Cost-Effectiveness Analysis of Molecular Testing for Indeterminate Thyroid Nodules in Nova Scotia.

BACKGROUND: The objective of the following retrospective review was to perform a cost-effectiveness analysis of the use of molecular testing of indeterminate thyroid nodules compared to current management practices in Nova Scotia, Canada. METHODS: All cases of cytologically indeterminate thyroid nodules from January 1st, 2014 to December 31st, 2018 were reviewed. All interventions related to an indeterminate thyroid nodule were recorded. Patients were excluded if less than 18 years old if no further information regarding medical management was electronically available beyond the diagnosis of an indeterminate thyroid nodule, history of radiation, or previous thyroid surgery prior to diagnosis of an indeterminate thyroid nodule in the remaining lobe. Microcosting was performed to determine the cost of all relevant interventions including repeat fine needle aspiration biopsy, ultrasound, thyroid surgery(s), and molecular testing. Institution-specific transition state probabilities were calculated and used to build a cost-effectiveness analysis model. Model output was an incremental cost-effectiveness ratio, defined as the ratio of cost difference to effectiveness difference between routine molecular testing and the current management strategy, yielding cost per surgery avoided. RESULTS: The mean effectiveness of the current management of indeterminate thyroid nodules in Nova Scotia based on the American Thyroid Association guidelines is 64% at a mean cost of $6431, while the simulated mean effectiveness of routine molecular testing is 89% at a mean cost of $8414. Differences in management strategies generated an incremental cost-effectiveness ratio of $7876 per surgery avoided. CONCLUSION: Routine molecular testing is the more effective strategy for the appropriate management of indeterminate thyroid nodules; however, it comes at a higher mean cost compared to the current management strategy. As the cost of molecular testing continues to decrease, and the cost of OR resources continues to rise, molecular testing is likely to become the optimal strategy in Nova Scotia.

Increases in Global and East Asian Nitrogen Trifluoride (NF3) Emissions Inferred from Atmospheric Observations.

Nitrogen trifluoride (NF3) is a potent and long-lived greenhouse gas that is widely used in the manufacture of semiconductors, photovoltaic cells, and flat panel displays. Using atmospheric observations from eight monitoring stations from the Advanced Global Atmospheric Gases Experiment (AGAGE) and inverse modeling with a global 3-D atmospheric chemical transport model (GEOS-Chem), we quantify global and regional NF3 emission from 2015 to 2021. We find that global emissions have grown from 1.93 ± 0.58 Gg yr-1 (± one standard deviation) in 2015 to 3.38 ± 0.61 Gg yr-1 in 2021, with an average annual increase of 10% yr-1. The available observations allow us to attribute significant emissions to China (0.93 ± 0.15 Gg yr-1 in 2015 and 1.53 ± 0.20 Gg yr-1 in 2021) and South Korea (0.38 ± 0.07 Gg yr-1 to 0.65 ± 0.10 Gg yr-1). East Asia contributes around 73% of the global NF3 emission increase from 2015 to 2021: approximately 41% of the increase is from emissions from China (with Taiwan included), 19% from South Korea, and 13% from Japan. For Japan, which is the only one of these three countries to submit annual NF3 emissions to UNFCCC, our bottom-up and top-down estimates are higher than reported. With increasing demand for electronics, especially flat panel displays, emissions are expected to further increase in the future.

Substantial increase in perfluorocarbons CF4 (PFC-14) and C2F6 (PFC-116) emissions in China.

