Publications by authors named "Xavier Geets"

Background: Lung cancer is a leading cause of cancer mortality and may require high-dose thoracic radiation therapy (RT). However, RT significantly increases the risk of radiation-induced cardiac events, such as pericarditis, cardiomyopathy, and ischemic heart diseases. Despite evidence from clinical trials showing that higher RT doses are associated with poorer survival outcomes due to these cardiac effects, data on dose-volume predictors of such events in lung cancer remain sparse.

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Article Synopsis
  • Online adaptive radiotherapy (oART) utilizes daily imaging to adapt treatment plans based on anatomical changes in patients, specifically targeting gastric MALT lymphomas in this study.
  • Researchers aimed to identify the necessary planning target volume (PTV) margins for oART via cone beam computed tomography (CBCT) scans, comparing adaptive and non-adaptive treatment approaches.
  • The study determined that a PTV margin of 4 mm for oART was effective, significantly lower than the 12 mm margin for non-adaptive treatment, while ensuring that all dosimetric constraints were satisfied for both approaches.
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Purpose: Radiation therapy for tumors subject to breathing-related motion during breath-holds (BHs) has the potential to substantially reduce the irradiated volume. Mechanically assisted and noninvasive ventilation (MANIV) could ensure the target repositioning accuracy during each BH while facilitating treatment feasibility through oxygen supplementation and a perfectly replicated mechanical support. However, there is currently no clinical evidence substantiating the use of MANIV-induced BH for moving tumors.

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Aim: To evaluate acute toxicity at 6 months after stereotactic body radiotherapy (SBRT) in patients with oligometastatic cancer within the OligoCare cohort.

Material And Methods: OligoCare is a prospective, registry-based, single-arm, observational study that aims to report prospective real-world data of patients with oligometastases from solid cancer treated with SBRT (NCT03818503). Primary tumor included non-small cell lung cancer (NSCLC), breast cancer (BC), colorectal cancer (CRC), and prostate cancer (PC).

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Background: Although stereotactic body radiotherapy (SBRT) was progressively adopted in clinical practice in Belgium, a reimbursement request in 2011 was not granted because of remaining clinical and economic uncertainty. A coverage with evidence development (CED) program on SBRT started in 2013, with the aim to assess clinical and technical patterns-of-care in Belgium and monitor survival per indication, in view of supporting inclusion in the reimbursement system.

Methods: The Belgian National Institute for Health and Disability Insurance (NIHDI) initiated this prospective observational registry.

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Introduction: The international phase II single-arm LungTech trial 22113-08113 of the European Organization for Research and Treatment of Cancer assessed the safety and efficacy of stereotactic body radiotherapy (SBRT) in patients with centrally located early-stage NSCLC.

Methods: Patients with inoperable non-metastatic central NSCLC (T1-T3 N0 M0, ≤7cm) were included. After prospective central imaging review and radiation therapy quality assurance for any eligible patient, SBRT (8 × 7.

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Most radiotherapy treatments are nowadays delivered with linear accelerators producing photons. This robust radiation technique improved outstandingly during the last three decades, allowing treatments for most tumoural indications with an exquisite accuracy, a formidable effectiveness, a low toxicity, and a very low cost for the society. Therefore, the reasons for using and developing the more expensive hadron therapy and more particularly proton therapy may seem futile.

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. Radio-opaque markers are recommended for image-guided radiotherapy in liver stereotactic ablative radiotherapy (SABR), but their implantation is invasive. We evaluate in thisstudy the feasibility of cone-beam computed tomography-guided stereotactic online-adaptive radiotherapy (CBCT-STAR) to propagate the target volumes without implanting radio-opaque markers and assess its consequence on the margin that should be used in that context.

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Article Synopsis
  • The study examines the optimal doses and fractionation in stereotactic body radiotherapy (SBRT) for patients with oligometastatic cancer, analyzing 1,099 registered patients from the OligoCare trial.
  • The analysis converted SBRT doses to biological effective doses (BED) using specific cancer types' α/β values, revealing that different cancers received varying doses based on type and metastasis locations.
  • Findings indicate that SBRT doses were adapted according to the primary cancers and metastasis sites, suggesting further research is needed on the safety and efficacy of this tailored approach.
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Purpose: Ethos proposes a template-based automatic dose planning (Etb) for online adaptive radiotherapy. This study evaluates the general performance of Etb for prostate cancer, as well as the ability to generate patient-optimal plans, by comparing it with another state-of-the-art automatic planning method, i.e.

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Purpose: Defining dosimetric rules to automatically detect patients requiring adaptive radiotherapy (ART) is not straightforward, and most centres perform ad-hoc ART with no specific protocol. This study aims to propose and analyse different steps to design a protocol for dosimetrically triggered ART of head and neck (H&N) cancer. As a proof-of-concept, the designed protocol was applied to patients treated in TomoTherapy units, using their available software for daily MVCT image and dose accumulation.

