Single-Dose Radiation Therapy Without Additional Surgery as a Treatment for Heterotopic Ossification Developing After Transfemoral Amputation

ABSTRACT

Heterotopic ossification is the development of mature lamellar bone in soft tissues. Heterotopic ossification can occur in up to 23% of patients after amputation. Heterotopic ossification is often painful, causing significant dysfunction. While radiotherapy is used to prevent heterotopic ossification before formation, there is a dearth of literature on using radiotherapy to treat existing heterotopic ossification. This case report describes the use of late radiotherapy for the management of existing heterotopic ossification that developed after a transfemoral amputation. A 61-yr-old woman with peripheral artery disease of her bilateral lower limbs status post stenting and ultimately left transfemoral amputation was diagnosed with symptomatic heterotopic ossification limiting her function. Another surgery was not felt to be warranted. She was not improving with medical therapy and was prescribed 800 cGy in one fraction. After treatment, she experienced significant relief in her pain, allowing her to resume physical therapy and use of her prosthesis. There are no other published examples of using radiation alone for treatment of heterotopic ossification formation after transfemoral amputation without surgical revision of the bone formation. Our case shows possible utility in single-dose radiation as a treatment to prevent progression of heterotopic ossification, especially when limiting functional progress.

INNV-03. DEVELOPMENT OF A NOVEL DUAL-MODALITY BALLOON IMPLANT FOR SIMULTANEOUS HIGH-DOSE-RATE BRACHYTHERAPY AND MAGNETIC NANOPARTICLE HYPERTHERMIA OF BRAIN TUMOR RESECTION CAVITIES

PURPOSE

To develop a novel thermobrachytherapy (TBT) balloon implant that delivers hyperthermia and radiation simultaneously, with three specific aims: 1) to fabricate a prototype TBT balloon device; 2) to verify compatibility of all heating and radiation delivery components and evaluate heat and radiation dosimetry in full size skull/brain phantom models; and 3) to characterize in vivo heating patterns in pig brain.

METHODS

Five 3cm diameter TBT balloons were fabricated. Each balloon has two layers: an inner layer to be filled with saline to expand the resection cavity, and an outer layer to be filled with magnetic nanoparticle (MNP) solution to absorb energy from an external magnetic field hence generate heat. The balloon shaft houses 4 ports to fill inner and outer layers, insert a high-dose-rate brachytherapy source into the balloon center, and a fiber optic sensor into the outer layer to monitor and control balloon temperature. A 3D-printed skull phantom was filled with brain tissue-equivalent gel for in-phantom measurements of heating around a TBT balloon. Optically stimulated luminescent dosimeters and Gafchromic film were used to measure radiation dose; while motorized temperature probes placed in catheters were inserted in surrounding gel for thermal mapping. For in vivo experiments, a 1cm balloon was specifically fabricated for pigs 40-50 kg.

RESULTS

The presence of MNP, magnetic field, and 43-55°C heating did not affect radiation dose significantly. Thermal mapping demonstrated spherically symmetric heating in both phantom and in vivo brain tissue, where a higher concentration of MNP and stronger magnetic field of 1.6-4.5 kA/m at 133 kHz was used to achieve temperatures of 55°C in the much smaller balloon.

CONCLUSION

Novel dual-modality balloons have been fabricated and tested successfully in the lab and in vivo, hence providing crucial information to validate thermal modeling for combined heat and radiation treatment of brain tumor resection cavities.

MRI-Guided Focused Ultrasound of Osseous Metastases: Treatment Parameters Associated With Successful Pain Reduction

BACKGROUND

A phase 3 multicenter trial demonstrated that magnetic resonance imaging (MRI)-guided focused ultrasound (US) is a safe, noninvasive treatment that alleviated pain from bone metastases. However, outcomes varied among institutions (from 0%-100% treatment success).

PURPOSE

The aim of this study was to identify patient selection, technical treatment, and imaging parameters that predict successful pain relief of osseous metastases after MRI-guided focused US.

MATERIALS AND METHODS

This was a secondary analysis of a phase 3 clinical study that included participants who received MRI-guided focused US treatment for painful osseous metastases. Noncontrast CT was obtained before treatment. T2-weighted and T1-weighted postcontrast MRIs at 1.5 T or 3 T were obtained before, at the time of, and at 3 months after treatment. Numerical Rating Scale pain scores and morphine equivalent daily dose data were obtained over a 3-month follow-up period. At the 3-month endpoint, participants were categorized as pain relief responders or nonresponders based on Numerical Rating Scale and morphine equivalent daily dose data. Demographics, technical parameters, and imaging features associated with pain relief were determined using stepwise univariable and multivariable models. Responder rates between the subgroup of participants with all predictive parameters and that with none of the parameters were compared using Fisher exact test.

RESULTS

The analysis included 99 participants (mean age, 59 ± 14 years; 56 women). The 3 variables that predicted successful pain relief were energy density on the bone surface (EDBS) (P = 0.001), the presence of postprocedural periosteal devascularization (black band, BB+) (P = 0.005), and female sex (P = 0.02). The subgroup of participants with BB+ and EDBS greater than 5 J/mm2 had a larger decrease in mean pain score (5.2; 95% confidence interval, 4.6-5.8) compared with those without (BB-, EDBS ≤ 5 J/mm2) (1.1; 95% confidence interval, 0.8-3.0; P < 0.001). Participants with all 3 predictive variables had a pain relief responder rate of 93% compared with 0% in participants having none of the predictive variables (P < 0.001).

CONCLUSIONS

High EDBS during treatment, postprocedural periosteal devascularization around the tumor site (BB+), and female sex increased the likelihood of pain relief after MRI-guided focused US of osseous metastasis.

