The effects of radiofrequency exposure on cognition: A systematic review and meta-analysis of human observational studies.

BACKGROUND: We aimed to assess evidence of long-term effects of exposure to radiofrequency (RF) electromagnetic fields (EMF) on indicators of cognition, including domains of learning and memory, executive function, complex attention, language, perceptual motor ability and social cognition, and of an exposure-response relationship between RF-EMF and cognition. METHODS: We searched PubMed, Embase, PsycInfo and the EMF-Portal on September 30, 2022 without limiting by date or language of publication. We included cohort or case-control studies that evaluated the effects of RF exposure on cognitive function in one or more of the cognitive domains. Studies were rated for risk of bias using the OHAT tool and synthesised using fixed effects meta-analysis. We assessed the certainty of the evidence using the GRADE approach and considered modification by OHAT for assessing evidence of exposures. RESULTS: We included 5 studies that reported analyses of data from 4 cohorts with 4639 participants consisting of 2808 adults and 1831 children across three countries (Australia, Singapore and Switzerland) conducted between 2006 and 2017. The main source of RF-EMF exposure was mobile (cell) phone use measured as calls per week or minutes per day. For mobile phone use in children, two studies (615 participants) that compared an increase in mobile phone use to a decrease or no change were included in meta-analyses. Learning and memory. There was little effect on accuracy (mean difference, MD -0.03; 95% CI -0.07 to 0.02) or response time (MD -0.01; 95% CI -0.04 to 0.02) on the one-back memory task; and accuracy (MD -0.02; 95%CI -0.04 to 0.00) or response time (MD -0.01; 95%CI -0.04 to 0.03) on the one card learning task (low certainty evidence for all outcomes). Executive function. There was little to no effect on the Stroop test for the time ratio ((B-A)/A) response (MD 0.02; 95% CI -0.01 to 0.04, very low certainty) or the time ratio ((D-C)/C) response (MD 0.00; 95% CI -0.06 to 0.05, very low certainty), with both tests measuring susceptibility to interference effects. Complex attention. There was little to no effect on detection task accuracy (MD 0.02; 95% CI -0.04 to 0.08), or response time (MD 0.02;95% CI 0.01 to 0.03), and little to no effect on identification task accuracy (MD 0.00; 95% CI -0.04 to 0.05) or response time (MD 0.00;95% CI -0.01 to 0.02) (low certainty evidence for all outcomes). No other cognitive domains were investigated in children. A single study among elderly people provided very low certainty evidence that more frequent mobile phone use may have little to no effect on the odds of a decline in global cognitive function (odds ratio, OR 0.81; 95% CI 0.42 to 1.58, 649 participants) or a decline in executive function (OR 1.07; 95% CI 0.37 to 3.05, 146 participants), and may lead to a small, probably unimportant, reduction in the odds of a decline in complex attention (OR 0.67;95%CI 0.27 to 1.68, 159 participants) and a decline in learning and memory (OR 0.75; 95% CI 0.29 to 1.99, 159 participants). An exposure-response relationship was not identified for any of the cognitive outcomes. DISCUSSION: This systematic review and meta-analysis found only a few studies that provided very low to low certainty evidence of little to no association between RF-EMF exposure and learning and memory, executive function and complex attention. None of the studies among children reported on global cognitive function or other domains of cognition. Only one study reported a lack of an effect for all domains in elderly persons but this was of very low certainty evidence. Further studies are needed to address all types of populations, exposures and cognitive outcomes, particularly studies investigating environmental and occupational exposure in adults. Future studies also need to address uncertainties in the assessment of exposure and standardise testing of specific domains of cognitive function to enable synthesis across studies and increase the certainty of the evidence. OTHER: This review was partially funded by the WHO radioprotection programme and prospectively registered on PROSPERO CRD42021257548.

Micro-environmental personal radio-frequency electromagnetic field exposures in Melbourne: A longitudinal trend analysis.

