Search results for "Treatment planning"
showing 10 items of 83 documents
NeXt for neuro-radiosurgery: A fully automatic approach for necrosis extraction in brain tumor MRI using an unsupervised machine learning technique
2017
Stereotactic neuro-radiosurgery is a well-established therapy for intracranial diseases, especially brain metastases and highly invasive cancers that are difficult to treat with conventional surgery or radiotherapy. Nowadays, magnetic resonance imaging (MRI) is the most used modality in radiation therapy for soft-tissue anatomical districts, allowing for an accurate gross tumor volume (GTV) segmentation. Investigating also necrotic material within the whole tumor has significant clinical value in treatment planning and cancer progression assessment. These pathological necrotic regions are generally characterized by hypoxia, which is implicated in several aspects of tumor development and gro…
Jaw in a day: Osseointegration of the implants in the patient’s leg before reconstructive surgery of a maxilla with ameloblastoma. A 4-year follow-up…
2021
Background To describe a clinical case of a cancer patient who underwent ablative tumor surgery, including treatment planning, surgical resection and subsequent implant rehabilitation. Case report A 61-year-old patient with a diagnosis of multicystic follicular ameloblastoma in the maxilla, in which it was necessary a multidisciplinary approach and two surgical steps. In the first surgical intervention osseointegrated implants (OII) were placed in the fibula, until their osseointegration period of 8 weeks was complete. Afterwards, in the second surgery, the micro-vascularized free fibular flap bearing the implants was transplanted into the oral cavity, in order to perform simultaneous recon…
Rapid prototyping modelling in oral and maxillofacial surgery: a two year retrospective study
2015
Background The use of rapid prototyping (RP) models in medicine to construct bony models is increasing. Material and Methods The aim of the study was to evaluate retrospectively the indication for the use of RP models in oral and maxillofacial surgery at Helsinki University Central Hospital during 2009-2010. Also, the used computed tomography (CT) examination – multislice CT (MSCT) or cone beam CT (CBCT) - method was evaluated. Results In total 114 RP models were fabricated for 102 patients. The mean age of the patients at the time of the production of the model was 50.4 years. The indications for the modelling included malignant lesions (29%), secondary reconstruction (25%), prosthodontic …
Reimbursement of radiotherapy in Germany.
2017
Reimbursement of radiotherapy in Germany is mainly based on a certain fixed fee for treatment planning and patient set up in addition to payment per fraction. This applies to outpatient care for patients with public health insurance or private health insurance. Payment per fraction has a considerable influence on reimbursement of inpatients as well. The advantage of payment per fraction is the simplicity and transparency. The disadvantage is an inadequate reimbursement for new treatment modalities like hypofractionation or stereotactic body radiotherapy.
Biological target volume segmentation for radiotherapy treatment planning
2016
[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…
2014
Background and purpose: A substantial reduction of uncertainties in clinical brachytherapy should result in improved outcome in terms of increased local control and reduced side effects. Types of uncertainties have to be identified, grouped, and quantified. Methods: A detailed literature review was performed to identify uncertainty components and their relative importance to the combined overall uncertainty. Results: Very few components (e.g., source strength and afterloader timer) are independent of clinical disease site and location of administered dose. While the influence of medium on dose calculation can be substantial for low energy sources or non-deeply seated implants, the influence…
SU-G-201-02: Application of RayStretch in Clinical Cases: A Calculation for Heterogeneity Corrections in LDR Permanent I-125 Prostate Brachytherapy
2016
Purpose: Tissue heterogeneities and calcifications have significant impact on the dosimetry of low energy brachytherapy (BT). RayStretch is an analytical algorithm developed in our institution to incorporate heterogeneity corrections in LDR prostate brachytherapy. The aim of this work is to study its application in clinical cases by comparing its predictions with the results obtained with TG-43 and Monte Carlo (MC) simulations. Methods: A clinical implant (71 I-125 seeds, 15 needles) from a real patient was considered. On this patient, different volumes with calcifications were considered. Its properties were evaluated in three ways by i) the Treatment planning system (TPS) (TG-43), ii) a M…
Towards clinical application of RayStretch for heterogeneity corrections in LDR permanent 125-I prostate brachytherapy
2017
Purpose RayStretch is a simple algorithm proposed for heterogeneity corrections in low-dose–rate brachytherapy. It is built on top of TG-43 consensus data, and it has been validated with Monte Carlo (MC) simulations. In this study, we take a real clinical prostate implant with 71 125I seeds as reference and we apply RayStretch to analyze its performance in worst-case scenarios. Methods and Materials To do so, we design two cases where large calcifications are located in the prostate lobules. RayStretch resilience under various calcification density values is also explored. Comparisons against MC calculations are performed. Results Dose–volume histogram–related parameters like prostate D90, …
Imaging Approach for Evaluation of Focal Liver Lesions
2009
Focal liver lesions are common in the general population. Radiology (imaging) plays a pivotal role for the diagnosis, staging, treatment planning, and follow-up of focal liver lesions. To maximize lesion detection and characterization, imaging needs to be performed with appropriate equipment by using protocols carefully designed on the basis of the underlying clinical context. In addition, the decision of an imaging modality cannot be based on the diagnostic accuracy of an imaging test solely but must also consider patient safety and cost-effectiveness.