Neuromonitoring for Proximal Fibular Osteochondroma Excision.

BACKGROUND: The peroneal nerve is at risk when excising tumors in the proximal fibula. The rate of nerve injuries during proximal fibular tumor resection varies from 3% to 20%. Our goal was to report our experience with resection of osteochondromas in the proximal fibula and describe the technique and utility of neuromonitoring during excision of proximal fibular osteochondromas (PFO). METHODS: Patients with a diagnosis of symptomatic PFO who had undergone excision at one institution from 1994 to 2018 were included. An institutional review board-approved retrospective review was performed. Intraoperative neuromonitoring was provided from 2006 on by a single group utilizing a multimodality protocol. RESULTS: This study contains 29 patients who had excision of osteochondromas in the proximal fibula. Of these 29 consecutively monitored patients, there were 34 involved extremities. Intraoperative neuromonitoring alerts occurred in 10/29 (34.5%) procedures, which included 3 electromyography (EMG) (30%), 2 motor-evoked potential (20%), 1 somatosensory-evoked potential (10%), and 4 alerts with a combination of EMG/motor-evoked potential/somatosensory-evoked potential changes (40%). The interventions that were taken resulted in resolution of the neuromonitoring changes in all procedures. Postoperatively, we noted 2 (6.9%) new mild sensory deficits, which resolved during follow up. There were 3 patients in whom pre-existing sensory-motor deficits improved but not completely after surgery, 1 motor weakness, and 2 with residual paresthesia. In those initially presenting with paresis, there was improvement in 8 of the 8 extremities by the last follow-up visit. Pain as a symptom was resolved in all cases. There were no iatrogenic foot drop injuries. The average follow up was 32.2 months. CONCLUSIONS: Neuromonitoring during PFO excision demonstrated a high number of alerts, all of which resolved following timely corrective action. The use of neuromonitoring may help decrease the risk of iatrogenic postoperative neurological deficits following fibular osteochondroma surgery. LEVEL OF EVIDENCE: Level IV.

Using tea as an artificial urine in a Canadian performance testing program for fission/activation products.

In recent years, the National Calibration Reference Centre for Bioassay and In Vivo Monitoring (NCRC) at the Radiation Protection Bureau (RPB), Health Canada, has been conducting investigations with black tea to develop a matrix that can be used to replace urine in each of the following performance testing programs (PTP): (1) tritium, (2) carbon-14, (3) the DUAL (i.e., 3H/14C), and (4) fission/activation products (F/AP). A 1% tea solution with thimerosal, which had worked successfully for tritium, carbon-14, and the DUAL, was selected and tested for the F/AP PTP because of its similarity to urine in color and UV-VIS spectra. However, application of this tea to samples of the F/AP program containing 133Ba, 137Cs, 57Co, and 60Co produced precipitates, which was an unexpected result. Further experiments showed that replacement of thimerosal with an alcohol at about 5% eliminated the precipitation problem. The alcohol can be ethanol, methanol, or isopropanol. In the experiments, the 1% tea, preserved with alcohol, remained clear and stable for at least 100 d. The duration of each PTP for the NCRC is limited to 90 d. Application of the CNSC S-106 regulatory standard to the tea produced acceptable accuracy and precision results. It was concluded that a suitable tea matrix for the F/AP program had been found.

Evaluation of tea as a matrix in a dual (3H/14C) performance testing program in Canada.

Urine is the most popular matrix used in performance testing programs (PTP) and inter-comparison programs (ICP) for bioassay. Because it comes from humans, there are concerns regarding its biosafety. For large programs, its collection can take several hours or days to complete. In addition, natural urine has an unpleasant smell, which tends to worsen with increasing storage time. In order to solve some of these problems, the Bioassay Section at the Radiation Protection Bureau in Health Canada has been investigating the use of tea in both PTP and ICP exercises. A method based on diluting tea steeps and scanning them in the UV-VIS range of the light spectrum to select appropriate concentrations as simulated urine for the programs has been published. So far, however, only single H and single C in tea have been studied. The results were found to be compatible and very successful under the S-106 standard of the Canadian Nuclear Safety Commission. This report is an extension of similar investigations and shows that tea samples spiked with both H and C (DUAL) are also compatible and produce excellent PTP results.

Evaluation of a commercial software package's ability to calibrate an in vivo counter for emergency response.

A commercial detector calibration package has been assessed for its use to calibrate the Human Monitoring Laboratory's Portable Whole Body Counter that is used for emergency response. The advantage of such a calibration software is that calibrations can be derived very quickly once the model has been designed. The commercial package's predictions were compared to experimental point source data and to predictions from Monte Carlo simulations. It was found that the software adequately predicted the counting efficiencies of a point source geometry to values derived from Monte Carlo simulations and experimental work. Both the standing and seated counting geometries agreed sufficiently well that the commercial package could be used in the field.

Preparation and application of steeps of tea as new simulations of urine for the performance testing programme of 14C.

