The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
J.-c. Latombe - One of the best experts on this subject based on the ideXlab platform.
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Treatment planning for a radiosurgical system with general kinematics
Proceedings of the 1994 IEEE International Conference on Robotics and Automation, 1994Co-Authors: A. Schweikard, R. Tombropoulos, L. Kavraki, J.r. Adler, J.-c. LatombeAbstract:In radiosurgery a beam of radiation is used as an ablative surgical instrument to destroy brain tumors. Treatment planning consists of computing a sequence of beam configurations for delivering a necrotic dose to the tumor, without damaging Healthy Tissue or particularly critical structures. In current systems, kinematic limitations severely constrain beam motion. This often results in inappropriate dose distributions. A new radiosurgical system has been implemented to overcome this disadvantage. In this system, a compact radiation source of high energy is moved by a 6-dof robotic arm. We describe algorithms for computing a motion with specified characteristics for this new system. Treatment plans used at test sites with earlier systems are compared to plans computed with the described algorithms. The experience reported shows that full kinematic flexibility combined with treatment planning algorithms allows for better protection of Healthy Tissue and higher dosage in tumors.
O Sanmartin - One of the best experts on this subject based on the ideXlab platform.
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mohs micrographic surgery in dermatofibrosarcoma protuberans allows tumour clearance with smaller margins and greater preservation of Healthy Tissue compared with conventional surgery a study of 74 primary cases
British Journal of Dermatology, 2015Co-Authors: C Serraguillen, B Llombart, Eduardo Nagore, C Guillen, C Requena, Victor Traves, S Kindem, Rebeca Alcala, N Rivas, O SanmartinAbstract:Summary Background Dermatofibrosarcoma protuberans (DFSP) is an uncommon skin tumour with aggressive local growth. Whether DFSP should be treated with conventional surgery (CS) or Mohs micrographic surgery (MMS) has long been a topic of debate. Objectives To calculate, in a large series of DFSP treated by MMS, the minimum margin that would have been needed to achieve complete clearance by CS. Secondly, to calculate the percentage of Healthy Tissue that was preserved by MMS rather than CS with 2- and 3-cm margins. Methods The minimum margin was calculated by measuring the largest distance from the visible edge of the tumour to the edge of the definitive surgical defect. Tumour and surgical defect areas for hypothetical CS with 2- and 3-cm margins were calculated using AutoCAD for Windows. Results A mean minimum margin of 1·34 cm was required to achieve complete clearance for the 74 tumours analysed. The mean percentages of skin spared using MMS rather than CS with 2- and 3-cm margins were 49·4% and 67·9%, respectively. Conclusions MMS can achieve tumour clearance with smaller margins and greater preservation of Healthy Tissue than CS.
Ersin Ülkür - One of the best experts on this subject based on the ideXlab platform.
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Changing the Donor Site Selection Concept of Facial Skin Expansion from Pure Healthy Tissue to Defect and Healthy Tissue Combination
Aesthetic Plastic Surgery, 2015Co-Authors: Sinan Oksuz, Murat Şahin Alagöz, Ersin ÜlkürAbstract:Facial defect reconstruction is a challenge for plastic surgeons due to unique esthetic and functional properties of the region. Facial Tissue expansion provides an ideal reconstruction resource. However, the donor site is limited in the facial region. Thus, a cost-effective expansion management is crucial for an efficient reconstruction. In this article, the evolution of our donor site preference for Tissue expansion from pure Healthy Tissue to a defect-Healthy Tissue combination is presented. Fifteen patients underwent skin reconstruction with local Tissue expansion for facial and cervical defects. The full facial or cervical region including the defect and Healthy Tissue combination was determined as the donor expansion site. The donor site was not limited only to pure Healthy Tissue. The largest size rectangular expander suitable for the combined expandable donor site size was placed under the defect and Healthy Tissue border, paying attention to carry the expander far beneath the defect site. The defect site and most adjacent Healthy Tissue were expanded simultaneously. Major complications such as infection, hematoma, rupture, or flap necrosis were not observed. The expansion of defect-Healthy Tissue border presented successful reconstruction results with acceptable scars. In the traditional Tissue expansion concept, using a large size expander to provide more abundant flap gain does not comply with the limited size of Healthy donor site in the face. Expanding the whole facial region, without restriction of the defect, supplies excess donor Tissue area for larger size expander use. Eventually, defect-Healthy Tissue border expansion with large expanders results in minimum final scar and less Tissue loss in flap relocation and enables optimal flap gain. This method can easily be adapted to any Tissue expansion site of the body. Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
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Changing the Donor Site Selection Concept of Facial Skin Expansion from Pure Healthy Tissue to Defect and Healthy Tissue Combination
Aesthetic Plastic Surgery, 2015Co-Authors: Sinan Oksuz, Murat Şahin Alagöz, Ersin ÜlkürAbstract:Facial defect reconstruction is a challenge for plastic surgeons due to unique esthetic and functional properties of the region. Facial Tissue expansion provides an ideal reconstruction resource. However, the donor site is limited in the facial region. Thus, a cost-effective expansion management is crucial for an efficient reconstruction. In this article, the evolution of our donor site preference for Tissue expansion from pure Healthy Tissue to a defect-Healthy Tissue combination is presented. Fifteen patients underwent skin reconstruction with local Tissue expansion for facial and cervical defects. The full facial or cervical region including the defect and Healthy Tissue combination was determined as the donor expansion site. The donor site was not limited only to pure Healthy Tissue. The largest size rectangular expander suitable for the combined expandable donor site size was placed under the defect and Healthy Tissue border, paying attention to carry the expander far beneath the defect site. The defect site and most adjacent Healthy Tissue were expanded simultaneously. Major complications such as infection, hematoma, rupture, or flap necrosis were not observed. The expansion of defect-Healthy Tissue border presented successful reconstruction results with acceptable scars. In the traditional Tissue expansion concept, using a large size expander to provide more abundant flap gain does not comply with the limited size of Healthy donor site in the face. Expanding the whole facial region, without restriction of the defect, supplies excess donor Tissue area for larger size expander use. Eventually, defect-Healthy Tissue border expansion with large expanders results in minimum final scar and less Tissue loss in flap relocation and enables optimal flap gain. This method can easily be adapted to any Tissue expansion site of the body. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
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Avoiding Extended Scar in Skin Expansion: Alagoz Technique.
