Automated Real-Time Detection of Lung Sliding Using Artificial Intelligence: A Prospective Diagnostic Accuracy Study

BACKGROUND

Rapid evaluation for pneumothorax is a common clinical priority. Although lung ultrasound (LUS) often is used to assess for pneumothorax, its diagnostic accuracy varies based on patient and provider factors. To enhance the performance of LUS for pulmonary pathologic features, artificial intelligence (AI)-assisted imaging has been adopted; however, the diagnostic accuracy of AI-assisted LUS (AI-LUS) deployed in real time to diagnose pneumothorax remains unknown.

RESEARCH QUESTION

In patients with suspected pneumothorax, what is the real-time diagnostic accuracy of AI-LUS to recognize the absence of lung sliding?

STUDY DESIGN AND METHODS

We performed a prospective AI-assisted diagnostic accuracy study of AI-LUS to recognize the absence of lung sliding in a convenience sample of patients with suspected pneumothorax. After calibrating the model parameters and imaging settings for bedside deployment, we prospectively evaluated its diagnostic accuracy for lung sliding compared with a reference standard of expert consensus.

RESULTS

Two hundred forty-one lung sliding evaluations were derived from 62 patients. AI-LUS showed a sensitivity of 0.921 (95% CI, 0.792-0.973), specificity of 0.802 (95% CI, 0.735-0.856), area under the receiver operating characteristic curve of 0.885 (95% CI, 0.828-0.956), and accuracy of 0.824 (95% CI, 0.766-0.870) for the diagnosis of absent lung sliding.

INTERPRETATION

Real-time AI-LUS shows high sensitivity and moderate specificity to identify the absence of lung sliding. Further research to improve model performance and optimize the integration of AI-LUS into existing diagnostic pathways is warranted.

Multicentre positive deviance seminar to generate best practice recommendations to reduce anastomotic leak and length of stay for patients undergoing oesophagectomy

BACKGROUND

We describe a novel process using positive deviance (PD) with the Canadian Association of Thoracic Surgeons members, to identify perioperative best practice to minimise anastomotic leak (AL) and length of stay (LOS) following oesophagectomy. To our knowledge, this is the first National combination of level 1 evidence with expert opinion (ie, PD seminar) aimed at reducing AL and LOS in oesophageal surgery. Our primary hypothesis is that a multicentre National PD seminar is feasible, and could lead to the generation of best practices recommendations aimed at reducing AL and LOS in patients with oesophageal cancer.

METHODS

Adverse events, LOS and AL incidence/severity following oesophagectomy were prospectively collected from seven Canadian thoracic institutions using Thoracic Morbidity and Mortality classification system (2017-2020). Anonymised display of centre's data were presented, with identification of centres demonstrating PD. Surgeons from PD sites discussed principles of care, culminating in the consensus recommendations, anonymously rated by all (5-point Likert scale).

RESULTS

Data from 795 esophagectomies were included, with 25 surgeons participating. Two centres were identified as having the lowest AL rates 44/395 (11.1%) (vs five centres 71/400 (17.8%) (p<0.01)) and shortest LOS 8 days 45 (IQR: 6-14) (vs 10 days (IQR: 8-18) (p<0.001)). Recommendations included preoperative (prehabilitation, smoking cessation, chemotherapy for patients with dysphagia, minimise stents/feeding tubes), intraoperative (narrow gastric conduit, intrathoracic anastomosis, avoid routine jejunostomy, use small diameter closed-suction drains), postoperative day (POD) (early (POD 2-3) enteral feeding initiation, avoid routine barium swallow studies, early removal of tubes/drains (POD 2-3)). All ranked above 80% (4/5) in agreement to implement recommendations into their practice.

CONCLUSION

We report the feasibility of a National multicentre PD seminar with the generation of best practice recommendations aimed at reducing AL and LOS following oesophagectomy. Further research is required to demonstrate whether National PD seminars can be an effective quality improvement tool.

Multicentre positive deviance to reduce adverse events and length of stay after pulmonary resection

BACKGROUND

Postoperative adverse events (AEs) following pulmonary resection enormously impact patient well-being, length of stay (LOS) and healthcare costs. Standardised AE data collection can be used to identify positive outliers demonstrating positive deviance (PD) who may be helpful to inform the best practice. Here, we describe our initial experience of a novel quality improvement process using PD to reduce LOS and AEs.

METHODS

AE rates and LOS were collected from four centres (2014-2020) using a common dictionary. Surgeons repeatedly participated in 60 to 90 min seminars consisting of the following process: identify outcome and procedure targeted, review relevant best evidence literature, view all data anonymised by surgeon or centre (if multicentre), choose and reveal identity of best performance PD outliers, who discuss their management principles while all receive self-evaluation reports, followed by collegial discussion to generate consensus recommendations, voted by all. We assessed overall impact on AEs and LOS using aggregate data in a before/after analysis.

RESULTS

A total of 131 surgeons (average 12/seminar) participated in 11 PD seminars (8 local and 3 multicentre), yielding 85 consensus recommendation (average 8/seminar). Median LOS following lobectomy decreased from 4.0 to 3.0 days (p=0.04) following local PD seminars and from 4.0 to 3.5 days (p=0.11) following multicentre seminars. Trends for reductions in multiple AE rates were also observed.

CONCLUSION

While limited by the longitudinal design, these findings provide preliminary support for this data-driven, collegial and actionable quality improvement process to help standardise and improve patient care, and merits further more rigorous investigation.

Surgery crisis simulation during the COVID-19 pandemic

COVID-19 puts health care providers at risk for infection with SARS-CoV-2. Personal protective equipment (PPE) can reduce viral transmission if used properly. We used simulation of an intraoperative crisis involving an infectious outbreak to assess PPE adherence and confidence in PPE use. Simulation of an intraoperative crisis with a patient with COVID-19 revealed gaps in PPE adherence; however, simulation training successfully increased confidence in PPE use and received positive feedback.

