Early educational attainment in children with major congenital anomaly in the UK.

OBJECTIVE: To describe early educational attainment and special educational needs (SEN) provision in children with major congenital anomaly (CA) compared with peers. DESIGN: Analysis of educational data linked to the ongoing Born in Bradford cohort study. Confounders were identified via causal inference methods and multivariable logistic regression performed. SETTING: Children born in Bradford Royal Infirmary (BRI), West Yorkshire. PATIENTS: All women planning to give birth at BRI and attending antenatal clinic from March 2007 to December 2010 were eligible. 12 453 women with 13 776 pregnancies (>80% of those attending) were recruited. Records of 555 children with major CA and 11 188 without were linked to primary education records. OUTCOMES: Key Stage 1 (KS1) attainment at age 6-7 years in Maths, Reading, Writing and Science. SEN provision from age 4 to 7 years. RESULTS: 41% of children with major CA received SEN provision (compared with 14% without), and 48% performed below expected standards in at least one KS1 domain (compared with 29% without). The adjusted odds of children with CA receiving SEN provision and failing to achieve the expected standard at KS1 were, respectively, 4.30 (95% CI 3.49 to 5.31) and 3.06 (95% CI 2.47 to 3.79) times greater than their peers. Those with genetic, heart, neurological, urinary, gastrointestinal and limb anomalies had significantly poorer academic achievement. CONCLUSIONS: These novel results demonstrate that poor educational attainment extends to children with urinary, limb and gastrointestinal CAs. We demonstrate the need for collaboration between health and education services to assess and support children with major CA, so every CA survivor can maximise their potential.

Visual Assessment of 2-Dimensional Levels Within 3-Dimensional Pathology Data Sets of Prostate Needle Biopsies Reveals Substantial Spatial Heterogeneity.

Prostate cancer prognostication largely relies on visual assessment of a few thinly sectioned biopsy specimens under a microscope to assign a Gleason grade group (GG). Unfortunately, the assigned GG is not always associated with a patient's outcome in part because of the limited sampling of spatially heterogeneous tumors achieved by 2-dimensional histopathology. In this study, open-top light-sheet microscopy was used to obtain 3-dimensional pathology data sets that were assessed by 4 human readers. Intrabiopsy variability was assessed by asking readers to perform Gleason grading of 5 different levels per biopsy for a total of 20 core needle biopsies (ie, 100 total images). Intrabiopsy variability (Cohen κ) was calculated as the worst pairwise agreement in GG between individual levels within each biopsy and found to be 0.34, 0.34, 0.38, and 0.43 for the 4 pathologists. These preliminary results reveal that even within a 1-mm-diameter needle core, GG based on 2-dimensional images can vary dramatically depending on the location within a biopsy being analyzed. We believe that morphologic assessment of whole biopsies in 3 dimension has the potential to enable more reliable and consistent tumor grading.

Nondestructive 3D pathology with analysis of nuclear features for prostate cancer risk assessment.

Prostate cancer treatment decisions rely heavily on subjective visual interpretation [assigning Gleason patterns or International Society of Urological Pathology (ISUP) grade groups] of limited numbers of two-dimensional (2D) histology sections. Under this paradigm, interobserver variance is high, with ISUP grades not correlating well with outcome for individual patients, and this contributes to the over- and undertreatment of patients. Recent studies have demonstrated improved prognostication of prostate cancer outcomes based on computational analyses of glands and nuclei within 2D whole slide images. Our group has also shown that the computational analysis of three-dimensional (3D) glandular features, extracted from 3D pathology datasets of whole intact biopsies, can allow for improved recurrence prediction compared to corresponding 2D features. Here we seek to expand on these prior studies by exploring the prognostic value of 3D shape-based nuclear features in prostate cancer (e.g. nuclear size, sphericity). 3D pathology datasets were generated using open-top light-sheet (OTLS) microscopy of 102 cancer-containing biopsies extracted ex vivo from the prostatectomy specimens of 46 patients. A deep learning-based workflow was developed for 3D nuclear segmentation within the glandular epithelium versus stromal regions of the biopsies. 3D shape-based nuclear features were extracted, and a nested cross-validation scheme was used to train a supervised machine classifier based on 5-year biochemical recurrence (BCR) outcomes. Nuclear features of the glandular epithelium were found to be more prognostic than stromal cell nuclear features (area under the ROC curve [AUC] = 0.72 versus 0.63). 3D shape-based nuclear features of the glandular epithelium were also more strongly associated with the risk of BCR than analogous 2D features (AUC = 0.72 versus 0.62). The results of this preliminary investigation suggest that 3D shape-based nuclear features are associated with prostate cancer aggressiveness and could be of value for the development of decision-support tools. © 2023 The Pathological Society of Great Britain and Ireland.

