Publications by authors named "Dinesh Vignarajah"

Objectives: Diffusion-weighted MRI (DWI) may provide biologically relevant target volumes for dose-escalated radiotherapy in locally advanced rectal cancer (LARC). This planning study assessed the dosimetric feasibility of delivering hypofractionated boost treatment to intra-tumoural regions of restricted diffusion prior to conventional long-course radiotherapy.

Methods: Ten patients previously treated with curative-intent standard long-course radiotherapy (50 Gy/25#) were re-planned.

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Magnetic resonance imaging (MRI) is being integrated into routine radiation therapy (RT) planning workflows. To reap the benefits of this imaging modality, patient positioning, image acquisition parameters and a quality assurance programme must be considered for accurate use. This paper will report on the implementation of a retrofit MRI Simulator for RT planning, demonstrating an economical, resource efficient solution to improve the accuracy of MRI in this setting.

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Background: Establishing a new head and neck cancer (HNC) treatment center requires multidisciplinary team management and expertise. To our knowledge, there are no clear recommendations or guidelines in the literature for the commencement of HNC radiation therapy (RT) at a new cancer center. We propose a novel framework outlining the necessary components required to set-up a new radiation therapy HNC treatment.

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Objective: The optimal method for delineation of dominant intraprostatic lesions (DIL) for targeted radiotherapy dose escalation is unclear. This study evaluated interobserver and intermodality variability of delineations on biparametric MRI (bpMRI), consisting of weighted (W) and diffusion-weighted (DWI) sequences, and Ga-PSMA-PET/CT; and compared manually delineated GTV contours with semi-automated segmentations based on quantitative thresholding of intraprostatic apparent diffusion coefficient (ADC) and standardised uptake values (SUV).

Methods: 16 patients who had bpMRI and PSMA-PET scanning performed prior to any treatment were eligible for inclusion.

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Objectives: To evaluate interobserver agreement for weighted (W) and diffusion-weighted MRI (DW-MRI) contours of locally advanced rectal cancer (LARC); and to evaluate manual and semi-automated delineations of restricted diffusion tumour subvolumes.

Methods: 20 cases of LARC were reviewed by 2 radiation oncologists and 2 radiologists. Contours of gross tumour volume (GTV) on W, DW-MRI and co-registered W/DW-MRI were independently delineated and compared using Dice Similarity Coefficient (DSC), mean distance to agreement (MDA) and other metrics of interobserver agreement.

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Objective: A cohort of high dose-rate (HDR) monotherapy patients was analyzed to (i) establish the frequency of non-malignant urethral stricture; (ii) explore the relation between stricture formation with the dose distribution along the length of the urethra, and MRI radiomics features of the prostate gland.

Methods: A retrospective review of treatment records of patients who received 19 Gy single fraction of HDR brachytherapy (BT) was carried out. A matched pair analysis used one control for each stricture case matched with pre-treatment International Prostate Symptom Score (IPSS) score, number of needles used and clinical target volume volume for each stricture case identified.

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Introduction: As a consequence of the development of improved treatment techniques and utilisation of digital records in radiation oncology, the RANZCR Peer Review Audit Tool has become outdated. The aim of this internal audit was to objectively evaluate the practice of our radiation oncology department to ensure that patients are being treated according to evidence-based national guidelines through the use of a new self-audit algorithm, the Radiation Oncology Quality Assessment Tool (ROQAT).

Methods: Using ROQAT, a retrospective audit was conducted of patients who received definitive treatment within the first six months (June 2017-November 2017) of opening a new radiation oncology department at the Sunshine Coast University Hospital.

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Introduction: The multidisciplinary team meeting (MDTM) approach is accepted as standard of care to optimise treatment for patients diagnosed with cancer. This retrospective audit reviews the proportion of patients whose care is being discussed at cancer MDTMs within the Sunshine Coast Hospital and Health Service (SCHHS).

Methods: Patients included were those diagnosed with cancer within the SCHHS between 2010 and 2015, and subsequently referred to a public MDTM for discussion.

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