The purpose of this study was to gain insight into the amount of language models (i.e., dose frequency) that Spanish-English bilingual children with and without specific language impairment (SLI) require in order to consistently produce challenging target grammatical forms for 6 morphemes, 3 in English and 3 in Spanish, via a structural priming task. Participants included two 2nd grade children with SLI, five typically developing kindergarten children, and three typically developing 2nd grade peers. Participants were administered 10 control and 10 experimental cloze phrase computer tasks for each morpheme. In the control condition participants finished cloze phrase sentences which targeted the target morpheme while in the experimental task participants heard a model of the target morpheme and were subsequently required to finish the cloze phrase. Results replicated results of structural priming for all groups in each language. Results also indicated that Spanish was more robust in producing morphological priming effects in comparison to English morphological forms possibly due to linguistic differences. Clinical and research implications are discussed. / text

The main purpose of this study was to evaluate medication use patterns (i.e., dose escalation, medication adherence, persistence, and switching) of rheumatoid arthritis (RA) patients on etanercept (ETN), infliximab (IFX) or adalimumab (ADA) and the associated healthcare utilization costs using Texas Medicaid data. Study participants were Medicaid beneficiaries (18-63 years) with an RA diagnosis (ICD-9-CM code 714.0x) who had no claim for a biologic agent in the 6-month pre-index period (July 1, 2003 - Dec 31, 2010). The index date was the first date when the patient had the first fill for any of the study TNF inhibitors (ETN, ADA or IFX) within the study identification period (Jan 1, 2004 – Aug 31, 2010). Data were extracted from July 1, 2003 to August 31, 2011. Prescription and medical claims were analyzed over an 18-month study period (i.e., 6-month pre-index and 12-month post-index periods). The primary study outcomes were adherence, persistence, dose escalation, switching and cost (i.e., total healthcare, RA-related and TNF inhibitor therapy cost). The study covariates were demographic factors (age, gender, race/ethnicity), pre-index use of other RA-related medications (pain, glucocorticoids and disease modifying antirheumatic drugs), total number of non-study RA-related medications used at index, pre-index RA and non-RA related visits, pre-index healthcare utilization cost and Charlson Comorbidity Index score. Conditional regression analyses, which accounts for matched samples, were used to address the study objectives. After propensity score matching, 822 patients (n=274/group) comprised the final sample. The mean age (±SD) was 48.9(±9.8) years, and the majority of the subjects were between 45 and 63 years (69.2%), Hispanic (53.7%) and female (88.0%). Compared to patients on ETN, the odds of having a dose escalation were ≈ 5 [Odds Ratio= 4.605 [95% CI= 1.605-12.677], p=0.0031] and ≈ 8 [Odds Ratio=7.520, [95% CI= 2.461-22.983], p=0.0004] times higher for IFX and ADA patients, respectively, while controlling for other variables in the model. Compared to ETN, patients on IFX (p=0.0171) were more adherent while adherence was comparable with patients on ADA (p=0.1144). Compared to patients on ETN, the odds of being adherent (MPR ≥ 80%) to IFX was ≈ 2 times higher [Odds Ratio= 2.437, [95% CI=1.592-3.731], p < 0.0001] while controlling for other variables in the model. Persistence to index TNF inhibitor therapy and likelihood to switch or discontinue index TNF inhibitor therapy were comparable among the 3 study groups. In addition, the duration of medication use (i.e., persistence) prior to switching or discontinuation of index therapy was comparable among the 3 study groups. Furthermore, for each of the cost variables (total healthcare, RA-related and TNF inhibitor therapy cost), costs incurred by patients on ETN were significantly lower (p < 0.01) than those incurred by ADA patients but significantly higher (p < 0.01) than those incurred by IFX patients. Finally, a positive and significant relationship (p < 0.0001) was found between RA-related healthcare cost, adherence and persistence to TNF inhibitor therapies. In conclusion, ETN was associated with lower rates of dose escalation compared to ADA or IFX. However, adherence was better and associated healthcare costs were lower with IFX. Clinicians should endeavor to work with each individual patient to identify patient-specific factors responsible for poor medication use behaviors with TNF-inhibitor therapies. Reducing the impact of these factors and improving adherence should be included as a major part of the treatment plan for each RA patient. RA patients need to be adequately educated on the importance of adhering and persisting to their TNF-inhibitor therapy as poor medication adherence/persistence negatively impacts the RA disease process. / text

