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1.
Clin Transplant ; 38(1): e15194, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37964668

RESUMEN

Alcohol-related liver disease (ALD) is the leading indication for liver transplantation worldwide. Since Mathurin et al. described their experience in providing early liver transplantation for patients with ALD in 2011, other centers have followed suit with generally favorable survival outcomes. This patient population poses a unique clinical challenge given the expedited nature of the evaluation and the lack of any significant sobriety period prior to transplantation. The SALT (Sustained Alcohol Use Post-Liver Transplant) score is a standardized psychometric tool increasingly used to help stratify the risk of relapse and guide listing decisions for these challenging clinical situations. In 2018, our center introduced a protocol for early liver transplantation for acute alcohol-related hepatitis (AAH). In this article, we offer a retrospective review of 26 patients transplanted between May 2018 and May 2021, including at least 1-year follow-up, and compare outcomes to initial SALT scores; we further identify additional factors that may impact post-transplant success. As transplant committees continue to weigh the ethical dilemma of denying lifesaving treatment against the obligation to remain stewards of a limited resource, we aim to contribute to a more nuanced understanding of risk regarding early transplantation for ALD.


Asunto(s)
Hepatitis Alcohólica , Hepatopatías Alcohólicas , Trasplante de Hígado , Humanos , Trasplante de Hígado/efectos adversos , Hepatitis Alcohólica/etiología , Hepatitis Alcohólica/cirugía , Hepatopatías Alcohólicas/etiología , Hepatopatías Alcohólicas/cirugía , Consumo de Bebidas Alcohólicas , Recurrencia
2.
J Appl Clin Med Phys ; 25(2): e14240, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38150580

RESUMEN

BACKGROUND: Monte Carlo (MC) simulations or measurements in anthropomorphic phantoms are recommended for estimating fetal dose in pregnant patients in radiotherapy. Among the many existing phantoms, there is no commercially available physical phantom representing the entire pregnant woman. PURPOSE: In this study, the development of a low-cost, physical pregnant female phantom was demonstrated using commercially available materials. This phantom is based on the previously published computational phantom. METHODS: Three tissue substitution materials (soft tissue, lung and bone tissue substitution) were developed. To verify Tena's substitution tissue materials, their radiation properties were assessed and compared to ICRP and ICRU materials using MC simulations in MV radiotherapy beams. Validation of the physical phantom was performed by comparing fetal doses obtained by measurements in the phantom with fetal doses obtained by MC simulations in computational phantom, during an MV photon breast radiotherapy treatment. RESULTS: Materials used for building Tena phantom are matched to ICRU materials using physical density, radiation absorption properties and effective atomic number. MC simulations showed that percentage depth doses of Tena and ICRU material comply within 5% for soft and lung tissue, up to 25 cm depth. In the bone tissue, the discrepancy is higher, but again within 5% up to the depth of 5 cm. When the phantom was used for fetal dose measurements in MV photon breast radiotherapy, measured fetal doses complied with fetal doses calculated using MC simulation within 15%. CONCLUSIONS: Physical anthropomorphic phantom of pregnant patient can be manufactured using commercial materials and with low expenses. The files needed for 3D printing are now freely available. This enables further studies and comparison of numerical and physical experiments in diagnostic radiology or radiotherapy.


Asunto(s)
Mujeres Embarazadas , Radiometría , Embarazo , Humanos , Femenino , Fotones/uso terapéutico , Planificación de la Radioterapia Asistida por Computador , Simulación por Computador , Fantasmas de Imagen , Método de Montecarlo , Dosificación Radioterapéutica
3.
Psychosomatics ; 61(6): 585-596, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32828569

