Polarimetric method of generating full Poincaré beams within a finite extent

A novel polarimetric method of generating a variety of Poincaré beams such as half Poincaré beams and full Poincaré beams using doubly inhomogeneous wave plates (d-plates) is proposed. In this method, every input state of polarization (SoP) through such a d-plate generates a unique Poincaré beam, thereby giving access to a potentially infinite number of them. Furthermore, the generation of full Poincaré beams is presented here as an instance of the geometrical problem of mapping the surface of a sphere onto a plane, and this insight allows one to design d-plates that convert the input SoP to every possible SoP, within a finite region of the beam. A gadget composed of three singly inhomogeneous wave plates for an equivalent realization of these d-plates is also presented.

Anesthetic management of women with heart failure during pregnancy: a retrospective cohort study

BACKGROUND

The incidence of heart failure among pregnant women with pre-existing cardiac disease is quoted as 13%, with 10% requiring hospitalization. There is limited literature on heart failure in the pregnant population. The study objective was to describe the etiology and management of women hospitalized in our institution for heart failure during pregnancy.

METHODS

A retrospective cohort study investigated women who presented with heart failure in pregnancy between 2004 and 2017. Hospital records were interrogated using International Classification of Diseases v10 codes for heart failure. Patient characteristics, investigations, treatment, obstetric and anesthetic management, and maternal-fetal outcome data were collected and summarized using descriptive statistics.

RESULTS

One-hundred-and-twenty cases (in 93 122 deliveries) were identified across the 13-year period (antepartum heart failure 51%, postpartum heart failure 49%).The most common etiologies were pre-eclampsia (28%), cardiomyopathy (22%), and valvular heart disease (18%). Cesarean delivery occurred in 76% of cases (13% because of the maternal cardiac condition). Neuraxial techniques were used for most deliveries (cesarean 83%; vaginal 90%). For cesarean delivery, titrated epidural or general anesthesia was employed in 48% and 16%, respectively. Cardiac arrest occurred in two cases (1.7%) and 44% required coronary or intensive care unit admission.

CONCLUSIONS

The incidence of heart failure was 0.13% (1:776 deliveries). Pre-eclampsia was the leading cause but may have been historically under-acknowledged. Anesthetic and obstetrical decisions were tailored by means of multidisciplinary input, with cesarean delivery and regional anesthesia used in the majority. The postpartum period warrants heightened attention for these patients.

Risk Factors, Causes, and Costs of Hospital Readmission After Head and Neck Cancer Surgery Reconstruction

Importance

Thirty-day hospital readmissions have substantial direct costs and are increasingly used as a measure of quality care. However, data regarding the risk factors and reasons for readmissions in head and neck cancer surgery reconstruction are lacking.

Objective

To describe the rate, risk factors, and causes of 30-day readmission in patients with head and neck cancer following free or pedicled flap reconstruction.

Design, Setting, and Participants

This retrospective, population-based cohort study analyzed medical records from the Nationwide Readmissions Database of 9487 patients undergoing pedicled or free flap reconstruction of head and neck oncologic defects between January 1, 2010, and December 31, 2014. Data analysis was performed in October 2017.

Exposures

Pedicled or free flap reconstruction of an oncologic head and neck defect.

Main Outcomes and Measures

The primary outcome was 30-day all-cause readmissions. Secondary outcomes included risk factors, causes, and costs of readmission. Multivariate regression analyses were conducted to determine factors independently associated with 30-day readmissions.

Results

Among 9487 patients included in the study (6798 male; 71.7%), the median age was 63 years (interquartile range, 55-71 years), and the 30-day readmission rate was 19.4% (n = 1839), with a mean cost per readmission of $15 916 (standard error of the mean, $785). The most common indication for readmission was wound complication (26.5%, n = 487). On multivariate regression, significant risk factors for 30-day readmission were median household income in the lowest quartile (vs highest quartile: odds ratio [OR], 1.58; 95% CI, 1.18-2.11), congestive heart failure (OR, 1.68; 95% CI, 1.14-2.47), liver disease (OR, 2.02; 95% CI, 1.22- 3.33), total laryngectomy (OR, 1.40; 95% CI, 1.12-1.75), pharyngectomy (OR, 1.47; 95% CI, 1.08-2.01), blood transfusion (OR, 1.30; 95% CI, 1.04-1.64), discharge to home with home health care (vs routine: OR, 1.32; 95% CI, 1.04-1.67), and discharge to a nursing facility (vs routine: OR, 1.77; 95% CI, 1.30-2.40).

