Cari Borras - Academia.edu (original) (raw)
Papers by Cari Borras
Clinical Engineering, 2016
Jurisdictions of all sizes, from tribal setting to national governments and from local families t... more Jurisdictions of all sizes, from tribal setting to national governments and from local families to global institutions, are concerned about saving life, protecting property, preserving the economic base of the community and the environment. When disaster strikes, those who have emergency plans and practice them routinely will be in a better position to ride out the event and to help the community. The burden is magnified when it comes to healthcare facilities, that by their nature protect lives, and to their staff who take care of patients due to the critical dependency of the today’s hospital community on its technology to support the delivery of services. This is especially true when an increased demand is placed on their triaging, medical and surgical services during and around disasters. A disaster has three stages: pre-disaster, during disaster, and disaster recovery. Each stage must include specific strategies for protecting systems and devices, especially those that are critical to life and those that present unique hazards like radiation-emitting devices and radioactive materials. Healthcare professionals need to proactively plan, implement management tools, and train their staff to help them deal with disasters in the most effective and safest way possible. The understanding of healthcare systems (including IT networks) and devices vulnerability is critical, especially in the case where radiation mitigation and contamination containment are necessary. Strengthening the resilience of the technology infrastructure prior to and planning for backup support prioritization during disasters are all crucial for the continuity of the hospital mission. In doing this, the coordinated role of clinical engineers and medical physicists is highly important.
Physica Medica, Dec 1, 2021
s / Physica Medica 92S1 (2021) S143–S266 S213 26–86 years), who underwent unilateral Vim thalamot... more s / Physica Medica 92S1 (2021) S143–S266 S213 26–86 years), who underwent unilateral Vim thalamotomy (left=50, 96.15%; right=2, 3.85%) for medication-refractory essential tremor (n=39; 78%) or Parkinson tremor (n=13; 22%) were considered. The data collected refers to patient-speci c features such as skull density ratio (SDR) and skull area (SA) and patient-speci c parameters such as sonication duration (Sd), user-de ned energy (E), e ective measured energy (Em), maximum temperature (Tmax). Results: The energy released onto the planned target was found to decrease with the SDR for all temperature ranges. A positive correlation was observed between the slope of Tmax vs. Em plot and the SDR (R2=0.765; p<0.001). In addition, the Tmax was positively correlated with SDR (R2=0.398; p<0.005). On the contrary, no significant correlation was found between SDR and SA or Tx. Conclusions: Our results con rm the factors that significantly influence the course of a tcMRgFUS procedure even when a 1.5-T MRI scanner is used for procedure guidance. The experience we gained in this study indicates that the SDR remains one of the most significant technical parameters to be considered in a tcMRgFUS procedure. The possibility of prospectively setting the sonication energy according to the presented curves of energy delivery as a function of SDR for each treatment stage could provide a further understanding and a greater awareness of this emerging technology.
To ensure quality of healthcare delivery, radiological equipment and personnel working in a medic... more To ensure quality of healthcare delivery, radiological equipment and personnel working in a medical imaging service require performance evaluation, including radiation safety assessments. It is necessary to establish and implement quality assurance/quality control (QA/QC), radiation protection and maintenance programs—the extent of which depend on the complexity of equipment and procedures. The programs should be established by professionals such as medical physicists or biomedical engineers but can be carried out by staff in the rural health center under the guidance (physical and/or virtual) of the professional experts. For the programs to function adequately, a person among the technical or nursing staff should assume the responsibilities for the QA/QC and maintenance programs. The same person may also function as a radiation safety officer, or such role may be entrusted to a clinical individual. This chapter outlines the elements of such programs and provides references to specific details.
