Deep learning application for abdominal organs segmentation on 0.35 T MR-Linac images.

Introduction: Linear accelerator (linac) incorporating a magnetic resonance (MR) imaging device providing enhanced soft tissue contrast is particularly suited for abdominal radiation therapy. In particular, accurate segmentation for abdominal tumors and organs at risk (OARs) required for the treatment planning is becoming possible. Currently, this segmentation is performed manually by radiation oncologists.

Six-probe scintillator dosimeter for treatment verification in HDR-brachytherapy.

Background: In vivo dosimetry (IVD) is gaining interest for treatment delivery verification in HDR-brachytherapy. Time resolved methods, including source tracking, have the ability both to detect treatment errors in real time and to minimize experimental uncertainties. Multiprobe IVD architectures holds promise for simultaneous dose determinations at the targeted tumor and surrounding healthy tissues while enhancing measurement accuracy.

Online adaptive radiotherapy and dose delivery accuracy: A retrospective analysis.

Purpose: With online adaptive radiotherapy (ART), patient-specific quality assurance (PSQA) testing cannot be performed prior to delivery of the adapted treatment plan. Consequently, the dose delivery accuracy of adapted plans (i.e.

Characterisation of a split gradient coil design induced systemic imaging artefact on 0.35 T MR-linac systems.

. The aim of this work was to highlight and characterize a systemic 'star-like' artefact inherent to the low field 0.35 T MRIdian MR-linac system, a magnetic resonance guided radiotherapy device.

Characterization of a miniaturized scintillator detector for time-resolved treatment monitoring in HDR-brachytherapy.

HDR brachytherapy combines steep dose gradients in space and time, thereby requiring detectors of high spatial and temporal resolution to perform accurate treatment monitoring. We demonstrate a miniaturized fiber-integrated scintillator detector (MSD) of unmatched compactness which fulfills these conditions.The MSD consists of a 0.

Evaluation of QA software system analysis for the static picket fence test.

Intensity modulation treatments are widely used in radiotherapy because of many known advantages. In this context, the picket fence test (PF) is a relevant test to check the Multileaf Collimator (MLC) performances. So this work compares and evaluates three analysis platforms for the PF used routinely by three different institutions.

Miniaturized scintillator dosimeter for small field radiation therapy.

The concept of a miniaturized inorganic scintillator detector is demonstrated in the analysis of the small static photon fields used in external radiation therapy. Such a detector is constituted by a 0.25 mm diameter and 0.

and impact of high-dose rate radiotherapy using flattening-filter-free beams on the anti-tumor immune response.

Introduction: Modern accelerators have the "flattening filter-free" (FFF) technique to deliver RT with a moderate high-dose rate, currently used in limited clinical indications. No scientifically established data are currently available on the possible effects of this high dose rate on the anti-tumor immune response. We therefore propose here to study these effects in a preclinical CT26 murine colorectal tumor model.

Patterns of Failure in Patients With Head and Neck Squamous Cell Carcinomas of Unknown Primary Treated With Chemoradiotherapy.

Background: To evaluate the patterns of failure in patients treated for head and neck carcinoma of unknown primary and to discuss treatment practices concerning radiotherapy target volumes definition and dose prescription.

Methods: Eleven patients presenting a locoregional recurrence after head and neck carcinoma of unknown primary treatment with curative-intent radiochemotherapy performed between 2007 and 2017 in the departments of radiation oncology of 2 French cancer institutes. Images of the computed tomography scan or the magnetic resonance imaging performed at the time of the recurrence were fused with those of the simulation computed tomography scan to delimit a volume corresponding to the recurrence and to define the area of relapse compared to the volumes treated.

Salvage extended field or involved field nodal irradiation in F-fluorocholine PET/CT oligorecurrent nodal failures from prostate cancer.

Purpose: The concept of metastasis-directed therapy for nodal oligorecurrences with stereotactic body radiotherapy is increasingly accepted. Hence, the comparison between salvage extended field radiotherapy (s-EFRT) and salvage involved field radiotherapy (s-IFRT) in patients with F-fluorocholine (FCH) PET/CT+ nodal oligorecurrences from prostate cancer is worthy of investigation.

Methods: Patients with oligorecurrent nodes on FCH PET/CT treated with salvage radiotherapy between 2009 and 2017 in a single tertiary cancer centre were selected for this study.

Salvage brachytherapy as a modern reirradiation technique for local cancer failure: The Phoenix is reborn from its ashes.

The treatment of local recurrence of a previously irradiated cancer or a second cancer arising in-field remains challenging. Ultimately, the objective of salvage therapy is to control disease while ensuring minimal collateral damage, thereby optimizing both cancer and toxicity outcomes. Reirradiation has historically been associated with unacceptable toxicity and a limited benefit.

Clinical and dosimetric study of radiotherapy for glioblastoma: three-dimensional conformal radiotherapy versus intensity-modulated radiotherapy.

Background And Purpose: We aimed to compare three-dimensional conformal radiotherapy (3D-CRT) with intensity-modulated radiotherapy (IMRT) for the treatment of glioblastoma.

Materials And Methods: Retrospective study of 220 patients with glioblastoma, treated with 3D-CRT or IMRT, with or without surgery. Dosimetric parameters as well as clinical and survival data for the two techniques were analyzed and compared.

[Quality control of dose delivered by in vivo dosimetry: can one tolerance be used for all localizations?].

Purpose: In vivo dosimetry measurements are accepted when the difference between measured and calculated dose is under 5%. A statistical analysis has been conducted to determine whether this tolerance matched the clinical practice for the studied localizations: pelvis, thorax, head and neck, breast.

Materials And Methods: The technical characteristics of the detectors were checked before being used in clinical practice.