Conclusions and Relevance

Using the Nationwide Readmissions Database, we demonstrate that approximately 1 in 5 patients undergoing head and neck cancer surgery reconstruction is readmitted within 30 days of surgery. Readmissions are most commonly associated with wound complications. Socioeconomic status, complex ablative procedures, and patient comorbidities are independent risk factors for readmission. These findings may be useful to clinicians in developing perioperative interventions aimed to reduce hospital readmissions and improve quality of patient care.

Effect of Radiation Doses to the Heart on Survival for Stereotactic Ablative Radiotherapy for Early-stage Non-Small-cell Lung Cancer: An Artificial Neural Network Approach

INTRODUCTION

The cardiac radiation dose is an important predictor of cardiac toxicity and overall survival (OS) for patients with locally advanced non-small-cell lung cancer (NSCLC). However, radiation-induced cardiac toxicity among patients with early-stage NSCLC who have undergone stereotactic ablative radiotherapy (SABR) has been less well-characterized. Our objective was to assess the associations between cardiac radiation dosimetry and OS in patients with early-stage NSCLC undergoing SABR.

MATERIALS AND METHODS

From 2009 to 2014, 153 patients with early-stage NSCLC had undergone SABR at a single institution. The maximum dose, mean dose, V_10Gy, V_25Gy, and V_50Gy to 15 cardiac substructures and the whole heart were analyzed for their association with OS using the Kaplan-Meier method. An artificial neural network (ANN) analysis was performed to modulate confounding behaviors of dosimetric variables to predict for OS.

RESULTS

A total of 112 patients were included in the present analysis. The right ventricle (RV) V_10Gy most negatively predicted for OS, such that patients who had received a RV V_10Gy dose < 4% had significantly longer OS than patients who had received a RV V_10Gy does > 4% (5.3 years vs. 2.4 years). On ANN analysis, 74 input features, including cardiac dosimetry parameters, predicted for survival with a test accuracy of 64.7%. A repeat ANN analysis using dosimetry to dose neutral structure confirmed the predictive power of cardiac dosimetry.

CONCLUSION

Cardiac dosimetry to subvolumes of the heart was associated with decreased OS in patients with early-stage NSCLC undergoing SABR. These data support the importance of minimizing the radiation dose to cardiac substructures. Further prioritizing the heart as an organ at risk might be warranted. Additionally, cardiac follow-up should be considered.

Fano resonance between coherent acoustic phonon oscillations and electronic states near the bandgap of photoexcited GaAs

Impulsive photo-excitation of solids results in a travelling strain pulse which manifests itself as coherent acoustic phonon oscillations. These oscillations have been extensively studied using time-resolved pump-probe spectroscopy. In the present work, we report the generation of extremely long-lived, coherent longitudinal acoustic phonon oscillations in intrinsic GaAs (100), with clear and unambiguous evidence of Fano interference between these oscillations and the continuum of electronic states close to the bandgap. Fano resonance is a widespread phenomenon observed in atomic systems and condensed media that arises from quantum interference between a continuum of quantum states and a discrete quantum state. Among other techniques, Fano resonance has been investigated with respect to optical phonons studied with Raman Spectroscopy. In the present work, we investigate Fano resonance in coherent phonon oscillations generated without the aid of any capping layer, dopants or substrate/interface effects. Since Fano resonance is sensitive to changes in electronic structure, doping and defects, these observations are important to the field of picosecond ultrasonics which is used for non-destructive depth profiling of solids and for carrier diffusion studies.

The impact of treatment package time on survival in surgically managed head and neck cancer in the United States

OBJECTIVES

Delays in the initiation of postoperative radiation have been associated with worse outcomes; however, the effect of the overall treatment package time (interval from surgery through the completion of radiation) remains undefined. The purpose of this study was to determine the impact of package time on survival and to evaluate this effect among different subgroups of head and neck cancer patients.

