A Phase 2 Study of In Situ Oncolytic Virus Therapy and Stereotactic Body Radiation Therapy Followed by Pembrolizumab in Metastatic Non-Small Cell Lung Cancer

PURPOSE

A phase 2 study of stereotactic body radiation therapy (SBRT) and in situ oncolytic virus therapy in metastatic non-small cell lung cancer (mNSCLC) followed by pembrolizumab (STOMP) was designed to explore the dual approach in enhancing single pembrolizumab with ADV/HSV-tk plus valacyclovir gene therapy and SBRT in mNSCLC.

METHODS AND MATERIALS

STOMP is a single-arm, open-label phase 2 study. Patients with mNSCLC received intratumoral injections of ADV/HSV-tk (5 × 1011 vp) and SBRT (30 Gy in 5 fractions) followed by pembrolizumab 200 mg IV every 3 weeks until disease progression or intolerable toxicity. The primary endpoint was overall response rate (ORR) (complete response [CR] and partial response [PR]). Secondary endpoints included clinical benefit rate (CBR) (CR, PR and stable disease [SD]), progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

28 patients were enrolled, of whom 27 were evaluated for response. The ORR was 33.3%, including 2 CR (7.4%) and 7 PR (25.9%). CBR was 70.4%. Six of eight (75.0%) patients who were immune checkpoint inhibitor (ICI) refractory derived clinical benefits. Responders had durable responses with median PFS, and OS not reached. The entire cohort had a median PFS of 7.4 months (95% CI, 5.1-9.6 months), and median OS of 18.1 months (95% CI, 15.4-20.9 months). The combination was well tolerated, with grade 3 or higher toxicity in 6 (21.4%) patients.

CONCLUSIONS

The dual approach of in situ ADV/HSV-tk plus valacyclovir gene therapy and SBRT as a chemotherapy-sparing strategy to enhance the antitumor effect of pembrolizumab is a well-tolerated encouraging treatment in patients with mNSCLC.

348 WHAT IS THE OLDER PATIENT’S VIEW ON RECEIVING DETAILED MEDICAL LETTERS?

Background

Sending copies of clinic letters to patients involves additional work for medical staff in formatting letters, administrative staff in printing and posting and is an added cost to the healthcare service. Though seen largely as good practice in some specialities, it is not done routinely in Geriatric medical services. We introduced this practice as standard in our service and wished to evaluate whether from the patient perspective, it is worthwhile.

Methods

We sent a questionnaire to n=80 older patients who were evaluated in the home setting (by the Integrated Care Team for Older People – ICTOP) or recently attended CGA (Comprehensive Geriatric Assessment) clinic or FLS (Fracture Liaison Service) clinic. We asked their opinion on the detailed medical letter sent to their General Practitioner (GP), which they received a copy of. The questionnaire could be completed by patient/carer/relative, and returned anonymously.

Results

N=30/80 were returned. Two said they found the letter difficult to understand; 1/30 said the letter caused them to worry but all said they still preferred that they had received it. N= 2 said they would like to have contributed to the letter for accuracy. All said they felt they should receive copies of all their medical correspondence. Free text comments showed overwhelming support for the process, in allowing them to self-manage their health, enhance communication with other healthcare professionals and was a useful document to refer back to when they are trying to process information during short consultations.

Conclusion

Though a small survey and limited by low response rate, older people expressed high levels of satisfaction in receiving copies of medical letters about their health. It supports the ongoing practice and should be adopted widely.

Fracture liaison services in Ireland-how do we compare to international standards?

In this first na tional survey of public hospitals in The Republic of Ireland, we found fracture liaison services (FLS) to be heterogeneous, limited in many cases and poorly supported. A national strategy is urgently needed to support the implementation and operation of an FLS, and thus help reduce the burden of fragility fractures for patients and the healthcare system.

