1
|
Teles P, Pereira P, Silva C, Vaz R, Santos Silva P. Minimally Invasive Treatment for Lumbar Disc Herniation: A Matched Comparison Between Tubular Microdiscectomy and Percutaneous Endoscopic Lumbar Discectomy. Cureus 2024; 16:e57589. [PMID: 38707033 PMCID: PMC11069225 DOI: 10.7759/cureus.57589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2024] [Indexed: 05/07/2024] Open
Abstract
Background and objectives Discectomy for lumbar disc herniation is the most common spinal surgical procedure. Technological advances have led to the emergence of minimally invasive surgical approaches such as tubular microdiscectomy (TMD) and percutaneous endoscopic lumbar discectomy (PELD). The purpose of this study was to compare the clinical outcomes of PELD to those of TMD at one-year follow-up. Materials and methods This observational registry-based (Spine Tango) cohort study included patients with symptomatic lumbar disc herniation submitted to PELD or TMD. The inclusion criteria were patients who underwent minimally invasive lumbar discectomy (PELD or TMD), patients who attended a follow-up after a minimum of 12 months post surgery, and valid pre- and postoperative questionaries. The primary endpoint was defined as the difference between pre- and postoperative Core Outcome Measures Index (COMI) for the back. The matching was based on a 1:1 nearest neighbor matching without replacement. Results A total of 109 patients were included in this study. Propensity score matching (PSM) was performed achieving 86 patients in the matched sample. Regarding COMI improvement, we found no significant difference between the PELD and TMD groups (paired t-test: estimate, -0.23; standard error, 0.6; p=0.7), and we also did not find any significant difference between groups concerning Oswestry Disability Index (ODI) and EuroQol 5 Dimension (EQ-5D). Medication usage and return to work were similar among the matched groups. Conclusions PELD is a technique that minimizes tissue damage achieving good clinical outcomes similar to TMD. This was observed one year after surgery from patient-reported outcome measures (PROMs) that measured pain improvement, disability, and quality of life.
Collapse
Affiliation(s)
- Pedro Teles
- Department of Neurosurgery, Centro Hospitalar Universitário de São João, Porto, PRT
| | - Paulo Pereira
- Department of Neurosurgery, Centro Hospitalar Universitário de São João, Porto, PRT
- Faculty of Medicine, University of Porto, Porto, PRT
| | - Carolina Silva
- Department of Neurosurgery, Centro Hospitalar Universitário de São João, Porto, PRT
| | - Rui Vaz
- Department of Neurosurgery, Centro Hospitalar Universitário de São João, Porto, PRT
| | - Pedro Santos Silva
- Department of Neurosurgery, Centro Hospitalar Universitário de São João, Porto, PRT
| |
Collapse
|
2
|
Arriaga A, Gonçalves C, Teles P, Santos J, Simãozinho P, Sousa P. Establishment of local diagnostic reference levels for abdomen and chest radiographies in the region of Algarve, Portugal. Eur J Radiol 2024; 170:111248. [PMID: 38103493 DOI: 10.1016/j.ejrad.2023.111248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 10/16/2023] [Accepted: 11/30/2023] [Indexed: 12/19/2023]
Abstract
PURPOSE To assess doses variabilities in the same abdomen and chest RX exams for adults, to check the need for dose harmonization. To calculate Diagnostic Reference Levels (DRL), mandatory in the European Union, for the Algarve district in Portugal. Our results can be a valuable reference for the Portuguese official determination of DRLs, still in progress. METHOD We considered 4,936 abdomen and 41,320 chest radiographs of adults, covering 7 health centres and 35 radiographers in Algarve. Entrance skin dose (ESD) was calculated for each radiograph and the corresponding uncertainty estimated. Mean doses per centre and per technician, and their uncertainties, were calculated to access dose variabilities. DRLs, set at the 3rd quartile of the total ESD distribution, were determined for a standard patient and for intervals of body mass index (BMI) to study their correlation with patient anatomical variations. Standard quartile errors were estimated. RESULTS Our results suggest significant dispersion in applied ESDs among different centres and radiographers. Estimates of DRLs also show small fluctuations across years and an important dependence on BMI intervals. For a standard patient, they are 8.7 ± 0.1 (abdomen) and 0.44 ± 0.01 (chest), while the European DRLs are, respectively, 5.1 and 0.2 (all in mGy). CONCLUSIONS Results suggest that there is room for dose optimization and harmonization with European DRLs, urging a national dose survey and the establishment of official national DRLs. Official DRLs in intervals of BMI would be quite beneficial, to avoid unnecessary dose exposures.