Long-term unmet supportive care needs of teenage and young adult (TYA) childhood brain tumour survivors and their caregivers: a cross-sectional survey.

INTRODUCTION: The supportive care needs of long-term childhood brain tumour survivors, now teenagers and young adults (TYAs), and their caregivers are largely unknown. We aimed to describe their supportive care needs and explore associations between needs and quality of life (QoL). METHODS: Participants were recruited from long-term follow-up clinics (in three NHS Trusts in England) and online. Participants included childhood brain tumour survivors, ≥ 5 years from diagnosis, currently aged 13-30, and their primary caregivers. Survivors completed the Supportive Care Needs Survey (SCNS) Short Form and caregivers the SCNS-Partners & Caregivers, alongside validated QoL questionnaires (Peds-FACT-Br and CQOLC). RESULTS: In total, 112 individuals (69 survivors/43 caregivers) participated. Survivors reported on average 9.4 (± 8.5) unmet needs. Needs were greatest in the psychological domain, with anxiety (60.3%), uncertainty about the future (50.7%) and feeling down and depressed (48.5%) most commonly reported. Caregivers reported on average 12.4 (± 12.3) unmet needs. Again, the greatest number of unmet needs was observed in the psychological domain. Many caregivers also reported information needs around financial support/government benefits (42.9%) and possible survivor fertility problems (42.9%). Multivariable linear regression analysis showed that female survivors, unemployed survivors, survivors further away from diagnosis and single caregivers were more likely to report unmet needs. More unmet needs were significantly associated with poorer QoL in survivors and caregivers. CONCLUSION: This research provides leads to improving supportive care and long-term follow-up services. Psychological support represents the biggest gap in care. Understanding unmet needs and recognising what services are required are critical to improving quality of long-term survival.

Unmet support needs in teenage and young adult childhood brain tumour survivors and their caregivers: "it's all the aftermath, and then you're forgotten about".

PURPOSE: Teenage and young adult (TYA) survivors of childhood brain tumours and their family caregivers can experience many late effects of treatment that can hamper the transition to living independent lives. Yet, their long-term supportive care needs are largely unknown. We investigated the supportive care needs of TYA survivors and their caregivers and explored the role and perceived use of support. METHODS: Face-to-face semi-structured interviews were conducted with survivors aged 16-30 (n = 11) who were ≥ 5 years after diagnosis and caregivers (n = 11). Interviews were recorded and transcriptions thematically analysed. RESULTS: Four themes emerged: (1) preferences for support and support services (unmet needs). Concerns regarding mental health, employment and financial uncertainty, the desire to live independently, and lack of support were emphasised. (2) Decline in support. Caregivers noted a drop-off in support available when transitioning to adult services. (3) Reasons for not obtaining adequate support. Several barriers to accessing support were raised, including distance and aging out of services. (4) The role of long-term hospital-based follow-up care. Participants highlighted the importance of, and reassurance from, long-term follow-up care but noted a more all-inclusive approach is required. CONCLUSIONS: Even many years after diagnosis, TYA childhood brain tumour survivors and their caregivers continue to have unmet supportive care needs. Both TYA survivors and their caregivers can benefit from support to meet their unique needs and improve long-term quality of life. Understanding unmet needs and recognising what services are required due to the late effects of treatment is critical to improving long-term quality of survival.