INTRODUCTION

Fragility/low-trauma fractures are a global concern, whose incidence is rising as the population ages. Many are preventable, and people with a prior fragility fracture are at particularly high risk of further fractures. This patient group is the target of the International Osteoporosis Foundation (IOF) Capture the Fracture campaign, advocating global adoption of fracture liaison services (FLS), with the aim of preventing secondary fragility fractures. We wished to determine the current availability and standards of an FLS in Ireland, ahead of the launch of a National FLS database.

METHODS

We devised a questionnaire encompassing the thirteen IOF standards for an FLS and asked all 16 public hospitals with an orthopaedic trauma unit in Ireland, to complete for the calendar year 2019 in patients aged ≥ 50 years.

RESULTS

All sites returned the questionnaire, i.e. 100% response rate. Nine hospitals stated that they have an FLS, additionally one non-trauma hospital running a FLS responded, and were included. These 10 FLS had identified and managed 3444 non-hip fractures in the year 2019. This figure represents 19% of the expected non-hip fragility fracture numbers occurring annually in Ireland. Implementation of the IOF standards was very variable. All sites reported being inadequately resourced to provide a high-quality service necessary to be effective.

CONCLUSION

The existence and functioning of FLS in Ireland are heterogeneous and suboptimal. A national policy to support the implementation of this programme in line with international standards of patient care is urgently needed.

Making decisions about antipsychotics: a qualitative study of patient experience and the development of a decision aid

BACKGROUND

Shared decision making is a widely accepted standard of patient-centred care that leads to improved clinical outcomes, yet it is commonly underutilised in the field of mental health. Furthermore, little is known regarding patient decision making around antipsychotic medication, which is often poorly adhered to. We aim to explore psychiatric patients' experiences of antipsychotic medication decision making in order to develop a patient decision aid to promote shared decision making.

METHODS

Focus groups were conducted with patients with chronic psychotic illnesses (n = 20) who had previously made a decision about taking or changing antipsychotic medication. Transcripts were coded and analysed for thematic content and continued until thematic saturation. These themes subsequently informed the development of a decision aid with the help of expert guidance. Further patient input was sought using the think aloud method (n = 3).

RESULTS

Twenty-three patients participated in the study. Thematic analysis revealed that 'adverse effects' was the most common theme identified by patients surrounding antipsychotic medication decision-making followed by 'mode and time of administration', 'symptom control' and 'autonomy'. The final decision aid is included to provoke further discussion and development of such aids.

CONCLUSIONS

Patients commonly report negative experiences of antipsychotic medication, in particular side-effects, which remain critical to future decision making around antipsychotic medication. Clinical encounters that increase patient knowledge and maximise autonomy in order to prevent early negative experiences with antipsychotic medication are likely to be beneficial.

Corticosteroids and risk of gastrointestinal bleeding in critically ill adults: Protocol for a systematic review

BACKGROUND

Corticosteroids are frequently prescribed to critically ill patients. However, their use may increase the risk of gastrointestinal (GI) bleeding, which is associated with morbidity and mortality. Accordingly, we aim to assess whether continued administration of corticosteroids for >24 hours increases the rate of GI bleeding in adult critically ill patients compared to placebo or no treatment.

METHODS/DESIGN

We will conduct a systematic review of randomized clinical trials with meta-analysis and trial sequential analysis. The participants will be adult (as defined in the included trials) critically ill patients. The intervention will be any corticosteroid administered systematically for >24 hours and the comparator will be placebo or no treatment. The primary outcome will be rate of clinically important GI bleeding. We will systematically search EMBASE, MEDLINE, Medline In-Process, Cochrane Library, Epistemonikos and trial registries for relevant literature, as well as perform a hand search. We will follow the recommendations by the Cochrane Collaboration and the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. The risk of systematic errors (bias) and random errors will be assessed and the overall quality of evidence will be evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

DISCUSSION

The risk of GI bleeding in adult critically ill patients treated with corticosteroids is unknown. Hence, there is need for a robust systematic review to assess this risk and provide clinicians with a clearer understanding of the strength and limitations of existing data.