The multidisciplinary clinic approach for bladder cancer treatment in the neoadjuvant therapy era

475

Background: As urologic oncology becomes increasingly complex, the coordination of optimal and efficient care to patients can be challenging. Within our institution, we initiated a multidisciplinary center (MDC) comprised of urology, oncology and radiation oncology in 1996 to help meet these needs. The positive benefits of this approach have been demonstrated in other settings, but outcomes related to bladder cancer remain unclear, especially in the era of neoadjuvant (NA) therapy. Methods: Patients with localized or node positive muscle invasive bladder cancer (MIBC) without prior treatment were obtained from available multidisciplinary appointment records, dating from 7/5/17 to 9/25/19. Charts were then retrospectively reviewed to gather demographic data, treatment data, and pathological outcomes. Results: 66 patients fitting study criteria were identified. Average age was 71.3 years. 45 (68%) patients from this cohort were deemed to be radical cystectomy (RC) candidates, with 37 RC operations completed at time of record review. Of RC-eligible patients, 35/45 (77%) had received NA therapy, either in the form of neoadjuvant chemotherapy (NAC) and/or immunotherapy (NAI). 3 patients declined RC after receiving NAC. 15 patients underwent chemoradiation treatment (23%), while 7 (11%) underwent supportive care without definitive treatment. Downstaging at RC from MIBC (<=T1) was seen in 12/37 patients (32%), with a pT0 rate of 10% (4/37). Conclusions: The coordination of care in bladder cancer remains a challenge for patients and physicians alike. We believe by utilizing a multidisciplinary approach, efficiency and quality of care increases. National database studies have reported overall utilization of neoadjuvant chemotherapy over the past 10 years, with most recent rates ranging from 14.8-20.9%. Our utilization of neoadjuvant therapy is notably higher at 77%, which also includes early adaptation of NAI in patients deemed ineligible for neoadjuvant NAC. Further studies are needed to examine a contemporary control population outside the multidisciplinary setting, however the above outcomes provide a basis for the integration of care and its positive outcomes in quality improvement.

Pathways impact on OCM drug cost

109

Background: Oncology care, including drugs, represents a significant portion of US healthcare spending. Cost of Part B drugs has increased at a rate 5.7x that of overall Medicare spending (1997-2004). As a participant in the Oncology Care Model (OCM), we found drug costs represent a majority of our total costs. To reduce treatment (Tx) variability, our NCI-designated cancer center chose to implement pathways. Pathways are a clinical decision-support tool that use evidence-based care maps accounting for efficacy, toxicity and cost. At one institution, use of pathways contributed to $15k in savings for stage IV lung cancer Tx. We hypothesized pathway driven Tx standardization would favorably impact total chemotherapy (CTx) costs at the implementation site. Methods: In July 2018, we implemented pathways in Medical and Radiation Oncology for new starts or changes in Tx. Oncologists accessed the tool through our EMR, selected and placed orders for Tx. OCM quarterly data was used to compare 2 quarters immediately pre- and post-pathway implementation. The cancer-mix-adjusted Per-Member-Per-Month (PMPM) Allowed Amounts for CTx were compared between 3 groups; patients on-pathway, patients off-pathway and patients for which the pathways tool was not used (no utilization). PMPMs were evaluated pre- and post-implementation and an ANOVA test was used to evaluate significance of the difference between the two periods. Results: PMPM CTx costs decreased 4.6% between pre- and post-pathway implementation when oncologists followed pathways. By comparison, the off-pathway cohort and the no utilization groups had increases of 0.9% and 17.7% respectively. An evaluation of cost difference proved significant (p < .0001). Breast patients on-pathway had a cost decrease of 20%, compared to increases of 32% and 11% for off-pathway and no utilization groups, respectively. Conclusions: Pathway use reduced variation, a known contributor to healthcare costs, and therefore may be an effective cost control tool. Additional quarters of claims data is needed post-implementation to fully define the impact of pathways on total cost.

[Table: see text]

Operation and performance of the ATLAS Tile Calorimeter in Run 1

The Tile Calorimeter is the hadron calorimeter covering the central region of the ATLAS experiment at the Large Hadron Collider. Approximately 10,000 photomultipliers collect light from scintillating tiles acting as the active material sandwiched between slabs of steel absorber. This paper gives an overview of the calorimeter's performance during the years 2008-2012 using cosmic-ray muon events and proton-proton collision data at centre-of-mass energies of 7 and 8 TeV with a total integrated luminosity of nearly 30 fb - 1 . The signal reconstruction methods, calibration systems as well as the detector operation status are presented. The energy and time calibration methods performed excellently, resulting in good stability of the calorimeter response under varying conditions during the LHC Run 1. Finally, the Tile Calorimeter response to isolated muons and hadrons as well as to jets from proton-proton collisions is presented. The results demonstrate excellent performance in accord with specifications mentioned in the Technical Design Report.

Presence of atopy increases the risk of asthma relapse

OBJECTIVES

To describe the point prevalence of respiratory viruses/atypical bacteria using PCR and evaluate the impact of respiratory viruses/atypical bacteria and atopy on acute severity and clinical recovery in children with hospitalised and non-hospitalised asthma exacerbations.

DESIGN

This was a prospective study performed during 2009-2011.

SETTING

The study was performed in the emergency departments of two hospitals.

PATIENTS

244 children aged 2-16 years presenting with acute asthma to the emergency departments were recruited. A nasopharyngeal aspirate and allergen skin prick test were performed.

MAIN OUTCOME MEASURES

The outcomes were divided into (1) acute severity outcomes (Australian National Asthma Council assessment, hospitalisation, Functional Severity Scale, Acute Asthma Score, asthma quality of life questionnaires for parents (PACQLQ) on presentation, asthma diary scores (ADS) on presentation and length of hospitalisation) and (2) recovery outcomes (PACQLQ for 21 days, ADS for 14 days and representation for asthma for 21 days).

RESULTS

PCR for viruses/atypical bacteria was positive in 81.7% of children (75.1% human rhinovirus, codetection in 14.2%). Mycoplasma pneumoniae and Chlamydophila pneumoniae were rarely detected. The presence of micro-organisms had little impact on acute asthma or recovery outcomes. Children with atopy were significantly more likely to relapse and represent for medical care by day 14 (OR 1.11, 95% CI 1.00 to 1.23).

CONCLUSIONS

The presence of any viruses is associated with asthma exacerbations but does not appear to influence asthma recovery. In contrast, atopy is associated with asthma relapse. M. pneumoniae and C. pneumoniae are rare triggers of acute asthma in young children.