The perfluorocarbons tetrafluoromethane (CF4, PFC-14) and hexafluoroethane (C2F6, PFC-116) are potent greenhouse gases with near-permanent atmospheric lifetimes relative to human timescales and global warming potentials thousands of times that of CO2. Using long-term atmospheric observations from a Chinese network and an inverse modeling approach (top-down method), we determined that CF4 emissions in China increased from 4.7 (4.2-5.0, 68% uncertainty interval) Gg y-1 in 2012 to 8.3 (7.7-8.9) Gg y-1 in 2021, and C2F6 emissions in China increased from 0.74 (0.66-0.80) Gg y-1 in 2011 to 1.32 (1.24-1.40) Gg y-1 in 2021, both increasing by approximately 78%. Combined emissions of CF4 and C2F6 in China reached 78 Mt CO2-eq in 2021. The absolute increase in emissions of each substance in China between 2011-2012 and 2017-2020 was similar to (for CF4), or greater than (for C2F6), the respective absolute increase in global emissions over the same period. Substantial CF4 and C2F6 emissions were identified in the less-populated western regions of China, probably due to emissions from the expanding aluminum industry in these resource-intensive regions. It is likely that the aluminum industry dominates CF4 emissions in China, while the aluminum and semiconductor industries both contribute to C2F6 emissions. Based on atmospheric observations, this study validates the emission magnitudes reported in national bottom-up inventories and provides insights into detailed spatial distributions and emission sources beyond what is reported in national bottom-up inventories.

Rising Perfluorocyclobutane (PFC-318, c-C4F8) Emissions in China from 2011 to 2020 Inferred from Atmospheric Observations.

Global atmospheric emissions of perfluorocyclobutane (c-C4F8, PFC-318), a potent greenhouse gas, have increased rapidly in recent years. Combining atmospheric observations made at nine Chinese sites with a Lagrangian dispersion model-based Bayesian inversion technique, we show that PFC-318 emissions in China grew by approximately 70% from 2011 to 2020, rising from 0.65 (0.54-0.72) Gg year-1 in 2011 to 1.12 (1.05-1.19) Gg year-1 in 2020. The PFC-318 emission increase from China played a substantial role in the overall increase in global emissions during the study period, contributing 58% to the global total emission increase. This growth predominantly originated in eastern China. The regions with high emissions of PFC-318 in China overlap with areas densely populated with polytetrafluoroethylene (PTFE) factories, implying that fluoropolymer factories are important sources of PFC-318 emissions in China. Our investigation reveals an emission factor of approximately 3.02 g of byproduct PFC-318 emissions per kg of hydrochlorofluorocarbon-22 (HCFC-22) feedstock use in the production of tetrafluoroethylene (TFE) (for PTFE production) and hexafluoropropylene (HFP) if we assume all HCFC-22 produced for feedstock uses in China are pyrolyzed to produce PTFE and HFP. Further facility-level sampling and analysis are needed for a more precise evaluation of emissions from these factories.

Sustained growth of sulfur hexafluoride emissions in China inferred from atmospheric observations.

Sulfur hexafluoride (SF6) is a potent greenhouse gas. Here we use long-term atmospheric observations to determine SF6 emissions from China between 2011 and 2021, which are used to evaluate the Chinese national SF6 emission inventory and to better understand the global SF6 budget. SF6 emissions in China substantially increased from 2.6 (2.3-2.7, 68% uncertainty) Gg yr-1 in 2011 to 5.1 (4.8-5.4) Gg yr-1 in 2021. The increase from China is larger than the global total emissions rise, implying that it has offset falling emissions from other countries. Emissions in the less-populated western regions of China, which have potentially not been well quantified in previous measurement-based estimates, contribute significantly to the national SF6 emissions, likely due to substantial power generation and transmission in that area. The CO2-eq emissions of SF6 in China in 2021 were 125 (117-132) million tonnes (Mt), comparable to the national total CO2 emissions of several countries such as the Netherlands or Nigeria. The increasing SF6 emissions offset some of the CO2 reductions achieved through transitioning to renewable energy in the power industry, and might hinder progress towards achieving China's goal of carbon neutrality by 2060 if no concrete control measures are implemented.

Management of positive resection margins following transoral laser microsurgery for glottic cancer.