RESUMEN

BACKGROUND: The pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as one of the biggest health threats of our generation. A significant portion of patients are presenting with delirium and neuropsychiatric sequelae of the disease. Unique examination findings and responses to treatment have been identified. OBJECTIVE: In this article, we seek to provide pharmacologic and treatment recommendations specific to delirium in patients with COVID-19. METHODS: We performed a literature search reviewing the neuropsychiatric complications and treatments in prior coronavirus epidemics including Middle Eastern respiratory syndrome and severe acute respiratory syndrome coronaviruses, as well as the emerging literature regarding COVID-19. We also convened a work group of consultation-liaison psychiatrists actively managing patients with COVID-19 in our hospital. Finally, we synthesized these findings to provide preliminary pharmacologic recommendations for treating delirium in these patients. RESULTS: Delirium is frequently found in patients who test positive for COVID-19, even in the absence of respiratory symptoms. There appears to be a higher rate of agitation, myoclonus, abulia, and alogia. No data are currently available on the treatment of delirium in patients with COVID-19. Extrapolating from general delirium treatment, Middle Eastern respiratory syndrome/severe acute respiratory syndrome case reports, and our experience, preliminary recommendations for pharmacologic management have been assembled. CONCLUSIONS: COVID-19 is associated with neuropsychiatric symptoms. Low-potency neuroleptics and alpha-2 adrenergic agents may be especially useful in this setting. Further research into the pathophysiology of COVID-19 will be key in developing more targeted treatment guidelines.


Asunto(s)
Agonistas de Receptores Adrenérgicos alfa 2/uso terapéutico , Antipsicóticos/uso terapéutico , Encefalopatías/fisiopatología , Infecciones por Coronavirus/fisiopatología , Delirio/tratamiento farmacológico , Agonistas de Dopamina/uso terapéutico , Neumonía Viral/fisiopatología , Betacoronavirus , Encefalopatías/psicología , COVID-19 , Depresores del Sistema Nervioso Central/uso terapéutico , Infecciones por Coronavirus/psicología , Delirio/fisiopatología , Delirio/psicología , Moduladores del GABA/uso terapéutico , Humanos , Lorazepam/uso terapéutico , Melatonina/uso terapéutico , Pandemias , Neumonía Viral/psicología , Guías de Práctica Clínica como Asunto , SARS-CoV-2
4.
Am J Transplant ; 18(12): 2869-2872, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30192432

RESUMEN

Opioid use disorder (OUD) is an increasing public health problem. Transplant centers worldwide are being confronted with increasing numbers of patients with opioid use disorder and end stage organ disease. Opioid agonist therapy (OAT; ie, methadone, buprenorphine, and buprenorphine/naloxone) is a scientifically proven, effective, physician-prescribed treatment for OUD. Although data in transplant populations remain limited, studies suggest that OAT does not appear to negatively affect graft or patient survival. Policies that require discontinuation of OAT for purposes of listing or transplantation contradict the evidence base for efficacy of OAT. Additional prospective outcomes studies on OAT and transplantation are needed. In the meantime, centers should not be asking patients to come off these effective treatments.


Asunto(s)
Analgésicos Opioides/uso terapéutico , Trastornos Relacionados con Opioides/terapia , Trasplante de Órganos , Obtención de Tejidos y Órganos , Supervivencia de Injerto , Humanos
7.
Health Info Libr J ; 33(4): 329-333, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27422676

RESUMEN

This is the 20th in a series of articles exploring international trends in health science librarianship in the 21st century. The focus of the present issue is the Balkan region (Serbia and Slovenia). The next regular feature will look at Russia and the Ukraine. JM.


Asunto(s)
Internacionalidad , Bibliotecas Médicas/tendencias , Humanos , Conducta en la Búsqueda de Información , Bibliotecólogos/educación , Serbia , Eslovenia
8.
J Clin Psychiatry ; 84(4)2023 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-37339367

RESUMEN

Objective: Mild vitamin C deficiency is a psychiatrically relevant nutritional state, with symptoms including apathy, fatigue, and low mood. Although complete vitamin C deficiency has largely been eradicated, mild deficiency remains common in certain populations. Here, we aimed to identify the prevalence of mild vitamin C deficiency in the inpatient psychiatric setting.Methods: We identified 221 patients with plasma vitamin C levels collected on an inpatient psychiatric unit serving a metropolitan area between January 1, 2015, and March 7, 2022. We identified demographic (age, sex, race, housing status, Area Deprivation Index [an index of neighborhood disadvantage]), substance use (tobacco use, alcohol use), diagnostic (depressive, bipolar, psychotic, anxiety, substance use, catatonia, neurocognitive, autism spectrum), and micronutrient (folate, vitamin B12, vitamin D) risk factors. DSM-5-TR was used as the diagnostic system. Bayesian log-normal regressions were constructed to predict vitamin C as a function of these risk factors. We used these same models to predict vitamin C as a function of significant risk factors.Results: We found that 64% (141 of 221; 95% confidence interval 57%-70%) of patients met criteria for mild vitamin C deficiency. While we did not identify robust demographic, substance use, or diagnostic-based risk factors, we found that folate and vitamin D strongly predicted vitamin C levels. To test the utility of these predictors, we simulated vitamin C as a function of folate and vitamin D and found that predicted deficiency remained high (∼ 50%-55%), even when folate/vitamin D were sufficiently replete.Conclusions: We find that vitamin C deficiency is highly prevalent in the inpatient psychiatric setting and remains high even when the relevant risk factor profile is favorable.


