Search results for "Radiation treatment"
showing 10 items of 78 documents
Skillful management of exodontia complication to prevent dreadful sequelae
2011
Successful surgical treatments depend upon accurate diagnosis, judicious treatment planning, selection and execution of an appropriate surgical technique, and on a well monitored post-operative period. However, despite these precautions, extraction of teeth (particularly third molar) is exposed to the accidents and complications common to all buccomaxillary and facial interventions. A maxillary third molar may be displaced in maxillary sinus, nearby soft tissue, or may migrate in a superioposterior direction towards paraphyrangeal space, or infratemporal fossa. Dislocating the maxillary third molar in infratemporal fossa is one of the worst nightmare as this area has complex anatomy consist…
Boron determination in liver tissue by combining quantitative neutron capture radiography (QNCR) and histological analysis for BNCT treatment plannin…
2011
The typical primary malignancies of the liver are hepatocellular carcinoma and cholangiocarcinoma, whereas colorectal liver metastases are the most frequently occurring secondary tumors. In many cases, only palliative treatment is possible. Boron neutron capture therapy (BNCT) represents a technique that potentially destroys tumor tissue selectively by use of externally induced, locally confined secondary particle irradiation. In 2001 and 2003, BNCT was applied to two patients with colorectal liver metastases in Pavia, Italy. To scrutinize the rationale of BNCT, a clinical pilot study on patients with colorectal liver metastases was carried out at the University of Mainz. The distribution o…
Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of hepatocellular carcinoma.
2021
Patients with advanced hepatocellular carcinoma (HCC) have historically had few options and faced extremely poor prognoses if their disease progressed after standard-of-care tyrosine kinase inhibitors (TKIs). Recently, the standard of care for HCC has been transformed as a combination of the immune checkpoint inhibitor (ICI) atezolizumab plus the anti-vascular endothelial growth factor (VEGF) antibody bevacizumab was shown to offer improved overall survival in the first-line setting. Immunotherapy has demonstrated safety and efficacy in later lines of therapy as well, and ongoing trials are investigating novel combinations of ICIs and TKIs, in addition to interventions earlier in the course…
Three-dimensional conformal radiotherapy in localized carcinoma of prostate: preliminary reports of toxicity in dose-escalation treatment
2007
Purpose Many studies confirmed the evidence of a dose-response relationship in prostate cancer. Escalation of dose using conventional techniques is however limited by rectal tolerance. IMRT and 3D-CRT have been designed to allow dose escalation while not exceeding rectal tolerance. We evaluated the acute and early late tolerance to surrounding organs upon dose escalation from 70 to 78 Gy in 3D-CRT setting, in order to introduce the IMRT process as a routine practice in prostate cancer treatment. Materials and Methods We compared clinical data from 35 patients with localized adenocarcinoma of the prostate, who received 70 Gy within a traditional reconstructed three-dimensional treatment plan…
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 …
Which factors influence orthodontists in their decision to extract? A questionnaire survey
2019
Background To evaluate the relative influence of different criteria in the choice between extraction and nonextraction treatment in current orthodontics, and to assess how the percentage of extractions has evolved over time. Material and methods Pre-treatment records (panoramic radiograph, lateral cephalogram, study casts and photographs) of fourteen cases in permanent dentition (adult or adolescent) with class I molar relationship and moderate anterior crowding were evaluated by 28 orthodontists. For each case, each orthodontist filled out a questionnaire reporting his treatment plan proposal (extraction or nonextraction) and the importance of specific parameters in his decision-making pro…
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…
Dosimetric characteristics of the CDC-type miniature cylindrical 137Cs brachytherapy sources
2002
The low dose rate CDC-type miniature cylindrical 137 Cs sources are available, with one or three active beads, for use in source trains in automatic and manual afterloading systems for gynecological brachytherapy. Absolute dose rate distributions in water have been calculated around these sources using the Monte CarloGEANT3 code and they are presented as conventional two-dimensional Cartesian lookup tables. The AAPM Task Group 43 formalism for dose calculation has been also applied. The dose rate constant obtained for the one bead source is Λ=1.113±0.003 cGyh −1 U −1 , and the value for the three bead source is Λ=1.103±0.003 cGyh −1 U −1 . Finally, for the treatment planning systems based o…
Dosimetry revisited for the HDR I192r brachytherapy source model mHDR-v2
2010
Purpose: Recently, the manufacturer of the HDR I 192 r mHDR-v2 brachytherapysource reported small design changes (referred to herein as mHDR-v2r) that are within the manufacturing tolerances but may alter the existing dosimetric data for this source. This study aimed to (1) check whether these changes affect the existing dosimetric data published for this source; (2) obtain new dosimetric data in close proximity to the source, including the contributions from I 192 r electrons and considering the absence of electronic equilibrium; and (3) obtain scatterdose components for collapsed cone treatment planning system implementation. Methods: Three different Monte Carlo(MC) radiation transport co…
An approach to using conventional brachytherapy software for clinical treatment planning of complex, Monte Carlo-based brachytherapy dose distributio…
2009
Certain brachytherapy dose distributions, such as those for LDR prostate implants, are readily modeled by treatment planning systems (TPS) that use the superposition principle of individual seed dose distributions to calculate the total dose distribution. However, dose distributions for brachytherapy treatments using high-Z shields or having significant material heterogeneities are not currently well modeled using conventional TPS. The purpose of this study is to establish a new treatment planning technique (Tufts technique) that could be applied in some clinical situations where the conventional approach is not acceptable and dose distributions present cylindrical symmetry. Dose distributi…