Nucleation and Atmospheric Aerosols, 2016
Commissioning of a relative stopping power to Hounsfield unit calibration curve for a Mevion prot... more Commissioning of a relative stopping power to Hounsfield unit calibration curve for a Mevion proton radiation treatment unit
Journal of Radiological Protection, Sep 11, 2013
There has been an expansion in the use of x-ray imaging during the last 20 years. Effective arran... more There has been an expansion in the use of x-ray imaging during the last 20 years. Effective arrangements for justification of exposures as well as for optimisation of protection are crucial. The amount of effort put into the latter, the way in which it is organised and the groups carrying this out vary across the globe. A simple survey of organisational arrangements relating to performance testing of x-ray equipment, management of patient dose and other aspects of implementing optimisation has been undertaken. A total of 137 completed survey forms were received from medical physicists in 48 countries. Results for individual countries from which more responses were received, or for groups of neighbouring ones, are compared to portray variations. Some performance testing of x-ray equipment was mandated in most countries (more than 90%), with the tests being performed primarily by hospital or private medical physicists, although other groups are involved. Testing of equipment prior to clinical use was generally high for most regions, but the frequency was lower in Latin America. There was considerable variation in the frequency and regularity of subsequent testing. The prevalence of patient dose surveys was high in Europe, but lower in other continents. Organisational arrangements for testing performance of x-ray equipment, patient dose surveys and implementing optimisation of protection in medical exposures across the globe can be divided into five main groups. Hospital medical physicists take the lead in western Europe and Australia with the involvement of radiographers. Private medical physicists test equipment in Brazil, the USA and New Zealand, and have some responsibility for optimisation in Brazil. University personnel have significant involvement, together with medical physicists in eastern Europe, but the extent of the coverage is uncertain. Government personnel and service engineers carry out equipment testing in many countries of Africa and Asia, while radiographers have a significant role in Thailand and other countries where the number of medical physicists is limited. In order for dose surveys to have an impact, action must be taken upon the findings, but there must be an effective link between surveyors and radiology facility staff to ensure that this is done.
Springer eBooks, 2017
The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.
Australasian Physical & Engineering Sciences in Medicine, Jun 1, 2004
“Rural health center” encompasses a variety of analogous terms that describe an establishment of ... more “Rural health center” encompasses a variety of analogous terms that describe an establishment of ambulatory primary health care attention, placed in a rural location and generally distant from urban areas. Depending on the place and the complexity of the services offered, the staff may be comprised essentially of a medical doctor, a nurse, and a technician. This chapter addresses the health challenges faced by such facilities and emphasizes that rural health centers should define what pathologies and health conditions they can manage and which ones should be referred to a district or general hospital. It also introduces the view that medical imaging may be useful to corroborate clinical findings.
Medical Physics, Jun 1, 2016
Joanna E. Cygler, Jan Seuntjens, J. Daniel Bourland, M. Saiful Huq, Josep Puxeu Vaque, Daniel Zuc... more Joanna E. Cygler, Jan Seuntjens, J. Daniel Bourland, M. Saiful Huq, Josep Puxeu Vaque, Daniel Zucca Aparicio, Tatiana Krylova, Yuri Kirpichev, Eric Ford, Caridad Borras Stereotactic Radiation Therapy (SRT) utilizes small static and dynamic (IMRT) fields, to successfully treat malignant and benign diseases using techniques such as Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT). SRT is characterized by sharp dose gradients for individual fields and their resultant dose distributions. For appropriate targets, small field radiotherapy offers improved treatment quality by allowing better sparing of organs at risk while delivering the prescribed target dose. Specialized small field treatment delivery systems, such as robotic-controlled linear accelerators, gamma radiosurgery units, and dynamic arc linear accelerators may utilize rigid fixation, image guidance, and tumor tracking, to insure precise dose delivery to static or moving targets. However, in addition to great advantages, small field delivery techniques present special technical challenges for dose calibration due to unique geometries and small field sizes not covered by existing reference dosimetry protocols such as AAPM TG-51 or IAEA TRS 398. In recent years extensive research has been performed to understand small field dosimetry and measurement instrumentation. AAPM, IAEA and ICRU task groups are expected to provide soon recommendations on the dosimetry of small radiation fields. In this symposium we will: 1] discuss the physics, instrumentation, methodologies and challenges for small field radiation dose measurements; 2] review IAEA and ICRU recommendations on prescribing, recording and reporting of small field radiation therapy; 3] discuss selected clinical applications and technical aspects for specialized image-guided, small field, linear accelerator based treatment techniques such as IMRT and SBRT. LEARNING OBJECTIVES 1. To learn the physics of small fields in contrast to dosimetry of conventional fields 2. To learn about detectors suitable for small fields 3. To learn about the role of Monte Carlo simulations in determination of small field output factors 4. To provide an overview of the IAEA small field dosimetry recommendations 5. To provide an overview of the content of the ICRU report on Prescribing, Reporting and Recording of Small Field Radiation Therapy. 6. To learn about special technical considerations in delivering IMRT and SBRT treatments 7. To appreciate specific challenges of IMRT implementation J. Seuntjens, Natural Sciences and Engineering Research Council; Canadian Institutes of Health Research.