Disentangling the relationship between sedentariness and obesity: Activity intensity, but not sitting posture, is associated with adiposity in women

BACKGROUND

The relationship between free-living sedentary behaviour (SB) and obesity is unclear. Studies may arrive at disparate conclusions because of inconsistencies and limitations when defining and measuring free-living SB. The aim of this cross-sectional study was to examine whether the relationship between SB and adiposity differed depending on the way SB was operationally defined and objectively measured.

METHODS

Sixty-three female participants aged 37.1 years (SD = 13.6) with a body mass index (BMI) of 29.6 kg/m² (SD = 4.7) had their body composition measured (BodPod, Concord, CA) then were continuously monitored for 5-7 days with the SenseWear Armband (SWA; sleep and activity intensity) and the activPAL (AP; posture). Data from both activity monitors were analysed separately and integrated resulting in a third measure of SB (activity intensity and posture; SED^INT). SB outputs were compared according to week or weekend day averages then correlated against body composition parameters after adjusting for moderate-to-vigorous physical activity (MVPA).

RESULTS

SED^SWA resulted in the most sedentary time 11.74 h/day (SD = 1.60), followed by SED^AP 10.16 h/day (SD = 1.75) and SED^INT 9.10 h/day (SD = 1.67). There was a significant positive association between SED^SWA and body mass [r(61) = 0.29, p = .02], BMI [r (61) = 0.33, p = .009] and fat mass [r(61) = 0.32, p = .01]. SED^AP and SED^INT were not associated with any of the indices of adiposity. Correlations between SB and adiposity were non-significant when controlling for MVPA.

CONCLUSIONS

The relationship between SB and adiposity differed depending on how SB was operationally defined and measured, and was dependent on MVPA. The definition of SB based on a sitting posture (SED^AP) was not strongly related to body fat, whereas the accumulation of any behaviour (sitting or standing) with an intensity of <1.5 METs (SED^SWA) (offset by the presence of MVPA) was positively associated with indices of adiposity. These data suggest that the postural element of SB (sitting) is not sufficient for the accumulation of adiposity, rather activities requiring low EE (<1.5 METs) and the absence of MVPA, regardless of posture, are associated with higher fat mass.

Cerebrovascular autoregulation monitoring and patient-centred outcomes after cardiac surgery: a systematic review

BACKGROUND

Impaired cerebrovascular autoregulation (CVAR) is observed in up to 20% of cardiac surgical patients. This systematic review aims to evaluate the association between impaired CVAR, measured by current monitoring techniques, and patient-centred outcomes in adults following cardiac surgery.

METHODS

MEDLINE, EMBASE, PubMed, MEDLINE In-Process and Cochrane Library were systematically searched through 8 December 2017. Studies were included if they assessed associations between CVAR and patient-centred outcomes in the adult cardiac surgical population. The primary outcome of this systematic review was mortality. Secondary outcomes were stroke, delirium and acute kidney injury. Risk of bias was systematically assessed, and the GRADE methodology was used to evaluate the quality of evidence across outcomes.

RESULTS

Eleven observational studies and no randomised controlled trials met the inclusion criteria. Due to methodological heterogeneity, meta-analysis was not possible. There was a high risk of bias within individual studies and low quality of evidence across outcomes. Of the included studies, one assessed mortality, five assessed stroke, four assessed delirium, and three assessed acute kidney injury. No reliable conclusions can be drawn from the one study assessing mortality. Interpretation of studies investigating CVAR and stroke, delirium and acute kidney injury was complicated by the lack of standardisation of monitoring techniques as well as varying definitions of impaired CVAR.

CONCLUSIONS

There is a paucity of high quality evidence for CVAR monitoring and its associations with outcome measures in post-cardiac surgical patients, highlighting the need for future studies.

Erratum: Observation of the hyperfine spectrum of antihydrogen

This corrects the article DOI: 10.1038/nature23446.

A novel integrative procedure for identifying and integrating three-dimensions of objectively measured free-living sedentary behaviour

BACKGROUND

The widely accepted definition of sedentary behaviour [SB] refers to any waking behaviour characterized by an energy expenditure ≤1.5 metabolic equivalents [METs] while in a sitting or reclining posture. At present, there is no single field-based device which objectively measures sleep, posture and activity intensity simultaneously. The aim of this study was to develop a novel integrative procedure [INT] to combine information from two validated activity monitors on sleep, activity intensity and posture, the three key dimensions of SB.

