Utility of 30-day mortality as a quality metric for palliative radiation treatment: A population-based analysis from Queensland, Australia.

INTRODUCTION: Palliative radiotherapy (PRT) is frequently used to treat symptoms of advanced cancer, however benefits are questionable when life expectancy is limited. The 30-day mortality rate after PRT is a potential quality indicator, and results from a recent meta-analysis suggest a benchmark of 16% as an upper limit. In this population-based study from Queensland, Australia, we examined 30-day mortality rates following PRT and factors associated with decreased life expectancy. METHODS: Retrospective population data from Queensland Oncology Repository was used. Study population data included 22,501 patients diagnosed with an invasive cancer who died from any cause between 2008 and 2017 and had received PRT. Thirty-day mortality rates were determined from the date of last PRT fraction to date of death. Cox proportional hazards models were used to identify factors independently associated with risk of death within 30 days of PRT. RESULTS: Overall 30-day mortality after PRT was 22.2% with decreasing trend in more recent years (P = 0.001). Male (HR = 1.20, 95% CI = 1.13-1.27); receiving 5 or less radiotherapy fractions (HR = 2.97, 95% CI = 2.74-3.22 and HR = 2.17, 95% CI = 2.03-2.32, respectively) and receiving PRT in a private compared to public facility (HR = 1.61, 95% CI = 1.51-1.71) was associated with decreased survival. CONCLUSION: The 30-day mortality rate in Queensland following PRT is higher than expected and there is scope to reduce unnecessarily protracted treatment schedules. We encourage other Australian and New Zealand centres to examine and report their own 30-day mortality rate following PRT and would support collaboration for 30-day mortality to become a national and international quality metric for radiation oncology centres.

Patterns of practice regarding use of radiation therapy following radical prostatectomy: A survey of Radiation Oncologists and Urologists in Australia and New Zealand.

INTRODUCTION: This study aimed to investigate the patterns of practices of radiation oncologists (ROs) and urologists in Australia and New Zealand with respect to the utilisation of post-prostatectomy radiation therapy (RT) and help guide the development of an update to the existing Faculty of Radiation Oncology Genito-Urinary Group post-prostatectomy guidelines. METHODS: ROs and urologists with subspecialty practice in prostate cancer from Australia and New Zealand were invited to participate in an online survey comprised of clinical scenarios regarding post-prostatectomy RT. RESULTS: Sixty-five ROs and 28 urologists responded to the survey. In the setting of low-risk biochemical relapse, the threshold for initiating RT was lower for ROs than urologists. ROs were more likely than urologists to recommend adjuvant RT for node-positive disease. When salvage RT was advised for a pT3N0R1 recurrence, there was no consensus amongst ROs on whether to add either ADT or nodal treatment over prostate bed RT alone. For a solitary PSMA-avid pelvic lymph node recurrence, whole pelvis RT with androgen deprivation therapy was the preferred treatment option (72% ROs, 43% urologists). Most ROs (92%) recommended conventionally fractionated RT to 66-70 Gy, with a boost to any PSMA PET avid recurrent disease. CONCLUSION: This survey highlights the marked discordance in practice for the management of prostate cancer relapse post-prostatectomy. This is seen not only between specialties but also within the radiation oncology community. This emphasises the need for an updated evidence-based guideline to be produced.

Canadian Pediatric Intensive Care Adaptations for Critically Ill Adults During the COVID-19 Pandemic: Survey Study.

BACKGROUND: The COVID-19 pandemic overwhelmed Canadian hospitals with adult admissions. A large number of adult patients required critical care therapies, placing significant strain on hospital resources. In order to decompress adult intensive care units, pediatric intensive care units (PICUs) introduced adapted models of traditional care to lessen these burdens. OBJECTIVE: We aimed to evaluate how PICUs across Canada adapted care for the high volumes of critically ill adults. METHODS: A survey containing 40 questions was sent to the medical directors of 14 Canadian PICUs where English was the primary clinical language. The survey was designed to gain perspective on the various adaptations that PICUs instituted during the COVID-19 pandemic. RESULTS: Of the 13 PICUs that returned survey responses (response rate: 13/14, 93%), 10 (77%) participated in at least one adaptation to support the influx of admitted adults with COVID-19. The key challenges included disorganization, loss of autonomy, and compromised patient care. The significant advantages of these adaptations included a sense of learning and comradery. CONCLUSIONS: Our study highlighted an unpreparedness in critical care surge capacity. During the COVID-19 pandemic, adaptations rapidly emerged in Canada that involved PICUs with adult care. In the future, preplanned adaptations for optimizing robust critical care services should be developed based on what has been learned from the COVID-19 pandemic.

