Impact of radiation dose distribution on nutritional supplementation needs in head and neck cancer radiotherapy: a voxel-based machine learning approach.

Objectives: To investigate the relationship between nutritional supplementation and radiation dose to the pharyngeal constrictor muscles and larynx for head and neck (HN) cancer patients undergoing radiotherapy. Methods: We retrospectively analyzed radiotherapy (RT) dose for 231 HN cancer patients, focusing on the pharyngeal constrictors and larynx. We defined nutritional supplementation as feeding tube utilization or >10% weight loss from baseline within 90 days after radiotherapy completion. Using deformable image registration (DIR), we mapped each patient's anatomical structures to a reference coordinate system, and corresponding deformations were applied to dose matrices. Voxel doses were utilized as features for ridge logistic regression models, optimized through 5-fold cross-validation. Model performance was assessed with area under the curve of a receiver operating curve (AUC) and F1 score. We built and compared models using 1) pharyngeal constrictor voxels, 2) larynx voxels, 3) clinical factors and mean regional dose metrics, and 4) clinical factors and dose-volume histogram metrics. Test set AUCs were compared among the models, and feature importance was evaluated. Results: DIR of the pharyngeal constrictors and larynx yielded mean Dice coefficients of 0.80 and 0.84, respectively. Pharyngeal constrictors voxels and larynx voxel models had AUC of 0.88 and 0.82, respectively. Voxel-based dose modeling identified the superior to middle regions of the pharyngeal constrictors and the superior region of larynx as most predictive of feeding tube use/weight loss. Univariate analysis found treatment setting, treatment laterality, chemotherapy, baseline dysphagia, weight, and socioeconomic status predictive of outcome. An aggregated model using mean doses of pharyngeal constrictors and larynx subregions had an AUC of 0.87 and the model using conventional DVH metrics had an AUC of 0.85 with p-value of 0.04. Feature importance calculations from the regional dose model indicated that mean doses to the superior-middle pharyngeal constrictor muscles followed by mean dose to the superior larynx were most predictive of nutritional supplementation. Conclusions: Machine learning modeling of voxel-level doses enables identification of subregions within organs that correlate with toxicity. For HN radiotherapy, doses to the superior-middle pharyngeal constrictors are most predictive of feeding tube use/weight loss followed by the doses to superior portion of the larynx.

Predictors of mortality within the first year post-hepatectomy for hepatocellular carcinoma.

BACKGROUND: Hepatic resection (HR) for hepatocellular carcinoma (HCC) is safe with good perioperative and long-term oncologic outcomes. There is a paucity of data with regards to intermediate-term outcomes (i.e., beyond 90-day and within 1-year mortality). This paper studies the risk factors for within 1-year mortality after elective HR with curative intent in patients with HCC. METHODS: An audit of patients who underwent curative HR for HCC from January 2007 to April 2016 was conducted. Univariate and multivariate analysis were sequentially performed on perioperative variables using Cox-regression analysis to identify factors predicting intermediate-term outcomes defined as within 1-year mortality. Kaplan-Meier survival curves and hazard ratios were obtained. RESULTS: Three hundred forty-eight patients underwent HR during the study period and 163 patients had curative hepatectomy for HCC. Fifteen patients (9.2%) died within 1-year after HR. Multivariate analysis identified Child-Pugh class B/C (HR 5.5, p = 0.035), multinodularity (HR 7.1, p = 0.001), macrovascular invasion (HR 4.2, p = 0.04) postoperative acute renal failure (HR 5.8, p = 0.049) and posthepatic liver failure (HR 9.6, p = 0.009) as significant predictors of 1-year mortality. CONCLUSION: One-year mortality following HR for HCC remains high and can be predicted preoperatively by multinodularity, Child-Pugh class, and macrovascular invasion. Postoperative acute renal failure and liver failure are associated with 1-year mortality.

Perceptions of Singaporeans towards informed consent: a cross-sectional survey.

INTRODUCTION: In a patient-centric health system, it is essential to know patients' views about informed consent. The objective of this study was to understand the perceptions of the local population regarding informed consent. METHODS: Spanning across six weeks from January 2016 to March 2016, a cross-sectional survey of adults attending General Surgery outpatient clinics at Tan Tock Seng Hospital was performed. Sociodemographic data, lifestyle and health-related information, perception and purpose of consent forms, and decision-making preferences were studied. RESULTS: 445 adults participated in the survey. Most participants were below 40 years old (n = 265, 60.1%), female (n = 309, 70.1%) and degree holders (n = 196, 44.4%). 56.9% of participants wanted to know every possible risk, while 28.3% wanted to know common and serious risks. On multivariate analysis, age (age 61-74 years: odds ratio [OR] 11.1, 95% confidence interval [CI] 2.2-56.1, p = 0.004; age > 75 years: OR 22.2, 95% CI 1.8-279.1, p = 0.017) was a predictor of not wanting to know any risks. Age also predicted risk of disclosure for death (age 61-74 years: OR 13.4, 95% CI 4.2-42.6, p < 0.001; age > 75 years: OR 32.0, 95% CI 4.5-228.0, p = 0.001). Most participants (48.1%) preferred making shared decisions with doctors, and an important predictor was employment status (OR = 4.8, 95% CI 1.9-12.2, p = 0.001). CONCLUSION: Sociodemographic factors and educational level influence decision-making, and therefore, the informed consent process should be tailored for each patient.