PATIENTS AND METHODS

In this observational cohort study, the National Cancer Database was used to identify 35,167 patients with resected nonmetastatic head and neck cancer who underwent adjuvant radiation from 2004 to 2014. Kaplan-Meier survival estimates and multivariate Cox regression analyses were performed to determine the effect of treatment package time on overall survival.

RESULTS

Median package time was 96 days (interquartile range, 85-112 days). After adjusting for covariates, package times of 11 weeks or less were associated with improved survival (adjusted hazard ratio (aHR), 0.90; 95% confidence interval, 0.83-0.97) compared to an interval of 12-13 weeks, whereas package times of more than 14 weeks were associated with worse survival (aHR, 1.14, 1.14, and 1.22 for 14-15, 15-17, and >17 weeks, respectively). A significant interaction was identified between package time and disease site, nodal status, and stage. Specifically, patients with oropharyngeal tumors, advanced stage (III or IV) disease, or nodal involvement experienced more pronounced increases in mortality risk with delays in treatment time.

CONCLUSIONS

Treatment package time independently impacts survival. This effect may be strongest for patients with oropharyngeal tumors or advanced stage disease.

Comparing Outcomes of Patients With Early-Stage Non-Small-Cell Lung Cancer Treated With Stereotactic Body Radiotherapy Based on Frailty Status

INTRODUCTION

Frailty of surgical patients has been associated with worse outcomes. There is limited literature discussing frailty in patients with lung cancer treated with stereotactic body radiotherapy (SBRT). This study assesses the relationship between frailty and overall survival (OS), tumor control, and toxicity in patients with early-stage non-small-cell lung cancer (NSCLC) treated with SBRT.

PATIENTS AND METHODS

A retrospective review of patients with early-stage NSCLC treated with SBRT at a single institution between February 2009 and September 2014 was performed. A modified frailty index (mFI) of 8 variables was created, and patients were categorized as nonfrail (mFI ≤ 2) and frail (mFI > 2). OS, recurrence-free survival (RFS), local control (LC), regional control, and distant control (DC) were compared between frail and nonfrail patients by Kaplan-Meier analysis and log-rank tests. Univariate and multivariable analyses were conducted.

RESULTS

One hundred forty cases of early-stage NSCLC were included, with 49 frail (35.0%) and 91 nonfrail (65.0%) subjects. OS was significantly lower in frail than nonfrail patients (P = .01) with 3-year OS of 59.3% versus 82.0%. LC and DC were significantly lower in frail than nonfrail patients (LC: P = .02, 3-year LC of 85.3% vs. 97.0%; DC: P = .03, 3-year DC of 80.6% vs. 93.4%), as was RFS (P = .01, 3-year RFS of 53.4% vs. 74.5%). Frailty remained a significant predictor for shorter OS on multivariable analysis (hazard ratio = 1.98; 95% confidence interval, 1.02-3.85; P = .04).

CONCLUSION

Frailty is associated with reduced OS in early-stage NSCLC patients treated with SBRT. Characterizing frailty using an mFI before treatment could help guide treatment decision making and patient counseling.

Endoscopic Management of Subglottic Stenosis

Importance

Optimal management of subglottic stenosis has not been established. Endoscopic techniques include balloon dilation, radial incisions with carbon dioxide laser or cold knife, and combinations of techniques. Adjunctive measures include mitomycin application and glucocorticoid injection.

Objective

To determine whether surgical technique or adjunctive measures are associated with duration between surgical procedures.

Design, Setting, and Participants

Adult patients with subglottic stenosis treated endoscopically between 1995-2015 at a quaternary academic medical center were identified. Patients with isolated subglottic (cricotracheal) stenosis 18 years and older were included. Patients with prior open surgical procedures, prior laryngeal surgical procedures, glottic stenosis, or vocal fold paralysis were excluded.

Interventions

Patients underwent endoscopic procedures including laser radial incisions, balloon dilation, or both, with some patients receiving topical mitomycin, glucocorticoid injection, or both.