Severity of Illness Scoring for Pediatric Interfacility Transport: A North American Survey.

OBJECTIVE: Severity of illness scoring during pediatric critical care transport may provide objective data to determine illness trajectory and disposition and contribute to quality assurance data for pediatric transport programs. The objective of this study was to ascertain the breadth of severity of illness scoring tool application among North American pediatric critical care transport teams. METHODS: A cross-sectional quantitative survey using REDCap was distributed to 137 North American pediatric transport programs. Baseline team characteristics were established along with questions related to severity of illness tool application.Descriptive statistics were used for analysis. RESULTS: There were 55 responses (40%), and of those, 13 (24%) use a severity of illness scoring tool within their practice. A variety of tools were used including: Transport Risk Index of Physiologic Stability, Children's Hospital Medical Center Cincinnati, Canadian Triage and Acuity Score, Transport Risk Assessment in Pediatrics, Pediatric Early Warning Scores, Levels of Acuity, Transport Pediatric Early Warning Scores, and an unspecified tool. The timing of scoring, team personnel who applied the score, and the frequency of analysis varied between transport programs. CONCLUSIONS: Severity of illness scoring is not consistently performed by pediatric interfacility transport programs in North America. Among the programs that use a scoring tool, there is variability in its application. There is no universally accepted or performed severity of illness scoring tool for pediatric interfacility transport.Future research to validate and standardize a pediatric transport severity of illness scoring tool for North America is necessary.

Prognostic factors for survival and ambulatory status at 8 weeks with metastatic spinal cord compression in the SCORAD randomised trial.

BACKGROUND: Metastatic spinal cord compression (MSCC) carries a poor prognosis and management is based on the likelihood of maintaining mobility and predicted survival. PATIENTS AND METHOD: SCORAD is a randomised trial of 686 patients comparing a single dose of 8 Gy radiotherapy with 20 Gy in 5 fractions. Data was split into a training set (412, 60%) and a validation set (274, 40%). A multivariable Cox regression for overall survival (OS) and a logistic regression for ambulatory status at 8 weeks were performed in the training set using baseline factors and a backward selection regression to identify a parsimonious model with p ≤ 0.10. Receiver Operating Characteristic (ROC) analysis evaluated model prognostic performance in the validation set. Validation of the final survival model was performed in a separate registry dataset (n = 348). RESULTS: The survival Cox model identified male gender, lung, gastrointestinal, and other types of cancer, compression at C1-T12, presence of non-skeletal metastases and poor ambulatory status all significantly associated with worse OS (all p < 0.05). The ROC AUC for the selected model was 75% (95%CI: 69-81) in the SCORAD validation set and 68% (95%CI: 62-74) in the external validation registry data. The logistic model for ambulatory outcome identified primary tumour breast or prostate, ambulatory status grade 1 or 2, bladder function normal and prior chemotherapy all significantly associated with increased odds of ambulation at 8 weeks (all p < 0.05). The ROC AUC for the selected model was 72.3% (95% CI 62.6-82.0) in the validation set. CONCLUSIONS: Primary breast or prostate cancer, and good ambulatory status at presentation, are favourable prognostic factors for both survival and ambulation after treatment.

Defining the expected 30-day mortality for patients undergoing palliative radiotherapy: A meta-analysis.

BACKGROUND: The expected 30-day mortality rate for patients treated with palliative radiationisnotestablished. The primary objective of this study is todefinetheproportion of patientswith advanced cancerwho diewithin 30-daysofpalliative radiotherapy(PR). Additionally, we explored the short term survival of patient subgroups undergoing PR treatment. METHODS: We searched MEDLINE, CINAHL, Embase and Cochrane Database of Systematic Reviews from January 1st 1980 to June 26, 2020. We included PUBMED's related search and reference lists to further identify articles. A meta-analysis of these research studies and reviews was performed. Published and unpublished English language randomized controlled trials, observational or prospective studies, and systematic reviews that reported 30-day mortality for patients with advanced cancer who received PR were eligible. Data extraction was done by two independent authors and included study quality indicators. To improve distribution and variance, all proportions were transformed using logit transformation. A random-effects model was used to pool data, using Der Simonian and Laird method of estimation where possible and appropriate. RESULTS: The data from 42 studies contributing 88,516 patients with advanced cancer who received PR were evaluated. The summary proportion of mortality in patients with advanced cancer within 30 days of receiving PR was 16% (95% CI = 14% to 18%). We found substantial heterogeneity in our data (I2 = 98.76%, p < 0.001), hence we applied subgroup analysis to identify potential moderating factors. We found a higher 30-day mortality rate after PR in the following groups: multiple treatment sites (QM(1) = 9.54, p = 0.002), hepatobiliary primary (QM(1) = 24.20, p < 0.001), inpatient status (QM(1) = 92.27, p < 0.001), Eastern Cooperative Oncology Group performance status (ECOG) 3-4 (QM(1) = 8.70, p = 0.003), United States (U.S.) patients (QM(1) = 28.70, p < 0.001) among others. CONCLUSIONS: We found that 16% of patients with advanced cancer receiving PR die within 30 days of treatment. Our findingcan be used asabenchmarktoestablishaglobal quality metric for radiation oncology practice audits.