Predicting pathological complete response (pCR) after stereotactic ablative radiation therapy (SABR) of lung cancer using quantitative dynamic [18F]FDG PET and CT perfusion: a prospective exploratory clinical study

BACKGROUND

Stereotactic ablative radiation therapy (SABR) is effective in treating inoperable stage I non-small cell lung cancer (NSCLC), but imaging assessment of response after SABR is difficult. This prospective study aimed to develop a predictive model for true pathologic complete response (pCR) to SABR using imaging-based biomarkers from dynamic [¹⁸F]FDG-PET and CT Perfusion (CTP).

METHODS

Twenty-six patients with early-stage NSCLC treated with SABR followed by surgical resection were included, as a pre-specified secondary analysis of a larger study. Dynamic [¹⁸F]FDG-PET and CTP were performed pre-SABR and 8-week post. Dynamic [¹⁸F]FDG-PET provided maximum and mean standardized uptake value (SUV) and kinetic parameters estimated using a previously developed flow-modified two-tissue compartment model while CTP measured blood flow, blood volume and vessel permeability surface product. Recursive partitioning analysis (RPA) was used to establish a predictive model with the measured PET and CTP imaging biomarkers for predicting pCR. The model was compared to current RECIST (Response Evaluation Criteria in Solid Tumours version 1.1) and PERCIST (PET Response Criteria in Solid Tumours version 1.0) criteria.

RESULTS

RPA identified three response groups based on tumour blood volume before SABR (BV_pre-SABR) and change in SUV_max (ΔSUV_max), the thresholds being BV_pre-SABR = 9.3 mL/100 g and ΔSUV_max = - 48.9%. The highest true pCR rate of 92% was observed in the group with BV_pre-SABR < 9.3 mL/100 g and ΔSUV_max < - 48.9% after SABR while the worst was observed in the group with BV_pre-SABR ≥ 9.3 mL/100 g (0%). RPA model achieved excellent pCR prediction (Concordance: 0.92; P = 0.03). RECIST and PERCIST showed poor pCR prediction (Concordance: 0.54 and 0.58, respectively).

CONCLUSIONS

In this study, we developed a predictive model based on dynamic [¹⁸F]FDG-PET and CT Perfusion imaging that was significantly better than RECIST and PERCIST criteria to predict pCR of NSCLC to SABR. The model used BV_pre-SABR and ΔSUV_max which correlates to tumour microvessel density and cell proliferation, respectively and warrants validation with larger sample size studies.

TRIAL REGISTRATION

MISSILE-NSCLC, NCT02136355 (ClinicalTrials.gov). Registered May 8, 2014, https://clinicaltrials.gov/ct2/show/NCT02136355.

Idiopathic Subglottic Stenosis: An Institutional Review of Outcomes With a Multimodality Surgical Approach

OBJECTIVES

This article reports on a unique cohort of patients with idiopathic subglottic stenosis spilt fairly equally between endoscopic and open surgical approaches. Patients' sequence of operations and reinterventions over time are outlined, offering insight to improve surgical counseling and allow for informative, autonomous patient decision making.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary care academic center.

METHODS

Cases of consecutive adults with idiopathic subglottic stenosis managed surgically over a 12-year period (January 2006-December 2017) were retrospectively reviewed. Surgical workflow, complications, and outcomes, including reinterventions and tracheotomy dependence, are reported.

RESULTS

Seventy-two patients (71 women; mean age, 50.4 years) with idiopathic subglottic stenosis requiring surgical airway intervention were identified. Six patients underwent tracheotomy prior to attempt at airway stenosis surgery. Initial surgical approach thereafter included endoscopic (73.5%, n = 53) and open (26.4%, n = 19) procedures. Thirty-one patients underwent cricotracheal resection; the reintervention rate was 22.5%. Sixty patients underwent 147 endoscopic procedures; the reintervention rate was 75.5%, and the mean time between dilations was 83 weeks (range, 5-402). Two (2.8%) patients remain tracheotomy dependent. Adverse events were significantly higher in the cricotracheal group, especially with respect to dysphonia and temporary gastrostomy tube placement (P < .01).

CONCLUSIONS

Endoscopic and open surgical airway intervention can be employed successfully to avoid tracheotomy dependence and maintain airway patency; however, multiple procedures are usually required, regardless of surgical approach. Cricotracheal reintervention rates are lower than endoscopic dilation but with increased morbidity. Quality-of-life outcomes should be clearly discussed with patients before deciding on a surgical management strategy.

SABR-BRIDGE: Stereotactic ABlative Radiotherapy Before Resection to AvoId Delay for Early-Stage LunG Cancer or OligomEts During the COVID-19 Pandemic

Surgical resection is the standard-of-care approach for early-stage non-small cell lung cancer (NSCLC). Surgery is also considered an acceptable standard infit patients with oligometastatic lesions in the lungs. The COVID-19 pandemic has led to worldwide issues with access to operating room time, with patients and physicians facing uncertainty as to when surgical resection will be available, with likely delays of months. Further compounding this are concerns about increased risks of respiratory complications with lung cancer surgery during active phases of the pandemic. In this setting, many thoracic oncology teams are embracing a paradigm where stereotactic ablative radiotherapy (SABR) is used as a bridge, to provide radical-intent treatment based on a combination of immediate SABR followed by planned surgery in 3–6 months. This pragmatic approach to treatment has been named SABR-BRIDGE (Stereotactic ABlative Radiotherapy Before Resection to avoId Delay for early-stage lunG cancer or oligomEts). This term has also been applied to the pragmatic study of the outcomes of this approach. In this paper, we discuss the standards of care in treatment of early-stage (NSCLC) and pulmonary oligometastases, the impetus for the SABR-BRIDGE approach, and the controversies surrounding assessment of pathological response to neo-adjuvant radiation therapy.

