PP209 Analysis Of The Efficacy And Safety Of Robotic Spinal Surgery

IntroductionRobotic surgery (RS) can offer benefits compared to freehand surgery (FS) in the treatment of patients with spinal diseases. The aim of this study was to assess efficacy and safety of RS versus FS in spinal fusion. The outcomes considered were accuracy in the placement of pedicle screws, surgical times, hospital stay, exposure to radiation, and complications.MethodsA systematic review and meta-analysis were performed by researchers at the Instituto de Salud Carlos III (ISCIII). Studies published until June 2019 in the English, Spanish, or French languages were retrieved. The data analyses and risk of bias assessments were undertaken using RevMan 5.3.ResultsEight randomized controlled trials including 610 patients (RS: 308, FS: 302) were found. The mean age of the patients ranged from 56 to 68 years in the FS group and from 55 to 68 years in the RS group. The percentage of women included ranged from 46 to 73 percent undergoing FS and from 33 to 70 percent undergoing RS. The main diagnosis was degenerative spine disease. The number of screws implanted ranged from 22 to 584 for FS and 23 to 532 for RS. The robots used were the SpineAssist and Renaissance Guidance System (Mazor Robotics, Ltd) and the TiRobot® Orthopaedic Robotic System (Beijing Tinavi Medical Technologies Co., Ltd). Pedicle screw placement within the safety zone (Grades A and B on the Gertzbein and Robbins scale) ranged from 93 to 100 percent in FS and from 85 to 100 percent in RS (relative risk 1.0, 95% confidence interval [CI] 0.99–1.03; p = 0.36) (I2=75%; p = 0.0005). Regarding intervention time, the meta-analysis showed a mean difference (MD) of 15.2 minutes (95% CI 5.35–25.05; p = 0.002) (I2 = 0%; p = 0.39) in favor of FS. The MD in hospital stay was 0.36 days (95% CI -1.03–0.31; p = 0.30) (I2 = 62%; p = 0.07), which was not statistically significant. Contradictory results were found for fluoroscopy time, although RS was associated with a lower radiation dose than FS (p < 0.05). In relation to safety, studies only reported on rates of surgical revision, which ranged from 0 to 2 after FS and from 0 to 10 after RS. The risk or bias was unclear in most studies.ConclusionsWe found no conclusive results suggesting benefits for spinal fusion using RS compared with FS. Further research with adequate selection of patients, type of robot, and comparator is needed.

Enhanced Immunogenicity of a Whole-Inactivated Influenza A Virus Vaccine Using Optimised Irradiation Conditions

Influenza A virus presents a constant pandemic threat due to the mutagenic nature of the virus and the inadequacy of current vaccines to protect against emerging strains. We have developed a whole-inactivated influenza vaccine using γ-irradiation (γ-Flu) that can protect against both vaccine-included strains as well as emerging pandemic strains. γ-irradiation is a widely used inactivation method and several γ-irradiated vaccines are currently in clinical or pre-clinical testing. To enhance vaccine efficacy, irradiation conditions should be carefully considered, particularly irradiation temperature. Specifically, while more damage to virus structure is expected when using higher irradiation temperatures, reduced radiation doses will be required to achieve sterility. In this study, we compared immunogenicity of γ-Flu irradiated at room temperature, chilled on ice or frozen on dry ice using different doses of γ-irradiation to meet internationally accepted sterility assurance levels. We found that, when irradiating at sterilising doses, the structural integrity and vaccine efficacy were well maintained in all preparations regardless of irradiation temperature. In fact, using a higher temperature and lower radiation dose appeared to induce higher neutralising antibody responses and more effective cytotoxic T cell responses. This outcome is expected to simplify irradiation protocols for manufacturing of highly effective irradiated vaccines.

A practical biphasic contrast media injection protocol strongly enhances the aorta and pulmonary artery simultaneously using a single CT angiography scan

Background Enhancement profiles of the pulmonary artery (PA) and aorta differ when using computed tomography (CT) angiography. Our aim was to determine the optimal CT protocol for a one-time CT scan that assesses both blood vessels. Methods We prospectively enrolled 101 cases of CT angiography in patients with suspected pulmonary embolism or aortic dissection from our center between 2018 and 2020. We also retrospectively collected the data of 40 patients who underwent traditional two-time CT scans between 2015 and 2018. Patients were divided into four groups: test bolus (TB) I, TB II, bolus-tracking (BT) I, and BT II. The enhancement of the PA and aorta, and the radiation doses used in the four groups were collected. Those who underwent two-time scans were classified into the traditional PA or aorta scan groups. Data were compared between the BT and traditional groups. Results The aortic enhancement was highest in BT II (294.78 ± 64.48 HU) followed BT I (285.18 ± 64.99 HU), TB II (186.58 ± 57.53 HU), and TB I (173.62 ± 69.70 HU). The radiation dose used was lowest in BT I (11.85 ± 5.55 mSv) and BT II (9.07 ± 3.44 mSv) compared with that used in the traditional groups (20.07 ± 7.78 mSv) and accounted for half of the traditional group (45.17–59.02%). The aortic enhancement was also highest in BT II (294.78 ± 64.48 HU) followed by BT I (285.18 ± 64.99 HU) when compared with that in the traditional aorta scan group (234.95 ± 94.18 HU). Conclusion Our CT protocol with a BT technique allows for a lower radiation dose and better image quality of the PA and aorta than those obtained using traditional CT scans. Trial registration: NCT04832633, retrospectively registered in April 2021 to the clinical trial registry.