Establishing a palliative Advanced Practice Radiation Therapist role: A viable alternative to a Rapid Access Palliative Radiation Therapy clinic in Australia.

INTRODUCTION: A recent survey found that Rapid Access Palliative Radiation Therapy (RAPRT) clinics have not been widely embraced in Australia and New Zealand for many reasons. The purpose of this narrative is to describe the transition of a Brisbane, Queensland, RAPRT clinic to an Advanced Practice Radiation Therapist (APRT) model to further improve access and delivery of palliative radiation therapy at that centre. METHODS: The weekly RAPRT clinic commenced in 2005, run by one Radiation Oncologist (RO). The role of the attending senior Radiation Therapist (RT) was mainly to facilitate rapid passage of patients from clinic to treatment. However, because individual ROs preferred to retain care of their own patients, capture of the relevant population was limited. It was therefore decided in 2012 to gradually transition to a model where the RT would work with all ROs and manage all palliative patients from referral to follow-up, under RO supervision. RESULTS: The steps to this palliative APRT pathway involved formulation of the role description, mentoring/training of the RT, overseas site visits, further post-graduate education, funding of the position, staff feedback surveys, evaluation studies and endorsement by professional bodies, leading to formal credentialing in 2017. Importantly, the APRT undertakes all steps in the pathway including field or volume delineation (with approval and sign-off by the responsible RO). The role has come to be highly valued by all disciplines. CONCLUSION: The successful establishment of a palliative APRT role in one Australian centre serves as a template for others wishing to create a similar position.

Lessons Learned from a Small Pediatric Continuous Renal Replacement Therapy Program.

Continuous renal replacement therapy (CRRT) has become a pillar of care in pediatric intensive care units (PICUs) over the past few decades. Quality indicators (QIs) have been evaluated that reflect safe and accountable CRRT. However, there is a paucity of data on outcomes and QIs in smaller-volume CRRT programming. The purpose of this retrospective study was to evaluate the efficiencies, effectiveness, and outcomes of a small-volume CRRT program. Eighty-two patients received CRRT over a 13-year period, and 79% survived to discharge. Sepsis or nonseptic shock (n = 11 (22%) versus n = 6 (50%); p value = 0.004) and time to CRRT initiation after PICU admission (1.1 versus 5.0 days; p value = 0.005) were independent predictors for mortality. The program also had positive outcomes for QIs related to CRRT efficiency and time of initiation, dosing delivery, and rate of adverse events. This study is important as it illustrates the opportunity that smaller centers have to initiate CRRT programming and provide safe and effective care.

Cost-effectiveness analysis of hydrogel spacer for rectal toxicity reduction in prostate external beam radiotherapy.

INTRODUCTION: Contemporary methods of external beam radiotherapy for prostate cancer have reduced toxicity rates through beam modulation and image guidance, however, rectal injury has not been eliminated completely in this population. For patients at greatest risk of developing rectal toxicities, hydrogel spacers are a viable option for risk reduction. Translation of clinical trial results into routine clinical practice relies on an understanding of the economic implications. This study completed a cost-effectiveness analysis of hydrogel spacers in the Australian healthcare setting. METHOD: Simulation of possible health states following treatment was performed using a Markov model. Model outcomes included the incremental cost-effectiveness ratio and the net monetary benefit (NMB) at three published willingness-to-pay thresholds derived from literature. Probabilistic sensitivity analyses were provided on these results. A baseline cohort without hydrogel spacer use was compared to treat all and selective use cohorts. Cost variation scenarios were also investigated to assess the impact of hydrogel spacer cost on outcomes. RESULTS: Using hydrogel spacers in a selective cohort was more likely to be cost-effective than giving to all patients (NMB -$43 versus -$997, respectively); however, the incremental cost-effectiveness ratio was not below the $28 000 willingness-to-pay threshold for a healthcare provider perspective. These outcomes were influenced by large parameter uncertainty. Cost variation strategies are worth investigating further as a method to achieve willingness-to-pay threshold targets. CONCLUSION: The influence of parameter uncertainty currently limits the cost-effectiveness of this intervention in the Australian public health setting. However, a cost variation solution has been demonstrated to improve cost-effectiveness estimates for selected patients and should be examined further.

