytic death mechanism involving plasma membrane targeting and intracellular calcium accumulation. Despite limited relative partitioning to the brain, tail-vein peptide injection revealed tumor targeting in intracranially implanted GBM PDX. These results indicate that MARCKS ED peptide therapeutics may overcome traditional GBM resistance mechanisms, supporting further development of similar agents.

Myristoylated alanine-rich C-kinase substrate effector domain phosphorylation regulates the growth and radiation sensitization of glioblastoma.

Glioblastoma harbors frequent alterations in receptor tyrosine kinases, phosphatidylinositol­3 kinase (PI3K) and phosphatase and tensin homolog (PTEN) that dysregulate phospholipid signaling driven tumor proliferation and therapeutic resistance. Myristoylated alanine­rich C­kinase substrate (MARCKS) is a 32 kDa intrinsically unstructured protein containing a polybasic (+13) effector domain (ED), which regulates its electrostatic sequestration of phospholipid phosphatidylinositol (4,5)­bisphosphate (PIP2), and its binding to phosphatidylserine, calcium/calmodulin, filamentous actin, while also serving as a nuclear localization sequence. MARCKS ED is phosphorylated by protein kinase C (PKC) and Rho­associated protein kinase (ROCK) kinases; however, the impact of MARCKS on glioblastoma growth and radiation sensitivity remains undetermined. In the present study, using a tetracycline­inducible system in PTEN­null U87 cells, we demonstrate that MARCKS overexpression suppresses growth and enhances radiation sensitivity in vivo. A new image cytometer, Xcyto10, was utilized to quantify differences in MARCKS ED phosphorylation on localization and its association with filamentous actin. The overexpression of the non­phosphorylatable ED mutant exerted growth­suppressive and radiation­sensitizing effects, while the pseudo­phosphorylated ED mutant exhibited an enhanced colony formation and clonogenic survival ability. The identification of MARCKS protein­protein interactions using co­immunoprecipitation coupled with tandem mass spectrometry revealed novel MARCKS­associated proteins, including importin­ß and ku70. On the whole, the findings of this study suggest that the determination of the MARCKS ED phosphorylation status is essential to understanding the impact of MARCKS on cancer progression.

Kinomics toolbox-A web platform for analysis and viewing of kinomic peptide array data.

Kinomics is an emerging field of science that involves the study of global kinase activity. As kinases are essential players in virtually all cellular activities, kinomic testing can directly examine protein function, distinguishing kinomics from more remote, upstream components of the central dogma, such as genomics and transcriptomics. While there exist several different approaches for kinomic research, peptide microarrays are the most widely used and involve kinase activity assessment through measurement of phosphorylation of peptide substrates on the array. Unfortunately, bioinformatic tools for analyzing kinomic data are quite limited necessitating the development of accessible open access software in order to facilitate standardization and dissemination of kinomic data for scientific use. Here, we examine and present tools for data analysis for the popular PamChip® (PamGene International) kinomic peptide microarray. As a result, we propose (1) a procedural optimization of kinetic curve data capture, (2) new methods for background normalization, (3) guidelines for the detection of outliers during parameterization, and (4) a standardized data model to store array data at various analytical points. In order to utilize the new data model, we developed a series of tools to implement the new methods and to visualize the various data models. In the interest of accessibility, we developed this new toolbox as a series of JavaScript procedures that can be utilized as either server side resources (easily packaged as web services) or as client side scripts (web applications running in the browser). The aggregation of these tools within a Kinomics Toolbox provides an extensible web based analytic platform that researchers can engage directly and web programmers can extend. As a proof of concept, we developed three analytical tools, a technical reproducibility visualizer, an ANOVA based detector of differentially phosphorylated peptides, and a heatmap display with hierarchical clustering.

MARCKS phosphorylation is modulated by a peptide mimetic of MARCKS effector domain leading to increased radiation sensitivity in lung cancer cell lines.

Lung cancer is the leading cause of cancer-associated mortality in the United States. Kinase hyperactivation is a known mechanism of tumorigenesis. The phosphorylation status of the plasma membrane-associated protein myristoylated alanine rich C-kinase substrate (MARCKS) effector domain (ED) was previously established as being important in the sensitivity of lung cancer to radiation. Specifically, when MARCKS ED was in a non-phosphorylated state, lung cancer cells were more susceptible to ionizing radiation and experienced prolonged double-strand DNA breaks. Additional studies demonstrated that the phosphorylation status of MARCKS ED is important for gene expression and in vivo tumor growth. The present study used a peptide mimetic of MARCKS ED as a therapeutic intervention to modulate MARCKS phosphorylation. Culturing A549, H1792 and H1975 lung cancer cell lines with the MARCKS ED peptide led to reduced levels of phosphorylated MARCKS and phosphorylated Akt serine/threonine kinase 1. Further investigation demonstrated that the peptide therapy was able to reduce lung cancer cell proliferation and increase radiation sensitivity. In addition, the MARCKS peptide therapy was able to prolong double-strand DNA breaks following ionizing radiation exposure. The results of the present study demonstrate that a peptide mimetic of MARCKS ED is able to modulate MARCKS phosphorylation, leading to an increase in sensitivity to radiation.