Objectives: The current literature provides limited guidance on the management of positive margins (PMs) following transoral laser microsurgery (TLM) for glottic squamous cell carcinoma (SCC). Long-term data exploring the treatment of PMs with both initial observation and re-resection are limited. Our objective was to determine the optimal treatment for PM patients following TLM for glottic SCC. Methods: Clinical information on glottic SCC patients with PMs following treatment with TLM was prospectively collected at our institution from 2007 to 2018. We use a laryngeal template during the initial TLM where the area of resection is outlined for future reference. Data were compared with univariate analysis and survival plots were generated using the Kaplan-Meier method. Results: A total of 29 patients with PMs were treated with either re-resection (19 patients), close observation (6 patients), or adjuvant radiation alone (4 patients). Re-resection patients had SCC or severe dysplasia on initial margin pathology and 23% with early-stage disease had recurrence (T1-T2). Five (83%) patients who underwent close observation required re-resection based on clinical suspicion of recurrence (confirmed on final pathology), which was significantly different from the re-resection patients (p < .05). Close observation was therefore discontinued as a management of PMs. Four patients (21%) had no residual malignancy on re-resection specimens. Deep margins only accounted for 17% of all PMs. Disease-specific survival for all PM patients at 5 years was 82.4% (SE 9.6%, CI 53.4%-91.6%). Conclusions: Our long-term experience with treating early-stage glottic SCC with TLM supports re-resection as an appropriate management for cases of PMs. Level of Evidence: 4.

Anthropogenic Chloroform Emissions from China Drive Changes in Global Emissions.

Emissions of chloroform (CHCl3), a short-lived halogenated substance not currently controlled under the Montreal Protocol on Substances that Deplete the Ozone Layer, are offsetting some of the achievements of the Montreal Protocol. In this study, emissions of CHCl3 from China were derived by atmospheric measurement-based "top-down" inverse modeling and a sector-based "bottom-up" inventory method. Top-down CHCl3 emissions grew from 78 (72-83) Gg yr-1 in 2011 to a maximum of 193 (178-204) Gg yr-1 in 2017, followed by a decrease to 147 (138-154) Gg yr-1 in 2018, after which emissions remained relatively constant through 2020. The changes in emissions from China could explain all of the global changes during the study period. The CHCl3 emissions in China were dominated by anthropogenic sources, such as byproduct emissions during disinfection and leakage from chloromethane industries. Had emissions continued to grow at the rate observed up to 2017, a delay of several years in Antarctic ozone layer recovery could have occurred. However, this delay will be largely avoided if global CHCl3 emissions remain relatively constant in the future, as they have between 2018 and 2020.

The impact of national holidays on postoperative radiotherapy of squamous cell carcinoma of the head and neck.

Background: Delays in starting postoperative radiotherapy (PORT) have been established as negative predictors for clinical outcomes in head and neck squamous cell carcinomas (HNSCC). Our study aimed to examine the effect of delays during PORT, and the impact of national holidays in Canada, a publicly funded system, on oncologic outcomes such as Overall Survival (OS) and Local Recurrence (LR). Methods: The provincial cancer registry was queried to obtain demographic, pathologic, and outcomes data from cancer patients treated for all squamous cell carcinomas of the head and neck region treated between January 1, 2007 and November 30, 2019. All extracted information was cross-referenced and supplemented by chart review of patient electronic medical records. Extracted data were analyzed for OS and LR, in the context of Canadian national holidays causing delays during PORT. Results: 1433 patients treated for HNSCCs were identified, of whom 338 were treated curatively with surgery followed by PORT. 68.6% of patients experienced at least one day of interruption during treatments due to holidays. LR was 15.4% and OS was 59.6% at 5 years. Treatment interruptions by holidays were predictive of local recurrence (HR, 2.38; 95% CI 1.17-4.83; p = 0.017). Patients that developed early recurrence prior to PORT had very poor oncologic outcomes. Conclusion: Our findings were consistent with previously published studies in limiting the interval between surgery and PORT. We identified the novel finding of paired holidays as a significant predictor in determining LR, suggesting the importance of modifying RT delivery schedules and timing.

