Professional

PhD in Medical Physics — University of Surrey (CVSSP)

Nuclear Medicine, SiPM-based PET/CT Imaging, Molecular Imaging, Radiation Therapy, Dose Painting, Image Quality, Image Processing, Problem Solving, Data Analysis, Research.

MSc in Medical Physics — University of Surrey

Radiation Safety and Measurement, Monte Carlo Simulation, Radiation Biology, Diagnostic Imaging, NonIonising Imaging, Mathematics, Biology, Anatomy, Problem Solving, Data Analysis, Research.

BSc in Physics — University of Kent

Medical Physics, Mathematics, Mechanics, Atomic Physics, Nuclear Physics, Quantum Physics, Electromagnetism, Optics, Special Relativity, Thermodynamics, Solid State Physics, Laboratory, 3D Printing.

Medical Physicist — East and North Hertfordshire NHS Trust

Providing physics support across nuclear medicine and diagnostic radiology, and acting as study lead on a clinical research project. I deliver regional annual and routine quality assurance on PET/CT, SPECT/CT, radionuclide calibrators, CT and diagnostic and interventional X-ray and fluoroscopy systems, alongside radiation protection, dose audit and dosimetry. I designed and built a QA database to capture, validate and trend results across modalities and sites, streamlining reporting and supporting compliance with legislation.

PhD in Medical Physics — University of Surrey

Led advanced quantitative characterisation of a GE Discovery MI Gen 2 SiPM-based PET/CT scanner and applied this to radiotherapy applications. I designed an independent Phantom Analysis Tool (PAT) to reproduce and extend NEMA image-quality analysis, modified NEMA phantoms with sub-centimetre spheres to probe small-lesion detectability (down to 4 mm), and developed an acquisition-time model demonstrating scan-time reductions while maintaining detectability. I also built a Performance Equalisation Algorithm to degrade SiPM images to PMT-equivalent quality for radiologist training, and applied SiPM imaging to head-and-neck dose-painting studies. Delivered as a collaboration with Royal Surrey NHS Foundation Trust, Alliance Medical and the National Physical Laboratory.

Collaboration & work experience — Royal Surrey NHS Foundation Trust, Alliance Medical & National Physical Laboratory

Experimental research, system commissioning, PACS training, annual QA and NEMA testing, precise radiation measurement, and shadowing including patient imaging and radiopharmaceutical preparation.

Collaboration & work experience — Lancashire Teaching Hospitals NHS Trust

Experimental research, shadowing including patient imaging and radiopharmaceutical preparation.

PhD Chapter — Independent Performance Characterisation Tool for PET Phantom Analysis

I designed and built a Phantom Analysis Tool (PAT) to independently reproduce and extend the NEMA NU 2 image-quality methodology, removing reliance on proprietary on-scanner software. The tool was validated against vendor analysis and used to characterise a GE Discovery MI Gen 2 SiPM PET/CT system against published performance standards.

PhD Chapter — Phantom Evaluation of Lesion Detectability in Silicon-Detector-Based PET

I modified the NEMA image-quality phantom with sub-centimetre spherical inserts (4.0–7.9 mm) and used contrast-to-noise ratio, a lesion detectability index and observer Likert scoring to quantify small-lesion detectability on the SiPM system, demonstrating reliable detection down to 4 mm. I also developed an acquisition-time model relating lesion size, signal-to-background ratio and detectability, showing scan-time savings of 36–65% for SiPM PET.

PhD Chapter — Degrading SiPM PET Images to Model Conventional PMT Imaging

I developed a Performance Equalisation Algorithm (PEA) that degrades high-resolution SiPM PET images to the spatial resolution and sensitivity of conventional PMT systems, using interpolation, an intensity transform and Gaussian filtering. Parameters were optimised and independently validated with gamma analysis, raising whole-phantom pass rates from 81% to 94% and enabling consistent cross-platform comparison and training data.

PhD Chapter — The Role of SiPM-Based PET in Functional Dose Modulation

I applied SiPM PET to radiotherapy dose painting for five head-and-neck cancer patients, comparing target-volume delineation and dose-painting prescriptions (by-contours and by-numbers) against degraded PMT-equivalent images. The SiPM system delineated volumes closer to the true geometric volume, producing prescribed-dose differences of up to 6% for the smallest, lowest-uptake tumours, with implications for tumour control probability modelling.

MSc Research Project — Optical Surface Capture for 3D Printing in Skin Radiotherapy

This project explored the use of Microsoft Azure Kinect 3D depth cameras to produce facial boluses for radiotherapy. Key aspects included evaluating the accuracy of the depth measurements against ground truth distances and comparing Open3D reconstruction techniques, such as Iterative Closest Point (ICP) and manual reconstruction, using both test data and data from a mannequin head. Additionally, data processing workflows were developed to convert raw captured data into a format suitable for further use.

MSc Experimental Project — Nuclear Medicine

This project involved experimentally assessing hardware and software of a Positron Emission Tomography (PET) system and conducting a glomerular filtration rate test. Pixel size, count number and collimator distance were assessed using a Williams Liver Phantom to determine the impact of these variables. This was extended post-imaging to include the impact of reconstruction methods and attenuation correction on the resulting images. Glomerular filtration rate was calculated for a number of patients and the importance of quality control in nuclear medicine was discussed.

MSc Experimental Project — Monte Carlo Modelling

The project involved employing the Tool for Particle Simulation (TOPAS) for Monte Carlo modeling to investigate Bremsstrahlung radiation from a tungsten plate at different X-ray energies. Additionally, the project examined the anode heel effect with respect to variations in detector distance and anode angle.

BSc Research Project — Building and Programming a Custom 3D-Printed Drone

This project involved designing and developing a custom drone using OpenSCAD for 3D modeling and printing. I programmed the power control system using Arduino to optimize power distribution and efficiency during flight and conducted detailed assessments of the drone's power management, ensuring stable and efficient performance. Results were assessed and presented for submission as my final year project.

Assessing small-lesion detectability and acquisition time optimisation in silicon-detector-based PET: a phantom study — EJNMMI Physics

Leybourne N, Prakash V, Hussein M, Fenwick A, Strouhal P, Evans P, Florescu L
10.1186/s40658-025-00821-9

The role of SiPM-based PET for accurate volume delineation — SPIE Medical Imaging 2025

Leybourne N, Hussein M, Fenwick A, Evans P, Florescu L
10.1117/12.3046960

Enhanced Performance Characteristics of Digital PET for Small Feature Detection Relative to Non-Digital PET — SPIE Medical Imaging 2024

Leybourne N, Gregory R, Berry O, Scuffham J, Evans P, Florescu L, et al.
10.1117/12.3006788