Not All Flat-Panel C-Arms Are Created Equal: A Comparison of Three Major Manufacturers

Introduction: Flat-panel detector C-arms (FCs) are reported to reduce radiation exposure and improve image quality compared with conventional image intensifier C-arms (CCs). The purpose of this study was to compare radiation exposure and image quality between three commonly used FCs. Materials and Methods: A cadaver model was placed in the prone position to simulate percutaneous nephrolithotomy. We compared the following three FCs: OEC Elite CFD from GE HealthCare, Zenition 70 from Philips, and Ziehm Vision RFD from Ziehm Imaging. To measure the radiation dose, optically stimulated luminescence dosimeters (OSLDs) were utilized during five 300-second trials, conducted under three settings: automatic exposure control (AEC), AEC with low dose (LD), and LD with the lowest pulse rate (LDLP). Ten blinded urologists evaluated the image quality. Data were statistically analyzed using the analysis of variance (ANOVA) and Tukey's B post hoc tests. Results: In the AEC setting, the Philips C-arm demonstrated lower ventral OSLD exposure (42,446 mrad) compared with both the GE (51,076 mrad) and Ziehm (83,178 mrad; p < 0.001) C-arms. Similarly, in the LD setting, the Philips C-arm resulted in less ventral OSLD exposure (25,926 mrad) than both the Ziehm (30,956 mrad) and GE (38,209 mrad; p < 0.001) C-arms. Meanwhile, in the LDLP setting, the Ziehm C-arm showed less ventral OSLD exposure (4019 mrad) than both the GE (7418 mrad) and Philips (8229 mrad; p < 0.001) C-arms. All three manufacturers received adequate image quality ratings at the AEC and LD settings. However, at LDLP, the Ziehm C-arm received inadequate ratings in 8% of images, whereas both the GE and Philips C-arms received 100% adequate ratings (p = 0.016). Conclusions: Radiation produced by flat-panel C-arms varies dramatically, with the highest exposure (Ziehm) being almost double the lowest (Philips) in AEC. Improved picture quality at the lowest settings may come at the cost of increased radiation dose. Surgeons should carefully select the machine and settings to minimize radiation exposure while still preserving the image quality.

Reducing hand radiation during renal access for percutaneous nephrolithotomy: a comparison of radiation reduction techniques

Percutaneous nephrolithotomy confers the highest radiation to the urologist's hands compared to other urologic procedures. This study compares radiation exposure to the surgeon's hand and patient's body when utilizing three different techniques for needle insertion during renal access. Simulated percutaneous renal access was performed using a cadaveric patient and separate cadaveric forearm representing the surgeon's hand. Three different needle-holding techniques were compared: conventional glove (control), a radiation-attenuating glove, and a novel needle holder. Five 300-s fluoroscopy trials were performed per treatment arm. The primary outcome was radiation dose (mSv) to the surgeon's hand. The secondary outcome was radiation dose to the patient. One-way ANOVA and Tukey's B post-hoc tests were performed with p < 0.05 considered significant. Compared to the control (3.92 mSv), both the radiation-attenuating glove (2.48 mSv) and the needle holder (1.37 mSv) reduced hand radiation exposure (p < 0.001). The needle holder reduced hand radiation compared to the radiation-attenuating glove (p < 0.001). The radiation-attenuating glove resulted in greater radiation produced by the C-arm compared to the needle holder (83.49 vs 69.22 mGy; p = 0.019). Patient radiation exposure was significantly higher with the radiation-attenuating glove compared to the needle holder (8.43 vs 7.03 mSv; p = 0.027). Though radiation-attenuating gloves decreased hand radiation dose by 37%, this came at the price of a 3% increase in patient exposure. In contrast, the needle holder reduced exposure to both the surgeon's hand by 65% and the patient by 14%. Thus, a well-designed low-density needle holder could optimize radiation safety for both surgeon and patient.

Time Efficiency and Performance of Single-Use vs Reusable Cystoscopes: A Randomized Benchtop and Simulated Clinical Assessment

Introduction: A flexible cystoscope is an indispensable tool for urologists, facilitating a variety of procedures in both the operating room and at bedside. Single-use cystoscopes offer benefits including accessibility and decreased burden for reprocessing. The aims of this study were to compare time efficiency and performance of single-use and reusable cystoscopes. Methods: Ten new Ambu® aScope™ 4 Cysto single-use and two Olympus CYF-5 reusable cystoscopes were compared in simulated bedside cystoscopy and benchtop testing. Ten urologists performed simulated cystoscopy using both cystoscopes in a randomized order. Times for supply-gathering, setup, cystoscopy, cleanup, and cumulative time were recorded, followed by a Likert feedback survey. For benchtop assessment, physical, optical, and functional specifications were assessed and compared between cystoscopes. Results: The single-use cystoscope demonstrated shorter supply-gathering, setup, cleanup, and cumulative times (824 vs 1231 seconds; p < 0.05) but a comparable cystoscopy time to the reusable cystoscope (202 vs 212 seconds; p = 0.32). The single-use cystoscope had a higher image resolution, but a narrower field of view. Upward deflection was greater for the single-use cystoscope (214.50° vs 199.45°; p < 0.01) but required greater force (2.5 × ). The working channel diameter and irrigation rate were greater in the reusable cystoscope. While the single-use cystoscope lacked tumor enhancing optical features, it had higher Likert scale scores for Time Efficiency and Overall Satisfaction. Conclusion: The single-use cystoscope demonstrates comparable benchtop performance and superior time efficiency compared to reusable cystoscopes. However, the reusable cystoscope has superior optical versatility and flow rate. Knowledge of these differences allows for optimal cystoscope selection based on procedure indication.