The Impact of the COVID-19 Pandemic on Genitourinary Cancer Care: Re-envisioning the Future.

CONTEXT: The coronavirus disease 2019 (COVID-19) pandemic necessitated rapid changes in medical practice. Many of these changes may add value to care, creating opportunities going forward. OBJECTIVE: To provide an evidence-informed, expert-derived review of genitourinary cancer care moving forward following the initial COVID-19 pandemic. EVIDENCE ACQUISITION: A collaborative narrative review was conducted using literature published through May 2020 (PubMed), which comprised three main topics: reduced in-person interactions arguing for increasing virtual and image-based care, optimisation of the delivery of care, and the effect of COVID-19 in health care facilities on decision-making by patients and their families. EVIDENCE SYNTHESIS: Patterns of care will evolve following the COVID-19 pandemic. Telemedicine, virtual care, and telemonitoring will increase and could offer broader access to multidisciplinary expertise without increasing costs. Comprehensive and integrative telehealth solutions will be necessary, and should consider patients' mental health and access differences due to socioeconomic status. Investigations and treatments will need to maximise efficiency and minimise health care interactions. Solutions such as one stop clinics, day case surgery, hypofractionated radiotherapy, and oral or less frequent drug dosing will be preferred. The pandemic necessitated a triage of those patients whose treatment should be expedited, delayed, or avoided, and may persist with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in circulation. Patients whose demographic characteristics are at the highest risk of complications from COVID-19 may re-evaluate the benefit of intervention for less aggressive cancers. Clinical research will need to accommodate virtual care and trial participation. Research dissemination and medical education will increasingly utilise virtual platforms, limiting in-person professional engagement; ensure data dissemination; and aim to enhance patient engagement. CONCLUSIONS: The COVID-19 pandemic will have lasting effects on the delivery of health care. These changes offer opportunities to improve access, delivery, and the value of care for patients with genitourinary cancers but raise concerns that physicians and health administrators must consider in order to ensure equitable access to care. PATIENT SUMMARY: The coronavirus disease 2019 (COVID-19) pandemic has dramatically changed the care provided to many patients with genitourinary cancers. This has necessitated a transition to telemedicine, changes in threshold or delays in many treatments, and an opportunity to reimagine patient care to maintain safety and improve value moving forward.

Long-term issues and supportive care needs of adolescent and young adult childhood brain tumour survivors and their caregivers: A systematic review.

OBJECTIVE: Long-term issues following diagnosis and treatment of a childhood brain tumour often become apparent as the survivor enters adolescence and young adulthood. Their caregivers may additionally face long-term impacts on their emotional and psychological functioning. This review synthesised evidence on the issues and supportive care needs of adolescent and young adult (AYA) survivors of a brain tumour diagnosed in childhood and their caregivers. METHODS: Electronic databases were searched up until September 2017. All studies reporting on issues or needs of childhood brain tumour survivors (aged 14-39) and their caregivers were included. Narrative synthesis methods were used to summarise, integrate, and interpret findings. RESULTS: Fifty-six articles (49 studies) met the inclusion criteria. Social issues (ie, isolation and impaired daily functioning) were most commonly reported by survivors, followed by cognitive (ie, impaired memory and attention) and physical issues (ie, endocrine dysfunctions and fatigue). Survivors experienced poorer social functioning and sexual functioning and were less likely to be employed or have children, when compared with other AYA cancer survivors. Caregivers experienced reduced support as the survivor moved into young adulthood. Caregivers reported uncertainty, increased responsibilities, and problems maintaining their own self-well-being and family relationships. Few studies reported on supportive care needs. Survivors expressed a need for better educational support and age-specific psychosocial services. CONCLUSIONS: Surviving a childhood brain tumour can be particularly challenging for AYA survivors and their caregivers. Robust structured research is needed to identify specific support needs of both survivors and their caregivers and how these can be optimally addressed.