Collapse
Affiliation(s)
- A Arriaga
- Departamento de Física da Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
| | - Cláudia Gonçalves
- Departamento de Física da Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; Centro Oncológico Dra Natalia Chaves, Joaquim Chaves Saúde, Rua Manuel Anastácio Alves, 2 2795-533 Carnaxide, Portugal
| | - P Teles
- Departamento de Física e Astronomia da Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal; Centro de Investigação do IPO-PORTO, Rua Dr. António Bernardino de Almeida, 4200-072 Porto, Portugal
| | - Joana Santos
- Instituto Politécnico de Coimbra, ESTESC - Coimbra Health School, Medical Imaging and Radiotherapy, Rua 5 de Outubro, S. Martinho do Bispo, 3046-854 Coimbra, Portugal
| | - Paula Simãozinho
- Administração Regional de Saúde, Algarve, Largo de São Pedro,15, 8000-145 Faro, Portugal
| | - Patrick Sousa
- GyRad, Lda, University of Algarve, Gambelas campus, Pav. H5, 8005-139 Faro, Portugal
| |
Collapse
|
3
|
Campos R, Teles P. INTRODUCING MYCO (MONTY CARLO) – A CYTHON POWERED MONTE CARLO PYTHON FRAMEWORK FOR THE SIMULATION OF PARTICLE TRANSPORT FOR MEDICAL PHYSICS APPLICATIONS. Phys Med 2022. [DOI: 10.1016/s1120-1797(22)02336-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
|
4
|
Ferrari P, Becker F, Campani L, Jansen J, Jovanović Z, Krstić D, Mariotti F, Teles P, Venturi G. ON THE PLACEMENT OF APRON DOSEMETERS AND DOSE ASSESSMENT IN INTERVENTIONAL CARDIOLOGY PROCEDURES: PRELIMINARY RESULTS. Radiat Prot Dosimetry 2022; 198:1495-1499. [PMID: 36156106 DOI: 10.1093/rpd/ncac188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 08/23/2022] [Accepted: 08/25/2022] [Indexed: 06/16/2023]
Abstract
Personnel involved in interventional practices are likely to be exposed to higher radiation doses than other workers in the medical field. Personnel monitoring and radiation protection measures play a crucial role in keeping these doses below the limits. EURADOS (European Radiation Dosimetry Group) Working Group 12 performed a series of investigations showing how the complexity of the scattered field reaching the operators can influence the doses to the operators. The present work was aimed at determining the possible effects on the registered doses of the scattered field and the actual position of a dosemeter on apron. This study has been performed through Monte Carlo simulations and it was validated through measurements. It does not claim to identify the 'best' position for the dosemeter, but to assess the variability of its response, showing how a variability of the order of +/- 30% to 40 should be taken into account.