Main Outcomes and Measures

Time interval between endoscopic treatments.

Results

A total of 101 patients (mean [SD] age, 52.3 [15.9] years; 77.2% female) were included in the analysis, with etiologies including idiopathic (47 [46.5%]), intubation (31 [30.7%]), granulomatosis with polyangiitis (9 [8.9%]), and other autoimmune diseases (6 [5.9%]). Among the 219 operations, both laser and balloon dilation were used in 117 (53.4%), while balloon dilation alone was used in 96 (43.8%) and laser alone in 6 (2.7%). Mitomycin application and steroid injection were used in 144 (65.8%) and 93 (42.5%) cases, respectively. Mitomycin application was associated with improvement in the mean interval to next procedure from 317 to 474 days (absolute difference, 157 days; 95% CI, 15-299 days). Advanced grade of stenosis, dilation technique, and steroid injection did not significantly alter the surgical intervals.

Conclusions and Relevance

Endoscopic surgery for subglottic stenosis is a critical aspect of patient management. Neither surgical technique nor grade of stenosis was seen to alter the surgical intervals. Mitomycin application was associated with an extended time interval between endoscopic treatments.

Radiotherapy versus radical prostatectomy for Gleason score 9-10 prostate adenocarcinoma: A multi-institutional comparative analysis of 1001 patients treated in the modern era

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Background: To compare the outcomes of a modern cohort of patients with Gleason Score (GS) 9-10 prostate adenocarcinoma (CaP) following treatment with external beam radiotherapy (EBRT), extremely dose-escalated radiotherapy (as exemplified by EBRT with a brachytherapy boost [EBRT+BT]), and radical prostatectomy (RP). Methods: One-thousand-and-one patients with biopsy GS 9-10 CaP who received definitive treatment between 2000 and 2013 were included (347 treated with EBRT, 330 with EBRT+BT, and 324 with RP). Kaplan-Meier analysis and multivariate Cox regression compared 5- and 10-year rates of distant metastasis-free survival (DMFS), cancer-specific survival (CSS), and overall survival (OS). Prostate cancer-mortality (PCSM) rates were compared with a competing risk analysis. Results: The median followup periods were 4.8, 6.4, and 5.1 years among patients receiving EBRT, EBRT + BT, and RP. The median doses among EBRT and EBRT+BT patients were equivalent to 78 Gy and 90 Gy in 2 Gy fractions. Over 90% of patients treated with EBRT or EBRT+BT received ADT (median durations of 18 months and 12 months, respectively). Nearly 40% of RP patients received postoperative RT, primarily in the salvage setting. Five- and 10-year DMFS rates were significantly higher with EBRT+BT (91.6% and 81.3%) than with EBRT (79.6% and 65.8%; p < 0.0001) or RP (77.9% and 60.1%; p < 0.0001). Five- and 10-year PCSM rates were significantly lower with EBRT+BT (3.8% and 14.1%) than with EBRT (10.3% and 25.2%; 5- and 10-year hazard ratios of 0.38 and 0.47; p = 0.003) or RP (8.9% and 20.3%; 5- and 10-year hazard ratios of 0.39 and 0.55; p = 0.02). Overall 5- and 10-year OS rates were 85.7% and 64.7% and were similar between cohorts (p > 0.1). Conclusions: Extremely dose-escalated radiotherapy offered improved systemic control and reduced PCSM when compared with either EBRT or RP. Notably, this was achieved despite a significantly shorter median duration of ADT than in the EBRT arm. This is hypothesis generating as it suggests that improved local control via dose-escalation may have systemic control and survival implications even for patients with very high risk disease.

Anatomic and dosimetric changes in patients with head and neck cancer treated with an integrated MRI-tri-60Co teletherapy device

OBJECTIVE

Prior studies have relied on CT to assess alterations in anatomy among patients undergoing radiation for head and neck cancer. We sought to determine the feasibility of using MRI-based image-guided radiotherapy to quantify these changes and to ascertain their potential dosimetric implications.