Can post-operative prostate fossa radiation be omitted in patients with high-risk features using a genomic classifier?

101

Background: At our institution, based upon the AUA/ASTRO guidelines, discussion of adjuvant radiation therapy (ART) for patients with adverse pathologic features (APF) (pT3/positive margins) occurs in a multidisciplinary setting. We had previously offered ART to approximately 50% of these patients. We describe our evaluation of Decipher genomic testing to select patients to offer observation following prostatectomy (RP). Methods: Since March 2014, patients at Thomas Jefferson University with APF and undetectable post-operative PSA underwent Decipher genomic testing. Collectively, we decided to offer observation with salvage radiation therapy (SRT) for patients with low or intermediate risk Decipher scores. The primary outcome of this analysis was biochemical progression free survival (bPFS) with failure defined as a PSA ≥0.1 ng/mL. Results: From March of 2014 through September of 2016, 47 patients met the above criteria. The median patient age was 64 and median follow up was 16 months. Median pre-treatment PSA was 6.0 ng/mL (2.94 to 22.7 ng/mL). With regard to pathologic stage: 19% had T2c, 68% had T3a, and 13% had T3b disease. Pathologic Gleason grouping was 6%, 49%, 34%, 6%, and 4% for groups 1-5, respectively. 51% of patients had positive margins, 36% had lymph-vascular space invasion, and 53% had perineural invasion. Four patients received ART and 1 patient was lost to follow up after his initial visit. Of the remaining 42 patients, 3 patients experienced biochemical failure at 8, 27, and 44 months. Conclusions: This is the first prospective report utilizing Decipher genomic testing to stratify men with undetectable PSA and adverse pathologic features into an observation cohort following RP. Despite the stringency of our definition of biochemical failure, our observed bPFS was 87% at 3 years. Historically, in an unselected population the 3 year bPFS was 90% in those receiving ART and 65% in those receiving SRT. While these initial findings are promising, longer follow up is warranted. Our findings demonstrate the utility of genomic classifiers in patient selection and provide a safe approach to reducing over treatment in the post RP setting.

Long-term outcomes of magnetic resonance image-guided partial prostate brachytherapy for favorable-risk prostate cancer

138

Background: To report long-term outcomes of magnetic resonance image-guided partial prostate brachytherapy of the peripheral zone. Methods: We conducted an institutional-board approved retrospective review of all men who underwent 0.5 Tesla GE Signa SP MRI-guided partial prostate brachytherapy to the peripheral zone. We estimated actuarial rates of biochemical progression (nadir +2 definition), as well as cumulative incidences of biopsy proven local recurrence, distant metastasis, and prostate cancer specific mortality. Fine and Gray’s competing risk regression was utilized in order to evaluate clinical factors associated with times to metastasis and prostate cancer specific mortality. Results: Between 1997 and 2008, 354 men underwent MRI-guided partial prostate brachytherapy. The numbers of patients with low and intermediate risk disease were 295 (83%) and 59 (17%), respectively. Sixty-seven (19%) patients received supplemental external beam radiotherapy. The median follow-up was 8.6 years. For National Cancer Center Network (NCCN) low risk-disease, 8-year estimates of biochemical progression, local recurrence, metastasis, and prostate cancer specific mortality were 23.5% (17.4-29.1), 6.4% (3.6-10.2), 2.0% (0.6-4.8), and 0%. Corresponding estimates for intermediate risk disease were 51.2% (31.3-65.4), 21.2% (10.2-34.9), 6.6% (1.7-16.3), and 5.4% (0.9-16.2). Twenty of 45 biopsy proven local recurrences occurred outside of the implanted peripheral zone. Of the 22 patients who developed distant metastases, 14 events occurred more than 10 years from therapy. On multivariate analyses, biopsy proven local recurrence was the only factor to demonstrate a significant association with metastasis (hazard ratio 2.50; p = 0.05) and a trend with prostate cancer specific mortality (5.02; p = 0.09). Conclusions: MRI-guided partial prostate brachytherapy to the peripheral zone in men with favorable risk prostate cancer is suboptimal with respect to long term cancer control outcomes. Additional studies using contemporary MRI techniques including 3 Tesla based multi-parametric imaging and fusion biopsy may lead to improved outcomes.

The epidemiology of tuberculosis in the Australia Capital Territory, 2006-2015

AIM

To review the epidemiology of tuberculosis (TB) in the Australian Capital Territory (ACT) over a 10 year period. Methods: A retrospective analysis of the ACT TB notification data from 1 January 2006 to 31 December 2015 was conducted.

RESULTS

Over the 10 year study period there were 171 TB notifications in the ACT, with an increasing trend in the number of notifications over time. The median age of cases was 36 years (range 14 to 91 years) and 53.8% of cases were male. Most TB cases (84.2%) were born overseas. Among Australian-born cases the most common risk factor for acquiring TB was close/household contact with a known case of TB (30.8%). The most common risk factor in the overseas-born population was past travel or residence in a high-risk country (86.9%). Of all the TB cases notified, 82.4% successfully completed treatment.

CONCLUSION

There was an increasing trend in the number of TB notifications in the ACT over the study period. The highest rate of TB notifications remained in the overseas-born population; with other studies suggesting this is commonly due to reactivation of latent tuberculosis infection (LTBI). As Australia starts working towards TB elimination, options for the screening and management of LTBI, especially in high risk populations, need to be explored.