Collapse
Affiliation(s)
- P Ferrari
- ENEA, IRP - Radiation Protection Institute, Bologna (BO), Italy
| | - F Becker
- KIT, Institute for Nuclear Waste Disposal, Eggenstein-Leopoldshafen, Germany
| | - L Campani
- ENEA, IRP - Radiation Protection Institute, Bologna (BO), Italy
| | - J Jansen
- UKHSA, Radiation, Chemical and Environmental Hazards, Chilton, UK
| | - Z Jovanović
- Faculty of Science, University of Kragujevac, Kragujevac, Serbia
| | - D Krstić
- Faculty of Science, University of Kragujevac, Kragujevac, Serbia
| | - F Mariotti
- ENEA, IRP - Radiation Protection Institute, Bologna (BO), Italy
| | - P Teles
- Faculty of Science, Physics and Astronomy Department, Universidade do Porto, Porto, Portugal
| | - G Venturi
- Medical Physics Department, Ravenna & Forlì Hospitals AUSL Romagna, Forlì (FC), Italy
| |
Collapse
|
5
|
Abreu PG, Romero C, Lourenço JAB, Pappamikail L, Brito M, Teles P, Correia J. Case report: Challenging post-traumatic pseudoarthrosis of C2 odontoid fracture and extreme C1-C2 subluxation. Surg Neurol Int 2022; 13:137. [PMID: 35509539 PMCID: PMC9062932 DOI: 10.25259/sni_10_2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Accepted: 03/24/2022] [Indexed: 11/08/2022] Open
Abstract
Background: Type II C2 odontoid fractures are common traumatic cervical spine lesions and have the highest risk of non-union without fusion. Pseudoarthrosis may lead to extreme anatomic deformation, and poor clinical outcomes. A 50-year-old male, following a traumatic C2 dens fracture treated when the patient was 44 years of age, newly presented at age 50 with pseudoarthrosis and severe C1-C2 subluxation that required a secondary fusion using a three-dimensional (3D) printed model for appropriate surgical planning. Case Description: A 44-year-old male underwent a C1 posterior arch osteotomy to treat cervical myelopathy after a type 2 odontoid fracture. Now at age 50, he newly presented with recurrent myelopathy, and marked cord compression due to a C2 odontoid-dens pseudoarthrosis, and extreme C1 subluxation over C2. A 3D model of the patients’ cervical-spine anatomy was created for surgical planning and led to an anterior C1-C2 freeing of the pseudoarthrosis, followed by a posterior C0-C1 decompression, deformity reduction, C0, C2 laminar, and C3/4 trans-articular arthrodesis. Six months postoperatively, the patient improved from a pre-operative mJOA score of 5 to a postoperative mJOA score of 14. Conclusion: A 3D model was successfully utilized to plan a secondary 360° fusion for a pseudoarthrosis diagnosed 6 years after an original C-C2type II odontoid fusion in a now 50-year-old male.
Collapse
|
6
|
Rodrigues M, Teles P, Pirraco R, Oliveira D, Costa P. Evaluation of fractionation schemes in breast cancer radiotherapy and dosimetric study of the main organs at risk. Phys Med 2021. [DOI: 10.1016/s1120-1797(22)00396-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
7
|
Campos R, Teles P. Monte Carlo: a particle transport simulation code in Python. Phys Med 2021. [DOI: 10.1016/s1120-1797(22)00562-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
|
8
|
Abreu PG, Pappamikail L, Pontinha C, Drago J, Lourenço JA, Romero C, Teles P, Correia JP. Case report: Rare convexity meningeal chondroma mimicking a meningioma. Surg Neurol Int 2021; 12:426. [PMID: 34513189 PMCID: PMC8422430 DOI: 10.25259/sni_558_2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 07/22/2021] [Indexed: 11/08/2022] Open
Abstract
Background: Intracranial chondromas account for 0.2–0.3% of all intracranial neoplastic lesions and less than a quarter arise in the convexity or falx. Despite its benign nature, exceedingly rare malignant transformations exist. The misdiagnosis with meningiomas is frequent and may be related with chondromas’ similar insidious clinical presentation and imaging features. Standalone surgery is advised and complete resection provides the definitive treatment. Case Description: A 44-year-old female presents with insidious headache, visual disturbances, and papilledema. The imaging studies were compatible with frontal parasagittal meningioma. Surgery revealed a meningeal based mass, mostly avascular and with a well-demarked surgical plane from the brain parenchyma. Complete resection with meningeal margins was achieved and the histopathologic examination revealed a chondroma. The patient symptoms subsided and no surgical complications existed. Conclusion: Intracranial convexity chondromas constitute a rare differential diagnosis for meningiomas. The present case reinforces the current scarce data and serves as reminder for clinicians diagnosing and treating intracranial tumors.
