Synthetic Megavoltage Cone Beam Computed Tomography Image Generation for Improved Contouring Accuracy of Cardiac Pacemakers.

In this study, we aimed to enhance the contouring accuracy of cardiac pacemakers by improving their visualization using deep learning models to predict MV CBCT images based on kV CT or CBCT images. Ten pacemakers and four thorax phantoms were included, creating a total of 35 combinations. Each combination was imaged on a Varian Halcyon (kV/MV CBCT images) and Siemens SOMATOM CT scanner (kV CT images). Two generative adversarial network (GAN)-based models, cycleGAN and conditional GAN (cGAN), were trained to generate synthetic MV (sMV) CBCT images from kV CT/CBCT images using twenty-eight datasets (80%). The pacemakers in the sMV CBCT images and original MV CBCT images were manually delineated and reviewed by three users. The Dice similarity coefficient (DSC), 95% Hausdorff distance (HD95), and mean surface distance (MSD) were used to compare contour accuracy. Visual inspection showed the improved visualization of pacemakers on sMV CBCT images compared to original kV CT/CBCT images. Moreover, cGAN demonstrated superior performance in enhancing pacemaker visualization compared to cycleGAN. The mean DSC, HD95, and MSD for contours on sMV CBCT images generated from kV CT/CBCT images were 0.91 ± 0.02/0.92 ± 0.01, 1.38 ± 0.31 mm/1.18 ± 0.20 mm, and 0.42 ± 0.07 mm/0.36 ± 0.06 mm using the cGAN model. Deep learning-based methods, specifically cycleGAN and cGAN, can effectively enhance the visualization of pacemakers in thorax kV CT/CBCT images, therefore improving the contouring precision of these devices.

Trigger related outcomes of takotsubo syndrome in a cancer population.

Background: Takotsubo syndrome (TTS) occurs more frequently in cancer patients than in the general population, but the effect of specific TTS triggers on outcomes in cancer patients is not well studied. Objectives: The study sought to determine whether triggering event (chemotherapy, immune-modulators vs. procedural or emotional stress) modifies outcomes in a cancer patient population with TTS. Methods: All cancer patients presenting with acute coronary syndrome (ACS) between December 2008 and December 2020 at our institution were enrolled in the catheterization laboratory registry. Demographic and clinical data of the identified patients with TTS were retrospective collected and further classified according to the TTS trigger. The groups were compared with regards to major adverse cardiac events, overall survival and recovery of left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) after TTS presentation. Results: Eighty one of the 373 cancer patients who presented with ACS met the Mayo criteria for TTS. The triggering event was determined to be "cancer specific triggers" (use of chemotherapy in 23, immunomodulators use in 7, and radiation in 4), and "traditional triggers" (medical triggers 22, and procedural 18 and emotional stress in 7). Of the 81 patients, 47 died, all from cancer-related causes (no cardiovascular mortality). Median survival was 11.9 months. Immunomodulator (IM) related TTS and radiation related TTS were associated with higher mortality during the follow-up. Patients with medical triggers showed the least recovery in LVEF and GLS while patients with emotional and chemotherapy triggers, showed the most improvement in LVEF and GLS, respectively. Conclusion: Cancer patients presenting with ACS picture have a high prevalence of TTS due to presence of traditional and cancer specific triggers. Survival and improvement in left ventricular systolic function seem to be related to the initial trigger for TTS.

Survey of Anesthesia, Sedation, and Non-sedation Practices for Children Undergoing Repetitive Cranial or Craniospinal Radiotherapy.