An exploratory study to investigate the immunomodulatory activity of radiation therapy in combination with pembrolizumab in patients with renal cell cancer

e16058

Background: Preclinical data suggest there are synergistic effects of radiation therapy (RT) and check point inhibitors in anticancer immunity. The primary objective of this study was to explore the immunomodulatory activity of RT alone or in combination with Pembrolizumab (pembro) in solid tumors including renal cell cancer (RCC) patients (pts). Methods: RCC pts who progressed after at least one front-line therapy were eligible. Pts were treated with either RT (8Gy x 1 or 4Gy x 5) followed by (f/b)pembro or 1 dose pembro f/b RT f/b pembro. Pre- and post RT tumor biopsy was obtained to evaluate PD-L1 expression (assay by QualTeck). Immune markers from peripheral blood before, during, and after treatment were analyzed using flow cytometry. Treatment response was measured based on modified RECIST criteria. Results: Twelve RCC patients were enrolled including 2 with non-clear cell subtype. One pt was not evaluable since pt quickly deteriorated and was taken off study. As of January 13, 2017, 2 pts are still on active treatment. Two pts had partial response (18%) and were on study for at 54 and 63 weeks. One responder was treated with 8 Gy f/b pembro while 1 was treated with 1 dose pembro f/b RT f/b pembro. Five pts had stable disease of 18 to 45 weeks and 4 pts (36%, non-responders) had progression in 9 weeks. For adverse events, 1 pt developed grade 3 pneumonitis after 10 cycles of pembro (RT to adrenal mets). Grade 3 AEs include Fatigue, Nausea, Hyperglycemia, Lymphopenia, thrombocytopenia and AST elevation (post RT for liver mets). PDL1 expression and tumor infiltrating lymphocytes presence after RT showed various patterns. Preliminary flow cytometry showed persistent higher numbers of monocytes in non-responders comparing with responders. CD4+, CD8+ and NK cells and other markers are under analyzed and the results will be presented. Conclusions: The combination of RT (8Gy or 20Gy) with pembro is feasible and tolerated, and demonstrates clinical activity. The AE profile is similar to single agent pembro. Monocytes, T and NK cell kinetics are being examined. (ClinicalTrials.gov ID: NCT02318771) Clinical trial information: NCT02318771.

Sleep apnea prevalence in chronic kidney disease - association with total body water and symptoms

Background

Sleep apnea is common and associated with poor outcome in severe chronic kidney disease, but validated screening tools are not available. Our objectives were to determine the prevalence of sleep apnea in this population, to assess the validity of screening for sleep apnea using an ApneaLink device and to investigate the relationship of sleep apnea to; symptoms, spirometry and body water.

Methods

Patients with glomerular filtration rate ≤30 mL/min/1.73 m², whether or not they were receiving haemodialysis, were eligible for enrolment. Participants completed symptom questionnaires, performed an ApneaLink recording and had total body water measured using bioimpedance. This was followed by a multi-channel polysomnography recording which is the gold-standard diagnostic test for sleep apnea.

Results

Fifty-seven participants were enrolled and had baseline data collected, of whom only 2 did not have sleep apnea. An apnea hypopnea index ≥30/h was found in 66% of haemodialysis and 54% of non-dialysis participants. A central apnea index ≥5/h was present in 11 patients, with only one dialysis patient having predominantly central sleep apnea. ApneaLink underestimated sleep apnea severity, particularly in the non-dialysis group. Neither total body water corrected for body size, spirometry, subjective sleepiness nor overall symptom scores were associated with sleep apnea severity.

Conclusions

This study demonstrates a very high prevalence of severe sleep apnea in patients with chronic kidney disease. Sleep apnea severity was not associated with quality of life or sleepiness scores and was unrelated to total body water corrected for body size. Routine identification of sleep apnea with polysomnography rather than screening is more appropriate in this group due to the high prevalence.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0544-3) contains supplementary material, which is available to authorized users.

An exploratory study to investigate the immunomodulatory activity of radiation therapy in combination with pembrolizumab in patients with renal cell cancer

518

Background: Preclinical data suggest there are synergistic effects of radiation therapy (RT) and check point inhibitors in anticancer immunity. The primary objective of this study was to explore the immunomodulatory activity of RT alone or in combination with Pembrolizumab (pembro) in solid tumors including renal cell cancer (RCC) patients (pts). Methods: RCC pts who progressed after at least one front-line therapy were eligible. Pts were treated with either RT (8Gy x 1 or 4Gy x 5) followed by (f/b) pembro or 1 dose pembro f/b RT f/b pembro. Pre- and post RT tumor biopsy was obtained to evaluate PD-L1 expression (assay by QualTeck). Immune markers from peripheral blood before, during, and after treatment were analyzed using flow cytometry. Treatment response was measured based on modified RECIST criteria. Results: 12 RCC patients were enrolled including 2 with non-clear cell subtype. One pt was not evaluable since pt quickly deteriorated and was taken off study. As of September 30, 2016, 5 pts were still on study with 3 pts having partial response (27.2%, responders) and were on study for at least 9.8 months. 2 responders were treated with 8 Gy f/b pembro while 1 was treated with pembro f/b RT f/b pembro. Six pts (54.5%, non-responders) had PFS between 2 – 4 m and were off study. For adverse events, 1 pt developed grade 4 pneumonitis after 10 cycles of pembro (RT to adrenal mets). Grade 3 AEs include fatigue, nausea, hyperglycemia, lymphopenia, thrombocytopenia, and AST elevation (post RT for liver mets). PDL1 expression and tumor infiltrating lymphocytes presence after RT showed various patterns. Preliminary flow cytometry showed persistent higher numbers of monocytes in non-responders compared with responders. CD4+, CD8+, and NK cells and other markers are under-analyzed and the results will be presented. Conclusions: The combination of RT (8Gy or 20Gy) with pembro is feasible and tolerated, and demonstrates clinical activity. The AE profile is similar to single agent pembro. Monocytes, T, and NK cell kinetics are being examined. Clinical trial information: NCT02318771.