Treatment for erectile dysfunction among older men in Northern Ireland.

BACKGROUND: Erectile dysfunction is common among older men; however, diagnosis and treatment compared to reported prevalence is low. We aim to identify the degree to which older men are offered treatment for the condition and determine the level of unmet need within Northern Ireland (NI). METHODOLOGY: Analysis of data collected using a cross-sectional survey was conducted for men aged ≥60 years with data weighted to the NI population by age and deprivation. Respondents answered questions on sociodemographic factors, health-related characteristics, ability to function sexually, level of sexual interest and activity, and any treatment offered to improve erections in the last 3 years. Results are presented as proportions reporting treatment receipt, with differences by respondent characteristics assessed using chi-square tests and multivariable logistic regression. RESULTS: Among 2597 respondents, 46.5% reported erectile dysfunction. One quarter (25.8%) recalled being offered either medication, devices, or specialised services to improve erections. The offer of treatment was associated with younger age, being separated or divorced, higher number of long-term conditions, and greater interest in sex. Of men reporting erectile dysfunction and offered medication, 28.8% found them helpful and currently use them. CONCLUSIONS: As a result of not being offered treatment or not finding treatment useful, 93% of men reporting erectile dysfunction have no help with the condition. This is a likely consequence of treatment availability through the NHS in NI, but also suggests that healthcare professionals need to engage more proactively with older men, discussing sexual health routinely and following up those treated for the condition.

Beam and tissue factors affecting Cherenkov image intensity for quantitative entrance and exit dosimetry on human tissue.

This study's goal was to determine how Cherenkov radiation emission observed in radiotherapy is affected by predictable factors expected in patient imaging. Factors such as tissue optical properties, radiation beam properties, thickness of tissues, entrance/exit geometry, curved surface effects, curvature and imaging angles were investigated through Monte Carlo simulations. The largest physical cause of variation of the correlation ratio between of Cherenkov emission and dose was the entrance/exit geometry (˜50%). The largest human tissue effect was from different optical properties (˜45%). Beyond these, clinical beam energy varies the correlation ratio significantly (˜20% for X-ray beams), followed by curved surfaces (˜15% for X-ray beams and ˜8% for electron beams), and finally, the effect of field size (˜5% for X-ray beams). Other investigated factors which caused variations less than 5% were tissue thicknesses and source to surface distance. The effect of non-Lambertian emission was negligible for imaging angles smaller than 60 degrees. The spectrum of Cherenkov emission tends to blue-shift along the curved surface. A simple normalization approach based on the reflectance image was experimentally validated by imaging a range of tissue phantoms, as a first order correction for different tissue optical properties.

Life after prostate cancer diagnosis: protocol for a UK-wide patient-reported outcomes study.

BACKGROUND: Prostate cancer and its treatment may impact physically, psychologically and socially; affecting the health-related quality of life of men and their partners/spouses. The Life After Prostate Cancer Diagnosis (LAPCD) study is a UK-wide patient-reported outcomes study which will generate information to improve the health and well-being of men with prostate cancer. METHODS AND ANALYSIS: Postal surveys will be sent to prostate cancer survivors (18-42 months postdiagnosis) in all 4 UK countries (n=∼70 000). Eligible men will be identified and/or verified through cancer registration systems. Men will be surveyed twice, 12 months apart, to explore changes in outcomes over time. Second, separate cohorts will be surveyed once and the design will include evaluation of the acceptability of online survey tools. A comprehensive patient-reported outcome measure has been developed using generic and specific instruments with proven psychometric properties and relevance in national and international studies. The outcome data will be linked with administrative health data (eg, treatment information from hospital data). To ensure detailed understanding of issues of importance, qualitative interviews will be undertaken with a sample of men who complete the survey across the UK (n=∼150) along with a small number of partners/spouses (n=∼30). ETHICS AND DISSEMINATION: The study has received the following approvals: Newcastle and North Tyneside 1 Research Ethics Committee (15/NE/0036), Health Research Authority Confidentiality Advisory Group (15/CAG/0110), NHS Scotland Public Benefit and Privacy Panel (0516-0364), Office of Research Ethics Northern Ireland (16/NI/0073) and NHS R&D approval from Wales, Scotland and Northern Ireland. Using traditional and innovative methods, the results will be made available to men and their partners/spouses, the funders, the NHS, social care, voluntary sector organisations and other researchers.

