Niall MacDougall

• PhD
• Queen Mary University of London

Complex radiotherapy techniques call for three-dimensional dosimetric methods with high spatial resolution. Radiation-sensitive polymer gel systems (e.g. commercially available BANG(TM) gel), read using MRI T2 mapping, offer a promising solution. A series of calibration test tubes is traditionally used to calculate the dose delivered to a larger, d...

Objective: To study the in vitro and in vivo (abdomen) variability of apparent diffusion coefficient (ADC) measurements at 1.5 T using a free-breathing multislice diffusion-weighted (DW) MRI sequence. Methods: DW MRI images were obtained using a multislice spin-echo echo-planar imaging sequence with b-values=0, 100, 200, 500, 750 and 1000 s mm(-...

There is increasing interest in stereotactic body radiotherapy (SBRT) for the management of prostate adenocarcinoma, with encouraging initial biological progression-free survival results. However, the limited literature is dominated by the use of the Cyberknife platform. This led to an international phase III study comparing outcomes for Cyberknife...

Objective: Radiotherapy treatments of post-mastectomy chest walls are complex, requiring treatment close to skin, necessitating bolus use. Commonly used 5- and 10-mm-thick boluses develop full skin dose, needing removal for the latter half of treatment and requiring two treatment plans to be generated. Can a thinner bolus be used for all treatment...

Objectives: A simple, robust method, for optimising cone-beam CT (CBCT) dose and image quality for pelvis treatment, based on patient-specific attenuation. Methods: Methods were investigated for grouping patients into four imaging categories (small [S], medium [M], large [L], extra large [XL]), based on planning-CT CTDIvol, and phantoms construc...

BACKGROUND Stereotactic Radiosurgery (SRS) for patients with intracranial disease is increasing, especially for smaller and more numerous metastases. In England, Varian HyperArc using a Truebeam linac is nationally commissioned via benchmarking. HyperArc contains SRS-specific optimisation and non-coplanar VMAT delivery and is an attractive option d...

Objectives To determine if Limbus, an artificial intelligence (AI) auto-contouring software, can offer meaningful time savings for prostate radiotherapy treatment planning. Methods Three clinical oncologists recorded the time taken to contour prostate and seminal vesicles, lymph nodes, bladder, rectum, bowel, and femoral heads on CT scans for 30 p...

Physics for Clinical Oncology is an essential text that teaches the clinically important physics of radiotherapy. Knowledge and understanding of the physics that underpins radiotherapy is essential for optimum practice. Updated for a second edition, capturing the developments of the last decade, the book begins with basic concepts and principles of...

Physics for Clinical Oncology is an essential text that teaches the clinically important physics of radiotherapy. Knowledge and understanding of the physics that underpins radiotherapy is essential for optimum practice. Updated for a second edition, capturing the developments of the last decade, the book begins with basic concepts and principles of...

Physics for Clinical Oncology is an essential text that teaches the clinically important physics of radiotherapy. Knowledge and understanding of the physics that underpins radiotherapy is essential for optimum practice. Updated for a second edition, capturing the developments of the last decade, the book begins with basic concepts and principles of...

Physics for Clinical Oncology is an essential text that teaches the clinically important physics of radiotherapy. Knowledge and understanding of the physics that underpins radiotherapy is essential for optimum practice. Updated for a second edition, capturing the developments of the last decade, the book begins with basic concepts and principles of...

The aim of this work was to evaluate the water-equivalence of new trial plastics designed specifically for light-ion beam dosimetry as well as commercially available plastics in clinical proton beams. The water-equivalence of materials was tested by computing a plastic-to-water conversion factor, Hpl,w. Trial materials were characterized experiment...

Objectives: Towards Safer Radiotherapy (1) recommended that radiotherapy centres should have protocols in place for in vivo dosimetry (IVD) monitoring at the beginning of patient treatment courses. This report determines IVD implementation in the UK in 2014, the methods used and makes recommendations on future use. Methods: Evidence from peer-re...

Water-equivalent plastics are frequently used in dosimetry for experimental simplicity. This work evaluates the water-equivalence of novel water-equivalent plastics specifically designed for light-ion beams, as well as commercially available plastics in a clinical high-energy carbon-ion beam. A plastic- to-water conversion factor was established to...