Evaluating the effect of therapy duration on survival in patients with metastatic castration-resistant prostate cancer receiving radium-223

e593

Background: The use of radium-223 in patients with metastatic castration-resistant prostate cancer (mCRPC) improves overall survival (OS) and quality of life. Combination of radium-223 with second-generation anti-androgens has further improved OS; however, the optimal length of radium-223 treatment for maximal effect remains unknown. Methods: We reviewed 35 consecutive patients with mCRPC who received radium-223 from December 2012 to August 2015 at Thomas Jefferson University. Patients were divided into two groups: those who received full treatment of 6 injections (n = 18) versus those who received less than 6 injections (n = 17). Kaplan-Meier analysis of OS were tested for difference by treatment group using Log Rank test. Univariable association with survival outcomes was calculated with univariable Cox regression and Log Rank tests. Results: Mean age was 73 ± 10 years and Karnofsky performance status (KPS) ranged from 50-90 (median, 80). Median follow-up was 13.9 months. Eighteen patients were receiving concurrent second generation anti-androgens at the start of treatment. Median OS was 12 months for patients who received 6 injections and 6.48 months for patients who received less than 6 injections (p = 0.0045). The results of univariate Cox regression analysis revealed full treatment was associated with increased OS (p = 0.0013). On multivariate analysis accounting for KPS, full treatment was significantly associated with improved OS (p = 0.0028). Conclusions: In this retrospective, single-institution analysis, we demonstrated that full course completion of radium-223 was associated with improved OS in patients with mCRPC. These patients should be optimally supported during treatment to allow for therapy completion.

Measurement of the centrality dependence of the charged-particle pseudorapidity distribution in proton-lead collisions at [Formula: see text] TeV with the ATLAS detector

The centrality dependence of the mean charged-particle multiplicity as a function of pseudorapidity is measured in approximately 1 [Formula: see text]b[Formula: see text] of proton-lead collisions at a nucleon-nucleon centre-of-mass energy of [Formula: see text] [Formula: see text] using the ATLAS detector at the Large Hadron Collider. Charged particles with absolute pseudorapidity less than 2.7 are reconstructed using the ATLAS pixel detector. The [Formula: see text] collision centrality is characterised by the total transverse energy measured in the Pb-going direction of the forward calorimeter. The charged-particle pseudorapidity distributions are found to vary strongly with centrality, with an increasing asymmetry between the proton-going and Pb-going directions as the collisions become more central. Three different estimations of the number of nucleons participating in the [Formula: see text] collision have been carried out using the Glauber model as well as two Glauber-Gribov inspired extensions to the Glauber model. Charged-particle multiplicities per participant pair are found to vary differently for these three models, highlighting the importance of including colour fluctuations in nucleon-nucleon collisions in the modelling of the initial state of [Formula: see text] collisions.

Two-particle Bose-Einstein correlations in pp collisions at [Formula: see text] 0.9 and 7 TeV measured with the ATLAS detector

The paper presents studies of Bose-Einstein Correlations (BEC) for pairs of like-sign charged particles measured in the kinematic range [Formula: see text] 100 MeV and [Formula: see text] 2.5 in proton collisions at centre-of-mass energies of 0.9 and 7 TeV with the ATLAS detector at the CERN Large Hadron Collider. The integrated luminosities are approximately 7 [Formula: see text]b[Formula: see text], 190 [Formula: see text]b[Formula: see text] and 12.4 nb[Formula: see text] for 0.9 TeV, 7 TeV minimum-bias and 7 TeV high-multiplicity data samples, respectively. The multiplicity dependence of the BEC parameters characterizing the correlation strength and the correlation source size are investigated for charged-particle multiplicities of up to 240. A saturation effect in the multiplicity dependence of the correlation source size parameter is observed using the high-multiplicity 7 TeV data sample. The dependence of the BEC parameters on the average transverse momentum of the particle pair is also investigated.

Identification and energy calibration of hadronically decaying tau leptons with the ATLAS experiment in pp collisions at [Formula: see text][Formula: see text]

This paper describes the trigger and offline reconstruction, identification and energy calibration algorithms for hadronic decays of tau leptons employed for the data collected from pp collisions in 2012 with the ATLAS detector at the LHC center-of-mass energy [Formula: see text] [Formula: see text]. The performance of these algorithms is measured in most cases with [Formula: see text] decays to tau leptons using the full 2012 dataset, corresponding to an integrated luminosity of 20.3 fb[Formula: see text]. An uncertainty on the offline reconstructed tau energy scale of 2-4 %, depending on transverse energy and pseudorapidity, is achieved using two independent methods. The offline tau identification efficiency is measured with a precision of 2.5 % for hadronically decaying tau leptons with one associated track, and of 4 % for the case of three associated tracks, inclusive in pseudorapidity and for a visible transverse energy greater than 20 [Formula: see text]. For hadronic tau lepton decays selected by offline algorithms, the tau trigger identification efficiency is measured with a precision of 2-8 %, depending on the transverse energy. The performance of the tau algorithms, both offline and at the trigger level, is found to be stable with respect to the number of concurrent proton-proton interactions and has supported a variety of physics results using hadronically decaying tau leptons at ATLAS.

Observation and measurements of the production of prompt and non-prompt [Formula: see text] mesons in association with a [Formula: see text] boson in [Formula: see text] collisions at [Formula: see text] with the ATLAS detector

The production of a [Formula: see text] boson in association with a [Formula: see text] meson in proton-proton collisions probes the production mechanisms of quarkonium and heavy flavour in association with vector bosons, and allows studies of multiple parton scattering. Using [Formula: see text] of data collected with the ATLAS experiment at the LHC in [Formula: see text] collisions at [Formula: see text], the first measurement of associated [Formula: see text] production is presented for both prompt and non-prompt [Formula: see text] production, with both signatures having a significance in excess of [Formula: see text]. The inclusive production cross-sections for [Formula: see text] boson production (analysed in [Formula: see text] or [Formula: see text] decay modes) in association with prompt and non-prompt [Formula: see text] are measured relative to the inclusive production rate of [Formula: see text] bosons in the same fiducial volume to be [Formula: see text] and [Formula: see text] respectively. Normalised differential production cross-section ratios are also determined as a function of the [Formula: see text] transverse momentum. The fraction of signal events arising from single and double parton scattering is estimated, and a lower limit of [Formula: see text] at [Formula: see text] confidence level is placed on the effective cross-section regulating double parton interactions.