BACKGROUND: A knowledge gap exists regarding longitudinal assessment of personal radio-frequency electromagnetic field (RF-EMF) exposures globally. It is unclear how the change in telecommunication technology over the years translates to change in RF-EMF exposure. This study aims to evaluate longitudinal trends of micro-environmental personal RF-EMF exposures in Australia. METHODS: The study utilised baseline (2015-16) and follow-up (2022) data on personal RF-EMF exposure (88 MHz-6 GHz) measured across 18 micro-environments in Melbourne. Simultaneous quantile regression analysis was conducted to compare exposure data distribution percentiles, particularly median (P50), upper extreme value (P99) and overall exposure trends. RF-EMF exposures were compared across six exposure source types: mobile downlink, mobile uplink, broadcast, 5G-New Radio, Others and Total (of the aforementioned sources). Frequency-specific exposures measured at baseline and follow-up were compared. Total exposure across different groups of micro-environment types were also compared. RESULTS: For all micro-environmental data, total (median and P99) exposure levels did not significantly change at follow-up. Overall exposure trend of total exposure increased at follow-up. Mobile downlink contributed the highest exposure among all sources showing an increase in median exposure and overall exposure trend. Of seven micro-environment types, five of them showed total exposure levels (median and P99) and overall exposure trend increased at follow-up.

Measuring dose in lung identifies peripheral tumour dose inaccuracy in SBRT audit.

PURPOSE: Stereotactic Body Radiotherapy (SBRT) for lung tumours has become a mainstay of clinical practice worldwide. Measurements in anthropomorphic phantoms enable verification of patient dose in clinically realistic scenarios. Correction factors for reporting dose to the tissue equivalent materials in a lung phantom are presented in the context of a national dosimetry audit for SBRT. Analysis of dosimetry audit results is performed showing inaccuracies of common dose calculation algorithms in soft tissue lung target, inhale lung material and at tissue interfaces. METHODS: Monte Carlo based simulation of correction factors for detectors in non-water tissue was performed for the soft tissue lung target and inhale lung materials of a modified CIRS SBRT thorax phantom. The corrections were determined for Gafchromic EBT3 Film and PTW 60019 microDiamond detectors used for measurements of 168 SBRT lung plans in an end-to-end dosimetry audit. Corrections were derived for dose to medium (Dm,m) and dose to water (Dw,w) scenarios. RESULTS: Correction factors were up to -3.4% and 9.2% for in field and out of field lung respectively. Overall, application of the correction factors improved the measurement-to-plan dose discrepancy. For the soft tissue lung target, agreement between planned and measured dose was within average of 3% for both film and microDiamond measurements. CONCLUSIONS: The correction factors developed for this work are provided for clinical users to apply to commissioning measurements using a commercially available thorax phantom where inhomogeneity is present. The end-to-end dosimetry audit demonstrates dose calculation algorithms can underestimate dose at lung tumour/lung tissue interfaces by an average of 2-5%.

Adoption of respiratory motion management in radiation therapy.

Background and Purpose: A survey on the patterns of practice of respiratory motion management (MM) was distributed to 111 radiation therapy facilities to inform the development of an end-to-end dosimetry audit including respiratory motion. Materials and methods: The survey (distributed via REDCap) asked facilities to provide information specific to the combinations of MM techniques (breath-hold gating - BHG, internal target volume - ITV, free-breathing gating - FBG, mid-ventilation - MidV, tumour tracking - TT), sites treated (thorax, upper abdomen, lower abdomen), and fractionation regimes (conventional, stereotactic ablative body radiation therapy - SABR) used in their clinic. Results: The survey was completed by 78% of facilities, with 98% of respondents indicating that they used at least one form of MM. The ITV approach was common to all MM-users, used for thoracic treatments by 89% of respondents, and upper and lower abdominal treatments by 38%. BHG was the next most prevalent (41% of MM users), with applications in upper abdominal and thoracic treatment sites (28% vs 25% respectively), but minimal use in the lower abdomen (9%). FBG and TT were utilised sparingly (17%, 7% respectively), and MidV was not selected at all. Conclusions: Two distinct treatment workflows (including use of motion limitation, imaging used for motion assessment, dose calculation, and image guidance procedures) were identified for the ITV and BHG MM techniques, to form the basis of the initial audit. Thoracic SABR with the ITV approach was common to nearly all respondents, while upper abdominal SABR using BHG stood out as more technically challenging. Other MM techniques were sparsely used, but may be considered for future audit development.