METHODS

Participants in this analysis were initially recruited from a series of three studies conducted between December 2014 and June 2016 at the University of Leeds. Sixty-three female participants aged 37.1 (13.6) years with a body mass index of 29.6 (4.7) kg/m² were continuously monitored for 5-7 days with the SenseWear Armband [SWA] (sleep and activity intensity) and the activPAL [AP] (posture). Data from both activity monitors were analysed separately and integrated resulting in three measures of sedentary time. Differences in Sedentary time between the three measurement methods were assessed as well as how well the three measures correlated.

RESULTS

The three measures of sedentary time were positively correlated, with the weakest relationship between SED^SWA (awake and <1.5 METs) and SED^AP (awake and sitting/lying posture) [r(61) = .37,p = .003], followed by SED^SWA and SED^INT (awake, <1.5 METs and sitting/lying posture) [r(61) = .58,p < .001], and the strongest relationship was between SED^AP and SED^INT [r(61) = .91,p < .001]. There was a significant difference between the three measures of sedentary time [F(1.18,73.15) = 104.70,p < .001]. Post-hoc tests revealed all three methods differed significantly from each other [p < .001]. SED^SWA resulted in the most sedentary time 11.74 (1.60) hours/day, followed by SED^AP 10.16 (1.75) hours/day, and SED^INT 9.10 (1.67) hours/day. Weekday and weekend day sedentary time did not differ for any of the measurement methods [p = .04-.25].

CONCLUSION

Information from two validated activity monitors was combined to obtain an objective measure of free-living SB based on posture and activity intensity during waking hours. The amount of sedentary time accumulated varied according to the definition of SB and its measurement. The novel data integration and processing procedures presented in this paper represents an opportunity to investigate whether different components of SB are differentially related to health end points.

Observation of the hyperfine spectrum of antihydrogen

The observation of hyperfine structure in atomic hydrogen by Rabi and co-workers and the measurement of the zero-field ground-state splitting at the level of seven parts in 10¹³ are important achievements of mid-twentieth-century physics. The work that led to these achievements also provided the first evidence for the anomalous magnetic moment of the electron, inspired Schwinger's relativistic theory of quantum electrodynamics and gave rise to the hydrogen maser, which is a critical component of modern navigation, geo-positioning and very-long-baseline interferometry systems. Research at the Antiproton Decelerator at CERN by the ALPHA collaboration extends these enquiries into the antimatter sector. Recently, tools have been developed that enable studies of the hyperfine structure of antihydrogen-the antimatter counterpart of hydrogen. The goal of such studies is to search for any differences that might exist between this archetypal pair of atoms, and thereby to test the fundamental principles on which quantum field theory is constructed. Magnetic trapping of antihydrogen atoms provides a means of studying them by combining electromagnetic interaction with detection techniques that are unique to antimatter. Here we report the results of a microwave spectroscopy experiment in which we probe the response of antihydrogen over a controlled range of frequencies. The data reveal clear and distinct signatures of two allowed transitions, from which we obtain a direct, magnetic-field-independent measurement of the hyperfine splitting. From a set of trials involving 194 detected atoms, we determine a splitting of 1,420.4 ± 0.5 megahertz, consistent with expectations for atomic hydrogen at the level of four parts in 10⁴. This observation of the detailed behaviour of a quantum transition in an atom of antihydrogen exemplifies tests of fundamental symmetries such as charge-parity-time in antimatter, and the techniques developed here will enable more-precise such tests.