Optical cone beam tomography of Cherenkov-mediated signals for fast 3D dosimetry of x-ray photon beams in water.

PURPOSE: To test the use of a three-dimensional (3D) optical cone beam computed tomography reconstruction algorithm, for estimation of the imparted 3D dose distribution from megavoltage photon beams in a water tank for quality assurance, by imaging the induced Cherenkov-excited fluorescence (CEF). METHODS: An intensified charge-coupled device coupled to a standard nontelecentric camera lens was used to tomographically acquire two-dimensional (2D) projection images of CEF from a complex multileaf collimator (MLC) shaped 6 MV linear accelerator x-ray photon beam operating at a dose rate of 600 MU/min. The resulting projections were used to reconstruct the 3D CEF light distribution, a potential surrogate of imparted dose, using a Feldkamp-Davis-Kress cone beam back reconstruction algorithm. Finally, the reconstructed light distributions were compared to the expected dose values from one-dimensional diode scans, 2D film measurements, and the 3D distribution generated from the clinical Varian ECLIPSE treatment planning system using a gamma index analysis. A Monte Carlo derived correction was applied to the Cherenkov reconstructions to account for beam hardening artifacts. RESULTS: 3D light volumes were successfully reconstructed over a 400 × 400 × 350 mm(3) volume at a resolution of 1 mm. The Cherenkov reconstructions showed agreement with all comparative methods and were also able to recover both inter- and intra-MLC leaf leakage. Based upon a 3%/3 mm criterion, the experimental Cherenkov light measurements showed an 83%-99% pass fraction depending on the chosen threshold dose. CONCLUSIONS: The results from this study demonstrate the use of optical cone beam computed tomography using CEF for the profiling of the imparted dose distribution from large area megavoltage photon beams in water.

Defining a standard set of patient-centered outcomes for men with localized prostate cancer.

BACKGROUND: Value-based health care has been proposed as a unifying force to drive improved outcomes and cost containment. OBJECTIVE: To develop a standard set of multidimensional patient-centered health outcomes for tracking, comparing, and improving localized prostate cancer (PCa) treatment value. DESIGN, SETTING, AND PARTICIPANTS: We convened an international working group of patients, registry experts, urologists, and radiation oncologists to review existing data and practices. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The group defined a recommended standard set representing who should be tracked, what should be measured and at what time points, and what data are necessary to make meaningful comparisons. Using a modified Delphi method over a series of teleconferences, the group reached consensus for the Standard Set. RESULTS AND LIMITATIONS: We recommend that the Standard Set apply to men with newly diagnosed localized PCa treated with active surveillance, surgery, radiation, or other methods. The Standard Set includes acute toxicities occurring within 6 mo of treatment as well as patient-reported outcomes tracked regularly out to 10 yr. Patient-reported domains of urinary incontinence and irritation, bowel symptoms, sexual symptoms, and hormonal symptoms are included, and the recommended measurement tool is the Expanded Prostate Cancer Index Composite Short Form. Disease control outcomes include overall, cause-specific, metastasis-free, and biochemical relapse-free survival. Baseline clinical, pathologic, and comorbidity information is included to improve the interpretability of comparisons. CONCLUSIONS: We have defined a simple, easily implemented set of outcomes that we believe should be measured in all men with localized PCa as a crucial first step in improving the value of care. PATIENT SUMMARY: Measuring, reporting, and comparing identical outcomes across treatments and treatment centers will provide patients and providers with information to make informed treatment decisions. We defined a set of outcomes that we recommend being tracked for every man being treated for localized prostate cancer.

