Outcome measures for use in trials of paediatric otorrhoea: A systematic review.

INTRODUCTION: Paediatric otorrhoea (PO) describes a middle ear infection that results in a perforation of the tympanic membrane and ear discharge, in children and young people (CYP). Prolonged infection may be associated with hearing loss and developmental delay. The current management of paediatric otorrhoea is variable, including non-invasive treatments (conservative, oral antibiotics, topical antibiotics) and surgery, reflecting the lack of a sufficiently strong evidence base. Outcome reporting is fundamental to producing reliable and meaningful evidence to inform best practice. OBJECTIVES: Primary objective: to determine which outcome measures are currently used to evaluate treatment success in studies of non-surgical treatments for paediatric otorrhoea. SECONDARY OBJECTIVES: to identify outcome measurement instruments used in the literature and assess their applicability for use in clinical trials of PO. METHODS: This systematic review was registered with PROSPERO (CRD42023407976). Database searches of EMBASE, MEDLINE and Cochrane was performed on June 6, 2023, covering from Jan 1995 to May 2023. Randomised controlled trials or study protocols involving CYP with PO were included following PRISMA guidelines. Risk of bias was assessed with Cochrane's tool. RESULTS: Of the 377 papers identified, six were included in the systematic review. The primary outcome of five of the studies related to otorrhoea cessation; both time to cessation and proportion recovered at various time points were used as measures. Two measurement instruments were identified: Otitis Media-6 Questionnaire and the Institute for Medical Technology Assessment Productivity Cost Questionnaire. Both were shown to be applicable measurement instruments when used in clinical trials of PO. CONCLUSIONS: To promote homogeneity and facilitate meaningful comparison and combination of studies, we propose that time to cessation of otorrhoea from onset of otorrhoea should be used as the primary outcome in future studies. Further research is needed to establish if this is the most important outcome to children and their caregivers.

Assessment of the setup dependence of detector response functions for mega-voltage linear accelerators.

PURPOSE: Accurate modeling of beam profiles is important for precise treatment planning dosimetry. Calculated beam profiles need to precisely replicate profiles measured during machine commissioning. Finite detector size introduces perturbations into the measured profiles, which, in turn, impact the resulting modeled profiles. The authors investigate a method for extracting the unperturbed beam profiles from those measured during linear accelerator commissioning. METHODS: In-plane and cross-plane data were collected for an Elekta Synergy linac at 6 MV using ionization chambers of volume 0.01, 0.04, 0.13, and 0.65 cm3 and a diode of surface area 0.64 mm2. The detectors were orientated with the stem perpendicular to the beam and pointing away from the gantry. Profiles were measured for a 10 x 10 cm2 field at depths ranging from 0.8 to 25.0 cm and SSDs from 90 to 110 cm. Shaping parameters of a Gaussian response function were obtained relative to the Edge detector. The Gaussian function was deconvolved from the measured ionization chamber data. The Edge detector profile was taken as an approximation to the true profile, to which deconvolved data were compared. Data were also collected with CC13 and Edge detectors for additional fields and energies on an Elekta Synergy, Varian Trilogy, and Siemens Oncor linear accelerator and response functions obtained. Response functions were compared as a function of depth, SSD, and detector scan direction. Variations in the shaping parameter were introduced and the effect on the resulting deconvolution profiles assessed. RESULTS: Up to 10% setup dependence in the Gaussian shaping parameter occurred, for each detector for a particular plane. This translated to less than a +/- 0.7 mm variation in the 80%-20% penumbral width. For large volume ionization chambers such as the FC65 Farmer type, where the cavity length to diameter ratio is far from 1, the scan direction produced up to a 40% difference in the shaping parameter between in-plane and cross-plane measurements. This is primarily due to the directional difference in penumbral width measured by the FC65 chamber, which can more than double in profiles obtained with the detector stem parallel compared to perpendicular to the scan direction. For the more symmetric CC13 chamber the variation was only 3% between in-plane and cross-plane measurements. CONCLUSIONS: The authors have shown that the detector response varies with detector type, depth, SSD, and detector scan direction. In-plane vs. cross-plane scanning can require calculation of a direction dependent response function. The effect of a 10% overall variation in the response function, for an ionization chamber, translates to a small deviation in the penumbra from that of the Edge detector measured profile when deconvolved. Due to the uncertainties introduced by deconvolution the Edge detector would be preferable in obtaining an approximation of the true profile, particularly for field sizes where the energy dependence of the diode can be neglected. However, an averaged response function could be utilized to provide a good approximation of the true profile for large ionization chambers and for larger fields for which diode detectors are not recommended.

Privacy as an enabler, not an impediment: building trust into health information exchange.

Building privacy and security protections into health information technology systems will bolster trust in such systems and promote their adoption. The privacy issue, too long seen as a barrier to electronic health information exchange, can be resolved through a comprehensive framework that implements core privacy principles, adopts trusted network design characteristics, and establishes oversight and accountability mechanisms. The public policy challenges of implementing this framework in a complex and evolving environment will require improvements to existing law, new rules for entities outside the traditional health care sector, a more nuanced approach to the role of consent, and stronger enforcement mechanisms.

Prospects for quantitative two-dimensional radiochromic film dosimetry for low dose-rate brachytherapy sources.

Radiochromic film (RCF) has been shown to be a precise and accurate two-dimensional dosimeter for acute exposure radiation fields. However, "temporal history" mismatch between calibration and brachytherapy films due to RCF dose-rate effects could introduce potentially large uncertainties in low dose-rate (LDR) brachytherapy absolute dose measurement. This article presents a quantitative evaluation of the precision and accuracy of a laser scanner-based RCF-dosimetry system and the effect of the temporal history mismatch in LDR absolute dose measurement. MD-55-2 RCF was used to measure absolute dose for a low dose-rate 137Cs brachytherapy source using both single- and double-exposure techniques. Dose-measurement accuracy was evaluated by comparing RCF to Monte Carlo photon-transport simulation. The temporal history mismatch effect was investigated by examining dependence of RCF accuracy on irradiation-to-densitometry time interval. The predictions of the empirical cumulative dose superposition model (CDSM) were compared with measurements. For the double-exposure technique, the agreement between measurement and Monte Carlo simulation was better than 4% in the 3-60 Gy dose range with measurement precisions (coverage factor k = 1) of <2% and <6% for the doses greater or less than 3 Gy, respectively. The overall uncertainty (k = 1) of dose rate/air-kerma strength measurements achievable by this dosimetry system for a spatial resolution of 0.1 mm is less than 4% for doses greater than 5 Gy. The measured temporal history mismatch systematic error is about 1.8% for a 48 h postexposure time when using the double exposure technique and agrees with CDSM's prediction qualitatively. This work demonstrates that the model MD-55-2 RCF detector has the potential to support quantitative dose measurements about LDR brachytherapy sources with precision and accuracy better than that of previously described dosimeters. The impacts of this work on the future use of new type of RCF were also discussed.