Rapid Access Palliative Radiation Therapy Clinics: The Evidence Is There, but Where Are the Clinics? An Australian and New Zealand Perspective.

PURPOSE: First developed in Canada in the 1990s, Rapid Access Palliative Radiation Therapy (RAPRT) clinics have subsequently spread internationally to expedite treatment for near end-of-life patients, sparing them the need for multiple visits to the department. A "classical" RAPRT clinic is herein defined as "a dedicated clinic specifically established to enable (ideally) same day consultation, planning for, and delivery of palliative radiation treatment." The aim of this work was to determine the current status of these clinics in Australia and New Zealand (ANZ). METHODS AND MATERIALS: A phone survey of all 100 Australian and 10 NZ radiation therapy centers was conducted in March and April 2021. The Chief Medical Officers of the 2 large private practices (GenesisCare and Icon) also approved the survey and answered on behalf of their 57 centers. A single page questionnaire was used, seeking information on the logistics and clinical details of past and present RAPRT clinics, and reasons why other centers do not have one. RESULTS: The survey response rate was 100%. There are only 3 current RAPRT clinics (2.7%). The dominant treatment indication is bone metastases (85%-90%), with most patients receiving single fractions (60%-90%), but commencement on the same day is variable (35%-90%). Five other clinics (4.5%) closed after 4 months to 7 years, but the clinical features were similar. By far, the most common reason (95%) given by the 107 centers without a current RAPRT clinic was that these patients are accommodated using existing resources. CONCLUSIONS: Classical RAPRT clinics have not been widely embraced in ANZ. There are alternative strategies such as the Advanced Practice Radiation Therapist model and techniques to avoid the conventional computed tomography-simulation step, which may also expedite treatment for palliative patients.

Prognostic tools for survival prediction in advanced cancer patients: A systematic review.

Survival prediction for palliative cancer patients by physicians is often optimistic. Patients with a very short life expectancy (<4 weeks) may not benefit from radiation therapy (RT), as the time to maximal symptom relief after treatment can take 4-6 weeks. We aimed to identify a prognostic tool (or tools) to predict survival of less than 4 weeks and less than 3 months in patients with advanced cancer to guide the choice of radiation dose and fractionation. We searched Embase, Medline (EBSCOhost) and CINAHL (EBSCOhost) clinical databases for literature published between January 2008 and June 2018. Seventeen studies met the inclusion criteria and were included in the review. Prediction accuracy at less than 4 weeks and less than 3 months were compared across the prognostic tools. Reporting of prediction accuracy among the different studies was not consistent: the Palliative Prognostic Score (PaP), Palliative Prognostic Index (PPI) and Number of Risk Factors (NRF) best-predicted survival duration of less than 4 weeks. The PPI, performance status with Palliative Prognostic Index (PS-PPI), NRF and Survival Prediction Score (SPS) may predict 3-month survival. We recommend PPI and PaP tools to assess the likelihood of a patient surviving less than 4 weeks. If predicted to survive longer and RT is justified, the NRF tool could be used to determine survival probability less than 3 months which can then help clinicians select dose and fractionation. Future research is needed to verify the reliability of survival prediction using these prognostic tools in a radiation oncology setting.

Computed Tomography Practice Standards for Severe Pediatric Traumatic Brain Injury in the Emergency Department: a National Survey.

Acute medical management of traumatic brain injury (TBI) can be challenging outside of the resuscitation bay, specifically while obtaining a computed tomography (CT) scan of the brain. We sought out to determine the management practices of Canadian traumatologists for pediatric patients with severe TBI requiring CT in the emergency department (ED). In 2019, surveys were sent to trauma directors in hospitals across Canada to ascertain their clinical practices. Team members present in the CT scan included physicians (89%), registered nurses (100%), and respiratory therapists (38%). The average time to and from the CT scanner was one hour. Over half of respondents (56%) had experienced an adverse event in CT with variable access (11-56%) to necessary resuscitation equipment and medications. Significant hypotension (44%) was the most common adverse event experienced. With the exception of an end tidal CO2 monitoring (56%), heart rate, rhythm, respiratory rate, saturation, and blood pressure were always monitored during a CT scan. Head of bed elevation had an approximately equal distribution of flat (44%) versus elevated (56%). The practice variability of Canadian traumatologists may reflect a lack of evidence to guide patient management. Future research and knowledge translation efforts are needed to optimize patient care during neuroimaging.