Measuring the Integration of Stereotactic Ablative Radiotherapy Plus Surgery for Early-Stage Non-Small Cell Lung Cancer: A Phase 2 Clinical Trial

Importance

Stereotactic ablative radiotherapy (SABR) is a standard treatment option in patients with medically inoperable early-stage non-small cell lung cancer (NSCLC), yet the pathologic complete response (pCR) rate after SABR is unknown. Neoadjuvant SABR in patients with cancer who are fit for resection has been hypothesized to improve local control and induce antitumor immune activity, potentially leading to better outcomes.

Objectives

To determine the pCR rate after SABR and to assess oncologic and toxicity outcomes after a combined approach of neoadjuvant SABR followed by surgery.

Design, Setting, and Participants

A phase 2, single-arm trial, with patient accrual from September 30, 2014, to August 15, 2017 (median follow-up, 19 months), was performed at a tertiary academic cancer center. Patients 18 years or older with T1T2N0M0 NSCLC and good performance status, with adequate pulmonary reserve to undergo surgical resection, were studied.

Interventions

Patients underwent neoadjuvant SABR using a risk-adapted fractionation scheme followed by surgery 10 weeks later.

Main Outcomes and Measures

The pCR rate as determined by hematoxylin-eosin staining.

Results

Forty patients (mean [SD] age, 68 [8] years; 23 [58%] female) were enrolled. Thirty-five patients underwent surgery and were evaluable for the primary end point. The pCR rate was 60% (95% CI, 44%-76%). The 30- and 90-day postoperative mortality rates were both 0%. Grade 3 or 4 toxic effects occurred in 7 patients (18%). In patients receiving surgery, 2-year overall survival was 77% (95% CI, 48%-91%), local control was 100% (95% CI, not defined), regional control was 53% (95% CI, 22%-76%), and distant control was 76% (95% CI, 45%-91%). Quality of life did not decline after treatment, with no significant changes in mean Functional Assessment of Cancer Therapy for Lung-Trial Outcome Index score during the first year of follow-up.

Conclusions and Relevance

The pCR rate after SABR for early-stage NSCLC was 60%, lower than hypothesized. The combined approach had toxic effects comparable to series of surgery alone, and there was no perioperative mortality. Further studies are needed to evaluate this combined approach compared with surgical resection alone.

Trial Registration

ClinicalTrials.gov identifier: NCT02136355.

The quality of life in neoadjuvant versus adjuvant therapy of esophageal cancer treatment trial (QUINTETT)

4052

Background: We compared the health-related quality-of-life (HRQOL) of standard neoadjuvant cisplatin and 5-FU chemotherapy plus radiotherapy (N) followed by surgical resection to adjuvant cisplatin, 5-FU, and epirubicin chemotherapy with concurrent extended volume radiotherapy (A) following surgical resection for resectable esophageal carcinoma. Methods: 96 patients with stage I to III resectable cancer of the esophagus were enrolled into a prospective randomized trial (NCT00907543) from April 2009 to November 2016. Patients were randomized into 2 groups: N (47 cases) and A (49 cases). The primary end point was HRQOL using the FACT-E at one year. The secondary endpoints included other HRQOL measures, overall survival (OS), disease-free survival (DFS), and adverse events. Results: The median follow-up was 5.0 years [95% CI :4.6 to 5.5]. The majority of patients had adenocarcinomas of the distal esophagus/gastroesophageal junction (80.9% vs 87.8%). The stage distribution was: I 9%; II 22%; III 58%; TxN0-1 10%. Using an intention-to-treat analysis there was no significant difference in the FACT-E total scores between arms at one year (p = 0.759), with 35.5% vs. 41.2% respectively showing an increase of ≥ 15 points ( a priori minimal clinical difference) compared to pre-treatment (p = 0.638). The HRQOL was temporarily significantly inferior at 2 months in the N arm for FACT-E, EORTC OG25, and EQ-5D-3L in the dysphagia, reflux, pain, taste, and coughing domains (p < 0.05). There were no 30-day mortalities but 2.1% vs. 10.2% 90-day mortalities (p = 0.204). There were no significant differences in either 5-year OS (37.9% vs 28.9%, p = 0.321) or DFS (34.0% vs 25.5%, p = 0.551. 48.9% of patients required chemotherapy to be modified or stopped in the N arm compared to 57.1% in the A arm (p = 0.421). 51.1% of patients were able to complete the prescribed N arm chemotherapy without modification compared to only 14.3% in the A arm (p < 0.001). Chemotherapy related adverse events significantly more frequent in the neoadjuvant arm (p < 0.05). Surgery related adverse events were significantly more frequent in the neoadjuvant arm (p < 0.05). Conclusions: Trimodality therapy is challenging for patients with resectable esophageal cancer regardless if it is given before or after surgery. Less toxic protocols are needed. Clinical trial information: 00907543.