Asunto(s)
Deficiencia de Ácido Ascórbico , Deficiencia de Ácido Fólico , Deficiencia de Vitamina B 12 , Humanos , Deficiencia de Vitamina B 12/diagnóstico , Deficiencia de Vitamina B 12/epidemiología , Deficiencia de Ácido Fólico/epidemiología , Pacientes Internos , Teorema de Bayes , Ácido Fólico , Deficiencia de Ácido Ascórbico/epidemiología , Vitamina D , Ácido Ascórbico
9.
Radiol Oncol ; 56(4): 541-551, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36259318

RESUMEN

BACKGROUND: The incidence of carcinoma during pregnancy is reported to be 1:1000-1:1500 pregnancies with the breast carcinoma being the most commonly diagnosed. Since the fetus is most sensitive to ionizing radiation during the first two trimesters, there are mixed clinical opinions and no uniform guidelines on the use of radiotherapy during pregnancy. Within this study the pregnant female phantom in the second trimester, that can be used for radiotherapy treatment planning (as DICOM data), Monte Carlo simulations (as voxelized geometry) and experimental dosimetry utilizing 3D printing of the molds (as .STL files), was developed. MATERIALS AND METHODS: The developed phantom is based on MRI images of a female patient in her 18th week of pregnancy and CT images after childbirth. Phantom was developed in such a manner that a pregnant female was scanned "in vivo" using MRI during pregnancy and CT after childbirth. For the treatment of left breast carcinoma, 3D conformal radiotherapy was used. The voxelized geometry of the phantom was used for Monte Carlo (MC) simulations using Monte Carlo N-Particle transport codeTM 6.2 (MCNP). CONCLUSIONS: The modeled photon breast radiotherapy plan, applied to the phantom, indicated that the fetus dose is 59 mGy for 50 Gy prescribed to the breast. The results clearly indicate that only 9.5% of the fetal dose is caused by photons that are generated in the accelerator head through scattering and leakage, but the dominant component is scattered radiation from the patient's body.


Asunto(s)
Neoplasias de la Mama , Fotones , Humanos , Embarazo , Femenino , Fantasmas de Imagen , Método de Montecarlo , Fotones/uso terapéutico , Radiometría/métodos , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/radioterapia
10.
Transplant Rev (Orlando) ; 36(4): 100715, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35853383

RESUMEN

Cannabinoid use in patients seeking solid organ transplantation (SOT) is an important and unsettled matter which all transplantation clinicians regularly encounter. It is also a multifaceted, interprofessional issue, difficult for any specialty alone to adequately address in a research article or during clinical care. Such uncertainty lends itself to bias for or against cannabinoid use accompanied by inconsistent policies and procedures. Scientific literature in SOT regarding cannabinoids often narrowly examines the issue and exists mostly in liver and kidney transplantation. Published recommendations from professional societies are mosaics of vagueness and specificity mirroring the ongoing dilemma. The cannabinoid information SOT clinicians need for clinical care may require data and perspectives from diverse medical literature which are rarely synthesized. SOT teams may not be adequately staffed or trained to address various neuropsychiatric cannabinoid effects and risks in patients. In this article, authors from US transplantation centers conduct a systematized review of the few existing studies regarding clinician perceptions, use rates, and clinical impact of cannabinoid use in SOT patients; collate representative professional society guidance on the topic; draw from diverse medical literature bases to detail facets of cannabinoid use in psychiatry and addiction pertinent to all transplantation clinicians; provide basic clinical and policy recommendations; and indicate areas of future study.