Antihydrogen accumulation for fundamental symmetry tests

Antihydrogen, a positron bound to an antiproton, is the simplest anti-atom. Its structure and properties are expected to mirror those of the hydrogen atom. Prospects for precision comparisons of the two, as tests of fundamental symmetries, are driving a vibrant programme of research. In this regard, a limiting factor in most experiments is the availability of large numbers of cold ground state antihydrogen atoms. Here, we describe how an improved synthesis process results in a maximum rate of 10.5 ± 0.6 atoms trapped and detected per cycle, corresponding to more than an order of magnitude improvement over previous work. Additionally, we demonstrate how detailed control of electron, positron and antiproton plasmas enables repeated formation and trapping of antihydrogen atoms, with the simultaneous retention of atoms produced in previous cycles. We report a record of 54 detected annihilation events from a single release of the trapped anti-atoms accumulated from five consecutive cycles.

Antihydrogen studies are important in testing the fundamental principles of physics but producing antihydrogen in large amounts is challenging. Here the authors demonstrate an efficient and high-precision method for trapping and stacking antihydrogen by using controlled plasma.

An experimental limit on the charge of antihydrogen

The properties of antihydrogen are expected to be identical to those of hydrogen, and any differences would constitute a profound challenge to the fundamental theories of physics. The most commonly discussed antiatom-based tests of these theories are searches for antihydrogen-hydrogen spectral differences (tests of CPT (charge-parity-time) invariance) or gravitational differences (tests of the weak equivalence principle). Here we, the ALPHA Collaboration, report a different and somewhat unusual test of CPT and of quantum anomaly cancellation. A retrospective analysis of the influence of electric fields on antihydrogen atoms released from the ALPHA trap finds a mean axial deflection of 4.1 ± 3.4 mm for an average axial electric field of 0.51 V mm(-1). Combined with extensive numerical modelling, this measurement leads to a bound on the charge Qe of antihydrogen of Q=(-1.3 ± 1.1 ± 0.4) × 10(-8). Here, e is the unit charge, and the errors are from statistics and systematic effects.

Isolation of viable Neospora caninum from brains of wild gray wolves (Canis lupus)

Neospora caninum is a common cause of abortion in cattle worldwide. Canids, including the dog and the dingo (Canis familiaris), the coyote (Canis latrans), and the gray wolf (Canis lupus) are its definitive hosts that can excrete environmentally resistant oocysts in the environment, but also can act as intermediate hosts, harboring tissue stages of the parasite. In an attempt to isolate viable N. caninum from tissues of naturally infected wolves, brain and heart tissue from 109 wolves from Minnesota were bioassayed in mice. Viable N. caninum (NcWolfMn1, NcWolfMn2) was isolated from the brains of two wolves by bioassays in interferon gamma gene knockout mice. DNA obtained from culture-derived N. caninum tachyzoites of the two isolates were analyzed by N. caninum-specific Nc5 polymerase chain reaction and confirmed diagnosis. This is the first report of isolation of N. caninum from tissues of any wild canid host.

Abstract P5-14-06: Outcomes in 500 patients from a large, retrospective study of APBI with a strut-based breast brachytherapy applicator

Purpose/Objectives:

The SAVI Collaborative Research Group (SCRG) is a coalition of 14 institutions who have retrospectively compiled a large database of APBI patients treated with a strut-based brachytherapy device (SAVI). This report details the findings of statistical correlations between numerous dosimetric variables and cosmetic outcome.

Materials/Methods:

The SCRG study enrolled 1005 patients. A subset of patients with complete dosimetry and more than 1 year of follow-up by a radiation oncologist were analyzed for toxicity, cosmesis and recurrence/survival. Dosimetric parameters were tabulated for patients, including: V90, V95, V100, V150, V200, skin spacing (skin-bridge), maximum skin dose, tumor size, PTV-Eval volume and applicator size (model). Toxicity (e.g., telangiectasia, fibrosis, fat necrosis, seroma) were graded by physicians for patients with at least 1 year of follow-up (up to 6 years) using the CTCAE v3 Scale and fat necrosis using a simplified CTCAE scale (Grade 1 asymptomatic but seen on imaging, grade 2 symptomatic without intervention, & grade 3 required intervention).