Toward Lung Tumor Localization based on Strain Variability of Lung Surface during Video-Assisted Thoracoscopic Surgery

Tumor localization, especially in case of minimally invasive lung tumor resection surgery, is extremely challenging due to the continuous motion of the organ. This motion can be troublesome as it results in spatial discrepancy corresponding to preoperative and intraoperative tumor location. In order to characterize lung tissue stiffness for the purpose of lung tumor localization, in this paper, we present a novel characterization approach based on variability in resistance of the healthy region vs. the tumorous region resulting from lung motion. The proposed approach is numerically validated on a Finite Element (FE) model of the lung with varying surface stiffnesses, where higher stiffness represents tumor and lower stiffness corresponds to healthy lung tissue. The numerical simulation validates the sensitivity of our mechanism for different grades of tumors by demonstrating that the strain on the healthy tissue is 31.8 and 67.1 times higher than that on the tumor surface for a selected relative stiffness variation of 3.6x and 24.4x respectively, at a pressure of 1.6 KPa. Additionally, a framework is developed to validate the proposed approach in a video of a video-assisted thoracoscopic surgery (VATS), where multiple landmarks on the lung surface are tracked. This enables us to quantify the motion of points residing on healthy surface and tumorous surface. The motion data is further analyzed to study the relative surface strain, and it is shown that the proposed approach differentiates a tumor from healthy surface.

Assessment of tumour response after stereotactic ablative radiation therapy for lung cancer: A prospective quantitative hybrid 18 F-fluorodeoxyglucose-positron emission tomography and CT perfusion study

INTRODUCTION

Stereotactic ablative radiotherapy (SABR) is a guideline-recommended treatment for inoperable stage I non-small cell lung cancer (NSCLC), but imaging assessment of response after SABR is difficult. The goal of this study was to evaluate imaging-based biomarkers of tumour response using dynamic ¹⁸ F-FDG-PET and CT perfusion (CTP).

METHODS

Thirty-one patients with early-stage NSCLC participated in this prospective correlative study. Each underwent dynamic ¹⁸ F-FDG-PET/CTP studies on a PET/CT scanner pre- and 8 weeks post-SABR. The dynamic ¹⁸ F-FDG-PET measured the tumour SUV_max , SUV_mean and the following parameters: K₁ , k₂ , k₃ , k₄ and K_i , all using the Johnson-Wilson-Lee kinetic model. CTP quantitatively mapped BF, BV, MTT and PS in tumours and measured largest tumour diameter. Since free-breathing was allowed during CTP scanning, non-rigid image registration of CT images was applied to minimize misregistration before generating the CTP functional maps. Differences between pre- and post-SABR imaging-based parameters were compared.

RESULTS

Tumour size changed only slightly after SABR (median 26 mm pre-SABR vs. 23 mm post-SABR; P = 0.01). However, dynamic ¹⁸ F-FDG-PET and CTP study showed substantial and significant changes in SUV_max , SUV_mean , k₃ , k₄ and K_i . Significant decreases were evident in SUV_max (median 6.1 vs. 2.6; P < 0.001), SUV_mean (median 2.5 vs. 1.5; P < 0.001), k₃ (relative decrease of 52%; P = 0.002), K_i (relative decrease of 27%; P = 0.03), whereas there was an increase in k₄ (+367%; P < 0.001).

CONCLUSIONS

Hybrid ¹⁸ F-FDG-PET/CTP allowed the response of NSCLC to SABR to be assessed regarding metabolic and functional parameters. Future studies are needed, with correlation with long-term outcomes, to evaluate these findings as potential imaging biomarkers of response.

Developing a National, Simulation-Based, Surgical Skills Bootcamp in General Thoracic Surgery

BACKGROUND

The use surgical simulation across all subspecialties has gained widespread adoption in the last decade. A number of factors, including the small number of trainees, identified gaps in surgical skill training from cross-sectional surveys, increased national collaboration, and support from the national specialty committee identified a need to construct a surgical skills "bootcamp" in thoracic surgery in Canada.

OBJECTIVE

The goals of the surgical skills bootcamp, as identified by the residency training program directors and the national specialty committee were to create a national, centralized, simulation-based skills workshop that focused on key foundational procedures within thoracic surgery, particularly those identified as areas of weakness by former residents; to smooth the transition to intraoperative teaching; to provide exposure to important but not necessarily universally available procedures such as advanced endoscopy; to teach non-medical expert competencies, and lastly to provide a venue for networking for residents across the country.

DESIGN

The curriculum committee has constructed a 3.5 day curriculum, with a focus on hands-on skills simulation, as well as lectures, on a breadth of topics including benign esophageal disorders, lung cancer staging, minimally invasive lung surgery, crisis management and advanced bronchoscopy and endoscopy. All residents across the country attend as well as faculty from a variety of institutions.

SETTING

The course is hosted centrally at the University of Toronto, Ontario over 3.5 days. A combination of auditorium and both animal and human operating room facilities are utilized.

METHODS

A needs-assessment based on a formal meeting of the program directors, as well feedback from surveys identified the target areas for curriculum development. A committee of interested faculty developed the content as well as the local construct and logistics required. Iterative feedback has evolved the duration and content over the initial 3 years.

RESULTS

Through formal resident feedback, national subspecialty committee review, and program director meetings the support for the bootcamp has been overwhelmingly positive. Specific resident feedback for structure, content and specific simulations has been favorable, but has also been used to modify the program.

CONCLUSION

In response to identified weaknesses in training, with the support of the national specialty committee, the residency program directors, and the faculty at the University of Toronto, an intensive simulation based thoracic surgery bootcamp has successfully been created for Canadian thoracic surgery residents.

Staging and surgical approaches in gastric cancer: a clinical practice guideline

BACKGROUND

Resection is the cornerstone of cure for gastric adenocarcinoma; however, several aspects of surgical intervention remain controversial or are suboptimally applied at a population level, including staging, extent of lymphadenectomy (lnd), minimum number of lymph nodes that have to be assessed, gross resection margins, use of minimally invasive surgery, and relationship of surgical volumes with patient outcomes and resection in stage iv gastric cancer.

METHODS

Literature searches were conducted in databases including medline (up to 10 June 2016), embase (up to week 24 of 2016), the Cochrane Library and various other practice guideline sites and guideline developer Web sites. A practice guideline was developed.

