Publications by authors named "Frank Andre Siebert"

Purpose: Implications of radiation dose exposure to the urethra on urinary morbidity after prostate radiotherapy are poorly understood, especially by long-term patient-reported outcomes (PRO). Therefore, our primary objective was to investigate associations of urethral dose and long-term patient-reported urinary morbidity after external beam radiotherapy and high-dose rate brachytherapy boost for prostate cancer.

Materials And Methods: We conducted a pre-registered (https://doi.

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Historically, several classification systems have been used for brachytherapy, and they were based on the type of clinical purpose, type of implant and timing of the implant, dose-rate, and type of loading for treatment delivery. However, over the last decades, there have been some major technological advancements, including the introduction of image-guidance and possibility to modulate the dose delivered, which have led several authors (in order to highlight the differences between old technique and new approach) to label it in a different way by replacing "brachytherapy" with "interventional radiotherapy". Modern interventional procedures involve several key aspects, which contribute to the complexity of implant phase, such as implant type, imaging used during the procedure, and role of multi-disciplinary team in operating room.

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Article Synopsis
  • * The authors developed a new, budget-friendly material system using sodium alginate hydrogel and coconut fat that allows for accurate adjustment of imaging properties for CT and ultrasound independently.
  • * This innovative approach is particularly advantageous in low-resource settings, as the materials are affordable (less than $1 USD/kg) and easily accessible, enabling the creation of versatile phantoms to improve surgical training and patient care.
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Article Synopsis
  • This review investigates how artificial intelligence (AI) can improve interventional radiotherapy (IRT) by making workflows more efficient and enhancing patient care.
  • Analyzing 78 studies from 2002 to 2024, it highlights advancements in areas like treatment planning, contouring, outcome prediction, and quality assurance.
  • While AI shows potential for reducing procedure times and personalizing treatments, challenges like clinical validation and quality assurance remain important to address.
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Aim: Ru eye plaque brachytherapy (BT, interventional radiotherapy) is an eye-preserving treatment for uveal melanoma performed in about 100 clinics worldwide. Despite this relatively low number, there is a considerable variation in clinical practice. In 2022, the BRAPHYQS and Head & Neck and Skin GEC-ESTRO working groups conducted a survey to map the current clinical practice.

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Background: Ideally, inverse planning for HDR brachytherapy (BT) should include the pose of the needles which define the trajectory of the source. This would be particularly interesting when considering the additional freedom and accuracy in needle pose which robotic needle placement enables. However, needle insertion typically leads to tissue deformation, resulting in uncertainty regarding the actual pose of the needles with respect to the tissue.

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Background/purpose: This study determines and compares the geometric setup errors between stereoscopic x-ray and kilo-voltage cone beam CT (CBCT) in phantom tests on a linear accelerator (linac) for image-guided (IG) stereotactic radiotherapy of intracranial tumors. Additionally, dose-volume metrics in the target volumes of the setup errors of CBCT were evaluated.

Materials/methods: A Winston-Lutz- and an anthropomorphic phantom were used.

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The introduction of model-based dose calculation algorithms (MBDCAs) in brachytherapy provides an opportunity for a more accurate dose calculation and opens the possibility for novel, innovative treatment modalities. The joint AAPM, ESTRO, and ABG Task Group 186 (TG-186) report provided guidance to early adopters. However, the commissioning aspect of these algorithms was described only in general terms with no quantitative goals.

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Interventional radiotherapy (IRT, brachytherapy) is a highly effective treatment method for non-melanoma skin cancer (NMSC). Traditionally, the maximum depth of NMSC lesions considered eligible for contact IRT was 5 mm; however, following several national surveys and recent recommendations, such cut-off, lesions thicker than 5 mm may be treated by contact IRT. The use of image guidance in defining the actual depth in treating NMSC to correctly identify clinical target volume (CTV) and prevent unnecessary toxicity is of paramount importance.

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Introduction: Performing lymphoscintigraphy in a separate room, frees up the conventional gamma camera, coupled with the desire to directly localize sentinel lymph nodes (SLN) in the operating theatre has led to the development of high-resolution semiconductor-detector based handheld gamma-cameras, CrystalCam.

Methods: This work consists of phantom and clinical studies. For the first part, a Jaszczak phantom with hollow spheres of various volumes were filled with the Tc and the camera's sensitivity was measured at various distances to assess the possibilities and limitations of the device.

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Background: Single-session cardiac stereotactic radiation therapy (SBRT) has demonstrated promising results for patients with refractory ventricular tachycardia (VT). However, the full safety profile of this novel treatment remains unknown and very limited data from prospective clinical multicenter trials are available.

Methods: The prospective multicenter multiplatform RAVENTA (radiosurgery for ventricular tachycardia) study assesses high-precision image-guided cardiac SBRT with 25 Gy delivered to the VT substrate determined by high-definition endocardial and/or epicardial electrophysiological mapping in patients with refractory VT ineligible for catheter ablation and an implanted cardioverter defibrillator (ICD).