Nucleation and Atmospheric Aerosols, 2001
Under the auspices of PAHO/WHO, a multicentric investigation is carried out in five Latin America... more Under the auspices of PAHO/WHO, a multicentric investigation is carried out in five Latin American countries. Its aim is to correlate quality indicators of radiology services with the accuracy of the radiological interpretation as determined by a panel of radiology experts. We present preliminary results from mammographic imaging facilities. Evaluation of the equipment performance and dose measurements in 21 mammographic
Health and Technology
Purpose Science diplomacy in medical physics is a relatively young research field and translation... more Purpose Science diplomacy in medical physics is a relatively young research field and translational practice that focuses on establishing international collaborations to address some of the questions biomedical professionals face globally. This paper aims to present an overview of science diplomacy in medical physics, from an international perspective, illustrating the ways collaborations within and across continents can lead to scientific and professional achievements that advance scientific growth and improve patients care. Methods Science diplomacy actions were sought that promote collaborations in medical physics across the continents, related to professional and scientific aspects alike. Results Several science diplomacy actions have been identified to promote education and training, to facilitate research and development, to effectively communicate science to the public, to enable equitable access of patients to healthcare and to focus on gender equity within the profession as well as healthcare provision. Scientific and professional organizations in the field of medical physics across all continents have adopted a number of efforts in their aims, many of them with great success, to promote science diplomacy and to foster international collaborations. Conclusions Professionals in medical physics can advance through international cooperation, by building strong communication across scientific communities, addressing rising demands, exchange scientific information and knowledge.
Este trabalho apresentou os resultados de tres metodos de calibracao de filmes radiocromicos GAFC... more Este trabalho apresentou os resultados de tres metodos de calibracao de filmes radiocromicos GAFCHROMIC XR-RV2, visando a sua utilizacao com feixes de raios X, qualidade radiodiagnostico. A resposta do filme radiocromico em funcao dose foi avaliada utilizando-se um scanner de reflexao e dois densitometros oticos, um comum, utilizado para filmes radiograficos convencionais e outro especifico para medidas de filmes radiocromicos. Os resultados encontrados com os varios metodos de calibracao avaliados nao apresentaram diferencas significativas. Entretanto, devido a facilidade de aquisicao e de uso do densitometro comum, concluiu-se que a determinacao da dose em pacientes com esse densitometro era uma opcao pratica.
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Defining the Medical Imaging Requirements for a Rural Health Center, 2016
In the planning of medical imaging services, it is important to consider the minimum requirements... more In the planning of medical imaging services, it is important to consider the minimum requirements of equipment and facilities. In this chapter, ultrasound and X-ray units considered appropriate for rural health centers are considered in terms of image quality, cost and tele-imaging capabilities. Equipment procurement issues such as acquisition schemes, development/review of technical specifications, warranties, and obsolescence issues are discussed. The need for the availability of operation and service manuals as well as replacement parts, accessories and software upgrades throughout the life of the machine is emphasized. Guidance is given on the actual process of acquiring a unit and the site preparations involved, including the various permits needed. Examples of ultrasound equipment for low resource settings and the possibility of having ultrasound probes connected to a personal computer are explored. WHO’s efforts in promoting the development of a versatile, high quality, low maintenance and inexpensive X-ray unit are reviewed.