Precision of orthodontic cephalometric measurements on ultra low dose-low dose CBCT reconstructed cephalograms

Objectives To analyze differences in variation of orthodontic diagnostic measurements on lateral cephalograms reconstructed from ultra low dose-low dose (ULD-LD) cone beam computed tomography (CBCT) scans (RLC) as compared to variation of measurements on standard lateral cephalograms (SLC), and to determine if it is justifiable to replace a traditional orthodontic image set for an ULD-LD CBCT with a reconstructed lateral cephalogram. Material and methods ULD-LD CBCT images and SLCs were made of forty-three dry human skulls. From the ULD-LD CBCT dataset, a lateral cephalogram was reconstructed (RLC). Cephalometric landmarks (13 skeletal and 7 dental) were identified on both SLC and RLC twice in two sessions by two calibrated observers. Thirteen cephalometric variables were calculated. Variations of measurements, expressed as standard deviations of the 4 measurements on SLC and RLC, were analyzed using a paired sample t-test. Differences in the number of observations deviating ≥ 2.0 mm or degrees from the grand mean between SLC and RLC were analyzed using a McNemar test. Results Mean SDs for 7 out of 13 variables were significantly smaller for SLCs than those for RLCs, but differences were small. For 9 out of 13 variables, there was no significant difference between SLC and RLC for the number of measurements outside the range of 2 mm or degrees. Conclusions Based on the lower radiation dose and the small differences in variation in cephalometric measurements on reconstructed LC compared to standard dose LC, ULD-LD CBCT with reconstructed LC should be considered for orthodontic diagnostic purposes. Clinical relevance ULD-LD CBCT with reconstructed LC should be considered for orthodontic purposes.

Radiation Dose Reduction in CT Torsion Measurement of the Lower Limb: Introduction of a New Ultra-Low Dose Protocol

This study analyzed the radiation exposure of a new ultra-low dose (ULD) protocol compared to a high-quality (HQ) protocol for CT-torsion measurement of the lower limb. The analyzed patients (n = 60) were examined in the period March to October 2019. In total, 30 consecutive patients were examined with the HQ and 30 consecutive patients with the new ULD protocol comprising automatic tube voltage selection, automatic exposure control, and iterative image reconstruction algorithms. Radiation dose parameters as well as the contrast-to-noise ratio (CNR) and diagnostic confidence (DC; rated by two radiologists) were analyzed and potential predictor variables, such as body mass index and body volume, were assessed. The new ULD protocol resulted in significantly lower radiation dose parameters, with a reduction of the median total dose equivalent to 0.17 mSv in the ULD protocol compared to 4.37 mSv in the HQ protocol (p < 0.001). Both groups showed no significant differences in regard to other parameters (p = 0.344–0.923). CNR was 12.2% lower using the new ULD protocol (p = 0.033). DC was rated best by both readers in every HQ CT and in every ULD CT. The new ULD protocol for CT-torsion measurement of the lower limb resulted in a 96% decrease of radiation exposure down to the level of a single pelvic radiograph while maintaining good image quality.

Guiding vacuum-assisted biopsy in prone position: digital breast tomosynthesis vs stereotactic

Purpose: To compare the performance of prone digital breast tomosynthesis (DBT)–vacuum-assisted biopsy (VAB) with prone stereotactic-guided VAB (sVAB), focusing on time of procedure, number of expositions, average glandular dose, and complications. Methods: The institutional review board approved this retrospective study and informed consent was waived. From July 2015 to January 2017, 306 patients with 306 suspicious mammographic findings (BI-RADS ⩾4) underwent mammography-guided biopsy, prone sVAB, or prone DBT-VAB. Student t test, chi-square, and multivariate regression statistics were used. Results: During the study period, 155 prone sVAB procedures in 155 patients (mean age, 56 years; age range, 39–84 years) and 151 DBT-VABs in 151 patients (mean age, 57 years; age range, 33–84 years) were performed. Mean procedure time was shorter with DBT-VAB versus sVAB (14.5 versus 17.4 minutes, respectively; p < 0.001), and fewer images were acquired with DBT-VAB versus sVAB (8 vs 11, respectively; p < 0.001); the average glandular dose was significantly lower in DBT-VAB versus sVAB (11.8 mGy versus 18 mGy, respectively; p < 0.001). There were no differences in the distribution of histologic results ( p = 0.74) or breast density ( p = 0.09) between the two groups. No major complications were observed in either group. Conclusion: Performance of prone DBT-VAB was superior to prone sVAB because it allowed a faster procedure with fewer radiologic expositions and lower radiation dose.