In-vivo dosimetry with diode detectors is used in radiation therapy as a quality assurance tool. The diode sensitivity under radiation depends upon temperature, dose rate and SDD (source-to-detector distance), field size, beam angle, and energy. This dissertation presents the first systematic and quantitative study of dosimetric characteristics for most of the commercial radiation diodes (n-type and p-type) under different radiation beams.In the temperature dependence study, the systematic study on the dose rate dependence of svwt (sensitivity variation with temperature) was performed. It was concluded that sufficient preirradiation can eliminate dose rate dependence of svwt. However, preirradiation cannot eliminate dose rate dependence of the diode sensitivity, S, itself. In the dose rate and SDD dependence study, it was shown that the p-type diodes do not always show less dose rate dependence than the n-type diodes. Preirradiation does not always reduce diode dose rate dependence. SDD dependence of diode sensitivity can be explained by the instantaneous dose rate dependence if sufficient buildup is provided to eliminate electron contamination. An empirical formula was proposed to fit the dose rate dependence of diode sensitivity. In the energy dependence study, the energy dependence diode detectors are quantified. The empirical theory to quantify this effect was developed. Monte Carlo simulation and the cavity theory are used to predict the energy dependence. It was concluded that the energy dependence does not depend on whether the diode is n- or p- type but rather depends mainly on the material around the die (buildup and its geometry). A systematic study of the correction factors for accurate diode dosimetry is presented in this dissertation.This dissertation has established a theoretical foundation for the modeling of the transient electric and radiation properties of the diode detectors, separately. We believe that the Monte Carlo simulations code for radiation transport should be coupled with the continuity equations to describe the charge transport in the diode detector, and thus provides a complete quantitative description of dosimetric characteristics of the diode detectors. The ultimate goal is to use the diode detector as an absolute dosimeter, rather than as a relative dosimeter.

The concentrations of some drug solutions are often expressed as ratios or percentages. This system simplified prescription and dispensing when Imperial measures such as grains and minims were used. Ampoules of powerful vasoactive drugs such as catecholamines and potentially toxic local anaesthetics are still labelled as ratios and percentages, seemingly through habit or tradition than for any useful clinical reason. This thesis argues that adherence to this outdated system is confusing, causes drug administration errors, and puts patients at risk. Internet-based questionnaires were used to quantify medical students’ and doctors’ understanding of ratios and percentages. A substantial minority of almost 3000 doctors could not convert between ratios, percentages and mass concentration correctly, made dosing errors of up to three orders of magnitude in written clinical scenarios, and struggled with conversions between metric units. These findings are strong arguments for expressing drug concentrations as mass concentration and providing better drug administration teaching. High fidelity patient simulation was used to examine the influence of clearer ampoule labelling and intensive drug administration teaching. This allowed critical incidents to be reproduced realistically, clinical performances to be assessed, and outcome measures to be accurately recorded. Randomised controlled trials were conducted that demonstrated positive influences of both interventions for doctors and students. The difficulties that nurses encounter when preparing infusions of these drugs on critical care units were also studied and are reported. The findings presented should be sufficient to persuade regulatory authorities to remove ratios and percentages from ampoule labels – a straightforward, cheap, commonsense intervention. The lack of effective clinical error reporting systems and the extreme practical difficulties of conducting clinical trials in this field mean that a firm link between this intervention and patient outcome is unlikely ever to be made, but this should not be an excuse for maintaining the status quo.

