Absolute calibration in vivo measurement systems

Lawrence Livermore National Laboratory (LLNL) is currently investigating a new method for obtaining absolute calibration factors for radiation measurement systems used to measure internally deposited radionuclides in vivo. Absolute calibration of in vivo measurement systems will eliminate the need to generate a series of human surrogate structures (i.e., phantoms) for calibrating in vivo measurement systems. The absolute calibration of in vivo measurement systems utilizes magnetic resonance imaging (MRI) to define physiological structure, size, and composition. The MRI image provides a digitized representation of the physiological structure, which allows for any mathematical distribution of radionuclides within the body. Using Monte Carlo transport codes, the emission spectrum from the body is predicted. The in vivo measurement equipment is calibrated using the Monte Carlo code and adjusting for the intrinsic properties of the detection system. The calibration factors are verified using measurements of existing phantoms and previously obtained measurements of human volunteers. 8 refs

Data resource profile: the Opioid Agonist Treatment and Safety (OATS) Study, New South Wales, Australia

Advance Access Publication Date: 16 October 2020Abstract not availableSarah Larney, Nicola Jones, David A Fiellin, Suzanne Nielsen, Matthew Hickman, Timothy Dobbins, Thomas Murphy, Robert Ali and Louisa Degenhard

Global opioid agonist treatment: a review of clinical practices by country

First published: 14 April 2020AIMS: We assessed how opioid agonist treatment (OAT) for opioid use disorder (OUD), specifically methadone and buprenorphine, including buprenorphine-naloxone, is delivered in routine clinical practice, with a focus on factors that affect access to and delivery of these services. The aims of this review were to summarize eligibility criteria for entry to OAT, doses in routine clinical practice, access to and eligibility for unsupervised dosing, and urine drug screening practices in OAT programs globally. METHODS: We completed searches of PubMed, Embase, and grey literature databases for cross-sectional or observational cohort studies of OAT using either methadone or buprenorphine. Dose data extracted from eligible studies were compared with guidelines provided by WHO. RESULTS: We found 140 reports from 41 countries that contained data for at least one of the relevant indicators. A diagnosis of opioid dependence or opioid use disorder was the most common eligibility requirement for OAT (13 or 17 countries). Reported mean or median doses for methadone ranged from 16 to 131 mg while range for buprenorphine was 2.5 - 19 mg. Access to unsupervised dosing under some conditions was reported in 18 of 27 countries. Frequency of regular urine drug screenings (UDS) ranged from several times a week to eight times per year (methadone) or as clinically indicated. CONCLUSIONS: Opioid agonist treatment practices, including doses prescribed, vary greatly both within and across countries. Of particular concern is the persistence of lower dose prescribing practices, in which patients may be prescribed doses below those proven to yield significant clinical benefits.Harry Jin, Brandon D. L. Marshall, Louisa Degenhardt, John Strang, Matt Hickman ... Robert Ali ... et al