RESULTS

One guideline, seven systematic reviews, and forty-eight primary studies were included in the evidence base for this guidance document. Seven recommendations are presented.

CONCLUSIONS

All patients should be discussed at a multidisciplinary team meeting, and computed tomography (ct) imaging of chest and abdomen should always be performed when staging patients. Diagnostic laparoscopy is useful in the determination of M1 disease not visible on ct images. A D2 lnd is preferred for curative-intent resection of gastric cancer. At least 16 lymph nodes should be assessed for adequate staging of curative-resected gastric cancer. Gastric cancer surgery should aim to achieve an R0 resection margin. In the metastatic setting, surgery should be considered only for palliation of symptoms. Patients should be referred to higher-volume centres and those that have adequate support to manage potential complications. Laparoscopic resections should be performed to the same standards as those for open resections, by surgeons who are experienced in both advanced laparoscopic surgery and gastric cancer management.

Short report: interim safety results for a phase II trial measuring the integration of stereotactic ablative radiotherapy (SABR) plus surgery for early stage non-small cell lung cancer (MISSILE-NSCLC)

Abstract

A phase II trial was launched to evaluate if neoadjuvant stereotactic ablative radiotherapy (SABR) before surgery improves oncologic outcomes in patients with stage I non-small cell lung cancer (NSCLC). We report a mandated interim safety analysis for the first 10 patients who completed protocol treatment. Operable patients with biopsy-proven T1-2 N0 NSCLC were eligible. SABR was delivered using a risk-adapted fractionation (54Gy/3 fractions, 55/5 or 60/8). Surgical resection was planned 10 weeks later at a high-volume center (>200 lung cancer resections annually). Patients were imaged with dynamic positron emission tomography-computed tomography scans using ¹⁸F-fludeoxyglucose (¹⁸F-FDG-PET CT) and dynamic contrast-enhanced CT before SABR and again before surgery. Toxicity was recorded using CTCAE version 4.0. Twelve patients were enrolled between 09/2014 and 09/2015. Two did not undergo surgery, due to patient or surgeon preference; neither patient has developed toxicity or recurrence. For the 10 patients completing both treatments, median age was 70 (range: 54–76), 60% had T1 disease, and 60% had adenocarcinoma. Median FEV₁ was 73% predicted (range: 54–87%). Median time to surgery post-SABR was 10.1 weeks (range: 9.3–15.6 weeks). Surgery consisted of lobectomy (n = 8) or wedge resection (n = 2). Median follow-up post-SABR was 6.3 months. After combined treatment, the rate of acute grade 3–4 toxicity was 10%. There was no post-operative mortality at 90 days. The small sample size included herein precludes any definitive conclusions regarding overall toxicity rates until larger datasets are available. However, these data may inform others who are designing or conducting similar trials.

Trial registration

NCT02136355. Registered 8 May 2014.

Teaching surgery takes time: the impact of surgical education on time in the operating room

BACKGROUND

It is generally accepted that surgical training is associated with increased surgical duration. The purpose of this study was to determine the magnitude of this increase for common surgical procedures by comparing surgery duration in teaching and nonteaching hospitals.

METHODS

This retrospective population-based cohort study included all adult residents of Ontario, Canada, who underwent 1 of 14 surgical procedures between 2002 and 2012. We used several linked administrative databases to identify the study cohort in addition to patient-, surgeon- and procedure-related variables. We determined surgery duration using anesthesiology billing records. Negative binomial regression was used to model the association between teaching versus nonteaching hospital status and surgery duration.

RESULTS

Of the 713 573 surgical cases included in this study, 20.8% were performed in a teaching hospital. For each procedure, the mean surgery duration was significantly longer for teaching hospitals, with differences ranging from 5 to 62 minutes across individual procedures in unadjusted analyses (all p < 0.001). In regression analysis, procedures performed in teaching hospitals were associated with an overall 22% (95% confidence interval 20%-24%) increase in surgery duration, adjusting for patient-, surgeon- and procedure-related variables as well as the clustering of patients within surgeons and hospitals.

CONCLUSION

Our results show that a wide range of surgical procedures require significantly more time to perform in teaching than nonteaching hospitals. Given the magnitude of this difference, the impact of surgical training on health care costs and clinical outcomes should be a priority for future studies.

Is it safe to wait? The effect of surgical wait time on survival in patients with non-small cell lung cancer

BACKGROUND

The effect of surgical wait times on survival in patients with non-small cell lung cancer (NSCLC) remains largely unknown. Our objective was to determine the effect of surgical wait time on survival and incidence of upstaging in patients with stage I and II NSCLC.

METHODS

All patients with clinical stage I and II NSCLC who underwent surgical resection in a single centre between January 2010 and December 2011 were reviewed. Analysis was stratified based on preoperative clinical stage. We assessed the effect of wait time on survival using a Cox proportional hazard model with wait time in months as a categorical variable. Incidence of upstaging at least 1 stage was assessed using logistic regression.

RESULTS

We identified 222 patients: 180 were stage I and 42 were stage II. For stage I, wait times up to 4 months had no significant effect on survival or incidence of upstaging. For stage II, patients waiting between 2 and 3 months had significantly decreased survival (hazard ratio 3.6, p = 0.036) and increased incidence of upstaging (odds ratio 2.0, p = 0.020) than those waiting 0 to 1 month. For those waiting between 1 and 2 months, there was no significant difference in survival or upstaging.

CONCLUSION

We did not identify an effect of wait time up to 4 months on survival or upstaging for patients with stage I NSCLC. For patients with stage II disease, wait times greater than 2 months adversely affected survival and upstaging.