Trends in brain cancers (glioma) in New Zealand from 1995 to 2020, with reference to mobile phone use.

BACKGROUND: Some case-control studies have suggested substantial increased risks of glioma in association with mobile phone use; these risks would lead to an increase in incidence over time. METHODS: Incidence rates of glioma from 1995 to 2020 by age, sex, and site in New Zealand (NZ) recorded by the national cancer registry were assessed and trends analysed. Phone use was based on surveys. RESULTS: In these 25 years there were 6677 incident gliomas, giving age-standardised rates (WHO world standard) of 6.04 in males, and 3.95 in females per 100,000. The use of mobile phones increased rapidly from 1990 to more than 50% of the population from about 2000, and almost all the population from 2006. The incidence of glioma from ages 10-69 has shown a small decrease over the last 25 years, during which time the use of mobile phones has become almost universal. Rates in the brain locations receiving most radiofrequency energy have also shown a small decrease. Rates at ages of 80 and over have increased. CONCLUSION: There is no indication of any increase related to the use of mobile phones. These results are similar to results in Australia and in many other countries. The increase in recorded incidence at ages over 80 is similar to that seen in other countries and consistent with improved diagnostic methods.

Mobile phone use and trends in the incidence of cancers of the parotid and other salivary glands.

BACKGROUND: There has been a significant increase in the use of mobile phones over the last three decades and a possible association with head cancers has been suggested, including cancers of the parotic and other salivary glands. We examined the incidence time trends of parotid and other salivary gland cancers in Australia to ascertain the influence of increased mobile phone use. METHODS: Analyses of incidence time trends were carried out using Poisson regression to estimate the annual percentage change (APC) in the incidence of salivary gland cancers of all available national registration data from 1982 to 2016, as well as specific time periods (1982-1993, 1994-2005, 2006-2016) representing changes in the prevalence of mobile phone use. RESULTS: The incidence of parotid gland cancer was stable for the periods 1982-1993 and 1994-2005. During 2006-2016 there was a large decrease in parotid gland cancer for males (APC: -3.71, 95 %CI: -6.66 to -0.67) and a large increase in females (4.80, 1.77-7.91) for adults aged 20-59 years. The incidence for other salivary gland cancers was stable during all the periods. CONCLUSIONS: The results do not indicate that mobile phone use increased the incidence of parotid or other salivary gland cancers. An increase in parotid gland cancer in females since 2006 may be attributed to other possible risk factors specific to this gender.

Updated Australian diagnostic reference levels for adult CT.

INTRODUCTION: In 2018, ARPANSA published updated national DRLs for adult CT, which were first published in 2012, and augmented the national DRL categories. This paper presents the updated national DRLs and describes the process by which they were produced. METHODS: Examine patient survey data submitted to the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) National Diagnostic Reference Level Service (NDRLS). Determine the quartiles of the distributions of median survey dose metrics with categorisation by procedure type. Engage a liaison panel representing the radiology professions to review procedure categories and recommend revised national DRLs. The revised NDRL procedure categories are: head (non-contrast brain (trauma/headache)), cervical spine (Non-contrast (trauma)), soft-tissue neck (post-contrast (oncology)), chest (post-contrast (oncology)), abdomen-pelvis (post-contrast (oncology)), kidney-ureter-bladder (non-contrast (suspected renal colic)), chest-abdomen-pelvis (post-contrast (oncology)) and lumbar spine (non-contrast (degenerative pain)). RESULTS: The existing six procedure categories were revised and refined. Updated Australian national diagnostic reference levels for adult CT were recommended and endorsed for eight procedure categories: head (52 mGy/880 mGycm), cervical spine (23 mGy/470 mGycm),soft-tissue neck (17 mGy/450 mGycm), chest (10 mGy/390 mGycm), abdomen-pelvis (13 mGy/600 mGycm), kidney-ureter-bladder (13 mGy/600 mGycm), chest-abdomen-pelvis (11 mGy/940 mGycm) and lumbar spine (26 mGy/670 mGycm). The updated national DRLs are between 12 and 26% lower than the previous DRLs for dose-length product and between 13 and 63% lower for volume computed tomography dose index. CONCLUSIONS: Australian national DRLs for adult CT have been reviewed and revised. The revised national DRLs are lower, better reflecting current practice among imaging facilities in Australia. The revised Australian national DRLs are similar to those in other developed countries.

