Quantitative validation of Monte Carlo SPECT simulation: application to a Mediso AnyScan GATE simulation.

Background: Monte Carlo (MC) simulations are used in nuclear medicine imaging as they provide unparalleled insight into processes that are not directly experimentally measurable, such as scatter and attenuation in an acquisition. Whilst MC is often used to provide a 'ground-truth', this is only the case if the simulation is fully validated against experimental data. This work presents a quantitative validation for a MC simulation of a single-photon emission computed tomography (SPECT) system.

Triple modality image reconstruction of PET data using SPECT, PET, CT information increases lesion uptake in images of patients treated with radioembolization with [Formula: see text] micro-spheres.

Purpose: Nuclear medicine imaging modalities like computed tomography (CT), single photon emission CT (SPECT) and positron emission tomography (PET) are employed in the field of theranostics to estimate and plan the dose delivered to tumors and the surrounding tissues and to monitor the effect of the therapy. However, therapeutic radionuclides often provide poor images, which translate to inaccurate treatment planning and inadequate monitoring images. Multimodality information can be exploited in the reconstruction to enhance image quality.

Development of a validation imaging dataset for Molecular Radiotherapy dosimetry multicenter intercomparison exercises based on anthropomorphic phantoms.

Unlabelled: Validation of a Molecular Radiotherapy (MRT) dosimetry system requires imaging data for which an accompanying "ground truth" pharmacokinetic model and absorbed dose calculation are known.

Methods: We present a methodology for production of a validation dataset for image based Lu dotatate dosimetry calculations. A pharmacokinetic model is presented with activity concentrations corresponding to common imaging timepoints.

Hybrid kernelised expectation maximisation for Bremsstrahlung SPECT reconstruction in SIRT with Y micro-spheres.

Background: Selective internal radiation therapy with Yttrium-90 microspheres is an effective therapy for liver cancer and liver metastases. Yttrium-90 is mainly a high-energy beta particle emitter. These beta particles emit Bremsstrahlung radiation during their interaction with tissue making post-therapy imaging of the radioactivity distribution feasible.

A multicentre and multi-national evaluation of the accuracy of quantitative Lu-177 SPECT/CT imaging performed within the MRTDosimetry project.

Purpose: Patient-specific dosimetry is required to ensure the safety of molecular radiotherapy and to predict response. Dosimetry involves several steps, the first of which is the determination of the activity of the radiopharmaceutical taken up by an organ/lesion over time. As uncertainties propagate along each of the subsequent steps (integration of the time-activity curve, absorbed dose calculation), establishing a reliable activity quantification is essential.

Absolute standardisation and determination of the half-life and gamma emission intensities of Zr.

An absolute standardisation of Zr was performed alongside determination of gamma emission intensities and half-life. The collected data were evaluated alongside complementary works from previous publications and new recommended nuclear data values are presented including a new evaluated T = 78.361(25) h and new absolute intensities for gamma transitions resulting from its decay to Y.

I intercomparison exercises: Assessment of measurement capabilities in UK hospitals.

Three comparison exercises have been performed in 1996, 1999 and 2015 with I to assess the UK hospitals measurement capabilities using radionuclide calibrators for this particular radionuclide. The exercise performed in 1996 showed that only 62% of the participants could measure the solution to within 10% of the standardised value and only 28% could measure within 5% of the certificated value. The intercomparison exercise performed in 1999 showed no improvement in the measurement capability, with only 66% of the participants measuring to within 10% of the standardised value.

Standardisation of (90)Y and determination of calibration factors for (90)Y microspheres (resin) for the NPL secondary ionisation chamber and a Capintec CRC-25R.

The use of (90)Y resin microspheres (SIR-Spheres® microspheres) in Nuclear Medicine has dramatically increased in recent years due to its favourable outcome in the treatment of liver cancer and liver metastases (Rajekar et al., 2011). The measurement of administered activity before and residual activity after treatment in radionuclide calibrators is required to determine total activity delivered to the patient.