Preoperative chemotherapy for resectable thoracic esophageal cancer

BACKGROUND

Surgery has been the treatment of choice for patients with localized esophageal cancer. Several studies have investigated whether preoperative chemotherapy followed by surgery leads to improvement in cure rates, but individual reports have provided conflicting results. An explicit systematic update of the role of preoperative chemotherapy in the treatment of patients with resectable thoracic esophageal cancer is, therefore, warranted.

OBJECTIVES

The objective of this review is to determine the role of preoperative chemotherapy in the treatment of patients with resectable thoracic esophageal carcinoma.

SEARCH METHODS

We identified trials by searching the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1966 to 2013), EMBASE (1988 to 2013), and CANCERLIT (1993 to 2013). We did not confine our search to English language publications. We updated searches in CENTRAL, MEDLINE, and EMBASE in October 2013.

SELECTION CRITERIA

All trials of patients with potentially resectable carcinoma of the esophagus (of any histologic type) who were randomly assigned to chemotherapy or no chemotherapy before surgery.

DATA COLLECTION AND ANALYSIS

The primary outcome was survival, which was assessed with the use of hazard ratios. This is an amendment to the original review, which used risk ratios to assess survival at yearly intervals. Hazard ratios (HRs) have now been introduced to summarize the complete survival experience in a single analysis. Risk ratios (RRs) were used to compare rates of resection, tumor recurrences, and treatment morbidity and mortality.

MAIN RESULTS

We identified a total of 13 randomized trials involving 2362 participants. Ten trials (2122 participants) reported sufficient detail on survival to be included in a meta-analysis for the primary outcome. Preoperative chemotherapy improves overall survival (HR 0.88, 95% confidence interval (CI) 0.80 to 0.96) and is associated with a significantly higher rate of complete (R0) resection (RR 1.11, 95% CI 1.03 to 1.19).No evidence suggests that the overall rate of resection (RR 0.96, 95% CI 0.92 to 1.01), tumor recurrence (RR 0.81, 95% CI 0.54 to 1.22) or nonfatal complications (RR 0.90; 95% CI 0.76 to 1.06) was different for preoperative chemotherapy compared with surgery alone. Trials reported risks of toxicity with chemotherapy that ranged from 11% to 90%.

AUTHORS' CONCLUSIONS

In summary, preoperative chemotherapy plus surgery offers a survival advantage compared with surgery alone for patients with resectable thoracic esophageal cancer, but the evidence is of moderate quality. Some evidence of toxicity and preoperative mortality have been associated with chemotherapy.

Long-term survival analysis of the Canadian Lung Volume Reduction Surgery trial

BACKGROUND

The Canadian Lung Volume Reduction Surgery (CLVRS) trial was a multicentered randomized controlled trial that concluded that lung volume reduction surgery improves functional status and health-related quality of life (for at least 2 years) in selected patients with advanced emphysema.

METHODS

This retrospective observational study assessed the long-term survival of patients enrolled in the CLVRS at 8 to 10 years after randomization. Vital statistics were gathered through telephone contact, physician records, and municipal obituaries. Survival analysis was undertaken using Kaplan-Meier and the Cox proportional hazards models.

RESULTS

Fifty-two patients (84% of the initial 62 patients randomized) had a median survival time of 4.11 years. A 16-month survival advantage and a 20% reduction in mortality was observed in the LVRS group as compared with the best medical care group. Although clinically meaningful, these differences were not statistically significant.

CONCLUSIONS

These findings echo those of other published reports and demonstrate the potential long-term benefit of LVRS in the treatment of end-stage emphysema.

Human alveolar epithelial cells attenuate pulmonary microvascular endothelial cell permeability under septic conditions

Acute lung injury (ALI) and its most severe form, acute respiratory distress syndrome (ARDS), are characterised by high-protein pulmonary edema and severe hypoxaemic respiratory failure due to increased permeability of pulmonary microvascular endothelial cells (PMVEC). Alveolar epithelial cells (AEC) contribute importantly to normal alveolar function, and AEC dysfunction in ALI/ARDS is associated with worse outcomes. We hypothesized that AEC can modulate human PMVEC barrier function, and investigated the effects of AEC presence on human PMVEC barrier under septic conditions in vitro. PMVEC isolated from human lung were treated in vitro with septic stimulation (lipopolysaccharide [LPS], a mixture of clinically-relevant cytokines [cytomix], or plasma from patients with severe sepsis), and the trans-PMVEC leak of Evans Blue dye-labeled albumin assessed. PMVEC septic responses were compared in the presence/absence of co-cultured A549 epithelial cell line or primary human AEC. Septic stimulation with LPS, cytomix, or septic plasma induced marked PMVEC hyper-permeability (10.2±1.8, 8.9±2.2, and 3.7±0.2 fold-increase vs. control, respectively, p<0.01 for all). The presence of A549 cells or primary human AEC in a non-contact co-culture model attenuated septic PMVEC hyper-permeability by 39±4% to 100±3%, depending on the septic stimulation (p<0.05). Septic PMVEC hyper-permeability was also attenuated following treatment with culture medium conditioned by previous incubation with either naïve or cytomix-treated A549 cells (p<0.05), and this protective effect of A549 cell-conditioned medium was both heat-stable and transferable following lipid extraction. Cytomix-stimulated PMN-dependent PMVEC hyper-permeability and trans-PMVEC PMN migration were also inhibited in the presence of A549 cells or A549 cell-conditioned medium (p<0.05). Human AEC appear to protect human PMVEC barrier function under septic conditions in vitro, through release of a soluble mediator(s), which are at least partly lipid in nature. This study suggests a scientific and potential clinical therapeutic importance of epithelial-endothelial cross talk in maintaining alveolar integrity in ALI/ARDS.