Cherenkov excited phosphorescence-based pO2 estimation during multi-beam radiation therapy: phantom and simulation studies.

Megavoltage radiation beams used in External Beam Radiotherapy (EBRT) generate Cherenkov light emission in tissues and equivalent phantoms. This optical emission was utilized to excite an oxygen-sensitive phosphorescent probe, PtG4, which has been developed specifically for NIR lifetime-based sensing of the partial pressure of oxygen (pO2). Phosphorescence emission, at different time points with respect to the excitation pulse, was acquired by an intensifier-gated CCD camera synchronized with radiation pulses delivered by a medical linear accelerator. The pO2 distribution was tomographically recovered in a tissue-equivalent phantom during EBRT with multiple beams targeted from different angles at a tumor-like anomaly. The reconstructions were tested in two different phantoms that have fully oxygenated background, to compare a fully oxygenated and a fully deoxygenated inclusion. To simulate a realistic situation of EBRT, where the size and location of the tumor is well known, spatial information of a prescribed region was utilized in the recovery estimation. The phantom results show that region-averaged pO2 values were recovered successfully, differentiating aerated and deoxygenated inclusions. Finally, a simulation study was performed showing that pO2 in human brain tumors can be measured to within 15 mmHg for edge depths less than 10-20 mm using the Cherenkov Excited Phosphorescence Oxygen imaging (CEPhOx) method and PtG4 as a probe. This technique could allow non-invasive monitoring of pO2 in tumors during the normal process of EBRT, where beams are generally delivered from multiple angles or arcs during each treatment fraction.

Video-rate optical dosimetry and dynamic visualization of IMRT and VMAT treatment plans in water using Cherenkov radiation.

PURPOSE: A novel technique for optical dosimetry of dynamic intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans was investigated for the first time by capturing images of the induced Cherenkov radiation in water. METHODS: A high-sensitivity, intensified CCD camera (ICCD) was configured to acquire a two-dimensional (2D) projection image of the Cherenkov radiation induced by IMRT and VMAT plans, based on the Task Group 119 (TG-119) C-Shape geometry. Plans were generated using the Varian Eclipse treatment planning system (TPS) and delivered using 6 MV x-rays from a Varian TrueBeam Linear Accelerator (Linac) incident on a water tank doped with the fluorophore quinine sulfate. The ICCD acquisition was gated to the Linac target trigger pulse to reduce background light artifacts, read out for a single radiation pulse, and binned to a resolution of 512 × 512 pixels. The resulting videos were analyzed temporally for various regions of interest (ROI) covering the planning target volume (PTV) and organ at risk (OAR), and summed to obtain an overall light intensity distribution, which was compared to the expected dose distribution from the TPS using a gamma-index analysis. RESULTS: The chosen camera settings resulted in 23.5 frames per second dosimetry videos. Temporal intensity plots of the PTV and OAR ROIs confirmed the preferential delivery of dose to the PTV versus the OAR, and the gamma analysis yielded 95.9% and 96.2% agreement between the experimentally captured Cherenkov light distribution and expected TPS dose distribution based upon a 3%/3 mm dose difference and distance-to-agreement criterion for the IMRT and VMAT plans, respectively. CONCLUSIONS: The results from this initial study demonstrate the first documented use of Cherenkov radiation for video-rate optical dosimetry of dynamic IMRT and VMAT treatment plans. The proposed modality has several potential advantages over alternative methods including the real-time nature of the acquisition, and upon future refinement may prove to be a robust and novel dosimetry method with both research and clinical applications.