Background Children undergoing cranial or craniospinal radiotherapy may require over 30 treatments within a six-week period. Facilitating these many treatments with the patient under anesthesia presents a significant challenge, and the most preferred anesthetic methods remain unknown. The primary goal of this study was to determine the most preferred anesthetic methods and agents for children undergoing daily cranial or craniospinal radiotherapy. Methods An 83-item web-based survey was developed. An introductory email was sent to 505 physicians and child-life specialists with expertise in pediatric anesthesia and/or affiliated with pediatric radiation oncology departments. Results The response rate was 128/505 (25%) and included specialists from Africa (5, 4%), Asia (18, 14%), Australia/Oceania (5, 4%), Europe (45, 35%), North America (50, 39%), and South America (5, 4%). The 128 respondents included 91 anesthesiologists (71%), 20 physicians who were not anesthesiologists (16%), 14 child life/social education specialists (11%), one radiotherapist, one pediatric radiation nurse, and one non-specified medical professional (all = 2%). Of the 128 respondents, 95 (74%) used anesthesia or sedation to facilitate repetitive cranial or craniospinal radiotherapy. Overall, total intravenous anesthesia without intubation was preferred by 67 of 95 (71%) specialists during one or more forms of radiotherapy. During photon-based radiotherapy, total intravenous anesthesia without intubation was the preferred anesthetic method with the patient in the supine (57/84, 68%) and prone positions (25/40, 63%). Propofol was the most used anesthetic agent for both supine (73/84, 87%) and prone positions (38/40, 95%). For proton radiotherapy, total intravenous anesthesia without intubation was the most preferred anesthetic method for the supine (32/42, 76%) and prone treatment positions (11/18, 61%), and propofol was the most used anesthetic (supine: 40/43, 93%; prone: 16/18, 89%). Conclusions In this survey of 95 specialists responsible for anesthesia or sedation of children undergoing repetitive cranial or craniospinal radiotherapy, propofol-based total intravenous anesthesia without intubation was the preferred anesthetic technique.

A retrospective evaluation of the impact of patient ethnicity on the use of epidural analgesia or blood transfusions in children undergoing major oncologic surgery.

BACKGROUND: The impact of patient ethnicity on healthcare delivery is well documented. In this study of children who had undergone open abdominal or pelvic surgery for tumor resection, we sought to compare the use of epidural analgesia or intraoperative blood transfusions between Caucasian and non-Caucasian children. METHODS: A retrospective study of 139 children was performed. Logistic regression models were used to evaluate the association between the specified perioperative factors and patient ethnicity. RESULTS: The average age (standard deviation) was 11 years (± 5), 50% were female, and 58% were Caucasian. Compared to Caucasian children, non-Caucasian children were younger (difference in mean, - 2.6 years; 95% confidence interval [- 4.3, - 0.9], p = 0.003), underwent shorter procedures (difference in mean anesthesia minutes, - 134; 95% confidence interval [-  230, - 39], p = 0.006), and had a lower proportion of patients who received epidural analgesia (66% versus 81%, p = 0.042) or blood transfusions (48% versus 65%, p = 0.039). In the adjusted model, patient ethnicity was not associated with the receipt of epidural analgesia (odds ratio 0.53, 95% confidence interval [0.23, 1.21], p = 0.132) or blood transfusions (odds ratio 0.77, 95% confidence interval [0.29, 2.04], p = 0.600). The use of epidural analgesia or blood transfusions was associated with abnormal coagulation factors (odds ratio 0.32, 95% confidence interval [0.14, 0.71], p = 0.005) and the duration of surgery (odds ratio 1.007, 95% confidence interval [1.005, 1.009], p < 0.001), respectively. CONCLUSION: In this study of children who had undergone major oncologic surgery, the use of epidural analgesia or blood transfusions was not associated with patient ethnicity.

An analysis of the survival impact of dexmedetomidine in children undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy.

OBJECTIVE: Recent evidence suggests the α2-adrenoreceptor agonist dexmedetomidine may promote metastasis of cancer cells. In this study we sought to evaluate the impact of dexmedetomidine administration on the survival of children and adolescents with cancer. DESIGN: Retrospective chart review. SETTING: Comprehensive cancer center. PATIENTS: Children and adolescents who had undergone cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for peritoneal carcinomatosis. INTERVENTION: Intraoperative and/or early postoperative (within 24 hours of surgery) administration of dexmedetomidine. MEASUREMENTS: Multivariable cox proportional hazard models were used to assess the association between dexmedetomidine administration and progression free survival (PFS) or overall survival (OS). MAIN RESULTS: Ninety-three patients were identified. The median age was 12 years, 42% were female, and 35% received dexmedetomidine. There were no significant differences between the baseline and perioperative characteristics of patients who received dexmedetomidine and those who did not. In the multivariable analysis, the administration of dexmedetomidine was not associated with PFS (HR = 1.20, 95% CI [0.60-2.41], p = .606) or OS (HR = 0.81, 95% CI [0.35-1.85], p = .611). CONCLUSION: In this retrospective study of children and adolescents who had undergone a major oncologic surgery, the intraoperative and/or early postoperative administration of dexmedetomidine was not associated with survival.

Metastatic Testicular Cancer to Left Atrium via the Left Inferior Pulmonary Vein: A Case Report.