Does renal failure worsen radiation cystitis following radical prostatectomy?

OBJECTIVE

To investigate the impact of renal function on the risk, severity, and management of radiation cystitis in patients who underwent postoperative radiation therapy for prostate cancer.

METHODS

Retrospective data was assessed from patients treated with adjuvant/salvage radiation therapy at a single academic institution between 2006 and 2020. The incidence, severity, and management of radiation cystitis were compared between three groups: CKD 0-2, CKD 3-4, and CKD 5. Associations of clinicopathologic factors with radiation cystitis were assessed in univariate and multivariate Cox regression models.

RESULTS

A total of 110 patients who underwent radiation therapy following robot-assisted laparoscopic radical prostatectomy were included. The incidence of radiation cystitis following postoperative radiation therapy was 17% with a median presentation time of 34 months (interquartile range 16-65 months). The incidence of radiation cystitis was 100% in CKD 5 patients compared to 15% in CKD 0-2 and 17% in CKD 3-4 patients (p < 0.001). CKD 5 patients required more treatments, emergency department visits, and longer hospitalization times than CKD 0-4 patients (all p < 0.001). Multivariate analyses identified CKD 5 as the only significant factor associated with radiation cystitis (HR = 10.39, p = 0.026).

CONCLUSION

End-stage renal failure is associated with the risk and severity of radiation cystitis in patients receiving postoperative radiation therapy. Knowledge of the potential morbidity of this complication in this population could guide physicians and patients as they evaluate risks and benefits prior to selecting adjuvant or salvage radiation therapy.

Abstract P5-07-13: Conceptual model of transdisciplinary science - Advocacy collaboration for the physical sciences and oncology: A case study focusing on breast density, biomarker discovery, and emerging therapeutics

BACKGROUND: What happens when you mix the foundations of tissue mechanics with advocacy? In a shared quest for exciting scientific frontiers, Bay Area physical scientists, clinical researchers, and advocates work in dynamic symbiotic relationships to integrate concepts drawn from their respective fields. Focusing on the mechanobiology of tumor progression in breast cancer, researchers and advocates are co-creating system change interventions for revamping convergent research processes.

METHODS:As vital catalysts of transdisciplinary innovation, advocates affiliated with the National Cancer Institute (NCI) Physical Sciences and Oncology Network (PS-ON) applied core principles that synergize with the evolving disciplines of Implementation Science (IS) and the Science of Team Science (STS). Diverse methodologies to describe the intersections of physical sciences, breast density, biomarker discovery, emerging therapeutics and advocacy are presented. Additionally, we introduce a theoretical framework and conceptual puzzle illustrating multimethod science advocacy engagement strategies, a typology of contextual factors influencing collaboration, as well as the antecedents, processes, strategic priorities, and overall potential impacts of collaborative transdisciplinary science advocacy exchanges.

RESULTS:Through proactive participation in four areas: 1) research and programmatic support, 2) education and outreach, 3) policy and strategy, and 4) representation and advisory, advocates, representing patient/consumer perspectives, worked toward a common set of goals with researchers and clinicians in determining how tumor microenvironments regulate cancer initiation and behavior through interactions among cell types (e.g., initiated cells, activated stromal cells, and components of the extracellular matrix). Applying NCI Office of Advocacy Relations (OAR) and NCI PS-ON Advocacy Working Group goals for strategic innovation, collaborative execution, and ethical codes of conduct, researchers and advocates codeveloped guiding conceptual frameworks based on organizational foundations, systems readiness, leadership commitment to change, and transdisciplinary levers to promote shared governance, bidirectional collaboration, advocacy inclusion, and the prioritization of research addressing questions of importance to patients.

DISCUSSION: Embedding advocate patient/consumer evidentiary and experiential insights/perspectives regarding mechanics-directed research priorities and clinical interventions in the early phase of convergent research efforts contributes to our understanding of the important role of the physical organization in cell-to-cell contacts, tissue architecture, tumor microenviroments, and mechanical properties in response to therapy. Notably, catalyzing and leveraging advocate engagement across the research continuum provides novel opportunities for advancing institutional changes, spurring unique training/mentoring exchanges, and fostering innovative research and translational opportunities.

