Impact of a contouring atlas on radiographer inter-observer variation in male pelvis radiotherapy.

Purpose/objective: To determine the impact of a MR-based contouring atlas for male pelvis radiotherapy delineation on inter-observer variation to support radiographer led real-time magnetic resonance image guided adaptive radiotherapy (MRgART).

Material/methods: Eight RTTs contoured 25 MR images in the Monaco treatment planning system (Monaco 5.40.

Feasibility of using a dual isocentre technique for treating cervical cancer on the 1.5 T MR-Linac.

Patients treated for cervical cancer exhibit large inter and intra-fraction anatomical changes. The Unity MR-Linac (MRL) can image these patients with MR prior to and during treatment which enables daily plan adaptation. However, the MRL has a limited treatment field in the sup/inf direction of 22 cm which can restrict the treatment of patients who require longer treatment fields.

To see or not to see: Evaluation of magnetic resonance imaging sequences for use in MR Linac-based radiotherapy treatment.

Background/purpose: This work evaluated the suitability of MR derived sequences for use in online adaptive RT workflows on a 1.5 Tesla (T) MR-Linear Accelerator (MR Linac).

Materials/methods: Non-patient volunteers were recruited to an ethics approved MR Linac imaging study.

The impact of gadolinium-based MR contrast on radiotherapy planning for oropharyngeal treatment on the MR Linac.

Purpose: Gadolinium-based contrast agents (GBCAs) may add value to magnetic resonance (MR)-only radiotherapy (RT) workflows including on hybrid machines such as the MR Linac. The impact of GBCAs on RT dose distributions however have not been well studied. This work used retrospective GBCA-enhanced datasets to assess the dosimetric effect of GBCAs on head and neck plans.

Developing electronic learning to deliver MR safety training in a radiotherapy department.

Introduction/background: Magnetic Resonance Imaging (MRI) is used in radiotherapy planning, and increasingly in on-treatment guidance. The potential for the MR environment to be hazardous, without stringent safe working practices, is real. Guidance suggests all workers in MRI undergo annual safety training.

MRI and CBCT for lymph node identification and registration in patients with NSCLC undergoing radical radiotherapy.

Purpose: This study compared MRI to CBCT for the identification and registration of lymph nodes (LN) in patients with locally advanced (LA)-NSCLC, to assess the suitability of targeting LNs in future MR-image guided radiotherapy (MRgRT) workflows.

Method: Radiotherapy radiographers carried out Visual Grading Analysis (VGA) assessment of image quality, LN registration and graded their confidence in registration for each of the 24 LNs on CBCT and two MR sequences, MR1 (T2w Turbo Spin Echo) and MR2 (T1w DIXON water only image).

Results: Pre-registration image quality assessment revealed MR1 and MR2 as significantly superior to CBCT in terms of image quality (p ≤ 0.

An unusual case of oedematous prostate volumetric changes observed over the course of radiotherapy on the MR linear accelerator.

Introduction: The integration of magnetic resonance (MR) imaging into radiotherapy through new technology, including the MR -linear accelerator (MRL), has allowed further advancements into image guided radiotherapy (IGRT). Better soft tissue visualisation has led to some unusual findings.

Case And Outcomes: A patient with T1c N0 M0 prostate adenocarcinoma received 60Gy in 20# radiotherapy on the MRL.

Therapeutic Radiographers at the Helm: Moving Towards Radiographer-Led MR-Guided Radiotherapy.

Introduction: Magnetic resonance-guided adaptive radiotherapy (MRgART) has the potential to improve treatment processes and outcomes for a variety of tumour sites; however, it requires significant clinical resources. Magnetic resonance linear accelerator (MR-linac) treatments require a daily multidisciplinary presence for delivery. To facilitate sustainable MRgART models, agreed protocols facilitating therapeutic radiographer (RTT)-led delivery must be developed to establish a service similar to conventional image-guided radiotherapy (IGRT).

Comparison of radiographer interobserver image registration variability using cone beam CT and MR for cervix radiotherapy.

Objectives: The aim of this study was to assess the consistency of therapy radiographers performing image registration using cone beam computed tomography (CBCT)-CT, magnetic resonance (MR)-CT, and MR-MR image guidance for cervix cancer radiotherapy and to assess that MR-based image guidance is not inferior to CBCT standard practice.

Methods: 10 patients receiving cervix radiation therapy underwent daily CBCT guidance and magnetic resonance (MR) imaging weekly during treatment. Offline registration of each MR image, and corresponding CBCT, to planning CT was performed by five radiographers.