Asunto(s)
Cannabinoides , Trasplante de Riñón , Trasplante de Órganos , Humanos , Cannabinoides/uso terapéutico
11.
Radiol Oncol ; 44(1): 62-6, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22933893

RESUMEN

BACKGROUND: Electron linear accelerators in medical radiotherapy have replaced cobalt and caesium sources of radiation. However, medical accelerators with photon energies over 10 MeV generate undesired fast neutron contamination in a therapeutic X-ray photon beam. Photons with energies above 10 MeV can interact with the atomic nucleus of a high-Z material, of which the target and the head of an accelerator consist, and lead to the neutron ejection. RESULTS AND CONCLUSIONS: Our neutron dosimeter, composed of the LR-115 track etch detector and boron foil BN-1 converter, was calibrated on thermal neutrons generated in the nuclear reactor of the Josef Stefan Institute (Slovenia), and applied to dosimetry of undesirable neutrons in photon radiotherapy by the linear accelerator 15 MV Siemens Mevatron. Having considered a high dependence of a cross-section between neutron and boron on neutron energy, and broad neutron spectrum in a photon beam, as well as outside the entrance door to maze of the Mevatron, we developed a method for determining the effective neutron detector response. A neutron dose rate in the photon beam was measured to be 1.96 Sv/h. Outside the Mevatron room the neutron dose rate was 0.62 µSv/h. PACS: 87.52. Ga; 87.53.St; 29.40.Wk.

12.
Radiol Oncol ; 54(2): 247-252, 2020 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-32374291

RESUMEN

Background High energy electron linear accelerators (LINACs) producing photon beams with energies higher than 10 MeV are widely used in radiation therapy. In these beams, fast neutrons are generated, which results in undesired contamination of the therapeutic beam. In this study, measurements and Monte Carlo (MC) simulations were used to obtain neutron spectra and dose equivalents in vicinity of linear accelerator. Materials and methods LINAC Siemens Oncor Expression in Osijek University Hospital is placed in vault that was previously used for 60Co machine. Then, the shielding of the vault was enhanced using lead and steel plates. Measurements of neutron dose equivalent around LINAC and the vault were done using CR-39 solid state nuclear track detectors. To compensate energy dependence of detectors, neutron energy spectra was calculated in measuring positions using MC simulations. Results The vault is a source of photoneutrons, but a vast majority of neutrons originates from accelerator head. Neutron spectra obtained from MC simulations show significant changes between the measuring positions. Annual neutron dose equivalent per year was estimated to be less than 324 µSv in the measuring points outside of the vault. Conclusions Since detectors used in this paper are very dependent on neutron energy, it is extremely important to know the neutron spectra in measuring points. Though, patient dosimetry should include neutrons, estimated annual neutron doses outside the vault were far below exposure limit of ionizing radiation for workers.


Asunto(s)
Neutrones Rápidos , Aceleradores de Partículas , Protección Radiológica/métodos , Método de Montecarlo , Neutrones , Dosis de Radiación , Monitoreo de Radiación/métodos , Radiometría/métodos , Factores de Tiempo
14.
Radiat Prot Dosimetry ; 131(4): 535-40, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18940818

RESUMEN

A national audit of mammography equipment performance, image quality and dose has been conducted in Croatia. Film-processing parameters, optical density (OD), average glandular dose (AGD) to the standard breast, viewing conditions and image quality were examined using TOR(MAM) test object. Average film gradient ranged from 2.6 to 3.7, with a mean of 3.1. Tube voltage used for imaging of the standard 45 mm polymethylmethacrylate phantom ranged from 24 to 34 kV, and OD ranged from 0.75 to 1.94 with a mean of 1.26. AGD to the standard breast ranged from 0.4 to 2.3 mGy with a mean of 1.1 mGy. Besides clinical conditions, the authors have imaged the standard phantom in the referent conditions with 28 kV and OD as close as possible to 1.5. Then, AGD ranged from 0.5 to 2.6 mGy with a mean of 1.3 mGy. Image viewing conditions were generally unsatisfying with ambient light up to 500 lx and most of the viewing boxes with luminance between 1000 and 2000 cd per m(2). TOR(MAM) scoring of images taken in clinical and referent conditions was done by local radiologists in local image viewing conditions and by the referent radiologist in good image viewing conditions. Importance of OD and image viewing conditions for diagnostic information were analysed. The survey showed that the main problem in Croatia is the lack of written quality assurance/quality control (QA/QC) procedures. Consequently, equipment performance, image quality and dose are unstable and activities to improve image quality or to reduce the dose are not evidence-based. This survey also had an educational purpose, introducing in Croatia the QC based on European Commission Guidelines.