During a risk assessment undertaken in a factory dealing with fiber reinforced plastic products in the northwestern part of Peninsular Malaysia, styrene was identified as the most potential hazard in the factory. It was therefore chosen to focus the rest of the risk assessment on this chemical. The purpose of this risk assessment was to find out which negative health effects styrene could have on the factory workers, especially on the laminators who are dealing daily with styrene at a close range during lamination through hand lay-up. This was investigated theoretically through a literature research and practically through measurements of styrene in the air in the factory. The styrene doses were measured on two occasions at several distances away from the potential sources. These measurements were high compared with dose-response relationships found in the literature and various national occupational exposure limit values with regards to styrene. The calculated risk quotient (RQ) was also greater than one and it is therefore likely that styrene has negative health effects on the workers in the factory. The various negative health effects identified in the literature were then included in a risk matrix were they were ranked according to the probability that they would have a negative effect on the factory workers. Hearing- and colourvision effects were ranked as very likely, effects on the central nervous system and the respiratory system as well as livertoxicity were classified as likely and genotoxicity was ranked as a possible negative health effect. In the future it would be interesting to talk to the current laminators and do health check-ups to see if they are suffering from any of the suggested negative health effects. It would also be interesting to follow them on a longterm basis to see if their health is changing and if this can be linked to the styrene handling in the factory. / Vid en riskbedömning i en fabrik i nordvästra Malaysia identifierades styren som den största hälsofaran för fabriksarbetarna, framförallt laminerarna eftersom de ofta hanterar styren på nära håll. Det valdes därför att fokusera den resterande riskbedömningen just på styren och dess möjliga negativa hälsoeffekter. Syftet med studien var att ta reda på om styren kan ha en negativ effekt på fabriksarbetarnas hälsa. Detta undersöktes teoretiskt genom en litteraturstudie och praktiskt genom mätningar av styrenhalten i fabriken. Vid två tillfällen mättes styrenhalten i fabriken. De uppmätta halterna jämfördes sedan med de dos-responssamband som funnits vid litteraturstudien, samt med olika nationella hygieniska gränsvärden för styren. De uppmätta värdena visade sig vara höga jämfört med de funna i litteraturen. Det bidrog tillsammans med den beräknade riskkvoten som visade sig vara större än ett, till slutsatsen att styren har en negativ effekt på fabriksarbetarnas hälsa. De möjliga negativa hälsoeffekter som identifierats i litteraturen rangordnas med hjälp av en riskmatris enligt sannolikheten att de skulle utgjöra en risk för arbetarna i fabriken. Effekter på hörseln och färgseendet ansågs vara mycket sannolikt, effekter på centrala nervsystemet (CNS) och levern samt irritation av andningssystemet ansågs sannolika och att styren skulle vara genotoxiskt ansågs möjligt. Övriga hälsoeffekter ansågs osannolika eller mycket osannolika. I framtida studier skulle det vara intressant att diskutera med de nuvarande laminerarna och undersöka dem medicinskt för att se om de har påverkats utav några av de förväntade hälsoeffekterna. Det vore också intressant att följa dessa arbetare under en längre tid för att se om deras hälsa ändras på något sätt som skulle kunna kopplas till styrenhanteringen i fabriken.

Σκοπός: Τα επιστημονικά δεδομένα για το κλινικό όφελος που μπορεί να έχει η στρατηγική καθυστέρησης της αγγειοπλαστικής των στεφανιαίων αρτηριών μετά τη χορήγηση δόσης φόρτισης κλοπιδογρέλης παραμένουν ασαφή. Συγκρίναμε σε ασθενείς με σταθερή ή ασταθή στηθάγχη, οι οποίοι δεν λάμβαναν προηγουμένως κλοπιδογρέλη, την αγγειοπλαστική που πραγματοποιείται με καθυστέρηση 2 ωρών, μετά τη στεφανιογραφία και τη χορήγηση δόσης φόρτισης κλοπιδογρέλης 900 mg, με την αγγειοπλαστική που πραγματοποιείται αμέσως μετά τον καθετηριασμό και τη λήψη των 900 mg κλοπιδογρέλης. Μέθοδοι: Στα πλαίσια τυχαιοποιημένης προοπτικής μελέτης, 199 ασθενείς υποβλήθηκαν είτε σε άμεση αγγειοπλαστική (ομάδα Α, n=103), είτε σε καθυστερημένη επέμβαση (ομάδα Β ή ομάδα προθεραπείας, n=96). Μετρήθηκαν