Mobile phone use and incidence of brain tumour histological types, grading or anatomical location: a population-based ecological study.

OBJECTIVE: Some studies have reported increasing trends in certain brain tumours and a possible link with mobile phone use has been suggested. We examined the incidence time trends of brain tumour in Australia for three distinct time periods to ascertain the influence of improved diagnostic technologies and increase in mobile phone use on the incidence of brain tumours. DESIGN: In a population-based ecological study, we examined trends of brain tumour over the periods 1982-1992, 1993-2002 and 2003-2013. We further compared the observed incidence during the period of substantial mobile phone use (2003-2013) with predicted (modelled) incidence for the same period by applying various relative risks, latency periods and mobile phone use scenarios. SETTING: National Australian incidence registration data on primary cancers of the brain diagnosed between 1982 and 2013. POPULATION: 16 825 eligible brain cancer cases aged 20-59 from all of Australia (10 083 males and 6742 females). MAIN OUTCOME MEASURES: Annual percentage change (APC) in brain tumour incidence based on Poisson regression analysis. RESULTS: The overall brain tumour rates remained stable during all three periods. There was an increase in glioblastoma during 1993-2002 (APC 2.3, 95% CI 0.8 to 3.7) which was likely due to advances in the use of MRI during that period. There were no increases in any brain tumour types, including glioma (-0.6, -1.4 to 0.2) and glioblastoma (0.8, -0.4 to 2.0), during the period of substantial mobile phone use from 2003 to 2013. During that period, there was also no increase in glioma of the temporal lobe (0.5, -1.3 to 2.3), which is the location most exposed when using a mobile phone. Predicted incidence rates were higher than the observed rates for latency periods up to 15 years. CONCLUSIONS: In Australia, there has been no increase in any brain tumour histological type or glioma location that can be attributed to mobile phones.

Bolus administration of intravenous lidocaine reduces pain after an elective caesarean section: Findings from a randomised, double-blind, placebo-controlled trial.

We conducted a randomised double-blind, placebo-controlled trial to assess whether a bolus dose of lidocaine during the induction of general anaesthesia would reduce postoperative pain over 24 h. Level of satisfaction with pain control at 48 h after surgery and Apgar score were also examined. A total of 100 women aged 20-35 years, who were candidates for elective caesarean section (CS) were randomised to receive either 1.5 mg/kg lidocaine or placebo during the induction of general anaesthesia. Results showed that lidocaine decreased pain intensity over 24 h after surgery (p < .001), and decreased postoperative morphine consumption from median (range) of 3.79 (0-9) mg in the placebo group to 0 (0-12) mg and in the lidocaine group (p <.001). Lidocaine was not associated with postoperative nausea and vomiting or any side effects in women and newborn babies. We conclude that a small bolus dose of lidocaine attenuates postoperative pain, thus reducing the requirement for opioid consumption in the postoperative period. Impact statement • With its anti-inflammatory, anti-hyperalgesic and analgesic properties, intravenous perioperative lidocaine infusion (IVLI) has been used for optimal postoperative care in different surgeries. Limited evidence suggests that IVLI may be a useful adjuvant during general anaesthesia. There is a report of a positive effect on several outcomes after surgery including postoperative pain over 24 h after laparoscopic abdominal surgery or open abdominal surgery. However, there was a paucity of information regarding the efficacy of a bolus dose of lidocaine in patients undergoing caesarean section (CS). In this randomized, placebo-controlled trial the use of a bolus dose of 1.5 mg/kg lidocaine 2%, compared with placebo, during the induction of general anaesthesia for elective CS resulted in a significant decrease in postoperative pain score as well as decreased postoperative morphine consumption over 24 h. Lidocaine use was not associated with any side effect in participants and newborns. • This study provides the first evidence that a bolus dose of lidocaine may be a safe and simple alternative therapeutic intervention for enhanced postoperative recovery in terms of pain and postoperative opioid consumption. Future studies are needed to examine pain reducing effect of perioperative bolus dose of lidocaine after CS under spinal or epidural anesthesia.