Optic Nerve Sheath Diameter in Preterm Infants: Suggested Values.

OBJECTIVE: Timely detection of elevated intracranial pressure (ICP) in highrisk preterm infants may be critical to avoid permanent neurologic sequelae. Size of optic nerve sheath diameter (ONSD) is highly correlated with changes in ICP. Normal ultrasonographic ONSD values for preterm infants have been published. This study sought to compare these data with MRI measured OSND and to propose suggested ultrasonographic ONSD values. METHODS: The ONSD in preterm MRIs were retrospectively measured and related to pre-existing ultrasonographic ONSD. Data were stratified for corrected gestational age. Simple linear regression between ONSD mean values and age was modeled for both eyes, and R2 was calculated. Suggested values for ultrasonographic ONSD were ascertained through linear regression and calculated prediction intervals. RESULTS: ONSD measurements demonstrated R2 values of 0.95 (right ONSD MRI), 0.95 (left ONSD MRI), 0.96 (right ONSD ultrasound), and 0.93 (left ONSD ultrasound). Suggested ONSD values were incremental with corrected gestational age. CONCLUSION: ONSD measurements with MRI and ultrasound are similar. The proposed suggested ONSD values may be helpful in clinical situations where ICPs are suspected or known.

Serial Clinical Scoring to Assess Transported Pediatric Patients.

OBJECTIVES: The objective of this study was to evaluate serial Transport Risk Assessment in Pediatrics (TRAP) scoring during pediatric critical care transport as a potential measure for specialized pediatric transport teams (PTTs). METHODS: This was a retrospective study with a provincial PTT from a tertiary hospital pediatric intensive care unit. All acutely ill children who were transported by the PTT between 2018 and 2019 were included in the study. The TRAP scores were measured at time of transport team arrival (TRAP1), time at arrival to tertiary center (TRAP2), and 4 hours postarrival to tertiary center (TRAP3). RESULTS: A total of 300 transports were included. Patients' mean age was 54 months, with lower respiratory tract infection (40.7%) as the most common diagnosis. There were significant differences between TRAP1-TRAP2 (P < 0.01) and TRAP1-TRAP3 (P < 0.01), but not between TRAP2-TRAP3 (P = 0.67). The most significant improvements of ΔTRAP1-TRAP2 scores were seen in septic shock (mean, 2.0; SD, 1.7). CONCLUSIONS: The TRAP scores improved following the PTTs' arrival to acutely ill children, particularly with sepsis. Serial TRAP scoring may present a system for evaluation of team performance and/or characterize disease states that are positively impacted by PTTs. Future prospective evaluation is needed to validate TRAP for this purpose.

Perspectives of Pediatric Providers on Patients With Complex Chronic Conditions: A Mixed-Methods Sequential Explanatory Study.

BACKGROUND: Children with complex chronic conditions present unique challenges to the pediatric intensive care unit, including prolonged length of stay, complex medical regimens, and complicated family dynamics. OBJECTIVES: To examine perspectives of pediatric intensive care unit health care providers regarding pediatric patients with complex chronic conditions, and to explore potential opportunities to improve these patients' care. METHODS: A prospective mixed-methods sequential explanatory study was conducted in a tertiary medical-surgical pediatric intensive care unit using surveys performed with REDCap (Research Electronic Data Capture) followed by semistructured interviews. RESULTS: The survey response rate was 70.6% (77 of 109). Perspectives of health care providers did not vary with duration of work experience. Ten semistructured interviews were conducted. Eight overarching themes emerged from the interviews: (1) the desire for increased formal education specific to pediatric complex chronic care patients; (2) designation of a primary intensivist; (3) modifying delivery of care to include a discrete location for care provision; (4) establishing daily, short-term, and long-term goals; (5) monitoring and documenting care milestones; (6) strengthening patient and family communications with the health care team; (7) optimizing discharge coordination and planning; and (8) integrating families into care responsibilities. CONCLUSIONS: Pediatric intensive care unit health care providers' perspectives of pediatric patients with complex chronic conditions indicated opportunities to refine the care provided by establishing daily goals, coordinating discharge planning, and creating occasions for close communication between patients, families, and providers.