Measurement of three-jet production cross-sections in [Formula: see text] collisions at 7 [Formula: see text] centre-of-mass energy using the ATLAS detector

Double-differential three-jet production cross-sections are measured in proton-proton collisions at a centre-of-mass energy of [Formula: see text] using the ATLAS detector at the large hadron collider. The measurements are presented as a function of the three-jet mass [Formula: see text], in bins of the sum of the absolute rapidity separations between the three leading jets [Formula: see text]. Invariant masses extending up to 5  TeV are reached for [Formula: see text]. These measurements use a sample of data recorded using the ATLAS detector in 2011, which corresponds to an integrated luminosity of [Formula: see text]. Jets are identified using the anti-[Formula: see text] algorithm with two different jet radius parameters, [Formula: see text] and [Formula: see text]. The dominant uncertainty in these measurements comes from the jet energy scale. Next-to-leading-order QCD calculations corrected to account for non-perturbative effects are compared to the measurements. Good agreement is found between the data and the theoretical predictions based on most of the available sets of parton distribution functions, over the full kinematic range, covering almost seven orders of magnitude in the measured cross-section values.

3D fluoroscopic image estimation using patient-specific 4DCBCT-based motion models

3D fluoroscopic images represent volumetric patient anatomy during treatment with high spatial and temporal resolution. 3D fluoroscopic images estimated using motion models built using 4DCT images, taken days or weeks prior to treatment, do not reliably represent patient anatomy during treatment. In this study we developed and performed initial evaluation of techniques to develop patient-specific motion models from 4D cone-beam CT (4DCBCT) images, taken immediately before treatment, and used these models to estimate 3D fluoroscopic images based on 2D kV projections captured during treatment. We evaluate the accuracy of 3D fluoroscopic images by comparison to ground truth digital and physical phantom images. The performance of 4DCBCT-based and 4DCT-based motion models are compared in simulated clinical situations representing tumor baseline shift or initial patient positioning errors. The results of this study demonstrate the ability for 4DCBCT imaging to generate motion models that can account for changes that cannot be accounted for with 4DCT-based motion models. When simulating tumor baseline shift and patient positioning errors of up to 5 mm, the average tumor localization error and the 95th percentile error in six datasets were 1.20 and 2.2 mm, respectively, for 4DCBCT-based motion models. 4DCT-based motion models applied to the same six datasets resulted in average tumor localization error and the 95th percentile error of 4.18 and 5.4 mm, respectively. Analysis of voxel-wise intensity differences was also conducted for all experiments. In summary, this study demonstrates the feasibility of 4DCBCT-based 3D fluoroscopic image generation in digital and physical phantoms and shows the potential advantage of 4DCBCT-based 3D fluoroscopic image estimation when there are changes in anatomy between the time of 4DCT imaging and the time of treatment delivery.

Search for [Formula: see text] decays in [Formula: see text] collisions at [Formula: see text] = 8 TeV with the ATLAS detector

A search for a massive [Formula: see text] gauge boson decaying to a top quark and a bottom quark is performed with the ATLAS detector in [Formula: see text] collisions at the LHC. The dataset was taken at a centre-of-mass energy of [Formula: see text] and corresponds to [Formula: see text] of integrated luminosity. This analysis is done in the hadronic decay mode of the top quark, where novel jet substructure techniques are used to identify jets from high-momentum top quarks. This allows for a search for high-mass [Formula: see text] bosons in the range 1.5-3.0 [Formula: see text]. [Formula: see text]-tagging is used to identify jets originating from [Formula: see text]-quarks. The data are consistent with Standard Model background-only expectations, and upper limits at 95 % confidence level are set on the [Formula: see text] cross section times branching ratio ranging from [Formula: see text] to [Formula: see text] for left-handed [Formula: see text] bosons, and ranging from [Formula: see text] to [Formula: see text] for [Formula: see text] bosons with purely right-handed couplings. Upper limits at 95 % confidence level are set on the [Formula: see text]-boson coupling to [Formula: see text] as a function of the [Formula: see text] mass using an effective field theory approach, which is independent of details of particular models predicting a [Formula: see text] boson.

Measurement of the top-quark mass in the fully hadronic decay channel from ATLAS data at [Formula: see text]

The mass of the top quark is measured in a data set corresponding to 4.6 [Formula: see text] of proton-proton collisions with centre-of-mass energy [Formula: see text] TeV collected by the ATLAS detector at the LHC. Events consistent with hadronic decays of top-antitop quark pairs with at least six jets in the final state are selected. The substantial background from multijet production is modelled with data-driven methods that utilise the number of identified [Formula: see text]-quark jets and the transverse momentum of the sixth leading jet, which have minimal correlation. The top-quark mass is obtained from template fits to the ratio of three-jet to dijet mass. The three-jet mass is calculated from the three jets produced in a top-quark decay. Using these three jets the dijet mass is obtained from the two jets produced in the [Formula: see text] boson decay. The top-quark mass obtained from this fit is thus less sensitive to the uncertainty in the energy measurement of the jets. A binned likelihood fit yields a top-quark mass of [Formula: see text].

Measurement of spin correlation in top-antitop quark events and search for top squark pair production in pp collisions at √s=8 TeV using the ATLAS detector

A measurement of spin correlation in tt[over ¯] production is presented using data collected with the ATLAS detector at the Large Hadron Collider in proton-proton collisions at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3  fb^{-1}. The correlation between the top and antitop quark spins is extracted from dilepton tt[over ¯] events by using the difference in the azimuthal angle between the two charged leptons in the laboratory frame. In the helicity basis the measured degree of correlation corresponds to A_{helicity}=0.38±0.04, in agreement with the standard model prediction. A search is performed for pair production of top squarks with masses close to the top quark mass decaying to predominantly right-handed top quarks and a light neutralino, the lightest supersymmetric particle. Top squarks with masses between the top quark mass and 191 GeV are excluded at the 95% confidence level.

Performance of the ATLAS muon trigger in pp collisions at [Formula: see text] TeV

The performance of the ATLAS muon trigger system is evaluated with proton-proton collision data collected in 2012 at the Large Hadron Collider at a centre-of-mass energy of 8 TeV. It is primarily evaluated using events containing a pair of muons from the decay of [Formula: see text] bosons. The efficiency of the single-muon trigger is measured for muons with transverse momentum [Formula: see text] GeV, with a statistical uncertainty of less than 0.01 % and a systematic uncertainty of 0.6 %. The [Formula: see text] range for efficiency determination is extended by using muons from decays of [Formula: see text] mesons, [Formula: see text] bosons, and top quarks. The muon trigger shows highly uniform and stable performance. The performance is compared to the prediction of a detailed simulation.