οι βασικές τιμές, οι τιμές αμέσως πριν την αγγειοπλαστική, στις 6-8 ώρες και στις 24 ώρες μετά την επέμβαση, της καρδιακής τροπονίνης Ι (cTnI) , της κινάσης της κρεατίνης MB (CK-MB) και της μυοσφαιρίνης, οι οποίες είναι δείκτες μυοκαρδιακής νέκρωσης, καθώς και οι τιμές της υψηλής ευαισθησίας C αντιδρώσας πρωτεΐνης (hs-CRP) και της διαλυτής P-σελεκτίνης (sPS), οι οποίες είναι δείκτες φλεγμονώδους αντίδρασης και ενεργοποίησης των αιμοπεταλίων αντίστοιχα. Το σύνθετο κύριο καταληκτικό σημείο της μελέτης ήταν ο συνδυασμός καρδιαγγειακού θανάτου, περιεπεμβατικού εμφράγματος του μυοκαρδίου (ΕΜ), αγγειακού εγκεφαλικού επεισοδίου (ΑΕΕ) και επείγουσας επαναγγείωσης, εντός 30 ημερών από την αγγειοπλαστική. Ως περιεπεμβατικό ΕΜ ορίσθηκε το κλινικώς προφανές έμφραγμα και/ή η τριπλάσια της ανώτερης φυσιολογικής τιμής (ΑΦΤ) τουλάχιστον αύξηση της cTnI. Ως δευτερεύοντα καταληκτικά σημεία θεωρήθηκαν οποιαδήποτε περιεπεμβατική αύξηση της CK-MB μεγαλύτερη του τριπλασίου της ΑΦΤ, οποιαδήποτε περιεπεμβατική αύξηση των δεικτών μυοκαρδιακής νέκρωσης μεγαλύτερη της ΑΦΤ, η μη βέλτιστη ροή στο αγγείο μετά την επέμβαση (ροή κατά TIMI <3), οποιαδήποτε μείζων αιμορραγία κατά ΤΙΜΙ, η θρομβοκυττοπενία με αριθμό αιμοπεταλίων <70.000/ml και οποιαδήποτε αύξηση της hs-CRP και της sPS. Αποτελέσματα : Το σύνθετο κύριο καταληκτικό σημείο συνέβη στο 12,6% της ομάδας άμεσης αγγειοπλαστικής έναντι του 15,6% των ασθενών της ομάδας της προθεραπείας (p=0,34). Δύο ασθενείς της ομάδας Α απεβίωσαν εντός 24ώρου από την επέμβαση, ενώ ουδείς απεβίωσε στην ομάδα της καθυστερημένης αγγειοπλαστικής (p=0,49). Το συχνότερο μεμονωμένο κύριο καταληκτικό σημείο ήταν το περιεπεμβατικό έμφραγμα (12,6% έναντι 14,6%, p=0,42). ΑΕΕ συνέβη σε έναν ασθενή της ομάδας της προθεραπείας και σε κανέναν της ομάδας της άμεσης αγγειοπλαστικής. Επείγουσα επαναγγείωση χρειάσθηκε ένας ασθενής της ομάδας Β και κανείς της ομάδας Α . Η hs-CRP αυξήθηκε μετά την αγγειοπλαστική και στις δύο ομάδες (p<0,0001), χωρίς να υπάρχει διαφορά στις τιμές της μεταξύ των δύο ομάδων (p=0,5). Οι αρχικές τιμές της sPS δεν διέφεραν μεταξύ των δύο ομάδων (p=0,5), και επίσης δεν υπήρχε μεταβολή στις τιμές της sPS μετά την αγγειοπλαστική. Μείζων αιμορραγία καταγράφηκε στο 2,9% των ασθενών της ομάδας της άμεσης αγγειοπλαστικής και στο 3,1% των ασθενών της ομάδας της προθεραπείας (p=0,9). Kαμία στατιστικά σημαντική διαφορά δεν υπήρξε επίσης στα υπόλοιπα δευτερεύοντα καταληκτικά σημεία μεταξύ των δύο ομάδων. Συμπέρασμα: Σε ασθενείς με σταθερή ή ασταθή στηθάγχη, οι οποίοι δεν λάμβαναν προηγουμένως κλοπιδογρέλη και υποβλήθηκαν σε αγγειοπλαστική των στεφανιαίων αρτηριών, η στρατηγική καθυστέρησης της αγγειοπλαστικής για 2 ώρες μετά τη χορήγηση υψηλής δόσης φόρτισης κλοπιδογρέλης 900 mg, δεν φαίνεται να προσφέρει επιπλέον κλινικό όφελος, συγκριτικά με την άμεση αγγειοπλαστική. / Aim: Εvidence that the strategy of delaying percutaneous coronary intervention (PCI) after clopidogrel loading is beneficial remains inconclusive. We compared the delayed for 2 hours PCI with the ad-hoc PCI, after loading with 900 mg of clopidogrel, in clopidogrel-naive patients with stable or unstable angina who had already underwent coronary angiography and were subjected to PCI. Methods: In a prospective randomized study 199 patients underwent either ad-hoc PCI (group A, n=103) or delayed PCI ( pretreatment group, group B, n=96). Cardiac troponin I (cTnI), creatine kinase-MB (CK-MB), myoglobin which are biomarkers of myocardial injury, high sensitivity C-reactive protein (hs-CRP), a marker of inflammatory status and soluble P-selectin (sPS), a marker of platelets activation were measured baseline, just before PCI, 6-8 hours after PCI and 24 hours later. Combined primary end point was the composite of cardiovascular death, periprocedural myocardial infarction (MI), stroke and urgent revascularization within 30 days after PCI. Periprocedural MI was defined as any clinical apparent MI and/or the increase of cTnI >3 times above the upper limit of normal (ULN). Secondary endpoints were considered any periprocedural increase of CK-MB above x3 ULN, any periprocedural increase of myocardial injury biomarkers above ULN, TIMI flow <3 after PCI, any major bleeding (TIMI criteria), thrombocytopenia with platelet count <70,000/mL and any elevation of hs-CRP and sPS. Results: The combined primary end point occurred in 12.6% of ad-hoc PCI group versus 15.6% of pretreatment group patients (p=0.34). There were 2 deaths in group A, which occurred within 24 hours post-PCI