Optical dosimetry of radiotherapy beams using Cherenkov radiation: the relationship between light emission and dose.

Recent studies have proposed that light emitted by the Cherenkov effect may be used for a number of radiation therapy dosimetry applications. There is a correlation between the captured light and expected dose under certain conditions, yet discrepancies have also been observed and a complete examination of the theoretical differences has not been done. In this study, a fundamental comparison between the Cherenkov emission and absorbed dose was explored for x-ray photons, electrons, and protons using both a theoretical and Monte Carlo-based analysis. Based on the findings of where dose correlates with Cherenkov emission, it was concluded that for x-ray photons the light emission would be optimally suited for narrow beam stereotactic radiation therapy and surgery validation studies, for verification of dynamic intensity-modulated and volumetric modulated arc therapy treatment plans in water tanks, near monoenergetic sources (e.g., Co-60 and brachy therapy sources) and also for entrance and exit surface imaging dosimetry of both narrow and broad beams. For electron use, Cherenkov emission was found to be only suitable for surface dosimetry applications. Finally, for proton dosimetry, there exists a fundamental lack of Cherenkov emission at the Bragg peak, making the technique of little use, although post-irradiation detection of light emission from radioisotopes could prove to be useful.

Superficial dosimetry imaging based on Cerenkov emission for external beam radiotherapy with megavoltage x-ray beam.

PURPOSE: Cerenkov radiation emission occurs in all tissue, when charged particles (either primary or secondary) travel at velocity above the threshold for the Cerenkov effect (about 220 KeV in tissue for electrons). This study presents the first examination of optical Cerenkov emission as a surrogate for the absorbed superficial dose for MV x-ray beams. METHODS: In this study, Monte Carlo simulations of flat and curved surfaces were studied to analyze the energy spectra of charged particles produced in different regions near the surfaces when irradiated by MV x-ray beams. Cerenkov emission intensity and radiation dose were directly simulated in voxelized flat and cylindrical phantoms. The sampling region of superficial dosimetry based on Cerenkov radiation was simulated in layered skin models. Angular distributions of optical emission from the surfaces were investigated. Tissue mimicking phantoms with flat and curved surfaces were imaged with a time domain gating system. The beam field sizes (50 × 50-200 × 200 mm(2)), incident angles (0°-70°) and imaging regions were all varied. RESULTS: The entrance or exit region of the tissue has nearly homogeneous energy spectra across the beam, such that their Cerenkov emission is proportional to dose. Directly simulated local intensity of Cerenkov and radiation dose in voxelized flat and cylindrical phantoms further validate that this signal is proportional to radiation dose with absolute average discrepancy within 2%, and the largest within 5% typically at the beam edges. The effective sampling depth could be tuned from near 0 up to 6 mm by spectral filtering. The angular profiles near the theoretical Lambertian emission distribution for a perfect diffusive medium, suggesting that angular correction of Cerenkov images may not be required even for curved surface. The acquisition speed and signal to noise ratio of the time domain gating system were investigated for different acquisition procedures, and the results show there is good potential for real-time superficial dose monitoring. Dose imaging under normal ambient room lighting was validated, using gated detection and a breast phantom. CONCLUSIONS: This study indicates that Cerenkov emission imaging might provide a valuable way to superficial dosimetry imaging in real time for external beam radiotherapy with megavoltage x-ray beams.

Health care policy and cancer survivorship.