Collapse
Affiliation(s)
- Pedro Gonçalo Abreu
- Department of Neurosurgery, Centro Hospitalar Universitário do Algarve, Faro, Portugal
| | - Lia Pappamikail
- Department of Neurosurgery, Centro Hospitalar Universitário do Algarve, Faro, Portugal
| | - Carlos Pontinha
- Department of Anatomical Pathology, Centro Hospitalar Universitário de Lisboa Central, Lisboa, Portugal
| | - José Drago
- Department of Radiology, Centro Hospitalar Universitário do Algarve, Faro, Portugal
| | - José Artur Lourenço
- Department of Neurosurgery, Centro Hospitalar Universitário do Algarve, Faro, Portugal
| | - Clara Romero
- Department of Neurosurgery, Centro Hospitalar Universitário do Algarve, Faro, Portugal
| | - Pedro Teles
- Department of Neurosurgery, Centro Hospitalar Universitário do Algarve, Faro, Portugal
| | - Joaquim Pedro Correia
- Department of Neurosurgery, Centro Hospitalar Universitário do Algarve, Faro, Portugal
| |
Collapse
|
9
|
Czarnecki D, Zink K, Pimpinella M, Borbinha J, Teles P, Pinto M. Monte Carlo calculation of quality correction factors based on air kerma and absorbed dose to water in medium energy x-ray beams. Phys Med Biol 2020; 65:245042. [PMID: 33120372 DOI: 10.1088/1361-6560/abc5c9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Clinical dosimetry is typically performed using ion chambers calibrated in terms of absorbed dose to water. As primary measurement standards for this quantity for low and medium energy x-rays are available only since a few years, most dosimetry protocols for this photon energy range are still based on air kerma calibration. For that reason, data for beam quality correction factors [Formula: see text], necessary for the application of dose to water based protocols, are scarce in literature. Currently the international IAEA TRS-398 Code of Practice is under revision and new [Formula: see text] factors for a large number of ion chambers will be introduced in the update of this protocol. Several international groups provided the IAEA with experimental and Monte Carlo based data for this revision. Within the European Community the EURAMET 16NRM03 RTNORM project was initiated for that purpose. In the present study, Monte Carlo based results for the beam quality correction factors in medium energy x-ray beams for six ion chambers applying different Monte Carlo codes are presented. Additionally, the perturbation factor p Q , necessary for the calculation of dose to water from an air kerma calibration coefficient, was determined. The beam quality correction factor [Formula: see text] for the chambers varied in the investigated energy range by about 4%-5%, and for five out of six chambers the data could be fitted by a simple logarithmic function, if the half-value-layer was used as the beam quality specifier. Corresponding data using different Monte Carlo codes for the same ion chamber agreed within 0.5%. For the perturbation factor p Q , the data did not obey a comparable simple relationship with the beam quality specifier. The variation of p Q for all ion chambers was in the range of 3%-4%. Compared to recently published data, our p Q data is around 1% larger, although the same Monte Carlo code has been used. Compared to the latest experimental data, there are even deviations in the range of 2%.