Clinical Engineering, 2016
Jurisdictions of all sizes, from tribal setting to national governments and from local families t... more Jurisdictions of all sizes, from tribal setting to national governments and from local families to global institutions, are concerned about saving life, protecting property, preserving the economic base of the community and the environment. When disaster strikes, those who have emergency plans and practice them routinely will be in a better position to ride out the event and to help the community. The burden is magnified when it comes to healthcare facilities, that by their nature protect lives, and to their staff who take care of patients due to the critical dependency of the today’s hospital community on its technology to support the delivery of services. This is especially true when an increased demand is placed on their triaging, medical and surgical services during and around disasters. A disaster has three stages: pre-disaster, during disaster, and disaster recovery. Each stage must include specific strategies for protecting systems and devices, especially those that are critical to life and those that present unique hazards like radiation-emitting devices and radioactive materials. Healthcare professionals need to proactively plan, implement management tools, and train their staff to help them deal with disasters in the most effective and safest way possible. The understanding of healthcare systems (including IT networks) and devices vulnerability is critical, especially in the case where radiation mitigation and contamination containment are necessary. Strengthening the resilience of the technology infrastructure prior to and planning for backup support prioritization during disasters are all crucial for the continuity of the hospital mission. In doing this, the coordinated role of clinical engineers and medical physicists is highly important.
Physica Medica, Dec 1, 2021
s / Physica Medica 92S1 (2021) S143–S266 S213 26–86 years), who underwent unilateral Vim thalamot... more s / Physica Medica 92S1 (2021) S143–S266 S213 26–86 years), who underwent unilateral Vim thalamotomy (left=50, 96.15%; right=2, 3.85%) for medication-refractory essential tremor (n=39; 78%) or Parkinson tremor (n=13; 22%) were considered. The data collected refers to patient-speci c features such as skull density ratio (SDR) and skull area (SA) and patient-speci c parameters such as sonication duration (Sd), user-de ned energy (E), e ective measured energy (Em), maximum temperature (Tmax). Results: The energy released onto the planned target was found to decrease with the SDR for all temperature ranges. A positive correlation was observed between the slope of Tmax vs. Em plot and the SDR (R2=0.765; p<0.001). In addition, the Tmax was positively correlated with SDR (R2=0.398; p<0.005). On the contrary, no significant correlation was found between SDR and SA or Tx. Conclusions: Our results con rm the factors that significantly influence the course of a tcMRgFUS procedure even when a 1.5-T MRI scanner is used for procedure guidance. The experience we gained in this study indicates that the SDR remains one of the most significant technical parameters to be considered in a tcMRgFUS procedure. The possibility of prospectively setting the sonication energy according to the presented curves of energy delivery as a function of SDR for each treatment stage could provide a further understanding and a greater awareness of this emerging technology.
To ensure quality of healthcare delivery, radiological equipment and personnel working in a medic... more To ensure quality of healthcare delivery, radiological equipment and personnel working in a medical imaging service require performance evaluation, including radiation safety assessments. It is necessary to establish and implement quality assurance/quality control (QA/QC), radiation protection and maintenance programs—the extent of which depend on the complexity of equipment and procedures. The programs should be established by professionals such as medical physicists or biomedical engineers but can be carried out by staff in the rural health center under the guidance (physical and/or virtual) of the professional experts. For the programs to function adequately, a person among the technical or nursing staff should assume the responsibilities for the QA/QC and maintenance programs. The same person may also function as a radiation safety officer, or such role may be entrusted to a clinical individual. This chapter outlines the elements of such programs and provides references to specific details.