Robustness testing of an in-situ caesium extraction unit.

Following on from the successful development and validation of a prototype automated unit for the extraction of radiocaesium from seawater, the unit was redesigned to be smaller, easier to transport and better suited for field work. An extension of the validation process was undertaken to include robustness testing. Robustness testing evaluates the behaviour of a procedure when deliberate small changes are made. This requires the identification and testing of experimental factors which could have an impact on the results. The Plackett-Burman approach was adopted to minimise the number of experiments needed for testing. The study showed that the analytical method was not sensitive to any of the factors tested, indicating that the method is robust.

Prediction of acute kidney injury within 30 days of cardiac surgery.

OBJECTIVE: To predict acute kidney injury after cardiac surgery. METHODS: The study included 28,422 cardiac surgery patients who had had no preoperative renal dialysis from June 2001 to June 2009 in 18 hospitals. Logistic regression analyses were undertaken to identify the best combination of risk factors for predicting acute kidney injury. Two models were developed, one including the preoperative risk factors and another including the pre-, peri-, and early postoperative risk factors. The area under the receiver operating characteristic curve was calculated, using split-sample internal validation, to assess model discrimination. RESULTS: The incidence of acute kidney injury was 5.8% (1642 patients). The mortality for patients who experienced acute kidney injury was 17.4% versus 1.6% for patients who did not. On validation, the area under the curve for the preoperative model was 0.77, and the Hosmer-Lemeshow goodness-of-fit P value was .06. For the postoperative model area under the curve was 0.81 and the Hosmer-Lemeshow P value was .6. Both models had good discrimination and acceptable calibration. CONCLUSIONS: Acute kidney injury after cardiac surgery can be predicted using preoperative risk factors alone or, with greater accuracy, using pre-, peri-, and early postoperative risk factors. The ability to identify high-risk individuals can be useful in preoperative patient management and for recruitment of appropriate patients to clinical trials. Prediction in the early stages of postoperative care can guide subsequent intensive care of patients and could also be the basis of a retrospective performance audit tool.

Hospital-level associations with 30-day patient mortality after cardiac surgery: a tutorial on the application and interpretation of marginal and multilevel logistic regression.

BACKGROUND: Marginal and multilevel logistic regression methods can estimate associations between hospital-level factors and patient-level 30-day mortality outcomes after cardiac surgery. However, it is not widely understood how the interpretation of hospital-level effects differs between these methods. METHODS: The Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) registry provided data on 32,354 patients undergoing cardiac surgery in 18 hospitals from 2001 to 2009. The logistic regression methods related 30-day mortality after surgery to hospital characteristics with concurrent adjustment for patient characteristics. RESULTS: Hospital-level mortality rates varied from 1.0% to 4.1% of patients. Ordinary, marginal and multilevel regression methods differed with regard to point estimates and conclusions on statistical significance for hospital-level risk factors; ordinary logistic regression giving inappropriately narrow confidence intervals. The median odds ratio, MOR, from the multilevel model was 1.2 whereas ORs for most patient-level characteristics were of greater magnitude suggesting that unexplained between-hospital variation was not as relevant as patient-level characteristics for understanding mortality rates. For hospital-level characteristics in the multilevel model, 80% interval ORs, IOR-80%, supplemented the usual ORs from the logistic regression. The IOR-80% was (0.8 to 1.8) for academic affiliation and (0.6 to 1.3) for the median annual number of cardiac surgery procedures. The width of these intervals reflected the unexplained variation between hospitals in mortality rates; the inclusion of one in each interval suggested an inability to add meaningfully to explaining variation in mortality rates. CONCLUSIONS: Marginal and multilevel models take different approaches to account for correlation between patients within hospitals and they lead to different interpretations for hospital-level odds ratios.