Collapse
Affiliation(s)
- Damian Czarnecki
- Institute of Medical Physics and Radiation Protection, University of Applied Sciences Giessen (THM), Giessen, Germany
| | | | | | | | | | | |
Collapse
|
10
|
Ferrari P, Jovanovic Z, Bakhanova E, Becker F, Krstic D, Jansen J, Principi S, Teles P, Clairand I, Knezevic Ž. Absorbed dose in the operator's brain in interventional radiology practices: evaluation through KAP value conversion factors. Phys Med 2020; 76:177-181. [PMID: 32693354 DOI: 10.1016/j.ejmp.2020.07.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/17/2020] [Accepted: 07/08/2020] [Indexed: 10/23/2022] Open
Abstract
In order to address the recent concerns over a possible increasing in brain tumour mortality among interventional radiologists and cardiologist, this work evaluated the exposure conditions of the operator's brain during interventional procedures using Monte Carlo simulations with anthropomorphic phantoms. The absorbed doses in several predefined segments of the operator's brain were estimated in a typical interventional radiology irradiation scenario. The doses were normalized to the KAP values simulated for ten X-ray beam qualities and four projections (PA, RAO 25°, LAO 25° and CRA 25°). For the interventional radiology scenario, because of the position of the operator, no difference was found in the exposure between the left and right regions of the brain for the first operator. However, for the second operator standing at a farer distance from the tube, the exposure of the left part of the brain is up to two times higher than that of the right part. The results are in agreement with dose measurements reported in the literature. The conversion factors, obtained as the absorbed dose per KAP, can be used to obtain a first estimate of the exposure of the brain of the operators during interventional procedures.
Collapse
Affiliation(s)
- Paolo Ferrari
- ENEA-IRP, Radiation Protection Institute, Bologna, Italy.
| | - Zoran Jovanovic
- Faculty of Science, University of Kragujevac, Kragujevac, Serbia
| | - Elena Bakhanova
- National Research Center for Radiation Medicine, Kyiv, Ukraine
| | - Frank Becker
- KIT, Institute for Nuclear Waste Disposal, Eggenstein-Leopoldshafen, Germany
| | - Dragana Krstic
- Faculty of Science, University of Kragujevac, Kragujevac, Serbia
| | - Jan Jansen
- Centre for Radiation, Chemical and Environmental Hazards (CRCE), PHE, Chilton, UK
| | - Sara Principi
- Biomedical Engineering Department, Marquette University, Milwaukee, USA
| | - Pedro Teles
- Centro de Ciências e Tecnologias Nucleares, C2TN, Bobadela, Portugal; Departamento de Física e Astronomia, Faculdade de Ciências da Universidade do Porto, Porto, Portugal
| | - Isabelle Clairand
- Institut de Radioprotection et de Sûreté Nucléaire, IRSN, Fontenay-aux-Roses, France
| | | |
Collapse
|
11
|
Teles P, Correia JP, Pappamikail L, Lourenço A, Romero C, Lopes F, Almeida GN, Abreu P. A spontaneous cervical epidural hematoma mimicking a stroke - A case report. Surg Neurol Int 2020; 11:157. [PMID: 32637210 PMCID: PMC7332487 DOI: 10.25259/sni_161_2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 05/27/2020] [Indexed: 01/30/2023] Open
Abstract
Background: A spontaneous cervical epidural hematoma (SCEH) is a rare occurrence. It usually presents with quadriparesis, but it may present with hemiparesis or hemiplegia and can easily be misdiagnosed as stroke. We present a case of stroke mimicking SCEH with hemiparesis worsened after tissue plasminogen activator therapy (tPA) followed by emergency cervical decompression laminectomy. Case Description: A 63-year-old female presented to the emergency department with sudden onset of posterior neck and left shoulder pain with the right side hemiparesis. On neurological examination, the patient had motor power of the right upper and lower limb of 2/5 Medical Research Council, and her whole left extremities were intact. Her medical history was unremarkable for trauma, hemorrhagic diathesis, or anticoagulation therapy. A head computed tomography was ordered ruling out intracranial hemorrhage. Assuming an acute ischemic stroke as the most likely diagnosis, alteplase (tPA) was administered 3 h after symptoms onset, however without any improvement in patient symptoms. A cervical magnetic resonance was performed revealing a right paramedian epidural mass-like lesion between C3-C6. The patient underwent cervical laminectomy C3-C6 with evacuation of epidural hematoma with significant clinical status improvement after surgery. Conclusion: tPA treatment is frequently used as first-line therapy for acute ischemic stroke. Therefore, physicians should be aware of the potential for the SCEH in patients presenting with hemiparesis, as tPA administration may increase cervical hematoma leading to clinical deterioration. With this case, we intended to warn about SCEH as a rare but possible entity, since its early recognition and prompt clinical intervention may improve neurological outcomes.