In Situ Observations of Halogenated Gases at the Shangdianzi Background Station and Emission Estimates for Northern China.

Halogenated gases include ozone-depleting substances and greenhouse gases, such as chlorofluorocarbons, halons, hydrochlorofluorocarbons, hydrofluorocarbons, and perfluorinated gases. In situ atmospheric observations of major halogenated gases were conducted at the Shangdianzi (SDZ) background station, China, from October 2020 to September 2021 using ODS5-pro, a newly developed measurement system. The measurement time series of 36 halogenated gases showed occasional pollution events, where background conditions represented 25% (CH2Cl2) to 81% (CF3Cl, CFC-13) of the measurements. The annual mean background mole fractions of most species at SDZ were consistent with those obtained at the Mace Head station in Ireland. The background conditions were distinguished from pollution events, and the enhanced mole fractions were used to estimate the emissions of four categories of fluorinated gases (F-gases) from northern China using a tracer ratio method. The CO2-equivalent (CO2-equiv) emission of F-gases from northern China reached 181 ± 18 Tg year-1 during 2020-2021. Among the four categories of F-gases estimated, SF6 accounted for the highest proportion of CO2-equiv emissions (24%), followed by HFC-23 (22%), HFC-125 (17%), HFC-134a (13%), NF3 (10%), CF4 (5.9%), HFC-143a (3.9%), HFC-32 (3.4%), and HFC-152a (0.2%).

Frequency and accuracy of intraoperative bone margin sampling for T4a cancers of the head and neck at the QEII Health Sciences Centre: a retrospective chart review.

BACKGROUND: Stage T4a cancers are associated with a 5-year survival of 21.6-59.0%. Adequate resection of these tumors is a critical factor in maximizing survival. Tumors invading bone pose a unique challenge to intraoperative bone margin assessment. Due to processing limitations, there had been no formal standardized protocol for intraoperative bone sampling at the QEII Health Sciences Centre. These resections often involve extensive reconstruction, making salvage surgery difficult if positive margins are detected post-surgically. The purpose of this study was to assess the accuracy and frequency of intraoperative bone margin assessment during the study period and to determine survival and recurrence rates associated with positive final bone margins. METHODS: A retrospective chart review was conducted including patients with stage T4a head and neck cancer involving bone that underwent primary surgical resection in Nova Scotia between 2009 and 2019. Eligible patients were identified through the Cancer Care Nova Scotia registry. Exclusion criteria included patients with stage T4a tumors involving bone that did not receive primary surgical treatment with curative intent and patients with stage T4a tumors that did not invade bone. RESULTS: Of 67 patients included, 50 were amenable to intraoperative bone margin sampling while 18 had intraoperative sampling. Four patients had positive intraoperative margins and one had final positive bone margins. The incidence of final bone margin positivity was 7.5%. Median survival following surgery was 4.56 years for patients with final negative bone margins (n = 62) and 3.98 years for patients with positive final bone margins (n = 5). All patients with final positive bone margins received adjuvant radiation therapy. Of patients with negative final bone margins, 16.1% received no adjuvant therapy, 61.3% received adjuvant radiation therapy and 21.0% received adjuvant chemoradiation therapy. CONCLUSION: Intraoperative bone margin sampling occurred in 26.8% of all cases and 36.0% of amenable cases. Median survival of patients with positive final bone margins was 0.58 years lower than those with negative final bone margins, although this difference did not reach statistical significance. This will provide baseline data for comparison of the standardized intraoperative bone margin sampling protocol implemented at the QEII Health Sciences Centre.

Five-year survival outcomes in oropharyngeal squamous cell carcinoma following transoral laser microsurgery.