General anaesthesia during radiofrequency ablation of atrial fibrillation is associated with improved procedural characteristics but with similar long-term outcomes: a single center study

Funding Acknowledgements Type of funding sources: None. Introduction General anaesthesia (GA) or conscious sedation can be used during radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) based on physician’s and patient’s preference. Increasing number of centers include GA in their institutional protocols for RFCA of AF. Purpose The current study aims to compare real-world data on procedural characteristics, complication rate and procedural outcomes in patients undergoing RFCA of AF under GA or sedation at a single center. Methods A total of 167 patients (116 males, age 57.53 ± 9.78 years) with paroxysmal or persistent AF undergoing RFCA were studied retrospectively. Patients underwent RFCA under GA (108 patients, Group 1) provided by the anaesthesia team at our institution or under conscious sedation (59 patients, Group 2) guided by the operator using bolus doses of midazolam and fentanyl. We compared procedural time, fluoroscopy time, dose-area product (DAP), number of lesions and cumulative RF time between the two groups. We also analysed the complication rates and the long-term outcome in the two groups. Results are presented as mean ± SD or median (25th – 75th percentile). Results Groups 1 and 2 were comparable in terms of baseline clinical characteristics. Group 1 patients demonstrated significantly shorter procedural time as compared to Group 2: 149.52 ± 41.31 min vs. 208.23 ± 77.10 min, P &lt; 0.0005. Fluoroscopy time was also shorter in Group 1 24 (20-31.75) min compared to 36 (22.5-46.5) min in Group 2, P &lt; 0.0001. This corresponded to lower radiation dose expressed by DAP which was also significantly lower in Group 1 patients: 3230 (1660-6793.2) cGy/cm2 vs. 13880 (4215-21324) cGy/cm2 for Group 2, P &lt; 0.0001. Administration of GA during the procedure was associated with lower number of RF applications: 52.49 ± 19.36 in Group 1 vs. 68.33 ± 30.74 in Group 2, P = 0.0001. This corresponded with the lower cumulative RF time noted in the patients from Group 1: 2499.2 ± 824.17 sec vs. 3220 ± 1357.26 sec in Group 2, P &lt; 0.0001. Procedural complications occurred in 5 patients from Group 1 (4.6%) and in 8 patients (13.6%) in Group 2, P = 0.066. There was a single case of atrioesophageal fistula in a patient from Group 1. After a median follow-up of 20 (8-41) months 75% of the patients from both Group 1 and Group 2 were arrhythmia-free following 1.5 ± 0.68 procedures (P = 1.0). Conclusion Performing RFCA of AF under GA is associated with shorter procedural time, lower radiation dose and with the need for less energy application. This does not result in significantly lower complication rates. Long-term procedural outcomes do not seem to be affected by the use of GA.

Voice Outcomes after Radiotherapy for Laryngeal Cancer

Objective The study was aimed to assess changes in voice outcomes after radiotherapy in laryngeal cancer patients. Materials and Methods The study included 60 laryngeal cancer patients treated with definitive radiotherapy or chemoradiotherapy between 2005 and 2012. The primary endpoint of this study was to assess abnormalities of the patients’ voices after the treatment. The Thai version of the Voice Handicap Index (VHI) and xerostomia questionnaire were conducted by telephone. Videostroboscopic examination was done to objectively assess voice outcomes. Results The median age of patients was 63 years. Most patients had glottic cancer (84.1%) and T1–2 disease (84.1%). The median time from treatment to the study was 46 months. In terms of the total VHI score, most patients were in the normal and slight handicap groups (22% and 71.4%, respectively). Only 4.8% and 1.6% of the patients were in moderate and severe handicap group, respectively. Twenty-eight patients had significant xerostomia. Videostroboscopy examination was done in 23 patients and most common findings were telangiectasia (95.7%), abnormal mucosal wave (47.8%), and abnormal glottic closure configuration (34.8%). Regarding total VHI score, lower radiation dose, conventional radiation dose per fraction, longer period after treatment, and significant xerostomia status were significantly correlated with worse voice outcomes. There were no statistically significant correlations between the videostroboscopic findings and VHI scores. Conclusion Voice outcomes in most of laryngeal cancer patients treated with radiotherapy had a normal or mild handicap at more than 1 year of follow-up. Only 4.8% and 1.6% of the patients had moderate and severe voice outcome handicap, respectively.

Update on Hand-Held X-Ray Devices in Dentistry: a Literature Review

In the last two decades, the use of portable intraoral X-ray devices, stabilized by the operator, has increased. While all radiographic devices present an inherent risk from ionizing radiation, improper use of portable devices can increase operator exposure. Use of portable devices on a tripod or powered from a protected area is recommended. However, in highly justified cases, for using without these accessories, recommendations should be followed to reduce operator exposure. Because radioprotection is essential when using X-rays, fixed dental radiographic devices should be favored over portable equipment since the first provides a lower radiation dose to the operator.