METHODS

6 patients with head and neck cancer were treated with intensity-modulated radiotherapy (IMRT) on a novel tri-⁶⁰Co teletherapy system equipped with a 0.35-T MRI (VR, ViewRay Incorporated, Oakwood Village, OH) to 66-70 Gy in 33 fractions (fx). Pre-treatment MRIs on Fx 1, 5, 10, 15, 20, 25, 30 and 33 were imported into a contouring interface, where the primary gross tumour volume (GTV) and parotid glands were delineated. The centre of mass (COM) shifts for these structures were assessed relative to Day 1. Dosimetric data were co-registered with the MRIs, and doses to the GTV and parotid glands were assessed.

RESULTS

Primary GTVs decreased significantly over the course of IMRT (median % volume loss, 38.7%; range, 29.5-72.0%; p < 0.05) at a median rate of 1.2%/fx (range, 0.92-2.2%/fx). Both the ipsilateral and contralateral parotid glands experienced significant volume loss (p < 0.05, for all) and shifted medially during IMRT. Weight loss correlated significantly with parotid gland volume loss and medial COM shift (p < 0.05).

CONCLUSION

Integrated on-board MRI can be used to accurately contour and analyze primary GTVs and parotid glands over the course of IMRT. COM shifts and significant volume reductions were observed, confirming the results of prior CT-based exercises. Advances in knowledge: The superior resolution of on-board MRI may facilitate online adaptive replanning in the future.

Clinical Outcomes for Patients with Gleason Score 9-10 Prostate Adenocarcinoma Treated With Radiotherapy or Radical Prostatectomy: A Multi-institutional Comparative Analysis

BACKGROUND

The long natural history of prostate cancer (CaP) limits comparisons of efficacy between radical prostatectomy (RP) and external beam radiotherapy (EBRT), since patients treated years ago received treatments considered suboptimal by modern standards (particularly with regards to androgen deprivation therapy [ADT] and radiotherapy dose-escalation]. Gleason score (GS) 9-10 CaP is particularly aggressive, and clinically-relevant endpoints occur early, facilitating meaningful comparisons.

OBJECTIVE

To compare outcomes of patients with GS 9-10 CaP following EBRT, extremely-dose escalated radiotherapy (as exemplified by EBRT+brachytherapy [EBRT+BT]), and RP.

DESIGN, SETTING, PARTICIPANTS

Retrospective analysis of 487 patients with biopsy GS 9-10 CaP treated between 2000 and 2013 (230 with EBRT, 87 with EBRT+BT, and 170 with RP). Most radiotherapy patients received ADT and dose-escalated radiotherapy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Kaplan-Meier analysis and multivariate Cox regression estimated and compared 5-yr and 10-yr rates of distant metastasis-free survival, cancer-specific survival (CSS), and overall survival (OS).

RESULTS AND LIMITATIONS

The median follow-up was 4.6 yr. Local salvage and systemic salvage were performed more frequently in RP patients (49.0% and 30.1%) when compared with either EBRT patients (0.9% and 19.7%) or EBRT+BT patients (1.2% and 16.1%, p<0.0001). Five-yr and 10-yr distant metastasis-free survival rates were significantly higher with EBRT+BT (94.6% and 89.8%) than with EBRT (78.7% and 66.7%, p=0.0005) or RP (79.1% and 61.5%, p<0.0001). The 5-yr and 10-yr CSS and OS rates were similar across all three cohorts.

CONCLUSIONS

Radiotherapy and RP provide equivalent CSS and OS. Extremely dose-escalated radiotherapy with ADT in particular offers improved systemic control when compared with either EBRT or RP. These data suggest that extremely dose-escalated radiotherapy with ADT might be the optimal upfront treatment for patients with biopsy GS 9-10 CaP.

PATIENT SUMMARY

While some prostate cancers are slow-growing requiring many years, sometimes decades, of follow-up in order to compare between radiation and surgery, high-risk and very aggressive cancers follow a much shorter time course allowing such comparisons to be made and updated as treatments, especially radiation, rapidly evolve. We showed that radiation-based treatments and surgery, with contemporary standards, offer equivalent survival for patients with very aggressive cancers (defined as Gleason score 9-10). Extremely-dose escalated radiotherapy with short-course androgen deprivation therapy offered the least risk of developing metastases, and equivalent long term survival.