Results:

Median follow up in this cohort was 29.2 months (range 2.4 to 72.2 months). Follow up was &gt;2 yr and &gt;3 yr for 323 and 191 subjects, respectively. Overall, in 500 subjects the late toxicity (grade ≥2) rates were less than 5% during follow up: telangiectasia 1.0%, fibrosis 4.1%, seroma 2.9% and fat necrosis 0.6%. Cosmesis was reported at various post-APBI follow-up visits following treatment completion (6, 12, 24, 36, 48 & 60+ months). For the 6 and 12 month intervals, 98% (n = 122) and 97% (n = 262) were reported excellent or good (E/G), respectively. At 24, 36, 48 and 60 month intervals, the E/G rates were 93% (n = 184), 90% (n = 98), 100% (n = 41) and 94% (n = 15), respectively. The raw rates of ipsilateral breast tumor recurrence (IBTR) and TR/MM were 1.6% (n = 8) and 1.2% (n = 6), respectively, in 500 patients with &gt;1 year of follow up. The 1- and 2-year actuarial rates of overall survival and disease-free survival were: 1-year, 99.6% & 99.4%, resp. and 2-year, 99.2% & 96.7%.

Conclusions:

APBI treatment with the strut-based applicators was well-tolerated, demonstrated low toxicity rates, favorable cosmetic outcomes and excellent local control over the follow-up to date. Patients with challenging breast anatomy were successfully treated with strut-based devices.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-14-06.

Autoresonant-spectrometric determination of the residual gas composition in the ALPHA experiment apparatus

Knowledge of the residual gas composition in the ALPHA experiment apparatus is important in our studies of antihydrogen and nonneutral plasmas. A technique based on autoresonant ion extraction from an electrostatic potential well has been developed that enables the study of the vacuum in our trap. Computer simulations allow an interpretation of our measurements and provide the residual gas composition under operating conditions typical of those used in experiments to produce, trap, and study antihydrogen. The methods developed may also be applicable in a range of atomic and molecular trap experiments where Penning-Malmberg traps are used and where access is limited.

Description and first application of a new technique to measure the gravitational mass of antihydrogen

Physicists have long wondered whether the gravitational interactions between matter and antimatter might be different from those between matter and itself. Although there are many indirect indications that no such differences exist and that the weak equivalence principle holds, there have been no direct, free-fall style, experimental tests of gravity on antimatter. Here we describe a novel direct test methodology; we search for a propensity for antihydrogen atoms to fall downward when released from the ALPHA antihydrogen trap. In the absence of systematic errors, we can reject ratios of the gravitational to inertial mass of antihydrogen >75 at a statistical significance level of 5%; worst-case systematic errors increase the minimum rejection ratio to 110. A similar search places somewhat tighter bounds on a negative gravitational mass, that is, on antigravity. This methodology, coupled with ongoing experimental improvements, should allow us to bound the ratio within the more interesting near equivalence regime.

The effect of triclosan on microbial community structure in three soils

The application of sewage sludge to land can expose soils to a range of associated chemical toxicants. In this paper we explore the effects of the broad spectrum anti-microbial compound triclosan on the phenotypic composition of the microbial communities of three soils of contrasting texture (loamy sand, sandy loam and clay) using phospholipid fatty-acid (PLFA) analysis. Each soil type was dosed and subsequently re-dosed 6 weeks later with triclosan at five nominal concentrations in microcosms (10, 100, 500, 1000 mg kg(-1) and a zero-dose control). PLFA profiles were analysed using multivariate statistics focussing on changes in the soil phenotypic community structure. Additionally, ratios of fungal:bacterial PLFA indicators and cyclo:mono-unsaturated PLFAs (a common stress indicator) were calculated. It was hypothesised that triclosan addition would alter the community structure in each soil with a particular effect on the fungal:bacterial ratio, since bacteria are likely to be more susceptible to triclosan than fungi. It was also hypothesised that the PLFA response to re-dosing would be suppressed due to acclimation. Although the microbial community structure changed over the course of the experiment, the response was complex. Soil type and time emerged as the most important explanatory factors. Principal component analysis was used to detect phenotypic responses to different doses of triclosan in each soil. As expected, there was a significant increase in the fungal:bacterial ratio with triclosan dose especially in treatments with the highest nominal concentrations. Furthermore, the PLFA response to re-dosing was negligible in all soils confirming the acclimation hypothesis.