Objectives: The purpose of this work was to assess heating and radiofrequency (RF) deposition and image quality effects of a prototype three-section carbon fibre flatbed insert for use in MRI. Methods: RF deposition was assessed using two different thermometry techniques, infrared thermometry and Bragg-grating thermometry. Image quality effects...

We report three patients who developed symptoms and signs of ocular neuromyotonia (ONM) 3-6 months after receiving gamma knife radiosurgery (GKS) for functioning pituitary tumours. All three patients were complex, requiring multi-modality therapy and all had received prior external irradiation to the sellar region. Although direct causality cannot...

The first portable graphite calorimeter for light-ion therapy was built at the National Physical Laboratory (NPL), UK. Dose conversion factors are required to convert the quantity measured, absorbed dose-to-graphite, to the quantity of interest, absorbed dose-to-water. Due to the difference between non-elastic nuclear interactions for different ele...

Objective: There remains concern regarding the use of fiducial-based image-guided radiotherapy (IGRT) in patients with high-risk prostate cancer also undergoing intensity-modulated radiotherapy (IMRT) to pelvic nodes. By a retrospective study, we aim to ascertain the impact of the use of fiducial-based IGRT on lymph node planned target volume (PTV...

Radiotherapy remains the major non-surgical treatment modality for malignant disease, with over 50% of patients receiving radiotherapy at some point in their treatment. The physics behind the administration of radiotherapy is essential to an understanding of how the treatment works, and therefore ensuring optimum practice. However, most oncologists...

Radiotherapy remains the major non-surgical treatment modality for malignant disease, with over 50% of patients receiving radiotherapy at some point in their treatment. The physics behind the administration of radiotherapy is essential to an understanding of how the treatment works, and therefore ensuring optimum practice. However, most oncologists...

Radiotherapy remains the major non-surgical treatment modality for malignant disease, with over 50% of patients receiving radiotherapy at some point in their treatment. The physics behind the administration of radiotherapy is essential to an understanding of how the treatment works, and therefore ensuring optimum practice. However, most oncologists...

Radiotherapy remains the major non-surgical treatment modality for malignant disease, with over 50% of patients receiving radiotherapy at some point in their treatment. The physics behind the administration of radiotherapy is essential to an understanding of how the treatment works, and therefore ensuring optimum practice. However, most oncologists...

Radiotherapy remains the major non-surgical treatment modality for malignant disease, with over 50% of patients receiving radiotherapy at some point in their treatment. The physics behind the administration of radiotherapy is essential to an understanding of how the treatment works, and therefore ensuring optimum practice. However, most oncologists...

Intensity-modulated radiotherapy (IMRT) is a relatively new technique of delivering external beam radiotherapy that is becoming increasingly available in the UK. This paper summarises the introduction and initial clinical work in IMRT over the period 2004-2009. Physics aspects of commissioning are described, including the development of a robust me...

This manuscript describes a direct comparison between radiation treatment plans in terms of dosimetric outcomes created by two different IMRT systems: TomoTherapy HiArt and dynamic linac intensity-modulated radiotherapy (dIMRT). Three patient cases were selected (with disease in different anatomical areas): vertebral metastasis re-treatment, radica...

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Post-implantation dosimetry is an important element of permanent prostate brachytherapy. This process relies on accurate localization of implanted seeds relative to the surrounding organs. Localization is commonly achieved using CT images, which provide suboptimal prostate delineation. On MR images, conversely, prostate visualization is excellent b...

New radiotherapy techniques call for three-dimensional dosimetric methods with high spatial resolution. Radiation sensitive gels read out using MRI T(2) mapping provide an extremely promising option, and commercially available BANG polymer gels provide a convenient route into gel dosimetry. Gel dosimetry is dependent on the ability to calibrate gel...

This article is in full in the PDF file below.

This article is in full in the PDF file below, with a reply by van der Laarse.

The purpose of this work is to undertake a critical appraisal of the evidence in the published literature concerning the basic parameters of accuracy and precision associated with the use of Fricke and polymer gels (in conjunction with MR imaging) as radiation dosimeters in photon radiotherapy, condensing and analysing the body of published informa...

The treatment parameters necessary for the isocentric treatment of an inclined volume have to be determined either analytically or through simulation. The derivation of the treatment parameters for the treatment of a transverse plane has been described previously. This work describes the derivation of the treatment parameters necessary for the isoc...