(14)C is one of the radionuclides for which the Canadian Nuclear Safety Commission has developed performance testing programmes (PTPs). During the PTP exercises, clients receive samples of natural urine containing spiked radionuclides, for testing. In these programmes, urine has disadvantages. These include (1) slow collection times from donors, (2) unpleasant smell and (3) potential to transmit diseases. To assist in solving some of these problems, the Canadian National Calibration Reference Centre for Bioassay and In Vivo Monitoring has conducted research with tea solutions, to find simpler, safer and more readily available alternatives to urine. This paper provides a new technique by which steeps of black tea have been successfully prepared for the (14)C PTP. The results of tea solutions compared well with those of urine. It was concluded that tea steeps, of which the spectroscopic and colour quenching properties have been adjusted, do provide appropriate urine simulations, suitable for use in PTPs.

Preparation and application of tea to a tritium performance testing programme.

A simple, but novel technique, for adjusting steeps of black tea to produce fluids, which are visually and spectroscopically similar to urine, has been developed at the National Calibration Reference Centre for Bioassay and In Vivo Monitoring in Canada. The method uses scans of absorbance versus wavelength, in the UV-VIS range (200-800 nm) to select diluted tea steeps that simulate urine. Tea solutions (1 and 10 %) were spiked with tritium and distributed to laboratories for performance testing (PT). The PT exercise was done as in a regular bioassay programme. The results showed that all samples satisfied the pass/fail conditions of the S-106 standard of the Canadian Nuclear Safety Commission, suggesting that adjusted tea successfully simulated urine for the tritium PT programmes. Also, since unlike urine whose use may increase the probability of contaminating and transmitting diseases (e.g. hepatitis C), tea is a safer alternative. When needed, it can readily be prepared for the laboratories.

Method comparison for 241Am emergency urine bioassay.

241Am is one of the high-risk radionuclides that might be used in a terrorist attack. 241Am in urine bioassay can identify the contaminated individuals who need immediate medical intervention and decontamination. This paper compares three methods for the measurement of 241Am in urine, namely liquid scintillation counting (LSC), inductively coupled plasma mass spectrometry (ICP-MS) and gamma spectrometry (GS), at two levels, 20 and 2 Bq l(-1). All three methods satisfied the ANSI N13.30 radio-bioassay criteria for accuracy and repeatability. ICP-MS offered the best sensitivity and fastest sample turnaround; however, the ICP-MS system used in this work may not be available in many bioassay laboratories. LSC and GS are more commonly available instruments. GS requires minimal or no sample preparation, which makes it a good candidate method. Moreover, the sample throughput can be significantly improved if the GS and LSC methods are automated.

Pilot assessment of HIV gene therapy-hematopoietic stem cell clinical trial acceptability among minority patients and their advisors.

Clinical trials involving technologically involved novel treatments such as gene therapy delivered through hematopoietic stem cells as human immunodeficiency virus (HIV) treatment will need to recruit ethnically diverse patients to ensure the acceptance among broad groups of individuals and generalizability of research findings. Five focus groups of 47 HIV-positive men and women, religious and community leaders and health providers, mostly from African American and low-income communities, were conducted to examine knowledge about gene therapy and stem cell research and to assess the moral and ethical beliefs that might influence participation in clinical trials. Three themes emerged from these groups: (1) the need for clarification of terminology and the ethics of understanding gene therapy-stem cell research, (2) strategies to avoid mistrust of medical procedures and provider mistrust, and (3) the conflict between science and religious beliefs as it pertains to gene therapy-stem cell research.

A methodology for improving throughput using portal monitors.

The National Internal Radiation Assessment Section (NIRAS), which operates the Canadian National Calibration Reference Centre for Bioassay and In Vivo Monitoring, has field deployable equipment for emergency response. A substantial part of this tool kit is a set of portal monitors that can be used to quickly screen people into the 'uncontaminated' and the 'contaminated'. The former term refers to a person who has <60 kBq (empirical practical detection limit) of activation/fission products and the latter group is contaminated by that amount or more. Recent field work has shown that one type of the NIRAS's portal monitors can be alarmed at significant distances if the level of contamination is high enough. The other types, which do not initiate a count until either an infra-red beam is broken or a proximity detector is activated, do not alarm but their background will be raised and this causes other problems. This paper proposes a method of group monitoring to help speed up the process of screening a large number of potentially contaminated persons using portal monitors. In short, the group of potentially contaminated persons will be kept isolated from the portal stations. Depending on a real-time estimate of the percentage of contaminated persons in the crowd, groups of persons will be selected for screening. The hypergeometric distribution has been used to decide on the sampling group size with an expectation that 90% of the time no contaminated person will be present in the group. Once removed from the main waiting area, the group will be pre-screened and then, depending on the result, sent to the appropriate portal. It is anticipated that this will greatly speed up processing as it substantially reduces the transit time. Transits times have also been estimated in addition to the number of personnel required to run all of NIRAS's field deployable equipment.