Asunto(s)
Carga Corporal (Radioterapia) , Análisis de Falla de Equipo , Mamografía/instrumentación , Mamografía/estadística & datos numéricos , Radiometría/estadística & datos numéricos , Croacia/epidemiología , Humanos , Dosis de Radiación
15.
Coll Antropol ; 32 Suppl 2: 217-9, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19138027

RESUMEN

From the prescription to the delivery of a radiotherapy treatment, a team of professionals from a number of disciplines is involved. In this way significant potential for errors leading to an accidental exposure becomes apparent. Comprehensive quality assurance/quality control (QA/QC) program to minimize such errors is, therefore, required. One aspect of QA/QC program is quality control of the equipment. In this paper we present experiences in establishing QC procedures in our centers. Also differences in QC practices in Croatian radiotherapy centers are reviewed in the light of recommendations given by international reports and publications. To obtain insight into the current employed protocols a questionnaire based on our QC protocols was made and it was sent to all radiotherapy institutions in Croatia. QC procedures and tools used, professionals involved, performance frequencies of the tests and tolerance/action levels are compared. All centers perform the great majority of QC tests, but some variations in the performance frequencies of QC tests and in personnel responsible for performing particular tests are found. Reviewing of QC practices and exchanging experience could help in evolving uniform protocol for QC procedures at national level.


Asunto(s)
Garantía de la Calidad de Atención de Salud/métodos , Radioterapia/instrumentación , Protocolos Clínicos , Croacia , Seguridad de Equipos , Humanos , Control de Calidad
16.
Coll Antropol ; 32 Suppl 2: 211-5, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19140284

RESUMEN

The size and shape of the treatment fields applied in radiotherapy account for uncertainties in the daily set-up of the patients during the treatment. We investigated the accuracy of daily patient positioning in the bellyboard pelvic radiotherapy in order to find out the magnitude of the patients movement during the treatment. Translational as well as rotational movements of the patients are explored. Film portal imaging is used in order to find patient positioning error during the treatment of the pelvic region. Patients are treated in the prone position using the bellyboard positioning device. Thirty six patients are included in the study; 15 patients were followed during the whole treatment and 21 during the first 5 consecutive treatment days. The image acquisition was completed in 85% and systematic and random positioning errors in 453 images are analyzed. Translation of the patient during the treatment caused set-up errors that ranged up to 30 mm and rotation of the sacrum ranged up to 14 degrees. We found out that most of the patients had time trend (drift of the position or angle during the time). This is predominant in the first few days while patient accommodate to uncomfortable prone position in the bellyboard. Safety margins that will ensure 90% probability of depositing at least 95% of the prescribed dose in the target are calculated according to translational movement of the patient. No action level, off line, set-up protocol is employed to correct patient position because of the translational movement. To correct for the rotation of the patient anatomy, correction of the custom shielding blocks should be employed.


Asunto(s)
Neoplasias de los Genitales Femeninos/radioterapia , Neoplasias Pélvicas/radioterapia , Postura , Garantía de la Calidad de Atención de Salud , Planificación de la Radioterapia Asistida por Computador , Neoplasias del Recto/radioterapia , Croacia , Femenino , Humanos , Posición Prona , Garantía de la Calidad de Atención de Salud/métodos , Rotación , Sacro
18.
Med Dosim ; 38(1): 100-4, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23246197

RESUMEN

Implementation of advanced techniques in clinical practice can greatly improve the outcome of radiation therapy, but it also makes the process much more complex with a lot of room for errors. An important part of the quality assurance program is verification of treatment planning system (TPS). Dosimetric verifications in anthropomorphic phantom were performed in 4 centers where new systems were installed. A total of 14 tests for 2 photon energies and multigrid superposition algorithms were conducted using the CMS XiO TPS. Evaluation criteria as specified in the International Atomic Energy Agency Technical Reports Series (IAEA TRS) 430 were employed. Results of measurements are grouped according to the placement of the measuring point and the beam energy. The majority of differences between calculated and measured doses in the water-equivalent part of the phantom were in tolerance. Significantly more out-of-tolerance values were observed in "nonwater-equivalent" parts of the phantom, especially for higher-energy photon beams. This survey was done as a part of continuous effort to build up awareness of quality assurance/quality control (QA/QC) importance in the Croatian radiotherapy community. Understanding the limitations of different parts of the various systems used in radiation therapy can systematically improve quality as well.