Collapse
Affiliation(s)
- Pedro Teles
- Department of Neurosurgery, Centro Hospitalar Universitario do Algarve, Rua Leao Penedo, Faro, Portugal
| | - Joaquim Pedro Correia
- Department of Neurosurgery, Centro Hospitalar Universitario do Algarve, Rua Leao Penedo, Faro, Portugal
| | - Lia Pappamikail
- Department of Neurosurgery, Centro Hospitalar Universitario do Algarve, Rua Leao Penedo, Faro, Portugal
| | - Artur Lourenço
- Department of Neurosurgery, Centro Hospitalar Universitario do Algarve, Rua Leao Penedo, Faro, Portugal
| | - Clara Romero
- Department of Neurosurgery, Centro Hospitalar Universitario do Algarve, Rua Leao Penedo, Faro, Portugal
| | - Fátima Lopes
- Department of Neurosurgery, Centro Hospitalar Universitario do Algarve, Rua Leao Penedo, Faro, Portugal
| | - Gonçalo Neto Almeida
- Department of Neurosurgery, Centro Hospitalar Universitario do Algarve, Rua Leao Penedo, Faro, Portugal
| | - Pedro Abreu
- Department of Neurosurgery, Centro Hospitalar Universitario do Algarve, Rua Leao Penedo, Faro, Portugal
| |
Collapse
|
12
|
Andreo P, Burns DT, Kapsch RP, McEwen M, Vatnitsky S, Andersen CE, Ballester F, Borbinha J, Delaunay F, Francescon P, Hanlon MD, Mirzakhanian L, Muir B, Ojala J, Oliver CP, Pimpinella M, Pinto M, de Prez LA, Seuntjens J, Sommier L, Teles P, Tikkanen J, Vijande J, Zink K. Determination of consensus k Q values for megavoltage photon beams for the update of IAEA TRS-398. ACTA ACUST UNITED AC 2020; 65:095011. [DOI: 10.1088/1361-6560/ab807b] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
13
|
Tikkanen J, Zink K, Pimpinella M, Teles P, Borbinha J, Ojala J, Siiskonen T, Gomà C, Pinto M. Calculated beam quality correction factors for ionization chambers in MV photon beams. Phys Med Biol 2020; 65:075003. [PMID: 31995531 DOI: 10.1088/1361-6560/ab7107] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The beam quality correction factor, [Formula: see text], which corrects for the difference in the ionization chamber response between the reference and clinical beam quality, is an integral part of radiation therapy dosimetry. The uncertainty of [Formula: see text] is one of the most significant sources of uncertainty in the dose determination. To improve the accuracy of available [Formula: see text] data, four partners calculated [Formula: see text] factors for 10 ionization chamber models in linear accelerator beams with accelerator voltages ranging from 6 MV to 25 MV, including flattening-filter-free (FFF) beams. The software used in the calculations were EGSnrc and PENELOPE, and the ICRU report 90 cross section data for water and graphite were included in the simulations. Volume averaging correction factors were calculated to correct for the dose averaging in the chamber cavities. A comparison calculation between partners showed a good agreement, as did comparison with literature. The [Formula: see text] values from TRS-398 were higher than our values for each chamber where data was available. The [Formula: see text] values for the FFF beams did not follow the same [Formula: see text], [Formula: see text] relation as beams with flattening filter (values for 10 MV FFF beams were below fits made to other data on average by 0.3%), although our FFF sources were only for Varian linacs.