Generation of Microtumors Using 3D Human Biogel Culture System and Patient-derived Glioblastoma Cells for Kinomic Profiling and Drug Response Testing.

The use of patient-derived xenografts for modeling cancers has provided important insight into cancer biology and drug responsiveness. However, they are time consuming, expensive, and labor intensive. To overcome these obstacles, many research groups have turned to spheroid cultures of cancer cells. While useful, tumor spheroids or aggregates do not replicate cell-matrix interactions as found in vivo. As such, three-dimensional (3D) culture approaches utilizing an extracellular matrix scaffold provide a more realistic model system for investigation. Starting from subcutaneous or intracranial xenografts, tumor tissue is dissociated into a single cell suspension akin to cancer stem cell neurospheres. These cells are then embedded into a human-derived extracellular matrix, 3D human biogel, to generate a large number of microtumors. Interestingly, microtumors can be cultured for about a month with high viability and can be used for drug response testing using standard cytotoxicity assays such as 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and live cell imaging using Calcein-AM. Moreover, they can be analyzed via immunohistochemistry or harvested for molecular profiling, such as array-based high-throughput kinomic profiling, which is detailed here as well. 3D microtumors, thus, represent a versatile high-throughput model system that can more closely replicate in vivo tumor biology than traditional approaches.

Use of nonsteroidal anti-inflammatory drugs in infants. A survey of members of the Association of Paediatric Anaesthetists of Great Britain and Ireland.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used as perioperative analgesics. Many are currently used off label. Diclofenac is currently licensed for use in children over 1 year of age for the treatment of juvenile rheumatoid arthritis, while ibuprofen is licensed for use in children weighing over 7 kg. The dose and interval in children is currently extrapolated from adult studies, as the pharmacokinetic (PK) and pharmacodynamic (PD) data are lacking in infants. METHODS: A postal questionnaire was sent to members of the Association of Paediatric Anaesthetist of Great Britain and Ireland seeking to clarify members' prescribing patterns of NSAIDs, especially in infants. Information regarding the choice of NSAIDS, route of administration, lower age limit, dose interval, dose and practice in two specific perioperative contexts (adenotonsillectomy and open heart surgery) was sought. RESULTS: The response rate was 80%. NSAIDs are used by 86% of responders in infants. Diclofenac is most commonly used intraoperatively (78%); while ibuprofen (73%) was used more frequently postoperatively. NSAIDs are used by 21% of respondents in ICU. Commonest routes of administration were oral (81%) and rectal (80%), rarely intravenously (9%). The commonest dose for diclofena is 1 mg x kg(-1) (59%); the dosing schedule employed being 8 hourly in 53% of cases. NSAIDs are used by 57% of responders as part of their analgesic regime for adenotonsillectomies. CONCLUSION: Members of the Association of Paediatric Anaesthetists of Great Britain and Ireland commonly prescribe NSAIDs in infants. This is despite the dearth of PK and PD data in this age group.

Aprotinin decreases the incidence of cognitive deficit following CABG and cardiopulmonary bypass: a pilot randomized controlled study.

PURPOSE: Cognitive deficit after coronary artery bypass surgery (CABG) has a high prevalence and is persistent. Meta-analysis of clinical trials demonstrates a decreased incidence of stroke after CABG when aprotinin is administrated perioperatively. We hypothesized that aprotinin administration would decrease the incidence of cognitive deficit after CABG. METHODS: Thirty-six ASA III-IV patients undergoing elective CABG were included in a prospective, randomized, single-blinded pilot study. Eighteen patients received aprotinin 2 x 10(6) KIU (loading dose), 2 x 10(6) KIU (added to circuit prime) and a continuous infusion of 5 x 10(5) KIU.hr(-1). A battery of cognitive tests was administered to patients and spouses (n = 18) the day before surgery, four days and six weeks postoperatively. RESULTS: Four days postoperatively new cognitive deficit (defined by a change in one or more cognitive domains using the Reliable Change Index method) was present in ten (58%) patients in the aprotinin group compared to 17 (94%) in the placebo group [95% confidence interval (CI) 0.10-0.62, P = 0.005); (P = 0.01)]. Six weeks postoperatively, four (23%) patients in the aprotinin group had cognitive deficit compared to ten (55%) in the placebo group (95% CI 0.80-0.16, P = 0.005); (P = 0.05). CONCLUSION: In this prospective pilot study, the incidence of cognitive deficit after CABG and cardiopulmonary bypass is decreased by the administration of high-dose aprotinin.