Objective: To determine the 5-year survival outcomes of patients with oropharyngeal cancer treated with transoral laser microsurgery at our institution. Methods: A prospective longitudinal cohort study of all cases of oropharyngeal squamous cell cancer or clinically unknown primaries diagnosed at our institution between September 1, 2014, to December 31, 2019, treated with primary transoral laser microsurgery were analyzed. Patients with a previous history of head and neck radiation were excluded from analysis. Kaplan-Meier survival curves were used to estimate 5-year overall survival, disease-specific survival, local control, and recurrence free survival rates in oropharyngeal squamous cell carcinoma. Results: Of 142 patients identified, 135 met criteria and were included in the survival analysis. Five-year local control rates in p16 positive and negative disease were 99.2% and 100%, respectively, with one locoregional failure in the p16 positive cohort. Five-year overall survival, disease-specific survival, and recurrence free survival in p16 positive disease were 91%, 95.2%, and 87% respectively (n = 124). Five-year overall survival, disease-specific survival, and recurrence free survival in p16 negative disease were 39.8%, 58.3%, and 60%, respectively (n = 11). The permanent gastrostomy tube rate was 1.5% and zero patients received a tracheostomy at the time of surgery. One patient (0.74%) required a return to the OR for a post-operative pharyngeal bleed. Conclusion: Transoral laser microsurgery is a safe primary treatment option for oropharyngeal squamous cell carcinoma with high 5-year survival outcomes, notably in p16 positive disease. More randomized trials are needed to compare survival outcomes and associated morbidity in transoral laser microsurgery compared to treatment with primary chemoradiation. Level of Evidence: 3.

Margin Sampling and Survival Outcomes in Oral Cavity and p16-Positive Oropharyngeal Squamous Cell Carcinoma.

Objective: To compare the association of margin sampling technique on survival outcomes in surgically treated cT1-2 oral cavity and oropharyngeal squamous cell carcinoma. Study Design: A prospective longitudinal cohort study. Setting: Tertiary care academic teaching hospital in Halifax, Nova Scotia. Methods: All cases of surgically treated cT1-2 oral cavity and oropharyngeal cancer undergoing specimen-oriented margin analysis between January 1, 2017, and December 31, 2018 were analyzed. The specimen-oriented cohort was compared with a cohort of patients from January 1, 2009, to December 31, 2014, where a defect-oriented margin sampling protocol was used. Kaplan-Meier survival curves were used to estimate 2-year overall survival, disease-specific survival, local control, and recurrence-free survival rates in oral cavity and p16-positive oropharyngeal squamous cell carcinoma. Cox proportional hazards models were used to assess the effect of margin sampling method on disease-specific survival and local control. Results: There was no significant association between margin sampling technique and 2-year survival outcomes for surgically treated cT1-2 oral cavity and oropharyngeal squamous cell carcinoma. In the multivariate Cox proportional hazard model, the hazard ratio (HR) of specimen-oriented sampling was not significantly different for disease-specific survival (HR, 1.32; 95% CI, 0.3032-5.727; P = .713) or local control (HR, 0.4087; 95% CI, 0.0795-2.099; P = .284). Conclusion: Intraoperative margin sampling method was not associated with a significant change in 2-year survival outcomes. Despite no effect on survival outcomes, implementation of a specimen-oriented sampling method has potential for cost avoidance by decreasing the number of re-resections for positive or close margins.

Injection laryngoplasty during transoral laser microsurgery for early glottic cancer: a randomized controlled trial.

