Pelvic stereotactic ablative body radiotherapy (SABR) reirradiation: UK SABR consortium guidance for use in routine clinical care.

Stereotactic ablative body radiotherapy (SABR) is routinely used for the management of oligometastatic disease. Increasingly, there is overlap of targets or organs at risk with previous radiotherapy fields. As substantial variation in delivery of clinical practice exists, the UK SABR Consortium worked with a collaborative national group to develop pelvic SABR re-irradiation consensus guidelines.

Analysis of sagittal plane cine magnetic resonance imaging for measurement of pancreatic tumor residual motion during breath hold and evaluation of gating margins used in radiotherapy treatment.

Background And Purpose: In pancreatic radiotherapy, residual tumor motion during treatment increases the risk of toxicity. Cine imaging acquired during magnetic resonance guided radiotherapy (MRgRT) enables real-time treatment gating in response to anatomical motion, which can reduce this risk; however, treatment gating can negatively impact the efficiency of treatment. This study aimed to quantify the extent of residual tumor motion during breath hold and evaluate the appropriateness of the treatment gating margins used in current clinical practice.

Evaluation of hypofractionated adaptive radiotherapy using the MR Linac in localised pancreatic cancer: protocol summary of the Emerald-Pancreas phase 1/expansion study located at Oxford University Hospital, UK.

Introduction: Online adaptive MR-guided radiotherapy allows for dose escalation to pancreatic cancer while sparing surrounding critical organs. We seek to evaluate the safety of delivering hypofractionated five-fraction, three-fraction and single-fraction MR-guided stereotactic ablative radiotherapy (SABR) to the pancreas.

Methods And Analysis: This is a single-centre three-arm phase 1 non-randomised safety study.

Automated scripting of the dosimetric evaluation of adaptive versus non-adaptive radiotherapy.

. To quantify the benefit of adaptive radiotherapy over non-adaptive radiotherapy it is useful to extract and compare dosimetric features of patient treatments in both scenarios. This requires Image-Guided Radiotherapy (IGRT) matching of baseline planning to adaptive fraction imaging, followed by extraction of relevant dose metrics.

SPARC, a phase-I trial of pre-operative, margin intensified, stereotactic body radiation therapy for pancreatic cancer.

Background And Purpose: Following resection of pancreatic cancer, risk of positive margins and local recurrence remain high, especially for borderline-resectable pancreatic cancer (BRPC). We aimed to establish the maximum tolerated dose of a margin-intensified five-fraction stereotactic body radiotherapy (SBRT) regimen designed to treat the region at risk.

Materials And Methods: We conducted a prospective multicentre phase-1 rolling-six dose-escalation study.

High Quality Clinical Stereotactic Radiosurgery Planning and Delivery With Standard Resolution (5 mm) Multileaf Collimation and Multiple Isocenters.

Purpose: Our purpose was to demonstrate the use of novel planning techniques in producing high-quality stereotactic radiosurgery (SRS) plans using a standard 5 mm multileaf collimator (MLC) and multiple isocenters delivered clinically at a local institution.

Methods And Materials: Novel planning techniques consisted of offset isocenter, variable asymmetrical jaws, and Digital Imagine and Communications in Medicine (DICOM) edits to reduce leaf tip transmission, all with the aim of maximizing dose conformity. A local institution clinical cohort was planned (1-4 targets), and plan conformity metrics common to SRS were compared against conformity metrics from selected previous publications comparing Gamma Knife to linear accelerator SRS using high-definition MLC (2.

Stereotactic body radiotherapy for moderately central and ultra-central oligometastatic disease: Initial outcomes.

Background: Delivery of SBRT to central thoracic tumours within 2 cm of the proximal bronchial tree (PBT), and especially ultra-central tumours which directly abut the PBT, has been controversial due to concerns about high risk of toxicity and treatment-related death when delivering high doses close to critical mediastinal structures. We present dosimetric and clinical outcomes from a group of oligometastatic patients treated with a risk-adapted SBRT approach.

Methods: Between September 2015 and October 2018, 27 patients with 28 central thoracic oligometastases (6 moderately central, 22 ultra-central) were treated with 60 Gy in 8 fractions under online CBCT guidance.

Tuning, optimization, and perovskite solar cell device integration of ultrathin poly(3,4-ethylene dioxythiophene) films via a single-step all-dry process.

For semicrystalline poly(3,4-ethylene dioxythiophene) (PEDOT), oxidative chemical vapor deposition (oCVD) enables systematic control over the -axis lattice parameter (π-π stacking distance). Decreasing the -axis lattice parameter increases the charge transfer integral, thus enhancing intracrystallite mobility. To reduce the barrier to intercrystallite transport, oCVD conditions were tailored to produce pure face-on crystallite orientation rather than the more common edge-on orientation.

Response of FDG avid pelvic bone marrow to concurrent chemoradiation for anal cancer.

Background And Purpose: To determine if suppression of active bone marrow, as defined on FDG PETCT, is seen in on-treatment imaging of anal cancer patients receiving concurrent chemoradiation.

Methods And Materials: Scans from 26 patients participating in the ART trial (full title: Anal squamous cell carcinoma: Investigation of functional imaging during chemoRadioTherapy), a single center observational study with FDG PETCT prior to radiotherapy and at fraction 8-10 of concurrent chemoradiation were analysed. Active bone marrow was contoured in both the pelvis and un-irradiated thoracic spine.

An Electrochemical Reaction-Diffusion Model of the Photocatalytic Effect of Photosystem I Multilayer Films.

The photosynthetic protein, photosystem I (PSI), has been used as a photoactive species within a host of biohybrid photoelectrochemical systems. PSI multilayer films at electrode surfaces provide greatly improved solar energy conversion relative to homologous monolayer films. While the photocatalytic effect of PSI multilayers has been theorized as an electrolyte-mediated mechanism, no comprehensive, first-principles modeling study has been presented.

Quantifying target-specific motion in anal cancer patients treated with intensity modulated radiotherapy (IMRT).

Background And Purpose: Intensity modulated radiotherapy requires all target areas to be treated by a single radiotherapy plan. In anal cancer, the pelvic nodes, inguinal nodes and primary tumour represent three different targets. We aim to calculate target-specific motion in anal cancer radiotherapy, when delivered using a single pelvic online auto-match.

Conformity analysis to demonstrate reproducibility of target volumes for Margin-Intense Stereotactic Radiotherapy for borderline-resectable pancreatic cancer.

Background And Purpose: Margin-directed neoadjuvant radiotherapy for borderline-resectable pancreatic cancer (BRPC) aims to facilitate clear surgical margins. A systematic method was developed for definition of a boost target volume prior to a formal phase-I study.

Material And Methods: Reference structures were defined by two oncologists and one radiologist, target structures were submitted by eight oncologist investigators and compared using conformity indices.

Modeling early haematologic adverse events in conformal and intensity-modulated pelvic radiotherapy in anal cancer.

Background And Purpose: To determine if there are differences between dose to pelvic bone marrow (PBM) using intensity modulated radiotherapy (IMRT) under UK guidance versus conformal radiotherapy (CRT) per ACT II protocol and if differences translate to rates of early haematological adverse events grade 3 or greater (HT3+).

Methods And Materials: Two groups of 20+ patients, treated under IMRT and CRT regimes respectively, were identified. All patients underwent weekly blood cell count: haemoglobin (HgB), white cell count (WCC), absolute neutrophil count (ANC) and platelets (plats).