Testicular cancer is one of the most common cancers diagnosed in young men. Frequent sites of metastasis include the retroperitoneum, lungs, liver, brain, and bone. Intra-cardiac metastasis has also been described. An 18-year-old boy with a history of mixed testicular germ cell tumor presented to our institution for surgical resection of his metastatic disease. Intraoperative transesophageal echocardiography during his surgery confirmed a tumor thrombus into the left atrium coming from the left pulmonary vein. We report a case of metastatic testicular cancer with rare tumor extension from the left inferior pulmonary vein into the left atrium. Perioperative transesophageal echocardiography was necessary to aid intraoperative diagnosis and confirmation of the intracardiac tumor, providing data to guide surgical strategy.

The Use of Intraoperative Dexmedetomidine Is Not Associated With a Reduction in Acute Kidney Injury After Lung Cancer Surgery.

OBJECTIVE: To evaluate whether the use of intraoperative dexmedetomidine (DEX) during lung cancer surgery may reduce the incidence of acute kidney injury (AKI). DESIGN: A retrospective study. SETTING: An academic hospital. PARTICIPANTS: Data were collected from 1,207 adult patients who underwent resection for non-small-cell lung cancer between January 2004 and December 2012. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: All patients had a general balanced anesthetic technique, and dexmedetomidine use was at the discretion of the anesthesiologist. Data analysis was done utilizing the Wilcoxon rank sum tests and Chi-square tests to compare continuous variables and categoric variables between the 2 groups, respectively. Multivariate logistic analysis with backward selection was fitted to find out factors for AKI incidence. Overall, 8.1% of the patients developed AKI during their hospital stay. There were no statistically significant differences in demographic, perioperative variables, and the incidence of AKI between patients who did and did not receive DEX. A logistic regression model was fitted to determine factors independently associated with AKI. Factors that were independently associated with AKI included body mass index, American Society of Anesthesiologists 3-4, hypertension, smoking status, and thoracotomy procedure. DISCUSSION: The authors hypothesized that DEX use would be associated with a decreased incidence of AKI in thoracic surgery; however, they were unable to prove this hypothesis. Their results did demonstrate that there are 5 factors independently associated with AKI.

Tracheal resection with regional anesthesia.

A 52-year-old man underwent tracheal resection during regional anesthesia with sedation. The patient had a prior history of tracheostomy resulting in tracheal stenosis and expiratory wheezing. Awake tracheal resection with spontaneous ventilation was performed. Patient cooperation was essential to identify the lesion and perform the resection safely.

Moderate hypothermia during aortic arch surgery is associated with reduced risk of early mortality.

OBJECTIVE: Selective antegrade cerebral perfusion (ACP) during hypothermic circulatory arrest (HCA) provides cerebral protection during aortic arch surgery. However, the ideal temperature for HCA during ACP remains unknown. Clinical outcomes were compared in patients who underwent moderate (nasopharyngeal temperature, ≥ 20 °C) versus deep (nasopharyngeal temperature, <20 °C) HCA with ACP during aortic arch repair. METHODS: By using a prospectively maintained clinical database, we analyzed data from 221 consecutive patients who underwent aortic arch replacement with HCA and ACP between December 2006 and May 2009. Seventy-eight patients underwent deep hypothermia (mean lowest temperature, 16.8 °C ± 1.7 °C) and 143 patients underwent moderate hypothermia (mean, 22.9 °C ± 1.4 °C) before systemic circulatory arrest was initiated. Multivariate stepwise logistic and linear regressions were performed to determine whether depth of hypothermia independently predicted postoperative outcomes and blood-product use. RESULTS: Compared with moderate hypothermia, deep hypothermia was associated independently with a greater risk of in-hospital death (7.7% vs 0.7%; odds ratio [OR], 9.3; 95% confidence interval [CI], 1.1-81.6; P = .005) and 30-day all-cause mortality (9.0% vs 2.1%; OR, 4.7; 95% CI, 1.2-18.6; P = .02), and with longer cardiopulmonary bypass time (154 ± 62 vs 140 ± 46 min; P = .008). Deep hypothermia also was associated with a higher incidence of stroke, although this association was not statistically significant (7.6% vs 2.8%; P = .073; OR, 4.3; 95% CI, 0.9-12.5). No difference was seen in acute kidney injury, blood product transfusion, or need for surgical re-exploration. CONCLUSIONS: Moderate hypothermia with ACP is associated with lower in-hospital and 30-day mortality, shorter cardiopulmonary bypass time, and fewer neurologic sequelae than deep hypothermia in patients who undergo aortic arch surgery with ACP.