The United States and the European Union (EU) vary widely in approaches to ensuring affordable health care coverage for our respective populations. Such variations stem from differences in the political systems and beliefs regarding social welfare. These variations are also reflected in past and future initiatives to provide high quality cancer survivorship care. The United States spends considerably more on health care compared to most European countries, often with no proven benefit. In the United States, individuals with chronic illnesses, such as cancer survivors, often experience difficulties affording insurance and maintaining coverage, a problem unknown to EU countries with national health insurance. This article reviews health policy development over time for the United States and EU and the impact for cancer survivors. For the United States, the impact of the Affordable Care Act on improving access to affordable care for cancer survivors is highlighted. For the EU, the importance of multiple-morbidity disease management, cancer plan development, and pan-European data collection for monitoring cancer outcomes is addressed. Given predicted workforce shortages and ever-increasing numbers of aging cancer survivors on both sides of the Atlantic, sharing lessons learned will be critical.

A GAMOS plug-in for GEANT4 based Monte Carlo simulation of radiation-induced light transport in biological media.

We describe a tissue optics plug-in that interfaces with the GEANT4/GAMOS Monte Carlo (MC) architecture, providing a means of simulating radiation-induced light transport in biological media for the first time. Specifically, we focus on the simulation of light transport due to the Cerenkov effect (light emission from charged particle's traveling faster than the local speed of light in a given medium), a phenomenon which requires accurate modeling of both the high energy particle and subsequent optical photon transport, a dynamic coupled process that is not well-described by any current MC framework. The results of validation simulations show excellent agreement with currently employed biomedical optics MC codes, [i.e., Monte Carlo for Multi-Layered media (MCML), Mesh-based Monte Carlo (MMC), and diffusion theory], and examples relevant to recent studies into detection of Cerenkov light from an external radiation beam or radionuclide are presented. While the work presented within this paper focuses on radiation-induced light transport, the core features and robust flexibility of the plug-in modified package make it also extensible to more conventional biomedical optics simulations. The plug-in, user guide, example files, as well as the necessary files to reproduce the validation simulations described within this paper are available online at http://www.dartmouth.edu/optmed/research-projects/monte-carlo-software.

Projection imaging of photon beams by the Cerenkov effect.

PURPOSE: A novel technique for beam profiling of megavoltage photon beams was investigated for the first time by capturing images of the induced Cerenkov emission in water, as a potential surrogate for the imparted dose in irradiated media. METHODS: A high-sensitivity, intensified CCD camera (ICCD) was configured to acquire 2D projection images of Cerenkov emission from a 4 × 4 cm(2) 6 MV linear accelerator (LINAC) x-ray photon beam operating at a dose rate of 400 MU∕min incident on a water tank with transparent walls. The ICCD acquisition was gated to the LINAC sync pulse to reduce background light artifacts, and the measurement quality was investigated by evaluating the signal to noise ratio and measurement repeatability as a function of delivered dose. Monte Carlo simulations were used to derive a calibration factor for differences between the optical images and deposited dose arising from the anisotropic angular dependence of Cerenkov emission. Finally, Cerenkov-based beam profiles were compared to a percent depth dose (PDD) and lateral dose profile at a depth of d(max) from a reference dose distribution generated from the clinical Varian ECLIPSE treatment planning system (TPS). RESULTS: The signal to noise ratio was found to be 20 at a delivered dose of 66.6 cGy, and proportional to the square root of the delivered dose as expected from Poisson photon counting statistics. A 2.1% mean standard deviation and 5.6% maximum variation in successive measurements were observed, and the Monte Carlo derived calibration factor resulted in Cerenkov emission images which were directly correlated to deposited dose, with some spatial issues. The dose difference between the TPS and PDD predicted by Cerenkov measurements was within 20% in the buildup region with a distance to agreement (DTA) of 1.5-2 mm and ±3% at depths beyond d(max). In the lateral profile, the dose difference at the beam penumbra was within ±13% with a DTA of 0-2 mm, ±5% in the central beam region, and 2%-3% in the beam umbra. CONCLUSIONS: The results from this initial study demonstrate the first documented use of Cerenkov emission imaging to profile x-ray photon LINAC beams in water. The proposed modality has several potential advantages over alternative methods, and upon future refinement may prove to be a robust and novel dosimetry method.