How efficacious are Octreotide and Somatostatin in the management of chylothorax in congenital cardiac surgical patients?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was how efficacious are Octreotide and Somatostatin in the management of chylothorax in congenital cardiac surgical patients. Altogether >55 papers were found using the reported search, of which 8 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The comparative data on LOS and chylothorax duration are mixed though interpretation is difficult since Octreotide has been instituted belatedly from the onset of chylothorax in multiple instances. There is also preliminary evidence to suggest that responders to Somatostatin and Octreotide are affected by single-ventricle physiology and CVP levels. Meanwhile, non-responders tend to have higher mortality and may merit earlier surgical intervention. The included studies thus far have significant limitations such as low-level evidence study design, selection bias, variability in duration and dosage of therapy and heterogenous comparative arms. Notwithstanding these limitations, Octreotide has shown to be an useful adjunct treatment in reducing chylothorax volume especially in patients with higher output chylothorax (>40 ml/kg/h) after the failure of conservative management.

Behind the Façade: Robotic-Assisted Resection of a Diaphragmatic Osteochondroma.

Neoplasms arising from the diaphragm are not typically seen in clinical practice, though they may inflict significant morbidity and mortality. In the realm of thoracic surgery, osteochondromas are only encountered at the thoracic wall or vertebra. In this study, we describe a case of an osteochondroma arising from the diaphragm masquerading as a malignant lesion. The tumor was resected via robotic-assisted means and the patient was discharged with no complications.

Inferior vena cava leiomyosarcoma in an octogenerian.

Inferior Vena Cava (IVC) leiomyosarcoma (LM) is a rare malignancy of mesenchymal origin with an incidence of 1/100,000. We present an 82-year-old lady with a past history of open cholecystectomy who presented with a large indeterminate mass on abdominal imaging. Open resection of the mass was performed and histology with immunohistochemical staining revealed leiomyosarcoma. She received adjuvant radiotherapy and remained disease free 4 years after.

Predicting morbidity of liver resection.

PURPOSE: Multiple models have attempted to predict morbidity of liver resection (LR). This study aims to determine the efficacy of American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) surgical risk calculator and the Physiological and Operative Severity Score in the enUmeration of Mortality and Morbidity (POSSUM) in predicting post-operative morbidity in patients who underwent LR. METHODS: A retrospective analysis was conducted on patients who underwent elective LR. Morbidity risk was calculated with the ACS-NSQIP surgical risk calculator and POSSUM equation. Two models were then constructed for both ACS-NSQIP and POSSUM-(1) the original risk probabilities from each scoring system and (2) a model derived from logistic regression of variables. Discrimination, calibration, and overall performance for ACS-NSQIP and POSSUM were compared. Sub-group analysis was performed for both primary and secondary liver malignancies. RESULTS: Two hundred forty-five patients underwent LR. Two hundred twenty-three (91%) had malignant liver pathologies. The post-operative morbidity, 90-day mortality, and 30-day mortality rate were 38.3%, 3.7%, and 2.4% respectively. ACS-NSQIP showed superior discriminative ability, calibration, and performance to POSSUM (p = 0.03). Hosmer-Lemeshow plot demonstrated better fit of the ACS-NSQIP model than POSSUM in predicting morbidity. CONCLUSION: In patients undergoing LR, the ACS-NSQIP surgical risk calculator was superior to POSSUM in predicting morbidity risk.

Cardiopulmonary bypass time: every minute counts.

BACKGROUND: This study was conducted to examine the impact of CPB times on postoperative outcomes. We sought to determine the optimum cut-offs of CPB per graft time and cumulative CPB time and their predictive accuracy for mortality in conjunction with EuroSCORE II. METHODS: The de-identified data of 1960 patients who had undergone isolated on-pump CABG from 2009 to 2014 were analyzed. The risk strata of cardiopulmonary bypass (CPB)/graft and cumulative CPB times, identified with a decision tree, were added into an augmented model for predicting short- and intermediate-term postoperative clinical events. RESULTS: Prolonged cumulative CPB time (>180 minutes) was significant in predicting mortality while adjusting for EuroSCORE II, postoperative complications, prolonged ICU stay and prolonged mechanical ventilation. Whereas prolonged CPB/graft time (>56 minutes) was marginally non-significant in terms of its direct effects, its indirect effect on mortality could be manifested through enhanced risks of complications, prolonged ICU stay (>48 hours) and prolonged mechanical ventilation (>24 hours). CONCLUSIONS: Prolonged CPB times could predict postoperative clinical events, in particular mortality. To minimize the occurrence of unfavorable adverse outcomes, it is recommended that the CPB/graft time and cumulative CPB time be kept below 56 minutes and 180 minutes respectively.