Journal of Craniofacial Surgery, 2015Co-Authors: Murat Şahin Alagöz, Sinan Oksuz, Emrah Kagan Yasar, Fikret Eren, Mustafa Hasdemir, Mustafa Keskin, Ersin ÜlkürAbstract:The principal aim of skin expansion is to provide additional donor Tissue without extra donor-site morbidity. Most of the reports about Tissue expansion are focused on the properties of expander. Donor-site decision is usually underestimated. Here, we offer to use the defect area and surrounding Healthy Tissue as the donor site.In 4 cases, expanders were placed just under the defect in a fashion to extend 1 to 2 cm more laterally toward the encircling Healthy Tissue. The expanded Tissue was not mobilized for longer distances; thus, there was no loss in flap gain. The resulting final scar was linear or crescentic. In the Alagoz technique, Tissue gain similar in size to the defect is sufficient for reconstruction. The simpler the flap, the best the resulting scar.
A. Schweikard - One of the best experts on this subject based on the ideXlab platform.
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Treatment planning for a radiosurgical system with general kinematics
Proceedings of the 1994 IEEE International Conference on Robotics and Automation, 1994Co-Authors: A. Schweikard, R. Tombropoulos, L. Kavraki, J.r. Adler, J.-c. LatombeAbstract:In radiosurgery a beam of radiation is used as an ablative surgical instrument to destroy brain tumors. Treatment planning consists of computing a sequence of beam configurations for delivering a necrotic dose to the tumor, without damaging Healthy Tissue or particularly critical structures. In current systems, kinematic limitations severely constrain beam motion. This often results in inappropriate dose distributions. A new radiosurgical system has been implemented to overcome this disadvantage. In this system, a compact radiation source of high energy is moved by a 6-dof robotic arm. We describe algorithms for computing a motion with specified characteristics for this new system. Treatment plans used at test sites with earlier systems are compared to plans computed with the described algorithms. The experience reported shows that full kinematic flexibility combined with treatment planning algorithms allows for better protection of Healthy Tissue and higher dosage in tumors.
Amod Kumar - One of the best experts on this subject based on the ideXlab platform.
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role of optical coefficients and Healthy Tissue sparing characteristics in gold nanorod assisted thermal therapy
International Journal of Hyperthermia, 2013Co-Authors: Sanjeev Soni, Himanshu Tyagi, Robert A Taylor, Amod KumarAbstract:PURPOSE: This study seeks to define parameters for gold nanorod assisted thermal therapy, to achieve the thermal ablation temperature (50-60°C) in the tumour region and spare Healthy Tissue surrounding the tumour. Also, a criterion for size selection of gold nanorods is described based on the role of optical coefficients. THEORY AND METHODS: In this study a Tissue domain (comprising a 3 mm tumour and 7 mm of surrounding Healthy Tissue) embedded with gold nanorods is irradiated with electromagnetic radiation within the therapeutic wavelength band. Optical interaction is captured using light scattering theory (Mie-electrostatic approach). The resulting temperature field is evaluated using Penne's bioheat model. The effect of key parameters, namely irradiation intensity, irradiation duration and volume fraction, on Tissue temperature is also modelled numerically. RESULTS: With increasing nanorod diameter - from 5 nm to 15 nm - the scattering coefficient increases ∼76 times as compared to a 1.7-fold increase in absorption coefficient. Scattering is considerably minimised by having smaller gold nanorods of 5 nm diameter. For this study, gold nanorods of 5 nm diameter and volume fraction 0.001%, irradiated with 50 W/m(2)-nm for 250 s ablated the tumour as well as spare Healthy Tissue 2 mm beyond the tumour region. CONCLUSION: Overall it may be concluded that tumour ablation as well as surrounding Healthy Tissue-sparing (within millimetres immediately adjacent to the tumour) can be achieved through a combination of specified parameters, namely diameter and volume fraction of gold nanorods, irradiation intensity and duration.