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Purpose: Automated treatment planning strategies are being widely implemented in clinical routines to reduce inter-planner variability, speed up the optimization process, and improve plan quality. This study aims to evaluate the feasibility and quality of intensity-modulated proton therapy (IMPT) plans generated with four different knowledge-based planning (KBP) pipelines fully integrated into a commercial treatment planning system (TPS).

Materials/methods: A data set containing 60 oropharyngeal cancer patients was split into 11 folds, each containing 47 patients for training, five patients for validation, and five patients for testing.

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Background And Purpose: Deep inspiration breath-hold (DIBH) protects critical organs-at-risk (OARs) for adjuvant breast radiotherapy. Guidance systems e.g.

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Stereotactic body radiotherapy (SBRT) for patients with metastatic cancer, especially when characterised by a low tumour burden (ie, oligometastatic disease), receiving targeted therapy or immunotherapy has become a frequently practised and guideline-supported treatment strategy. Despite the increasing use in routine clinical practice, there is little information on the safety of combining SBRT with modern targeted therapy or immunotherapy and a paucity of high-level evidence to guide clinical management. A systematic literature review was performed to identify the toxicity profiles of combined metastases-directed SBRT and targeted therapy or immunotherapy.

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Background: There has been growing evidence of the benefits of high-intensity aerobic interval training (HIIT) and resistance training (RES) for populations with cancer. However, these two modalities have not yet been performed alone in rectal cancer patients undergoing neoadjuvant chemoradiotherapy (NACR T). Therefore, this study aimed to determine the feasibility of HIIT and RES in rectal cancer patients undergoing NACR T.

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Protons offer a more conformal dose delivery compared to photons, yet they are sensitive to anatomical changes over the course of treatment. To minimize range uncertainties due to anatomical variations, a new CT acquisition at every treatment session would be paramount to enable daily dose calculation and subsequent plan adaptation. However, the series of CT scans results in an additional accumulated patient dose.

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Detection and segmentation of abnormalities on medical images is highly important for patient management including diagnosis, radiotherapy, response evaluation, as well as for quantitative image research. We present a fully automated pipeline for the detection and volumetric segmentation of non-small cell lung cancer (NSCLC) developed and validated on 1328 thoracic CT scans from 8 institutions. Along with quantitative performance detailed by image slice thickness, tumor size, image interpretation difficulty, and tumor location, we report an in-silico prospective clinical trial, where we show that the proposed method is faster and more reproducible compared to the experts.

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Article Synopsis
  • The study investigates the effectiveness of definitive radiotherapy (dRT) for treating unresectable soft-tissue sarcomas (STS) in patients from 2009 to 2020, noting a lack of previous data.
  • Key findings include that out of 116 patients, over half achieved stable disease or partial response, with 3-year local failure, progression-free survival, and overall survival rates of 43.2%, 16.6%, and 34%, respectively.
  • The research concludes that modern dRT is a safe and effective option for selected patients with unresectable STS, with certain factors like tumor grade and radiation dosage impacting survival outcomes.
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  • Definitive external beam radiotherapy (EBRT) is an uncommon but potential treatment for unresectable soft-tissue sarcomas (STS), with recent advancements in particle therapies possibly enhancing its effectiveness.
  • A systematic review of 29 studies covering 1,409 patients highlighted that photon and particle therapies achieve 5-year local control rates between 28-73%, though overall survival and progression-free survival rates remained low.
  • It is suggested that delivering a dose of 64-66 Gy may be both safe and effective for treating unresectable STS, and future research should explore biomarkers to better identify patients who could benefit from this treatment.
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Background And Purpose: The Quality Assurance project for stage III non-small cell lung cancer radiotherapy ProCaLung performed a multicentric two-step exercise evaluating mediastinal nodal Target Volume Definition and Delineation (TVD) variability and the opportunity for standardization. The TVD variability before and after providing detailed guidelines and the value of qualitative contour reviewing before applying quantitative measures were investigated.

Materials And Methods: The case of a patient with stage III NSCLC and involved mediastinal lymph nodes was used as a basis for this study.

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Purpose: Planning target volume (PTV) definition based on Mid-Position (Mid-P) strategy typically integrates breathing motion from tumor positions variances along the conventional axes of the DICOM coordinate system. Tumor motion directionality is thus neglected even though it is one of its stable characteristics in time. We therefore propose the directional MidP approach (MidP dir), which allows motion directionality to be incorporated into PTV margins.

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Background: The role of postoperative radiation therapy (PORT) in stage III N2 NSCLC is controversial. We analyzed decision-making for PORT among European radiation oncology experts in lung cancer.

Methods: Twenty-two experts were asked before and after presentation of the results of the LungART trial to describe their decision criteria for PORT in the management of pN+ NSCLC patients.

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Background And Purpose: There are several alternatives to the widespread ITV strategy in order to account for breathing-induced motion in PTV margins. The most sophisticated one includes the generation of a motion-compensated CT scan with the CTV placed in its average position - the mid-position approach (MidP). In such configuration, PTV margins integrate breathing as another random error.

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