Nucleation and Atmospheric Aerosols, 2016
Commissioning of a relative stopping power to Hounsfield unit calibration curve for a Mevion prot... more Commissioning of a relative stopping power to Hounsfield unit calibration curve for a Mevion proton radiation treatment unit
Journal of Radiological Protection, Sep 11, 2013
There has been an expansion in the use of x-ray imaging during the last 20 years. Effective arran... more There has been an expansion in the use of x-ray imaging during the last 20 years. Effective arrangements for justification of exposures as well as for optimisation of protection are crucial. The amount of effort put into the latter, the way in which it is organised and the groups carrying this out vary across the globe. A simple survey of organisational arrangements relating to performance testing of x-ray equipment, management of patient dose and other aspects of implementing optimisation has been undertaken. A total of 137 completed survey forms were received from medical physicists in 48 countries. Results for individual countries from which more responses were received, or for groups of neighbouring ones, are compared to portray variations. Some performance testing of x-ray equipment was mandated in most countries (more than 90%), with the tests being performed primarily by hospital or private medical physicists, although other groups are involved. Testing of equipment prior to clinical use was generally high for most regions, but the frequency was lower in Latin America. There was considerable variation in the frequency and regularity of subsequent testing. The prevalence of patient dose surveys was high in Europe, but lower in other continents. Organisational arrangements for testing performance of x-ray equipment, patient dose surveys and implementing optimisation of protection in medical exposures across the globe can be divided into five main groups. Hospital medical physicists take the lead in western Europe and Australia with the involvement of radiographers. Private medical physicists test equipment in Brazil, the USA and New Zealand, and have some responsibility for optimisation in Brazil. University personnel have significant involvement, together with medical physicists in eastern Europe, but the extent of the coverage is uncertain. Government personnel and service engineers carry out equipment testing in many countries of Africa and Asia, while radiographers have a significant role in Thailand and other countries where the number of medical physicists is limited. In order for dose surveys to have an impact, action must be taken upon the findings, but there must be an effective link between surveyors and radiology facility staff to ensure that this is done.
Springer eBooks, 2017
The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.
Australasian Physical & Engineering Sciences in Medicine, Jun 1, 2004
“Rural health center” encompasses a variety of analogous terms that describe an establishment of ... more “Rural health center” encompasses a variety of analogous terms that describe an establishment of ambulatory primary health care attention, placed in a rural location and generally distant from urban areas. Depending on the place and the complexity of the services offered, the staff may be comprised essentially of a medical doctor, a nurse, and a technician. This chapter addresses the health challenges faced by such facilities and emphasizes that rural health centers should define what pathologies and health conditions they can manage and which ones should be referred to a district or general hospital. It also introduces the view that medical imaging may be useful to corroborate clinical findings.
Medical Physics, Jun 1, 2016
Joanna E. Cygler, Jan Seuntjens, J. Daniel Bourland, M. Saiful Huq, Josep Puxeu Vaque, Daniel Zuc... more Joanna E. Cygler, Jan Seuntjens, J. Daniel Bourland, M. Saiful Huq, Josep Puxeu Vaque, Daniel Zucca Aparicio, Tatiana Krylova, Yuri Kirpichev, Eric Ford, Caridad Borras Stereotactic Radiation Therapy (SRT) utilizes small static and dynamic (IMRT) fields, to successfully treat malignant and benign diseases using techniques such as Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT). SRT is characterized by sharp dose gradients for individual fields and their resultant dose distributions. For appropriate targets, small field radiotherapy offers improved treatment quality by allowing better sparing of organs at risk while delivering the prescribed target dose. Specialized small field treatment delivery systems, such as robotic-controlled linear accelerators, gamma radiosurgery units, and dynamic arc linear accelerators may utilize rigid fixation, image guidance, and tumor tracking, to insure precise dose delivery to static or moving targets. However, in addition to great advantages, small field delivery techniques present special technical challenges for dose calibration due to unique geometries and small field sizes not covered by existing reference dosimetry protocols such as AAPM TG-51 or IAEA TRS 398. In recent years extensive research has been performed to understand small field dosimetry and measurement instrumentation. AAPM, IAEA and ICRU task groups are expected to provide soon recommendations on the dosimetry of small radiation fields. In this symposium we will: 1] discuss the physics, instrumentation, methodologies and challenges for small field radiation dose measurements; 2] review IAEA and ICRU recommendations on prescribing, recording and reporting of small field radiation therapy; 3] discuss selected clinical applications and technical aspects for specialized image-guided, small field, linear accelerator based treatment techniques such as IMRT and SBRT. LEARNING OBJECTIVES 1. To learn the physics of small fields in contrast to dosimetry of conventional fields 2. To learn about detectors suitable for small fields 3. To learn about the role of Monte Carlo simulations in determination of small field output factors 4. To provide an overview of the IAEA small field dosimetry recommendations 5. To provide an overview of the content of the ICRU report on Prescribing, Reporting and Recording of Small Field Radiation Therapy. 6. To learn about special technical considerations in delivering IMRT and SBRT treatments 7. To appreciate specific challenges of IMRT implementation J. Seuntjens, Natural Sciences and Engineering Research Council; Canadian Institutes of Health Research.