Collapse
Affiliation(s)
- J Tikkanen
- Radiation and Nuclear Safety Authority (STUK), Helsinki, Finland. Helsinki Institute of Physics, University of Helsinki, Helsinki, Finland
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Borbinha J, Romanets Y, Teles P, Corisco J, Vaz P, Carvalho D, Brouwer Y, Luís R, Pinto L, Vale A, Ventura R, Areias B, Reis AB, Gonçalves B. Performance Analysis of Geiger-Müller and Cadmium Zinc Telluride Sensors Envisaging Airborne Radiological Monitoring in NORM Sites. Sensors (Basel) 2020; 20:s20051538. [PMID: 32164377 PMCID: PMC7085614 DOI: 10.3390/s20051538] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 02/26/2020] [Accepted: 03/06/2020] [Indexed: 11/16/2022]
Abstract
Radiological monitoring is fundamental for compliance with radiological protection policies in the aftermath of radiological events, such as nuclear accidents, terrorism, and out-of-commission uranium mines. An effective strategy for radiation monitoring is to use radiation detectors coupled with Unmanned Aerial Vehicles (UAVs), enabling for quicker surveillance of large areas without involving the need of human presence in the target area. The main aim of this study was to formulate the parameters for a UAV flight strategy in preparation for future field measurements using Geiger-Muller Counters (GMC) and Cadmium Zinc Telluride (CZT) spectrometers. As a proof of concept, the prepared flight strategy will be used to survey out-of-commission uranium mines in northern Portugal. Procedures to assure the calibration of the CZT and verification of the GMCs were conducted, as well as a sensitivity analysis of the sensors considering different acquisition times, distance to source, and detector response time. This article reports specific parameters, such as UAV distance to ground, time of exposition, speed, and the methodology to perform the identification and calculate the activity of possible radioactive sources. An effective flight strategy is also presented, aiming to use radiation detectors coupled with UAVs to undertake extensive monitoring of areas with enhanced levels of environmental radiation, which is of prime importance due to the lasting hazardous effects of enhanced environmental radiation in the nearby ecosystem and population.
Collapse
Affiliation(s)
- Jorge Borbinha
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, ao km 139,7. 2695-066 Bobadela, Portugal; (Y.R.); (P.T.); (J.C.); (P.V.)
- Correspondence:
| | - Yuriy Romanets
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, ao km 139,7. 2695-066 Bobadela, Portugal; (Y.R.); (P.T.); (J.C.); (P.V.)
| | - Pedro Teles
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, ao km 139,7. 2695-066 Bobadela, Portugal; (Y.R.); (P.T.); (J.C.); (P.V.)
| | - José Corisco
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, ao km 139,7. 2695-066 Bobadela, Portugal; (Y.R.); (P.T.); (J.C.); (P.V.)
| | - Pedro Vaz
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, ao km 139,7. 2695-066 Bobadela, Portugal; (Y.R.); (P.T.); (J.C.); (P.V.)
| | - Diogo Carvalho
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal; (D.C.); (Y.B.); (R.L.); (L.P.); (A.V.); (B.G.)
| | - Yoeri Brouwer
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal; (D.C.); (Y.B.); (R.L.); (L.P.); (A.V.); (B.G.)
| | - Raul Luís
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal; (D.C.); (Y.B.); (R.L.); (L.P.); (A.V.); (B.G.)
| | - Luís Pinto
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal; (D.C.); (Y.B.); (R.L.); (L.P.); (A.V.); (B.G.)
| | - Alberto Vale
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal; (D.C.); (Y.B.); (R.L.); (L.P.); (A.V.); (B.G.)
| | - Rodrigo Ventura
- Institute for Systems and Robotics, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal;
| | - Bruno Areias
- Instituto de Telecomunicações, Universidade de Aveiro, 3810-193 Aveiro, Portugal; (B.A.); (A.B.R.)
| | - Andre B. Reis
- Instituto de Telecomunicações, Universidade de Aveiro, 3810-193 Aveiro, Portugal; (B.A.); (A.B.R.)