Citation Format: Samson S, Northey JJ, Baas C, Weaver VM. Conceptual model of transdisciplinary science - Advocacy collaboration for the physical sciences and oncology: A case study focusing on breast density, biomarker discovery, and emerging therapeutics [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-07-13.

A comparison of rapid point-of-care tests for the detection of avian influenza A(H7N9) virus, 2013

Six antigen detection-based rapid influenza point-of-care tests were compared for their ability to detect avian influenza A(H7N9) virus. The sensitivity of at least four tests, standardised by viral infectivity (TCID50) or RNA copy number, was lower for the influenza A(H7N9) virus than for seasonal A(H3N2), A(H1N1)pdm09 or other recent avian A(H7) viruses. Comparing detection limits of A(H7N9) virus with Ct values of A(H7N9) clinical specimens suggests the tests would not have detected most clinical specimens.

Infection of mice with a human influenza A/H3N2 virus induces protective immunity against lethal infection with influenza A/H5N1 virus

The transmission of highly pathogenic avian influenza (HPAI) A viruses of the H5N1 subtype from poultry to man and the high case fatality rate fuels the fear for a pandemic outbreak caused by these viruses. However, prior infections with seasonal influenza A/H1N1 and A/H3N2 viruses induce heterosubtypic immunity that could afford a certain degree of protection against infection with the HPAI A/H5N1 viruses, which are distantly related to the human influenza A viruses. To assess the protective efficacy of such heterosubtypic immunity mice were infected with human influenza virus A/Hong Kong/2/68 (H3N2) 4 weeks prior to a lethal infection with HPAI virus A/Indonesia/5/05 (H5N1). Prior infection with influenza virus A/Hong Kong/2/68 reduced clinical signs, body weight loss, mortality and virus replication in the lungs as compared to naive mice infected with HPAI virus A/Indonesia/5/05. Priming by infection with respiratory syncytial virus, a non-related virus did not have a beneficial effect on the outcome of A/H5N1 infections, indicating that adaptive immune responses were responsible for the protective effect. In mice primed by infection with influenza A/H3N2 virus cytotoxic T lymphocytes (CTL) specific for NP(366-374) epitope ASNENMDAM and PA(224-232) SCLENFRAYV were observed. A small proportion of these CTL was cross-reactive with the peptide variant derived from the influenza A/H5N1 virus (ASNENMEVM and SSLENFRAYV respectively) and upon challenge infection with the influenza A/H5N1 virus cross-reactive CTL were selectively expanded. These CTL, in addition to those directed to conserved epitopes, shared by the influenza A/H3N2 and A/H5N1 viruses, most likely contributed to accelerated clearance of the influenza A/H5N1 virus infection. Although also other arms of the adaptive immune response may contribute to heterosubtypic immunity, the induction of virus-specific CTL may be an attractive target for development of broad protective vaccines. Furthermore the existence of pre-existing heterosubtypic immunity may dampen the impact a future influenza pandemic may have.

The pitfalls of clinical case research: lessons from the Delphi Project

Delphi is a project to make high-quality cases treated with homeopathy available for study. The project encountered a number of major difficulties including small numbers of cases submitted, ethical problems and problems of analysis. The nature of these problems and possible solutions are discussed.

Integrins and osteoclastic resorption in three bone organ cultures: differential sensitivity to synthetic Arg-Gly-Asp peptides during osteoclast formation

We investigated possible inhibitory effects of five synthetic Arg-Gly-Asp (RGD)-containing peptides on osteoclastic resorption in three distinct in vitro resorption assays (17-day-old fetal mouse bone organ cultures) that differ in stages of osteoclast differentiation. RGD peptides, which can bind the adhesion receptors called integrins, inhibited osteoclastic resorption (45Ca release) in fetal mouse bone explants in which osteoclast precursors have yet to adhere to the mineralized matrix and develop into mature osteoclasts (metacarpals and coculture system). Treatment of metacarpals with RGD peptides inhibited the formation of multinucleated TRAP+ osteoclasts in the mineralized matrix because their mononuclear TRAP+ osteoclast precursors remained localized in the periosteum. In particular, echistatin, a viper venom protein with known affinity for alpha v beta 3 integrin, and GdRGDSP inhibited osteoclastic resorption dose dependently in these systems (ED50 10(-9) and 10(-4) M, respectively) but did not alter the activity of mature resorbing osteoclasts in radii. In addition, 45Ca release was significantly inhibited by the cyclic peptide GPenGRGDSPCA, which has a relatively higher affinity for the vitronectin than fibronectin receptor(s). In contrast, GRDGdSP, which has a much higher affinity for the fibronectin receptor (than the vitronectin receptors), had no effect on resorption at similar concentrations in any resorption system used. In summary, the data presented in this paper show that peptides with RGD motifs are capable of inhibiting osteoclastic resorption in bone organ cultures. Our studies not only support the hypothesis concerning the importance of alpha v beta 3 in osteoclastic resorption but also suggest an important role of integrin(s) in events preceding the actual resorption of calcified matrix by osteoclasts.