BACKGROUND: Transoral laser microsurgery is widely used for treating T1/T2 glottic cancers. Hyaluronic acid (HA) is commonly used in vocal cord augmentation. We investigated the impact of intra-operative injection laryngoplasty on voice outcomes in early glottic cancer. METHODS: Twenty patients were randomized to the treatment group receiving HA injection to the vocal cord contralateral to the lesion; or the control group, receiving no injection. Patients had a Voice Handicap Index-10 (VHI-10) questionnaire and a Maximum Phonation Time (MPT) measurement preoperatively and at 3, 12 and 24 months post-operatively. Mean change in VHI-10 and MPT, compared to baseline and between time points, were compared. Survival estimates were calculated. RESULTS: Mean VHI-10 scores improved over time amongst all patients. There were no changes in mean VHI-10 from pre-operative values to 3, 12 or 24 months post-operatively. There were no significant differences when comparing various timepoints between groups. There were no significant changes in MPT amongst the groups, or the time-points compared. Two-year overall survival was 91.7%; disease free survival was 80.9%; no difference in recurrence free survival was seen between the groups. CONCLUSION: Subjective voice scores improved over time in both groups; there were no improvements in VHI-10 or MPT scores in the injection group, over control, at any time points. We saw no significant impact for intra-operative HA injection laryngoplasty on subjective or objective voice outcomes following surgery for early glottic cancers.

Volume-outcome relationships in laryngeal trauma processes of care: a retrospective cohort study.

PURPOSE: The extent to which patients with laryngeal trauma undergo investigation and intervention is largely unknown. The objective of this study was to therefore determine the association between hospital volume and processes of care in patients sustaining laryngeal trauma. METHODS: This retrospective cohort study used the American College of Surgeons Trauma Quality Improvement Program database. Adult patients (≥ 18) who sustained traumatic laryngeal injuries between 2012 and 2016 were eligible. The exposure of interest was average annual laryngeal trauma volume categorized into quartiles. The primary and secondary outcomes of interest were the performances of diagnostic and therapeutic laryngeal procedures respectively. Multivariable logistic regression under a generalized estimating equations approach was utilized. RESULTS: In total, 1164 patients were included. The average number of laryngeal trauma cases per hospital ranged from 0.2 to 7.2 per year. Diagnostic procedures were performed in 31% of patients and therapeutic in 19%. In patients with severe laryngeal injuries, diagnostic procedures were performed on a higher proportion of patients at high volume centers than low volume centers (46% vs 25%). In adjusted analysis, volume was not associated with the performance of diagnostic procedures. Patients treated at centers in the second (OR 1.94 [95% CI 1.29-2.90]) and third (OR 1.67 [95% CI 1.08-2.57]) volume quartiles had higher odds of undergoing a therapeutic procedure compared to the lowest volume quartile. CONCLUSION: Hospital volume may be associated with processes of care in laryngeal trauma. Additional research is required to investigate how these findings relate to patient and health system outcomes.

Oncological and functional outcomes following treatment of T1a glottic squamous cell carcinoma with transoral laser microsurgery.

BACKGROUND: Laryngeal cancers of glottic origin comprise a large proportion of head and neck malignancies. Transoral laser microsurgery (TLM) and radiation therapy are mainstays in the treatment of early stage glottic cancer, but debate persists as to which modality is functionally superior. Furthermore, there is a paucity of North American data related to functional and oncological outcomes in T1a glottic cancer. Here, we assessed oncological and functional outcomes of T1a glottic squamous cell carcinoma (SCC) with TLM to supplement evidence from jurisdictions outside North America. METHODS: This study is a retrospective cohort study performed from a prospectively collected tertiary center institutional TLM database. Patients who were diagnosed with T1a glottic SCC and underwent TLM as their primary treatment were included. Functional outcomes were analyzed using the Voice Handicap Index-10 (VHI-10) questionnaire. Ultimate control with TLM only was considered to be those patients with locoregional control with repeat TLM procedures, but without addition of other modalities. Student's t-test was used to test significance and Kaplan-Meier survival analysis was used to assess oncological outcomes. RESULTS: 48 patients met study criteria. The mean follow-up time was 74 months. The 5-year locoregional, ultimate control with TLM only and laryngeal preservation rates were 83.2%, 90.4% and 100%, respectively. The overall survival and disease-specific survival were 87.2% and 100%, respectively. VHI-10 scores were available for 13/48 patients and mean scores improved non-significantly from pre-op (mean: 11.23; range: 2 to 30; median: 10) and post op (mean: 7.92; range: 0 to 18; median: 8) scoring (p-value = 0.15). Sub-stratification of voice data revealed a significant improvement between pre and post-operative scores (mean difference - 10.6, 95% CI: - 0.99 to - 20.21, p-value = 0.035) for patients with abnormal pre-operative scores (VHI > 11). CONCLUSION: To our knowledge, the current work represents one of the first North American studies to report both functional and oncologic outcomes for TLM treatment of T1a glottic SCC. The oncologic and functional outcomes presented here add to existing evidence in favor of TLM as a safe and effective primary treatment option for early staged T1a glottic cancer.