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Purpose: To provide the first clinical test case for commissioning of Ir brachytherapy model-based dose calculation algorithms (MBDCAs) according to the AAPM TG-186 report workflow.

Acquisition And Validation Methods: A computational patient phantom model was generated from a clinical multi-catheter Ir HDR breast brachytherapy case. Regions of interest (ROIs) were contoured and digitized on the patient CT images and the model was written to a series of DICOM CT images using MATLAB.

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Background And Purpose: Risk management in radiotherapy is of high importance. There is not much data published on errors occurring in the treatment planning process of external beam techniques. The aim of this study was to investigate errors occurring during physics plan review in external beam radiotherapy.

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The vast majority of radiotherapy departments in Europe using brachytherapy (BT) perform temporary implants of high- or pulsed-dose rate (HDR-PDR) sources with photon energies higher than 50 keV. Such techniques are successfully applied to diverse pathologies and clinical scenarios. These recommendations are the result of Working Package 21 (WP-21) initiated within the BRAchytherapy PHYsics Quality Assurance System (BRAPHYQS) GEC-ESTRO working group with a focus on HDR-PDR source calibration.

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The aim of this publication is the assessment of the existing guidelines for non-melanoma skin cancer (NMSC) superficial brachytherapy (BT) and make a critical review based on the existing literature about the maximum dose prescription depth, bolus thickness and maximum skin surface dose (D) of the published clinical practice. A systematic review of NMSC superficial BT published articles was carried out by the GEC-ESTRO Head & Neck and Skin (HNS) Working Group (WG). 10 members and 2 external reviewers compared the published clinical procedures with the recommendations in the current guidelines and examined the grade of evidence.

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Purpose: Monte Carlo (MC) simulation studies, aimed at evaluating the magnitude of tissue heterogeneity in I prostate permanent seed implant brachytherapy (BT), customarily use clinical post-implant CT images to generate a virtual representation of a realistic patient model (virtual patient model). Metallic artifact reduction (MAR) techniques and tissue assignment schemes (TAS) are implemented on the post-implant CT images to mollify metallic artifacts due to BT seeds and to assign tissue types to the voxels corresponding to the bright seed spots and streaking artifacts, respectively. The objective of this study is to assess the combined influence of MAR and TAS on MC absorbed dose calculations in post-implant CT-based phantoms.

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Purpose: Cardiac radioablation is a novel treatment option for patients with refractory ventricular tachycardia unsuitable for catheter ablation. The quality of treatment planning depends on dose specifications, platform capabilities, and experience of the treating staff. To harmonize the treatment planning, benchmarking of this process is necessary for multicenter clinical studies such as the RAdiosurgery for VENtricular TAchycardia trial.

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This is an evidence-based guideline for prostate brachytherapy. Throughout levels of evidence quoted are those from the Oxford Centre for Evidence based Medicine (https://www.cebm.

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Background And Purpose: Brachytherapy treatment outcomes depend on the accuracy of the delivered dose distribution, which is proportional to the reference air-kerma rate (). Current societal recommendations require the medical physicist to compare the measured values to the manufacturer source calibration certificate. The purpose of this work was to report agreement observed in current clinical practice in the European Union.

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Background And Purpose: The COVID-19 pandemic has imposed changes in radiotherapy (RT) departments worldwide. Medical physicists (MPs) are key healthcare professionals in maintaining safe and effective RT. This study reports on MPs experience during the first pandemic peak and explores the consequences on their work.

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The use of brachytherapy (interventional radiotherapy) in the treatment of gynecological cancers is a crucial element in both definitive and adjuvant settings. The recent developments in high-dose rate remote afterloaders, modern applicators, treatment-planning software, image guidance, and dose monitoring systems have led to improvement in the local control rates and in some cases improved the survival rates. The development of these highly advanced and complicated treatment modalities has been accompanied by challenges, which have made the existence of quality assurance protocols a must to ensure the integrity of the treatment process.

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Purpose: Cardiac radioablation is a novel treatment option for therapy-refractory ventricular tachycardia (VT) ineligible for catheter ablation. Three-dimensional clinical target volume (CTV) definition is a key step, and this complex interdisciplinary procedure includes VT-substrate identification based on electroanatomical mapping (EAM) and its transfer to the planning computed tomography (PCT). Benchmarking of this process is necessary for multicenter clinical studies such as the RAVENTA trial.

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The surface brachytherapy Task Group report number 253 discusses the common treatment modalities and applicators typically used to treat lesions on the body surface. Details of commissioning and calibration of the applicators and systems are discussed and examples are given for a risk-based analysis approach to the quality assurance measures that are necessary to consider when establishing a surface brachytherapy program.

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