Neoadjuvant or adjuvant therapy for resectable gastric cancer: a systematic review and practice guideline for North America

BACKGROUND

Gastric cancer is a global health problem accounting for 10% of all new cancer cases and 12% of all cancer deaths worldwide. Many clinical trials and meta-analyses have explored the value of neoadjuvant or adjuvant chemotherapy and radiation therapy in gastric cancer; however, these studies have produced conflicting results. The purpose of this guidance document was to determine whether patients with resectable gastric cancer should receive neoadjuvant or adjuvant therapy in addition to surgery. Outcomes of interest were overall survival, disease-free survival, and adverse events.

METHODS

A systematic review was undertaken to inform recommendations regarding neoadjuvant and adjuvant therapy in resectable gastric cancer in Ontario, Canada. MEDLINE and EMBASE databases, as well as American Society of Clinical Oncology (ASCO) annual meeting proceedings and American Society for Therapeutic Radiology and Oncology (ASTRO) proceedings were systematically searched from 2002 to 2010. Oral fluoropyrimidine trials were excluded owing to the unavailability of these agents in North America.

RESULTS

Overall, 22 randomized controlled trials (RCTs), 13 meta-analyses, and two secondary analyses were included. The systematic review informed the development of a clinical practice guideline with the following recommendations. Postoperative 5-fluorouracil-based chemoradiotherapy based on the Macdonald approach or perioperative ECF (epirubicin, cisplatin, fluorouracil) chemotherapy based on the Cunningham/MAGIC (Medical Research Council Adjuvant Gastric Infusional Chemotherapy) approach are both acceptable standards of care in North America. Choice of treatment should be made on a case-by-case basis. Adjuvant chemotherapy is a reasonable option for those patients for whom the Macdonald and MAGIC protocols are contraindicated. All patients with resectable gastric cancer should undergo a pretreatment multidisciplinary assessment to determine the best plan of care.

CONCLUSIONS

Overall survival in patients with resectable gastric cancer is significantly improved with the use of either postoperative chemoradiation (Macdonald approach) or perioperative ECF (MAGIC protocol).

Management of chest tubes after pulmonary resection: a systematic review and meta-analysis

BACKGROUND

We performed a systematic review and meta-analysis to determine the effect of suction with water seal, compared with water seal alone, applied to intra pleural chest tubes on the duration of air leaks in patients undergoing pulmonary surgery.

METHODS

We searched MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials to find randomized controlled trials (RCTs) comparing the effect of the 2 methods on the duration of air leaks. Trials were systematically assessed for eligibility and validity. Data were extracted in duplicate and pooled across studies using a random-effects model.

RESULTS

The search yielded 7 RCTs that met the eligibility criteria. No difference was identified between the 2 methods in duration of air leak (weighted mean difference [WMD] 1.15 days, favours water seal; 95% confidence interval [CI] -0.64 to 2.94), time to discharge (WMD 2.19 d, favours water seal; 95% CI -0.63 to 5.01), duration of chest tubes (WMD 0.96 d, favours water seal; 95% CI -0.12 to 2.05) or incidence of prolonged air leaks (absolute risk reduction [ARR] 0.04, favours water seal; 95% CI -0.01 to 0.09). Water seal was associated with a significantly increased incidence of postoperative pneumothorax (ARR -0.14, 95% CI -0.21 to -0.07).

CONCLUSION

No differences were identified in terms of duration of air leak, incidence of prolonged air leak, duration of chest tubes and duration of hospital stay when chest tubes were placed to suction rather than water seal. Chest tube suction appears to be superior to water seal in reducing the incidence of pneumothorax; however, the clinical significance of this finding is unclear.

What are the factors that predict outcome at relapse after previous esophagectomy and adjuvant therapy in high-risk esophageal cancer?

OBJECTIVES

The present study investigated factors affecting outcome at relapse after previous surgery and adjuvant chemoradiation (crt) in high-risk esophageal cancer patients.

PATIENTS AND METHODS

From 1989 to 1999, we followed high-risk resected esophageal cancer patients who had completed postoperative crt therapy. Patients who relapsed with a disease-free interval of less than 3 months were treated with palliative crt when appropriate. Patients with a disease-free interval of 3 months or more were treated with best supportive care. Post-recurrence survival was estimated using the Kaplan-Meier technique, and statistical comparisons were made using log-rank chi-square tests and Cox regression.

RESULTS

Of the 69 patients treated with adjuvant crt after esophagectomy, 46 experienced recurrence. Median time to relapse was 28 months (range: 0.1-40 months). Among the 46 relapsed patients, median age was 61 years (range: 37-82 years), and 42 were men. At the initial staging, 44 of 46 were node-positive; 31 of 46 had adenocarcinoma. In 33 of 46, post-esophagectomy resection margins were clear. Median follow-up after recurrence was 30.5 months (range: 1.3-100 months). Median overall survival after recurrence was 5.8 months, and the 12-month, 24-month, and 36-month survival rates were 20%, 10%, and 5% respectively. Of the prognostic factors analyzed, only resection margin status and interval to recurrence were statistically significant for patient outcome in univariate and multivariate analysis. Patients who had positive resection margins and who relapsed 12 or fewer months after surgery and adjuvant crt had a median post-recurrence overall survival of 0.85 months as compared with 6.0 months in other patients (more than 12 months to relapse, or negative resection margins, or both; log-rank p = 0.003).

CONCLUSIONS

Resection margin status and interval to disease relapse are significant independent prognostic factors for patient outcome after adjuvant crt therapy.

Postoperative extended-volume external-beam radiation therapy in high-risk esophageal cancer patients: a prospective experience

Background and Purpose

Extended-volume external-beam radiation therapy (rt) following esophagectomy is controversial. The present prospective study evaluates the feasibility of extended-volume rt treatment in high-risk esophagectomy patients with a cervical anastomosis receiving postoperative combined chemoradiation therapy.