Fate of triclosan in field soils receiving sewage sludge

The anti-microbial substance triclosan can partition to sewage sludge during wastewater treatment and subsequently transfer to soil when applied to land. Here, we describe the fate of triclosan in a one-year plot experiment on three different soils receiving sludge. Triclosan and methyl-triclosan concentrations were measured in soil samples collected monthly from three depths. A large fraction of triclosan loss appeared to be explained by transformation to methyl-triclosan. After 12 months less than 20% of the initial triclosan was recovered from each soil. However, the majority was recovered as methyl-triclosan. Most of the chemical recovered at the end of the experiment (both triclosan and methyl-triclosan) was still in the top 10 cm layer, although there was translocation to lower soil horizons in all three soils. Between 16.5 and 50.6% of the applied triclosan was unaccounted for after 12 months either as a consequence of degradation or the formation of non-extractable residues.

Resonant quantum transitions in trapped antihydrogen atoms

The hydrogen atom is one of the most important and influential model systems in modern physics. Attempts to understand its spectrum are inextricably linked to the early history and development of quantum mechanics. The hydrogen atom's stature lies in its simplicity and in the accuracy with which its spectrum can be measured and compared to theory. Today its spectrum remains a valuable tool for determining the values of fundamental constants and for challenging the limits of modern physics, including the validity of quantum electrodynamics and--by comparison with measurements on its antimatter counterpart, antihydrogen--the validity of CPT (charge conjugation, parity and time reversal) symmetry. Here we report spectroscopy of a pure antimatter atom, demonstrating resonant quantum transitions in antihydrogen. We have manipulated the internal spin state of antihydrogen atoms so as to induce magnetic resonance transitions between hyperfine levels of the positronic ground state. We used resonant microwave radiation to flip the spin of the positron in antihydrogen atoms that were magnetically trapped in the ALPHA apparatus. The spin flip causes trapped anti-atoms to be ejected from the trap. We look for evidence of resonant interaction by comparing the survival rate of trapped atoms irradiated with microwaves on-resonance to that of atoms subjected to microwaves that are off-resonance. In one variant of the experiment, we detect 23 atoms that survive in 110 trapping attempts with microwaves off-resonance (0.21 per attempt), and only two atoms that survive in 103 attempts with microwaves on-resonance (0.02 per attempt). We also describe the direct detection of the annihilation of antihydrogen atoms ejected by the microwaves.

Centrifugal separation and equilibration dynamics in an electron-antiproton plasma

Charges in cold, multiple-species, non-neutral plasmas separate radially by mass, forming centrifugally separated states. Here, we report the first detailed measurements of such states in an electron-antiproton plasma, and the first observations of the separation dynamics in any centrifugally separated system. While the observed equilibrium states are expected and in agreement with theory, the equilibration time is approximately constant over a wide range of parameters, a surprising and as yet unexplained result. Electron-antiproton plasmas play a crucial role in antihydrogen trapping experiments.

Autoresonant excitation of antiproton plasmas

We demonstrate controllable excitation of the center-of-mass longitudinal motion of a thermal antiproton plasma using a swept-frequency autoresonant drive. When the plasma is cold, dense, and highly collective in nature, we observe that the entire system behaves as a single-particle nonlinear oscillator, as predicted by a recent theory. In contrast, only a fraction of the antiprotons in a warm plasma can be similarly excited. Antihydrogen was produced and trapped by using this technique to drive antiprotons into a positron plasma, thereby initiating atomic recombination.

Evaporative cooling of antiprotons to cryogenic temperatures

We report the application of evaporative cooling to clouds of trapped antiprotons, resulting in plasmas with measured temperature as low as 9 K. We have modeled the evaporation process for charged particles using appropriate rate equations. Good agreement between experiment and theory is observed, permitting prediction of cooling efficiency in future experiments. The technique opens up new possibilities for cooling of trapped ions and is of particular interest in antiproton physics, where a precise CPT test on trapped antihydrogen is a long-standing goal.