Isotopic signatures of methane emissions from tropical fires, agriculture and wetlands: the MOYA and ZWAMPS flights.

We report methane isotopologue data from aircraft and ground measurements in Africa and South America. Aircraft campaigns sampled strong methane fluxes over tropical papyrus wetlands in the Nile, Congo and Zambezi basins, herbaceous wetlands in Bolivian southern Amazonia, and over fires in African woodland, cropland and savannah grassland. Measured methane δ13CCH4 isotopic signatures were in the range -55 to -49‰ for emissions from equatorial Nile wetlands and agricultural areas, but widely -60 ± 1‰ from Upper Congo and Zambezi wetlands. Very similar δ13CCH4 signatures were measured over the Amazonian wetlands of NE Bolivia (around -59‰) and the overall δ13CCH4 signature from outer tropical wetlands in the southern Upper Congo and Upper Amazon drainage plotted together was -59 ± 2‰. These results were more negative than expected. For African cattle, δ13CCH4 values were around -60 to -50‰. Isotopic ratios in methane emitted by tropical fires depended on the C3 : C4 ratio of the biomass fuel. In smoke from tropical C3 dry forest fires in Senegal, δ13CCH4 values were around -28‰. By contrast, African C4 tropical grass fire δ13CCH4 values were -16 to -12‰. Methane from urban landfills in Zambia and Zimbabwe, which have frequent waste fires, had δ13CCH4 around -37 to -36‰. These new isotopic values help improve isotopic constraints on global methane budget models because atmospheric δ13CCH4 values predicted by global atmospheric models are highly sensitive to the δ13CCH4 isotopic signatures applied to tropical wetland emissions. Field and aircraft campaigns also observed widespread regional smoke pollution over Africa, in both the wet and dry seasons, and large urban pollution plumes. The work highlights the need to understand tropical greenhouse gas emissions in order to meet the goals of the UNFCCC Paris Agreement, and to help reduce air pollution over wide regions of Africa. This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part 2)'.

A renewed rise in global HCFC-141b emissions between 2017-2021.

Global emissions of the ozone-depleting gas HCFC-141b (1,1-dichloro-1-fluoroethane, CH3CCl2F) derived from measurements of atmospheric mole fractions increased between 2017 and 2021 despite a fall in reported production and consumption of HCFC-141b for dispersive uses. HCFC-141b is a controlled substance under the Montreal Protocol, and its phase-out is currently underway, after a peak in reported consumption and production in developing (Article 5) countries in 2013. If reported production and consumption are correct, our study suggests that the 2017-2021 rise is due to an increase in emissions from the bank when appliances containing HCFC-141b reach the end of their life, or from production of HCFC-141b not reported for dispersive uses. Regional emissions have been estimated between 2017-2020 for all regions where measurements have sufficient sensitivity to emissions. This includes the regions of northwestern Europe, east Asia, the United States and Australia, where emissions decreased by a total of 2.3 ± 4.6 Ggyr-1, compared to a mean global increase of 3.0 ± 1.2 Ggyr-1 over the same period. Collectively these regions only account for around 30% of global emissions in 2020. We are not able to pinpoint the source regions or specific activities responsible for the recent global emission rise.

Rapid increase in dichloromethane emissions from China inferred through atmospheric observations.

