Search results for "Treatment planning"

Theragnostic Use of Radiolabelled Dota-Peptides in Meningioma: From Clinical Demand to Future Applications.

2019

Meningiomas account for approximately 30% of all new diagnoses of intracranial masses. The 2016 World Health Organization’s (WHO) classification currently represents the clinical standard for meningioma’s grading and prognostic stratification. However, watchful waiting is frequently the chosen treatment option, although this means the absence of a certain histological diagnosis. Consequently, MRI (or less frequently CT) brain imaging currently represents the unique available tool to define diagnosis, grading, and treatment planning in many cases. Nonetheless, these neuroimaging modalities show some limitations, particularly in the evaluation of skull base lesions. The emerging evidence supp…

Dosimetry comparison between TG-43 and Monte Carlo calculations using the Freiburg flap for skin high-dose-rate brachytherapy

2012

Abstract Purpose The purpose of this work was to evaluate whether the delivered dose to the skin surface and at the prescription depth when using a Freiburg flap applicator is in agreement with the one predicted by the treatment planning system (TPS) using the TG-43 dose-calculation formalism. Methods and Materials Monte Carlo (MC) simulations and radiochromic film measurements have been performed to obtain dose distributions with the source located at the center of one of the spheres and between two spheres. Primary and scatter dose contributions were evaluated to understand the role played by the scatter component. A standard treatment plan was generated using MC- and TG-43-based TPS appl…

Benchmarking Wilms’ tumor in multisequence MRI data: why does current clinical practice fail? Which popular segmentation algorithms perform well?

2019

Wilms' tumor is one of the most frequent malignant solid tumors in childhood. Accurate segmentation of tumor tissue is a key step during therapy and treatment planning. Since it is difficult to obtain a comprehensive set of tumor data of children, there is no benchmark so far allowing evaluation of the quality of human or computer-based segmentations. The contributions in our paper are threefold: (i) we present the first heterogeneous Wilms' tumor benchmark data set. It contains multisequence MRI data sets before and after chemotherapy, along with ground truth annotation, approximated based on the consensus of five human experts. (ii) We analyze human expert annotations and interrater varia…

Radiolucent Carbon Fiber–Reinforced Pedicle Screws for Treatment of Spinal Tumors: Advantages for Radiation Planning and Follow-Up Imaging

2016

Objective Surgical treatment of spinal tumors regularly includes spinal instrumentation with pedicle screws. Most modern pedicle screws are made of titanium alloy, which is associated with artifacts on postoperative imaging such as computed tomography and/or magnetic resonance imaging. These artifacts hamper radiation treatment planning and execution and follow-up imaging. Recently, carbon fiber–reinforced polyetheretherketone (CFRP) implants became available for posterior instrumentation with the aim to reduce imaging artifacts by implants. Methods Patients harboring spinal tumors underwent posterior stabilization using CFRP pedicle screws. Postoperative imaging was evaluated for implant a…

Utility of imaging techniques in the diagnosis of oral cancer.

2015

Abstract Purpose Imaging techniques such as magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography (PET) are often used to complement the clinical exploration and staging of oral squamous cell carcinoma (OSCC). Which of these techniques is best in establishing correct staging and treatment planning is not clear, however. This study aims to determine which technique is most appropriate for diagnosing the primary tumor and for detecting bone invasion and neck metastases. Material and methods A Medline literature search was made over the last 10 years. In each selected study, we recorded the sample size and sensitivity, specificity and precision. Strengths…

Preoperative Evaluation and Treatment Planning. Zygomatic Implant Critical Zone (ZICZ) Location

2021

Calculation of bone graft volume using 3D reconstruction system.

2010

Objectives: To obtain bone ?bioreplicas? for determining precisely the amount of biomaterial required for bone regeneration procedure. Study design: A case-control comparison with a total sample size of 20 cases, 10 control and 10 test samples. ?Bioreplicas? were generated from helical CAT scans with 0.5 mm slices, without 3D reconstruction or image filters. Bone defects in premolar and molar areas were treated with titanium mesh and xenograft (MP3) combined with resorbable carriers. Time taken to carry out procedures with and without the use of ?bioreplicas? (in minutes), discrepancies between the grafts performed with and without ?bioreplicas? and bone defects (mm), and postoperative comp…

9 Development of an experimental tool to evaluate normal tissue 3D doses in external-beam radiotherapy

2018

Introduction Recently, cancer treatment improvement enabled an increase in patients’ survival rate. In more than half of the cases, radiotherapy participates in the cure for cancer. The efficacy of this technique is well known but it inevitably delivers doses to normal tissues exposing them to radio-induced complications risks [1] . Moreover, the longer patients’ life expectancy increases the risk of developing long-term complications such as second cancers. Thus, evaluating the risks following cancer treatment involving radiotherapy constitutes a major challenge. In this context, an experimental tool has been developed to evaluate normal tissue doses delivered by the different radiotherapy…

Influence of Three-dimensional Imaging on Implant Treatment Planning: Implant Diameter and Length

2018

Aim To investigate the influence of the radiographic modalities panoramic radiography (PR) and cone beam computed tomography (CBCT) on selection of implant length and diameter. Materials and methods Potential implant sites (59 sites, 40 patients) with available PRs and CBCTs were selected from the databases of two University dental schools. Six experienced clinicians were asked to select the appropriate implant length and diameter based on PR and CBCT. Results were compared with the actual surgical procedure and intra- /interrater agreement was calculated using Cohen's kappa. Results On average, greater implant length was more often planned based on PR (24.2 vs 8.8% with CBCT), while wider …

[I062] The roles of radiographers in medical imaging and radiotherapy in Europe

2018

Very fast development of technologies in medical imaging and therapy has changed the role of radiographer in Europe. Over the past ten years education and necessary skills and competencies for radiographers has become more similar in most EU countries due to input of EFRS Educational Wing, but there are still rather significant differences in the roles of radiographers between countries. Role expansion is often initiated by external and internal factors that lead to advanced practice for radiographers. However, there is also a limiting factor that functions as a barrier for development of radiographer’s role and mainly that is connected to resistance when radiologists/medical physicists obj…