Noninvasive ventilation for pediatric interfacility transports: a retrospective study.

BACKGROUND: To characterize pediatric patients supported with continuous positive airway pressure and bilevel positive airway pressure (CPAP/BiPAP) or high-flow nasal cannula (HFNC) during interfacility transport (IFT). METHODS: A retrospective study with a provincial pediatric transport team from a tertiary hospital pediatric intensive care unit. Pediatric patients aged 28 days to < 17 years, who required IFT between January 2017 and December 2018, were identified through a transport registry and were included in the study. RESULTS: A total of 118 (26.7%) patients received CPAP/BIPAP or HFNC support for IFT. The most common respiratory diagnosis was bronchiolitis (46%). These patients were placed on respiratory support, 31.4 minutes after the transport team's arrival. None required intubation during their IFT, despite mean transport times of 163 minutes. CONCLUSIONS: This study may provide important information for programs with large catchment areas, in which large distances and transport times should not be barriers to NIV implementation.

Comparison of statistical machine learning models for rectal protocol compliance in prostate external beam radiation therapy.

PURPOSE: Limiting the dose to the rectum can be one of the most challenging aspects of creating a dosimetric external beam radiation therapy (EBRT) plan for prostate cancer treatment. Rectal sparing devices such as hydrogel spacers offer the prospect of increased space between the prostate and rectum, causing reduced rectal dose and potentially reduced injury. This study sought to help identify patients at higher risk of developing rectal injury based on estimated rectal dosimetry compliance prior to the EBRT simulation and planning procedure. Three statistical machine learning methods were compared for their ability to predict rectal dose outcomes with varied classification thresholds applied. METHODS: Prostate cancer patients treated with conventionally fractionated EBRT to a reference dose of 74-78 Gy were invited to participate in the study. The dose volume histogram data from each dosimetric plan was used to quantify planned rectal volume receiving 50%, 83% 96%, and 102% of the reference dose. Patients were classified into two groups for each of these dose levels: either meeting tolerance by having a rectal volume less than a clinically acceptable threshold for the dose level (Y) or violating the tolerance by having a rectal volume greater than the threshold for the dose level (N). Logistic regression, classification and regression tree, and random forest models were compared for their ability to discriminate between class outcomes. Performance metrics included area under the receiver operator characteristic curve (AUC), sensitivity, specificity, positive predictive value and negative predictive value. Finally, three classification threshold levels were evaluated for their impact on model performance. RESULTS: A total of 176 eligible participants were recruited. Variable importance differed between model methods. Area under the receiver operator characteristic curve performance varied greatly across the different rectal dose levels and between models. Logistic regression performed best at the 83% reference dose level with an AUC value of 0.844, while random forest demonstrated best discrimination at the 96% reference dose level with an AUC value of 0.733. In addition to the standard classification probability threshold of 50%, the clinically representative threshold of 10%, and the best threshold from each AUC plot was applied to compare metrics. This showed that using a 50% threshold and the best threshold from the AUC plots yields similar results. Conversely, applying the more conservative clinical threshold of 10% maximized the sensitivity at V83_RD and V96_RD for all model types. Based on the combination of the metrics, logistic regression would be the recommendation for rectal protocol compliance prediction at the 83% reference dose level, and random forest for the 96% reference dose level, particularly when using the clinical probability threshold of 10%. CONCLUSIONS: This study demonstrated the efficacy of statistical machine learning models on rectal protocol compliance prediction for prostate cancer EBRT dosimetric planning. Both logistic regression and random forest modeling approaches demonstrated good discriminative ability for predicting class outcomes in the upper dose levels. Application of a conservative clinical classification threshold maximized sensitivity and further confirmed the value of logistic regression and random forest models over classification and regression tree.

Brain Death Criteria: Medical Dogma and Outliers.

The diagnosis of brain death (BD) is legally and medically accepted. Recently, several high-profile cases have led to discussions regarding the integrity of current criteria, and many physiologic problems have been identified to support the necessity for their reevaluation. These include a global variability of the criteria, the suggestion of a clinical "hierarchy," and the resultant approximation of BD. Further ambiguity has been exposed through case reports of reversible BD, and an inconsistent understanding from physicians who are viewed as experts in this domain. Meeting BD criteria clearly does not equate to a physiologic "death" of the brain, and a greater community perspective should be considered as the dialogue moves forward.