Objective. The aim of this work was to develop and validate a method for remote dosimetric auditing that enables dose-volume histogram parameter comparisons of measured and planned dose in the patient CT volume. Approach . The method is derived by adapting and combining a remote electronic portal imaging (EPID) based auditing method (Virtual Epid based Standard Phantom Audit—VESPA) and a method to estimate 3D in-patient dose distributions from planar dosimetric measurements. The method was tested with a series of error-induced plans including monitor unit and multileaf collimator (MLC) positioning errors. A pilot audit study was conducted with eleven radiotherapy centres. IMRT plans from two clinical trials, a post-prostatectomy (RAVES trial) plan and a head and neck (HPV trial) plan were utilized. Clinically relevant DVH parameters for the planned dose and estimated measured dose were compared. Main results . The method was found to reproduce the induced dose errors within 0.5% and was sensitive to MLC positioning errors as small as 0.5 mm. For the RAVES plan audit all DVH results except one were within 3% and for the HPV plan audit all DVH results were within 3% except three with a maximum difference of 3.2%. Significance . The results from the audit method produce clinically meaningful DVH metrics for the audited plan and could enable an improved understanding of a centre’s radiotherapy quality.

The SAFRON II trial was a phase 2 trial comparing single fraction (SF) SBRT and multi-fraction (MF) SBRT. Patients with 1-3 pulmonary oligometastases from solid tumors located away from the central airways were randomized 1:1 between 28Gy in 1 and 48Gy in 4 fraction arms. There were no differences between arms in efficacy or toxicity. We performed an analysis to assess differences in pulmonary function tests (PFTs) between arms, assess relationship between change in PFTs and the number and total volume of targets treated.

Abstract BACKGROUND The O-(2-[18F]-fluoroethyl)-L-tyrosine positron emission tomography (FET-PET) in Glioblastoma (FIG) study is a prospective study evaluating the management impact of FET-PET imaging in up to 210 newly diagnosed adult glioblastoma patients across 10 Australian sites. Patients undergo contrast MRI and FET-PET at 3 timepoints: pre-chemoradiotherapy (CRT), one-month post-CRT and at suspected progression. MRI QA programme components, approach and integrated workflows are described here. MATERIAL AND METHODS The FIG MRI protocol comprised 3D-T1, 3D-FLAIR, Axial 2D DWI (including derived ADC map), DCE (including T1 mapping), DSC, Axial T2 and 3D T1-post-contrast (T1C) sequences, with SWI and 3D DIR sequences optional. QA components included data acquisition quality and completeness (standard and advanced), motion artefact, low contrast to noise or signal to noise, series description and susceptibility artifacts. Suitability of T1/T1C using modified RANO (mRANO) criteria was assessed. An optimised workflow involved site upload from local PACS systems to centralised database via TROG Central Quality Management System (CQMS) platform and collation into a central imaging database utilising MIM software. The MRI QA workflow encompassed automated anonymisation of DICOM data, data completeness and reconstruction evaluation, then review by two expert neuroimaging analysts. Sites received feedback with request for resubmission where required. RESULTS Between December 2021 and February 2023, MRI data in 74 patients across 9 sites with median of 6 patients (range 2-17) per site was submitted. A total of 141 MRI datasets across all timepoints were collected (per site range:4-35, median:13), with 43 imaging time-points selected for QA (per site range:3-12, median: 4). Importantly, 41/43 (95%) of initial datasets were deemed suitable for mRANO assessment, but only 13/43 (30%) were suitable for advanced MRI analysis. Very few datasets had motion or susceptibility artifacts, low contrast to noise or signal to noise, or incorrect series description. Technical issues identified included incomplete data (DCE - missing T1 maps, DWI - missing ADC maps), incorrect sequence reconstruction (DCE split series and Axial/Sagittal/Coronal reformats for 3D images) and lack of non-mandatory SWI sequences. Feedback to sites resulted in improvements in DCE sequence acquisition from split series in 11/45 (24%) to preferred single series in 18/24 (75%) and similar increases in T1 maps completeness from 7/19 (37%) to 7/7 (100%). CONCLUSION Despite challenges in multisite workflow and substantial multi-modality site and central data management, a robust MRI QA program has confirmed 95% compliance for mRANO assessment. Site specific feedback resulted in increased compliance with advanced MRI sequences to enable detailed future analysis.

Co-occurring pathological mutations in non-small cell lung cancer (NSCLC) may account for clinical heterogeneity not explained by the single driver mutation model. The prognostic significance of various co-mutations and adjuvant treatment modalities has been explored in early-stage NSCLC, but there has not been a focus on the impact of smoking and EGFR co-mutations in early-stage NSCLC. This study aims to characterize the frequency of co-mutations in EGFR-mutated (EGFRm) early-stage resected NSCLC; to describe relationships between smoking history and co-mutation status; and to determine whether prognosis differs by co-mutation status and smoking status among patients with EGFRm NSCLC.

Multiple clinical trials and meta-analyses have demonstrated the benefit of adjuvant chemotherapy for patients with early-stage resected NSCLC. Using a real-world registry of patients with early-stage NSCLC, we evaluated the effects of adjuvant chemotherapy, adjuvant radiation, and adjuvant chemoradiation on overall survival (OS).

Congenital achromatopsia is characterised by an absence of functioning cone photoreceptors, resulting in poor visual acuity and no colour vision. While previous psychophysical studies have investigated basic functions including acuity and contrast sensitivity, little is known about the effects of achromatopsia on mid- and higher-level vision. We measured coherence thresholds for form, motion and biological motion in four patients and six controls under varying light levels, including scotopic conditions in which controls and patients were comparable in being reliant only on rods. The patient group showed higher coherence thresholds at all light levels for the form and motion tests, while their biological motion thresholds were comparable to controls. Additional tests confirmed that poor contrast sensitivity could not account for these results in three out of four of the patients. The second phase of the study will use vERPs to measure and localise cortical responses to these stimuli. Previous research with controls has shown distinct patterns of activation in response to coherent form and motion, namely a midline response to motion and a lateralised response to form [Wattam-Bell et al, 2010, Current Biology, 20, 411-415]. Data we have collected with controls has also demonstrated a specific right hemisphere response to biological motion. These results will be compared to those from patients in order to determine the extent to which elevated form and motion thresholds reflect atypical patterns of cortical processing. Our results show that visual impairment in congenital achromatopsia extends beyond previously examined low-level visual functions, to include coherent form and motion perception. This suggests that atypical photoreceptor function can affect the development of cortical visual processing. Potential advances in treatments for genetic visual disorders including retinal gene replacement therapy raise questions regarding neural plasticity, including the extent to which cortical visual processing can be reorganised following restoration of photoreceptor function. Meeting abstract presented at VSS 2013