Nucleation and Atmospheric Aerosols, 2001
Under the auspices of PAHO/WHO, a multicentric investigation is carried out in five Latin America... more Under the auspices of PAHO/WHO, a multicentric investigation is carried out in five Latin American countries. Its aim is to correlate quality indicators of radiology services with the accuracy of the radiological interpretation as determined by a panel of radiology experts. We present preliminary results from mammographic imaging facilities. Evaluation of the equipment performance and dose measurements in 21 mammographic
Health and Technology
Purpose Science diplomacy in medical physics is a relatively young research field and translation... more Purpose Science diplomacy in medical physics is a relatively young research field and translational practice that focuses on establishing international collaborations to address some of the questions biomedical professionals face globally. This paper aims to present an overview of science diplomacy in medical physics, from an international perspective, illustrating the ways collaborations within and across continents can lead to scientific and professional achievements that advance scientific growth and improve patients care. Methods Science diplomacy actions were sought that promote collaborations in medical physics across the continents, related to professional and scientific aspects alike. Results Several science diplomacy actions have been identified to promote education and training, to facilitate research and development, to effectively communicate science to the public, to enable equitable access of patients to healthcare and to focus on gender equity within the profession as well as healthcare provision. Scientific and professional organizations in the field of medical physics across all continents have adopted a number of efforts in their aims, many of them with great success, to promote science diplomacy and to foster international collaborations. Conclusions Professionals in medical physics can advance through international cooperation, by building strong communication across scientific communities, addressing rising demands, exchange scientific information and knowledge.
Este trabalho apresentou os resultados de tres metodos de calibracao de filmes radiocromicos GAFC... more Este trabalho apresentou os resultados de tres metodos de calibracao de filmes radiocromicos GAFCHROMIC XR-RV2, visando a sua utilizacao com feixes de raios X, qualidade radiodiagnostico. A resposta do filme radiocromico em funcao dose foi avaliada utilizando-se um scanner de reflexao e dois densitometros oticos, um comum, utilizado para filmes radiograficos convencionais e outro especifico para medidas de filmes radiocromicos. Os resultados encontrados com os varios metodos de calibracao avaliados nao apresentaram diferencas significativas. Entretanto, devido a facilidade de aquisicao e de uso do densitometro comum, concluiu-se que a determinacao da dose em pacientes com esse densitometro era uma opcao pratica.
Defining the Medical Imaging Requirements for a Rural Health Center, 2016
In the planning of medical imaging services, it is important to consider the minimum requirements... more In the planning of medical imaging services, it is important to consider the minimum requirements of equipment and facilities. In this chapter, ultrasound and X-ray units considered appropriate for rural health centers are considered in terms of image quality, cost and tele-imaging capabilities. Equipment procurement issues such as acquisition schemes, development/review of technical specifications, warranties, and obsolescence issues are discussed. The need for the availability of operation and service manuals as well as replacement parts, accessories and software upgrades throughout the life of the machine is emphasized. Guidance is given on the actual process of acquiring a unit and the site preparations involved, including the various permits needed. Examples of ultrasound equipment for low resource settings and the possibility of having ultrasound probes connected to a personal computer are explored. WHO’s efforts in promoting the development of a versatile, high quality, low maintenance and inexpensive X-ray unit are reviewed.