and no death in the delayed PCI group (p=0.49). Among the components of the combined primary end point, periprocedural MI was the most frequently encountered event (12.6% versus 14.6%, p=0.42). Stroke occurred in one patient of the pretreatment group, and in no patient of the ad-hoc PCI group. Urgent revascularization was performed in one patient of group B and in no patient of group A. High sensitivity CRP increased in both groups after PCI (p<0.0001) without difference between groups (p=0.5). Baseline sPS levels did not differ between the 2 groups (p=0.5) and there was no significant change of sPS over time. Major bleeding occurred in 2.9% ad-hoc PCI group versus 3.1% pretreatment group patients (p=0.9). There was also no difference in any other secondary end point between the two groups. Conclusion: In clopidogrel-naive patients with stable or unstable angina, a strategy of delaying PCI for 2 hours after high-dose clopidogrel loading of 900 mg does not seem to confer any benefit compared to ad-hoc PCI.

Σκοπός της παρούσας εργασίας είναι η μελέτη με την βοήθεια της τεχνικής Monte Carlo των φασμάτων εκτός πεδίου του γραμμικού επιταχυντή SL- 18 της ELEKTA. Η μελέτη έδειξε συσχέτιση μεταξύ δόσης και απόστασης από των άξονα της δέσμης. / The aim of this study was to investigate the energy spectrum outside the field limits of therapeutic high energy photon beams. Monte Carlo simulations were used in order to determine the dose and to confirm or to try to re-estimate the Energy correction factors used in off-field in-vivo dosimetry. The ELEKTA-SL18 medical accelerator was simulated for 6MV and 15MV, using the EGSnrc code. The simulation includes the regular jaws and the MLC. The output of each simulation was a square scoring plane at SSD 100cm. The energy spectrum, the mean energy, the energy fluence and other parameters were studied for annular areas centred on the Z axis, and for 1cm2 rectangular areas centred on both X and Y axis. These regions were selected every 1cm inside and outside the reference (10x10) cm2 field of the primary beam. The spectra and all the aforementioned parameters were found to be in relation to the position, and their comparison revealed differences, that exceeded the statistical error, between areas that had the same distance from the center but were located on different axes. These differences were more important for the lower energy (6MV), as the contribution from leakage radiation is relatively higher. Their comparison served to study the influence of the spectral differences on the measurements of this energy-dependent dosimetric system outside the treatment field. The ELEKTA SL-18 LINAC was simulated for photon beams of 6MV and 15MV with and without MLCs. The photon energies and the dose to the out-field areas close to treatment field are considerable and this should be taken into account when radiosensitive organs are close to the field limits. This could be more important to complicated IMRT treatments where the treatment time is altered.

An important objective in statistical risk assessment is estimation of minimum exposure levels, called Benchmark Doses (BMDs) that induce a pre-specified Benchmark Response (BMR) in a target population. Established inferential approaches for BMD analysis typically involve one-sided, frequentist confidence limits, leading in practice to what are called Benchmark Dose Lower Limits (BMDLs). Appeal to hierarchical Bayesian modeling and credible limits for building BMDLs is far less developed, however. Indeed, for the few existing forms of Bayesian BMDs, informative prior information is seldom incorporated. Here, a new method is developed by using reparameterized quantal-response models that explicitly describe the BMD as a target parameter. This potentially improves the BMD/BMDL estimation by combining elicited prior belief with the observed data in the Bayesian hierarchy. Besides this, the large variety of candidate quantal-response models available for applying these methods, however, lead to questions of model adequacy and uncertainty. Facing this issue, the Bayesian estimation technique here is further enhanced by applying Bayesian model averaging to produce point estimates and (lower) credible bounds. Implementation is facilitated via a Monte Carlo-based adaptive Metropolis (AM) algorithm to approximate the posterior distribution. Performance of the method is evaluated via a simulation study. An example from carcinogenicity testing illustrates the calculations.