Patients and Methods

From 2001 to 2006, 15 patients with resected esophageal cancer were prospectively accrued to this pilot study to evaluate the adverse effects of extended-volume rt. Postoperative management was carried out at London Regional Cancer Program. Eligibility criteria were pathology-proven esophageal malignancy (T3–4, N0–1), disease amenable to surgical resection, and esophagectomy with or without resection margin involvement. Patients with distant metastases (M1) and patients treated with previous rt were excluded. All 15 study patients received 4 cycles of 5-fluorouracil–based chemotherapy. External-beam rt was conducted using conformal computed tomography planning, with multi-field arrangement tailored to the pathology findings, with coverage of a clinical target volume encompassing the primary tumour bed and the anastomotic site in the neck. The radiation therapy dose was 50.40 Gy at 1.8 Gy per fraction. The rt was delivered concurrently with the third cycle of chemotherapy. The study outcomes—disease-free survival (dfs) and overall survival (os)—were calculated by the Kaplan–Meier method. Treatment-related toxicities were assessed using the U.S. National Cancer Institute’s Common Toxicity Criteria.

Results

The study accrued 10 men and 5 women of median age 64 years (range: 48–80 years) and TNM stages T3N0 (n = 1), T2N1 (n = 2), T3N1 (n = 11), and T4N1 (n = 1). Histopathology included 5 adenocarcinomas and 10 squamous-cell carcinomas. Resection margins were clear in 10 patients. The median follow-up time was 19 months (range: 3.5–53.4 months). Before radiation therapy commenced, delay in chemotherapy occurred in 20% of patients, and dose reduction was required in 13.3%. During the concurrent chemoradiation therapy phase, 20% of the patients experienced chemotherapy delay, and 6.6% experienced dose reduction. No patient experienced treatment-related acute and chronic esophagitis above grade 2. Disease recurred in 40% of the patients (6/15), and median time to relapse was 24 months. No tumour recurred at the anastomotic site. The median dfs was 23 months, and the median os was 21 months.

Conclusions

Extended-volume external-beam rt encompassing the tumour bed and the anastomotic site is feasible and safe for high-risk T3–4, N0–1 esophageal cancer patients after esophagectomy.

WITHDRAWN. Combined chemotherapy and radiotherapy (without surgery) compared with radiotherapy alone in localized carcinoma of the esophagus

BACKGROUND

Esophageal carcinoma can be managed primarily with either a surgical or non-surgical radiotherapeutic approach. Combination chemotherapy (CT) and radiotherapy (RT) has been incorporated into clinical practice and applied increasingly, especially in North America.

OBJECTIVES

To evaluate combined CT and RT (CTRT) versus RT alone in patients with localized esophageal carcinoma. Outcomes included overall survival, cause-specific survival, local recurrence, dysphagia relief, quality of life, acute and chronic toxicities.

SEARCH STRATEGY

The Cochrane strategy for identifying randomized trials was combined with relevant MeSH headings. The Cochrane Library, MEDLINE, CancerLIT and EMBASE were last searched in April 2005. References from relevant articles and personal files were included.

SELECTION CRITERIA

Randomized controlled trials in patients with localized esophageal cancer comparing RT alone with combined CTRT were included. Studies comparing non-chemotherapy agents such as pure radiotherapy sensitisers, immunostimulants, planned esophagectomy, were excluded.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted data independently. Trial quality was assessed using the Jadad scale and Detsky checklist. Sensitivity analyses were planned to examine the effect of concomitant versus sequential treatment, study quality, radiotherapy dose, and whether the drug regimen contained cisplatin or 5-fluorouracil were performed.

MAIN RESULTS

Nineteen randomized trials were included, with eleven concomitant and eight sequential RTCT studies. Concomitant RTCT provided significant reduction in mortality with a harms ratio (HR) of 0.73 (95% confidence interval (CI) 0.64 to 0.84). Using an estimated mortality rate for the control group of 62% at year one and 83% at year two, the absolute survival benefit for RTCT was 9% (95% CI 5 to 12%) and 4% (95% CI 3 to 6%]) respectively. There was an absolute reduction of local recurrence rate of 12% (95% CI 3 to 22%), number needed to treat (NNT) of 9, when the local recurrence rate for the RT alone arm was 68%. This was associated with a significant risk of severe and life-threatening toxicities (number needed to harm (NNH)of 6). Sensitivity analyses did not identify any factors that interacted with the results. The results from sequential RTCT studies showed no significant benefit in survival or local control but significant toxicities.

AUTHORS' CONCLUSIONS

Based on the available data, when a non-operative approach is selected then concomitant RTCT is superior to RT alone for patients with localized esophageal cancer but with significant toxicities. In patients who are in good general condition, and the risk benefit has been thoroughly discussed with the patient, concomitant RTCT should be considered for the management of esophageal cancer compared with radiotherapy alone.

The 4th Annual Ontario Thoracic Cancer Conference at Niagara-on-the-Lake

The 4th annual Ontario Thoracic Cancer Conference at Niagara-on-the-Lake focused on the themes of innovations in the management of lung cancer, controversies in the management of esophageal cancer, and molecular targeted therapies in lung cancer. This conference summary highlights the presentations and provides clinicians with a referenced update on these topics.

The 4th Annual Ontario Thoracic Cancer Conference at Niagara-on-the-Lake

The 4th annual Ontario Thoracic Cancer Conference at Niagara-on-the-Lake focused on the themes of innovations in the management of lung cancer, controversies in the management of esophageal cancer, and molecular targeted therapies in lung cancer. This conference summary highlights the presentations and provides clinicians with a referenced update on these topics.