Phase I trial of weekly cabazitaxel with concurrent intensity-modulated radiation therapy (IMRT) and androgen deprivation therapy (ADT) for the treatment of high-risk prostate cancer (PCa)

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Background: Cabazitaxel (C) improves overall survival and has been approved in second line chemotherapy for patients (pts) with metastatic castrate resistant PCa. We hypothesized that C is a radiosensitizer and performed a phase I trial of weekly C with standard IMRT and ADT for pts with high risk localized PCa. Methods: Conventional “3 + 3” design. Pts with newly diagnosed high risk PCa defined as either Gleason score (GS) 8 – 10, or T3/T4 with GS 7, or PSA > 20 with GS 7 are eligible. Dose escalation occurred only after all the cohort pts completed weekly C ( 4 cohorts at the dose of 4, 6, 8 and 10 mg/m2) and the total planned dose IMRT. ADT was started two months prior to C and IMRT then continued on for a total of 24 months. Daily bicalutamide started within 1 day to 2 weeks prior to LHRH agonist therapy and stopped on the last day of IMRT for approximately 4 month duration. IMRT is delivered to a total dose of 75.6 Gy at 1.8 Gy daily fraction for 8.5 – 9 wks. The primary objective of this study was to determine the safe dose of the combination of weekly C with IMRT and ADT . Results: At present, 14 pts of mean age 62 yrs (range 53 – 82), T2 - T4; mean PSA 89 (range 4 – 253); and median GS 9 (GS 7 – 10) were enrolled and 10 pts completed the chemo-radiation therapy. Grade 3 dose-limiting toxicites in the first two pts at the 8 mg/m2 C dose level were diarrhea and elevated transaminase, thus the maximum tolerable dose (MTD) of C with IMRT was determined to be 6 mg/m2. An expansion cohort is ongoing. In this dose level, there were ≤ grade 2 toxicities only (diarrhea, hypophosphatemia and leukopenia). No long term toxicities are observed. Standardized measurement of health status and quality of life will be presented. Conclusions: Concurrent weekly C with current standard IMRT is feasible with no unexpected toxicity. In combination with IMRT and ADT, the MTD of weekly C is 6 mg/m2 in pts with newly diagnosed high risk PCa. Clinical trial information: NCT01420250.

Search for Higgs boson pair production in the γγbb[over ¯] final state using pp collision data at sqrt[s]=8 TeV from the ATLAS detector

Searches are performed for resonant and nonresonant Higgs boson pair production in the γγbb[over ¯] final state using 20  fb^{-1} of proton-proton collisions at a center-of-mass energy of 8 TeV recorded with the ATLAS detector at the CERN Large Hadron Collider. A 95% confidence level upper limit on the cross section times branching ratio of nonresonant production is set at 2.2 pb, while the expected limit is 1.0 pb. The difference derives from a modest excess of events, corresponding to 2.4 standard deviations from the background-only hypothesis. The limit observed in the search for a narrow X→hh resonance ranges between 0.7 and 3.5 pb as a function of the resonance mass.

Search for dark matter in events with heavy quarks and missing transverse momentum in [Formula: see text] collisions with the ATLAS detector

This article reports on a search for dark matter pair production in association with bottom or top quarks in [Formula: see text] of [Formula: see text] collisions collected at [Formula: see text] TeV by the ATLAS detector at the LHC. Events with large missing transverse momentum are selected when produced in association with high-momentum jets of which one or more are identified as jets containing [Formula: see text]-quarks. Final states with top quarks are selected by requiring a high jet multiplicity and in some cases a single lepton. The data are found to be consistent with the Standard Model expectations and limits are set on the mass scale of effective field theories that describe scalar and tensor interactions between dark matter and Standard Model particles. Limits on the dark-matter-nucleon cross-section for spin-independent and spin-dependent interactions are also provided. These limits are particularly strong for low-mass dark matter. Using a simplified model, constraints are set on the mass of dark matter and of a coloured mediator suitable to explain a possible signal of annihilating dark matter.

Measurements of the Nuclear Modification Factor for Jets in Pb+Pb Collisions at √(s)NN]=2.76 TeV with the ATLAS detector

Measurements of inclusive jet production are performed in pp and Pb+Pb collisions at √(s)NN=2.76  TeV with the ATLAS detector at the LHC, corresponding to integrated luminosities of 4.0 and 0.14  nb(-1), respectively. The jets are identified with the anti-k(t) algorithm with R=0.4, and the spectra are measured over the kinematic range of jet transverse momentum 32<p(T)<500  GeV and absolute rapidity |y|<2.1 and as a function of collision centrality. The nuclear modification factor R(AA) is evaluated, and jets are found to be suppressed by approximately a factor of 2 in central collisions compared to pp collisions. The R(AA) shows a slight increase with p(T) and no significant variation with rapidity.

Measurements of the [Formula: see text] production cross sections in association with jets with the ATLAS detector

This paper presents cross sections for the production of a [Formula: see text] boson in association with jets, measured in proton-proton collisions at [Formula: see text] with the ATLAS experiment at the large hadron collider. With an integrated luminosity of [Formula: see text], this data set allows for an exploration of a large kinematic range, including jet production up to a transverse momentum of [Formula: see text] and multiplicities up to seven associated jets. The production cross sections for [Formula: see text] bosons are measured in both the electron and muon decay channels. Differential cross sections for many observables are also presented including measurements of the jet observables such as the rapidities and the transverse momenta as well as measurements of event observables such as the scalar sums of the transverse momenta of the jets. The measurements are compared to numerous QCD predictions including next-to-leading-order perturbative calculations, resummation calculations and Monte Carlo generators.