Pressurized metered dose inhalers (pMDIs) are widely utilized to manage diseases of the lungs, such as asthma and chronic obstructive pulmonary disease. They can be formulated such that the drug and/or nonvolatile excipients are dissolved or dispersed in the formulation, rendering a solution or suspension formulation, respectively. While the formulation process for solution pMDIs is well defined, the formulation process of pMDIs with any type of suspended entity can be lengthy and empirical. The use of suspended drug or the addition of a second drug or excipient in a suspension pMDI formulation may non-linearly impact the product performance of the drug of interest in the formulation; this requires iterative testing of a series of pMDIs in order to identify a formulation with the most potential for success. One of the primary attributes used to characterize the product performance and quality control of inhaled medications is the residual aerodynamic particle size distribution (APSD) of the aerosolized drug. Along with clinical factors, formulation and device parameters have a significant impact on APSD. In this study, a computational model was developed using the principles of statistics and physical chemistry to predict the residual APSD generated by suspension pMDIs based on formulation, device, and raw drug or excipient substance considerations. The formulations modeled and experimentally evaluated consist of a suspended drug or excipient with/without a dissolved drug or excipient in a cosolvent-propellant system. The in silico model enables modeling a process that is difficult to delineate experimentally and contributes to understanding the link between pMDI formulation and device to product performance. The ability to identify and understand the variables that affect atomization and/or aerosol disposition , such as initial droplet size, suspended micronized drug or excipient size, and drug or excipient concentration, facilitates defining the design space for suspension pMDIs during development and improves recognizing the sensitive of the APSD is on each hardware and formulation variable. This model can later be applied to limit batch-to-batch variation in the manufacturing process and selecting plausible suspension pMDI formulations with quality design as the end goal.

The goal of radiotherapy is to operate within the therapeutic window - delivering doses of ionizing radiation to achieve locoregional tumour control, while minimizing normal tissue toxicity. A greater therapeutic ratio can be achieved by utilizing radiosensitizing agents designed to enhance the effects of radiation at the tumour. Gold nanoparticles (AuNP) represent a novel radiosensitizer with unique and attractive properties. AuNPs enhance local photon interactions, thereby converting photons into localized damaging electrons. Experimental reports of AuNP radiosensitization reveal this enhancement effect to be highly sensitive to irradiation source energy, cell line, and AuNP size, concentration and intracellular localization. This thesis explored the physics and some of the underlying mechanisms behind AuNP radiosensitization. A Monte Carlo simulation approach was developed to investigate the enhanced photoelectric absorption within AuNPs, and to characterize the escaping energy and range of the photoelectric products. Simulations revealed a 10^3 fold increase in the rate of photoelectric absorption using low-energy brachytherapy sources compared to megavolt sources. For low-energy sources, AuNPs released electrons with ranges of only a few microns in the surrounding tissue. For higher energy sources, longer ranged photoelectric products travelled orders of magnitude farther. A novel radiobiological model called the AuNP radiosensitization predictive (ARP) model was developed based on the unique nanoscale energy deposition pattern around AuNPs. The ARP model incorporated detailed Monte Carlo simulations with experimentally determined parameters to predict AuNP radiosensitization. This model compared well to in vitro experiments involving two cancer cell lines (PC-3 and SK-BR-3), two AuNP sizes (5 and 30 nm) and two source energies (100 and 300 kVp). The ARP model was then used to explore the effects of AuNP intracellular localization using 1.9 and 100 nm AuNPs, and 100 and 300 kVp source energies. The impact of AuNP localization was most significant for low-energy sources. At equal mass concentrations, AuNP size did not impact radiosensitization unless the AuNPs were localized in the nucleus. This novel predictive model of AuNP radiosensitization could help define the optimal use of AuNPs in potential clinical strategies by determining therapeutic AuNP concentrations, and recommending when active approaches to cellular accumulation are most beneficial.