Asunto(s)
Garantía de la Calidad de Atención de Salud/normas , Oncología por Radiación/normas , Planificación de la Radioterapia Asistida por Computador/normas , Croacia , Adhesión a Directriz , Guías como Asunto
19.
Addict Sci Clin Pract ; 7: 12, 2012 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-23186222

RESUMEN

BACKGROUND: Alcohol withdrawal delirium (AWD) is associated with significant morbidity and mortality. Pellagra (niacin deficiency) can be a cause of delirium during alcohol withdrawal that may often be overlooked. OBJECTIVES: We present a three-patient case series of pellagrous encephalopathy (delirium due to pellagra) presenting as AWD. METHODS: We provide a brief review of pellagra's history, data on pellagra's epidemiology, and discuss pellagra's various manifestations, particularly as related to alcohol withdrawal. We conclude by providing a review of existing guidelines on the management of alcohol withdrawal, highlighting that they do not include pellagrous encephalopathy in the differential diagnosis for AWD. RESULTS: Though pellagra has been historically described as the triad of dementia, dermatitis, and diarrhea, it seldom presents with all three findings. The neurocognitive disturbance associated with pellagra is better characterized by delirium rather than dementia, and pellagra may present as an isolated delirium without any other aspects of the triad. DISCUSSION: Although endemic pellagra is virtually eradicated in Western countries, it continues to present as pellagrous encephalopathy in patients with risk factors for malnutrition such as chronic alcohol intake, homelessness, or AIDS. It may often be mistaken for AWD. Whenever pellagra is suspected, treatment with oral nicotinamide (100 mg three times daily for 3-4 weeks) prior to laboratory confirmation is recommended as an inexpensive, safe, and potentially life-saving intervention.


Asunto(s)
Delirio por Abstinencia Alcohólica/epidemiología , Encefalopatías/complicaciones , Encefalopatías/diagnóstico , Pelagra/diagnóstico , Pelagra/epidemiología , Delirio por Abstinencia Alcohólica/diagnóstico , Alcoholismo/epidemiología , Diagnóstico Diferencial , Suplementos Dietéticos , Femenino , Personas con Mala Vivienda , Humanos , Masculino , Persona de Mediana Edad , Pelagra/tratamiento farmacológico , Guías de Práctica Clínica como Asunto , Factores de Riesgo
20.
Arh Hig Rada Toksikol ; 62(3): 261-7, 2011 Sep.
Artículo en Croata | MEDLINE | ID: mdl-21971111

RESUMEN

An external beam radiotherapy (EBRT) using megavoltage beam of linear accelerator is usually the treatment of choice in cancer patients. The goal of EBRT is to deliver the prescribed dose to the target volume, with as low as possible dose to the surrounding healthy tissue. A large number of procedures and different professions involved in radiotherapy, uncertainty of equipment and daily patient set-up errors can cause a difference between the planned and delivered dose.We investigated a part of this difference caused by measuring daily patient set-up errors for 35 patients. These set-up errors were simulated on five patients, using 3D treatment planning software XiO. The simulation investigated differences in dose distributions between the planned and shifted geometry. Additionally, we investigated the influence of the error on treatment plan selection by analysing changes in dose volume histograms, planning target volume conformity index (CIPTV), and homogeneity index (HI).Simulations showed that patient daily set-up errors can cause significant differences between the planned and actual dose distributions. Moreover, for some patients, those errors could affect the choice of treatment plan since CIPTV fell under 97%. Surprisingly, HI was not as sensitive to set-up errors as CIPTV. Our results have confirmed the need to minimise daily set-up errors through quality assurance programmes.


Asunto(s)
Aceleradores de Partículas , Posicionamiento del Paciente , Neoplasias Pélvicas/radioterapia , Pelvis/efectos de la radiación , Errores de Configuración en Radioterapia , Radioterapia de Alta Energía , Humanos , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador , Radioterapia Conformacional
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