Search for invisible particles produced in association with single-top-quarks in proton-proton collisions at [Formula: see text] with the ATLAS detector

A search for the production of single-top-quarks in association with missing energy is performed in proton-proton collisions at a centre-of-mass energy of [Formula: see text] with the ATLAS experiment at the large hadron collider using data collected in 2012, corresponding to an integrated luminosity of [Formula: see text] fb[Formula: see text]. In this search, the [Formula: see text] boson from the top quark is required to decay into an electron or a muon and a neutrino. No deviation from the standard model prediction is observed, and upper limits are set on the production cross-section for resonant and non-resonant production of an invisible exotic state in association with a right-handed top quark. In the case of resonant production, for a spin-[Formula: see text] resonance with a mass of [Formula: see text] GeV, an effective coupling strength above [Formula: see text] is excluded at 95[Formula: see text] confidence level for the top quark and an invisible spin-[Formula: see text] state with mass between [Formula: see text] and [Formula: see text] GeV. In the case of non-resonant production, an effective coupling strength above [Formula: see text] is excluded at 95[Formula: see text] confidence level for the top quark and an invisible spin-[Formula: see text] state with mass between [Formula: see text] and [Formula: see text] GeV.

Search for resonant diboson production in the [Formula: see text] final state in [Formula: see text] collisions at [Formula: see text] TeV with the ATLAS detector

This paper reports on a search for narrow resonances in diboson production in the [Formula: see text] final state using [Formula: see text] collision data corresponding to an integrated luminosity of [Formula: see text] fb[Formula: see text] collected at [Formula: see text] TeV with the ATLAS detector at the Large Hadron Collider. No significant excess of data events over the Standard Model expectation is observed. Upper limits at the 95 % confidence level are set on the production cross section times branching ratio for Kaluza-Klein gravitons predicted by the Randall-Sundrum model and for Extended Gauge Model [Formula: see text] bosons. These results lead to the exclusion of mass values below 740 and 1590 GeV for the graviton and [Formula: see text] boson respectively.

Measurement of the production and lepton charge asymmetry of [Formula: see text] bosons in Pb+Pb collisions at [Formula: see text] with the ATLAS detector

A measurement of [Formula: see text] boson production in lead-lead collisions at [Formula: see text] is presented. It is based on the analysis of data collected with the ATLAS detector at the LHC in 2011 corresponding to an integrated luminosity of 0.14 [Formula: see text] and 0.15 [Formula: see text] in the muon and electron decay channels, respectively. The differential production yields and lepton charge asymmetry are each measured as a function of the average number of participating nucleons [Formula: see text] and absolute pseudorapidity of the charged lepton. The results are compared to predictions based on next-to-leading-order QCD calculations. These measurements are, in principle, sensitive to possible nuclear modifications to the parton distribution functions and also provide information on scaling of [Formula: see text] boson production in multi-nucleon systems.

Predicting overall survival for patients with periampullary carcinoma

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Background: The purpose of this study was to develop a model predicting the overall survival of patients with peri-ampullary cancer (PAC) following resection, with or without adjuvant therapy. This will help guide physicians in providing optimal post-operative care. Methods: Patients treated between 2006-2012 in our institutional pancreatic tumor registry were analyzed. All patients underwent pancreaticoduodenectomy for PAC. 334 patients had adequate records for analysis and were used to develop a multivariate model based on Cox regression. The variables used in our analysis were age, gender, T-stage, tumor differentiation, positive lymph node ratio (# positive/total), positive resection margins, chemotherapy, radiation therapy (RT), and tumor histology. Multivariate Cox hazards regression tested significance. Model performance was evaluated by the concordance index (c-index). Results: Median age of the cohort was 65 years. 54% of the patients were male. Median follow-up time was 16 months. Median overall survival was 19 months. T-stages were as follows: 7% T1, 9% T2, 77% T3, and 8% T4. 27% of the patients had a positive tumor margin, 68% of patients had positive lymph node spread. 81% of the patients had tubular adenocarcinoma, 9% ampullary adenocarcinoma, 5% cholangiocarcinoma, and 4% duodenal carcinoma. T-stage, tumor differentiation, tumor histology, positive lymph node (PLN) ratio, and adjuvant chemotherapy had a statistically significant association with overall survival (Table 1). The model performance c-index was evaluated as 0.630 with 95% CI as [0.571, 0.690], from a bootstrapping internal validation test on 3-year-survival. Conclusions: This model shows promise in predicting survival following resection for patients with PAC. More patient cases and further analysis of additional factors including specific RT related parameters and specific chemotherapy regimen are needed for development of a more robust model. [Table: see text]

Jet energy measurement and its systematic uncertainty in proton-proton collisions at [Formula: see text] TeV with the ATLAS detector

The jet energy scale (JES) and its systematic uncertainty are determined for jets measured with the ATLAS detector using proton-proton collision data with a centre-of-mass energy of [Formula: see text] TeV corresponding to an integrated luminosity of [Formula: see text][Formula: see text]. Jets are reconstructed from energy deposits forming topological clusters of calorimeter cells using the anti-[Formula: see text] algorithm with distance parameters [Formula: see text] or [Formula: see text], and are calibrated using MC simulations. A residual JES correction is applied to account for differences between data and MC simulations. This correction and its systematic uncertainty are estimated using a combination of in situ techniques exploiting the transverse momentum balance between a jet and a reference object such as a photon or a [Formula: see text] boson, for [Formula: see text] and pseudorapidities [Formula: see text]. The effect of multiple proton-proton interactions is corrected for, and an uncertainty is evaluated using in situ techniques. The smallest JES uncertainty of less than 1 % is found in the central calorimeter region ([Formula: see text]) for jets with [Formula: see text]. For central jets at lower [Formula: see text], the uncertainty is about 3 %. A consistent JES estimate is found using measurements of the calorimeter response of single hadrons in proton-proton collisions and test-beam data, which also provide the estimate for [Formula: see text] TeV. The calibration of forward jets is derived from dijet [Formula: see text] balance measurements. The resulting uncertainty reaches its largest value of 6 % for low-[Formula: see text] jets at [Formula: see text]. Additional JES uncertainties due to specific event topologies, such as close-by jets or selections of event samples with an enhanced content of jets originating from light quarks or gluons, are also discussed. The magnitude of these uncertainties depends on the event sample used in a given physics analysis, but typically amounts to 0.5-3 %.