Development and international multicentre pilot testing of a postal dosimetry audit methodology for high dose rate brachytherapy.

Background And Purpose: Dosimetry audits are essential for reducing errors in brachytherapy. A postal dosimetry audit methodology was developed and tested in an international multicentre pilot, to assess the accuracy of the Reference Air Kerma Rate of Ir and Co brachytherapy sources.

Materials And Methods: A compact phantom made of polymethyl methacrylate was developed to accommodate two catheters, a radiophotoluminescence dosimeter (RPLD) for dose measurements and a Gafchromic (RTQA2) film strip for source position verification.

Monte Carlo simulated correction factors for high dose rate brachytherapy postal dosimetry audit methodology.

Background And Purpose: Full-scatter conditions in water are impractical for postal dosimetry audits in brachytherapy. This work presents a method to obtain correction factors that account for deviations from full-scatter water-equivalent conditions for a small plastic phantom.

Material And Methods: A 16 × 8 × 3 cm phantom (PMMA) with a radiophotoluminescent dosimeter (RPLD) at the centre and two catheters on either side was simulated using Monte Carlo (MC) to calculate correction factors accounting for the lack of scatter, non-water equivalence of the RPLD and phantom, source model and backscatter for HDR Co and Ir sources.

Well calculated is better than quickly calculated: Comparison of Pencil beam and Monte Carlo algorithms according to the number of lesions and fractionation in radiosurgery of multiple brain metastases.

Purpose: In this work we compared pencil beam (PB) and Monte Carlo (MC) algorithms in single isocenter plans of multiple brain metastases radiosurgery (SIMM-SRS) plans using the quality indices reported for SRS.

Method: The plans were evaluated concerning the prescribed dose, fractions and the number of metastases. The quality indices studied were mean dose (D), D95, Paddick conformity index (PCI), Radiation Therapy Oncology Group (RTOG) homogeneity (HI) and quality of coverage indices (Q), gradient index (GI), efficiency index for targets (Gη) and organs at risk (OARη) and V-V for brain.

An international film dosimetry intercomparison to establish a multi-center audit framework.

Background: In 2021, a Technical Meeting was hosted by the International Atomic Energy Agency (IAEA) where it was recommended that a standardized method for assessing the accuracy of film dose calculations should be established.

Purpose: To design an audit that evaluates the accuracy of film dosimetry processes. To propose a framework for identifying out-of-tolerance results and to perform an international pilot study to test the audit design.

Novel Competitive ELISA Utilizing Trimeric Spike Protein of SARS-CoV-2, Could Identify More Than RBD-RBM Specific Neutralizing Antibodies in Hybrid Sera.

Since the initiation of the COVID-19 pandemic, there has been a need for the development of diagnostic methods to determine the factors implicated in mounting an immune response against the virus. The most promising indicator has been suggested to be neutralizing antibodies (nAbs), which mainly block the interaction between the Spike protein (S) of SARS-CoV-2 and the host entry receptor ACE2. In this study, we aimed to develop and optimize conditions of a competitive ELISA to measure serum neutralizing titer, using a recombinant trimeric Spike protein modified to have six additional proline residues (S(6P)-HexaPro) and h-ACE2.