The Triple Threat of Recurrence after Breast Conserving Therapy: Race, Receptor Status and Age

PurposeThe purpose of this study is to evaluate the impact of race, receptor status, and age on recurrence in patients undergoing breast conserving therapy (BCT).MethodsThe study population consisted of 510 primary invasive female breast cancer patients (excluding Stage IV), who resided in Fulton-Dekalb counties, in Atlanta, GA. These patients were diagnosed in 2003-2004 and treated within the Emory University Affiliated Hospitals. Data was obtained from the SEER cancer registry and augmented with medical record abstraction. Median follow-up was 3.5 and 4.4 years for recurrence and survival, respectively. Breast tumors were categorized as either triple negative (TN), which were estrogen, progesterone, and Her2-neu receptor negative tumors, versus (vs) non-TN, all other possible iterations. Women were evaluated for recurrence and death by TN status, race (African American (AA) vs Caucasian (C)), age, grade, tumor size, nodal status, socioeconomic status (SES), and receipt of chemotherapy. Both recurrence and survival were evaluated using chi-square, fisher exact, and cox regression analyses, p ≤ 0.05 significance.ResultsOf the 510 women, 193 received BCT. Of the 193, 92% completed radiation therapy and 45% received chemotherapy. Of the 184 women with known recurrence status, 11 recurred locally, 11 distantly, and none regionally. Compared to patients with non-TN tumors, TN patients had significantly higher local (13% vs 5%) and distant (16% vs 4%) recurrence rates. AA women had non-significant higher local recurrence than C women (7% vs 4%) and a higher distant recurrence rate (8% vs 3%). Finally, compared to women ≥50 years old, women age &lt;50 had a significantly higher local and distant recurrence rates, (13% vs 4%) and (9% vs 5%) respectively.Unadjusted hazard ratios (HR) and 95% confidence intervals (CI) for any recurrence were calculated: TN status (HR=2.8, 95%CI 1.2-6.5), AA race (HR=2.3, 95% CI 0.9-5.8), age &lt;50 years (HR= 2.3, 95%CI 1.0-5.1), grade 2/3 vs 1 (HR=2.3, 95%CI 1.0-5.1), and chemotherapy receipt (HR=3.0, 95%CI 1.2-7.4). Factors that were highly non-statistically significant included stage, tumor size, nodal status, and SES.In a multivariate model including receptor status, race, and age results were similar (HR = 2.5, 2.1, and 2.1 respectively). When tumor size, nodal status, grade, SES, and chemotherapy status were included in the previous model, only AA race independently predicted recurrence (HR=3.4, 95%CI 1.1-11.1), while TN status demonstrated a trend (HR=1.9, 95%CI 0.8-5.7).In survival analyses, neither TN status, AA race, nor age &lt;50 years predicted outcome in any of the models described above. However, TN status did show a trend for significance (HR=2.6, 95%CI 0.8-9.0).ConclusionWe observed that there was a significant increase in local and distant metastatic recurrence rates after BCT among patients diagnosed with TN breast cancers, AA women, and women &lt;50 years old. In contrast, we did not observe differences in survival, with the exception of TN breast cancers. This study suggests that among women who receive BCT, current standard radiation and systemic therapies may not be adequate in preventing recurrence among women with TN breast cancers, of AA race, or younger age.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6045.

Antiproton, positron, and electron imaging with a microchannel plate/phosphor detector

A microchannel plate (MCP)/phosphor screen assembly has been used to destructively measure the radial profile of cold, confined antiprotons, electrons, and positrons in the ALPHA experiment, with the goal of using these trapped particles for antihydrogen creation and confinement. The response of the MCP to low energy (10-200 eV, <1 eV spread) antiproton extractions is compared to that of electrons and positrons.

Compression of antiproton clouds for antihydrogen trapping

Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report the first detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile and its relation to that of the electron plasma.