Measuring professionalism in residency training programs in Iran.

BACKGROUND AND AIM: To assess the Farsi (Persian) translated and modified version of the questionnaire of the American Board of Internal Medicine (ABIM) for measuring professionalism, and also, measuring the professional attitudes and behaviors associated with the medical residency training environment in Iran. METHODS: After a pilot study, a 17-item questionnaire was distributed to 282 medical residents of two major universities of Iran, from December 2006 through February 2007. RESULTS: Of the 282 distributed questionnaires, 259 (95.2%) were used in the analysis. Based on the analyses, two items were omitted and 15 items were retained for further analysis. The mean score was 106 (Standard Deviation (SD), 22.4) out of maximum 150, whereas the item mean was 6.12 (SD, 0.37) out of maximum 10. Corrected item-to-total correlations ranged from low to moderate. The internal reliability of the scale, based on Cronbach's alpha, meets Nunnally's minimal requirement. A factor analysis was performed, based on principal components and varimax rotation. The solution identified three factors (subscales) including excellence, honor/integrity and altruism/respect. Together these factors represented 58.8% of the common variance. CONCLUSION: This study showed the content validity and internal reliability of the Farsi version of the ABIM questionnaire. Therefore, it can be considered as an encouraging step toward developing a short, reliable and valid instrument for measuring professionalism in medical environments.

Intravitreal Bevacizumab versus Combined Bevacizumab and Triamcinolone Acetonide for Neovascular Age-Related Macular Degeneration.

PURPOSE: To compare the short-term outcomes of intravitreal bevacizumab (IVB) with the combination of IVB and intravitreal triamcinolone acetonide (IVB/IVT) for treatment of neovascular age-related macular degeneration (AMD). METHODS: This randomized clinical trial was performed on 92 eyes of 90 patients with subfoveal and juxtafoveal choroidal neovascularization (CNV) secondary to AMD. The eyes were randomly assigned to receive IVB 1.25 mg alone (53 eyes) or in combination with IVT 2 mg (39 eyes). Best-corrected visual acuity (BCVA) and fundus autofluorescence were assessed, and fluorescein angiography (FA) and optical coherence tomography (OCT) were performed at baseline and repeated 6 weeks after treatment. RESULTS: Mean age was 70.6±8.7 (range 50-89) years and 57.7% of the patients were male. BCVA improved from 1.03±0.40 to 0.93±0.38 logMAR (P=0.001) in the IVB group and from 1.08±0.33 to 0.91±0.38 logMAR (P=0.008) in the IVB/IVT group. There was a trend toward greater visual improvement with combined therapy (P=0.06). BCVA improvement was greater in eyes with +1 versus those with +2 (P=0.049) and +3 (P<0.001) fundus autofluorescence at baseline. Mean decrease in central macular thickness was 113±115 µm (P<0.001) in the IVB group versus 53.96±125 µm (P=0.008) in the IVB/IVT group with no intergroup difference (P=0.38). FA showed decreased leakage in 57.4%, increased leakage in 12.8% and no change in 29.8% of patients in the IVB group. Corresponding figures were 60.0%, 5.7% and 34.3% in the IVB/IVT group (P=0.556). CONCLUSION: Addition of triamcinolone acetonide to bevacizumab for treatment of neovascular AMD does not seem to significantly increase its short-term efficacy. More severe fundus autofluorescence appears to be predictive of poorer response to treatment.