With the successful implementation of the Montreal Protocol on Substances that Deplete the Ozone Layer, the atmospheric abundance of ozone-depleting substances continues to decrease slowly and the Antarctic ozone hole is showing signs of recovery. However, growing emissions of unregulated short-lived anthropogenic chlorocarbons are offsetting some of these gains. Here, we report an increase in emissions from China of the industrially produced chlorocarbon, dichloromethane (CH2Cl2). The emissions grew from 231 (213-245) Gg yr-1 in 2011 to 628 (599-658) Gg yr-1 in 2019, with an average annual increase of 13 (12-15) %, primarily from eastern China. The overall increase in CH2Cl2 emissions from China has the same magnitude as the global emission rise of 354 (281-427) Gg yr-1 over the same period. If global CH2Cl2 emissions remain at 2019 levels, they could lead to a delay in Antarctic ozone recovery of around 5 years compared to a scenario with no CH2Cl2 emissions.

Functional and Oncologic Outcomes of Octogenarians Undergoing Transoral Laser Microsurgery for Laryngeal Cancer.

OBJECTIVE: To evaluate the oncologic and functional outcomes of transoral laser microsurgery (TLM) for glottic cancers in patients ≥80 years. STUDY DESIGN: Prospectively collected case series. SETTING: QEII Health Sciences Centre, Halifax, Canada. METHODS: This case series used a prospectively collected glottic cancer database to examine consecutive elderly patients (≥80 years old) undergoing TLM. Kaplan-Meier analysis was used to evaluate rates of disease-free, disease-specific, and overall survival as the primary end points of oncologic control. Secondary functional outcomes included voice function, length of hospital stay, and time to readmission. RESULTS: From 2005 to 2017, 17 octogenarian patients underwent TLM for glottic cancer. Median follow-up was 4.19 years (interquartile range, 0.71-6.95). Kaplan-Meier estimates of 5-year survival were 78.4% (disease free), 92.9% (disease specific), and 81.9% (overall). The median length of hospital stay was 1 day (range, 0-8). There was only 1 readmission within 30 days of surgery. No patients in this study developed significant surgical or postoperative complications requiring unplanned readmissions. Patient-perceived voice function improved to normal after treatment in 62.5% of patients. CONCLUSION: The results of this study suggest that TLM is a safe and effective treatment modality for glottic cancer in patients aged ≥80 years, providing good oncologic control and satisfactory functional outcomes.

Management of Peritonsillar Abscesses in Adults: Survey of Otolaryngologists in Canada and the United States.

OBJECTIVE: The management of peritonsillar abscess (PTA) has evolved over time. We sought to define contemporary practice patterns for the diagnosis and treatment of PTA. STUDY DESIGN: Cross-sectional survey. SETTING: The 15-question survey was distributed to members of the Canadian Society of Otolaryngology-Head and Neck Surgery (CSO) and the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS). METHODS: An iterative, consensus-based process was used for survey development. Primary outcomes were to determine methods of diagnosis and first-line treatments for PTA. Exploratory, secondary outcomes were analyzed using multivariable logistic regression models. RESULTS: The survey response rate was 12.6% (n = 1176). Most participants were attending staff (86%) in a community hospital setting (60%) and had been in practice for more than 20 years (38%). Most respondents (78%) indicated that at least half of the time, cross-sectional imaging had already been performed before they were consulted. Half of respondents (49%) indicated that they perform incision and drainage of the abscess as first-line treatment, while few (16%) provide medical management alone. In exploratory analysis, participants from the AAO-HNS had higher odds of imaging already being performed before consultation (odds ratio [OR], 11.7; 95% CI, 4.6-29.4) and increased odds of using medical management alone as a first-line treatment (OR, 2.4; 95% CI, 1.3-4.2) compared to respondents from the CSO. CONCLUSION: There is wide practice variation in the diagnosis and management of acute, uncomplicated PTA among otolaryngologists in Canada and the United States. The use of cross-sectional imaging and medical management alone may differ between countries of practice.