| | - Bruno Gonçalves
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal; (D.C.); (Y.B.); (R.L.); (L.P.); (A.V.); (B.G.)
| |
Collapse
|
15
|
Machado F, Aguiar T, Valente R, Ferraz T, Amorim P, Pimentel A, Teles P, Montenegro N, Drummond M. Evaluation of obstructive sleep apnea screening questionnaires in obese women in the first trimester of pregnancy. Sleep Med 2019. [DOI: 10.1016/j.sleep.2019.11.663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
16
|
Berkovskyy V, Ratia G, Bonchuk Y, Vrba T, Gregoratto D, Broggio D, Teles P, Lopez MA. A robust methodology for assessing thyroid absorbed doses based on individual monitoring data after a severe nuclear accident. RADIAT MEAS 2019. [DOI: 10.1016/j.radmeas.2019.106183] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
17
|
Broggio D, Teles P, Vrba T, Berkovskyy V. Assessment from in vivo measurements of thyroid dose due to iodine-131 inhalation when stable iodine has been administered. RADIAT MEAS 2019. [DOI: 10.1016/j.radmeas.2019.106144] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
18
|
Teles P, Mendes M, Zankl M. Corrigendum to: ASSESSMENT OF THE ABSORBED DOSE IN THE KIDNEY OF NUCLEAR NEPHROLOGY PAEDIATRIC PATIENTS USING ICRP BIOKINETIC DATA AND MONTE CARLO SIMULATIONS WITH MASS-SCALED PAEDIATRIC VOXEL PHANTOMS. Radiat Prot Dosimetry 2019; 183:541. [PMID: 31145804 DOI: 10.1093/rpd/ncz132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Indexed: 06/09/2023]
|
19
|
Delaunay F, Andersen C, De Prez L, Duane S, Pimpinella M, Teles P, Tikkanen J, Zink K. SP-0236 MV reference dosimetry in TRS-398: State-ofthe art and research supporting an updated code of practice. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)30656-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
20
|
Struelens L, Covens P, Benadjaoud M, Auvinen A, Gianicolo E, Wegener A, Domienik J, Carinou E, Dragusin O, Teles P, Widmark A, Ciraj-Bjelac O, Andreassi MG, Padovani R. 69. The European epidemiological study (EURALOC) on radiation-induced lens opacities among interventional cardiologists. Phys Med 2018. [DOI: 10.1016/j.ejmp.2018.04.079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
|
21
|
Domienik-Andrzejewska J, Ciraj-Bjelac O, Askounis P, Covens P, Dragusin O, Jacob S, Farah J, Gianicolo E, Padovani R, Teles P, Widmark A, Struelens L. Past and present work practices of European interventional cardiologists in the context of radiation protection of the eye lens-results of the EURALOC study. J Radiol Prot 2018; 38:934-950. [PMID: 29780037 DOI: 10.1088/1361-6498/aac64b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This paper investigates over five decades of work practices in interventional cardiology, with an emphasis on radiation protection. The analysis is based on data from more than 400 cardiologists from various European countries recruited for a EURALOC study and collected in the period from 2014 to 2016. Information on the types of procedures performed and their annual mean number, fluoroscopy time, access site choice, x-ray units and radiation protection means used was collected using an occupational questionnaire. Based on the specific European data, changes in each parameter have been analysed over decades, while country-specific data analysis has allowed us to determine the differences in local practices. In particular, based on the collected data, the typical workload of a European cardiologist working in a haemodynamic room and an electrophysiology room was specified for various types of procedures. The results showed that when working in a haemodynamic room, a transparent ceiling-suspended lead shield or lead glasses are necessary in order to remain below the recommended eye lens dose limit of 20 mSv. Moreover, the analysis revealed that new, more complex cardiac procedures such as chronic total occlusion, valvuloplasty and pulmonary vein isolation for atrial fibrillation ablation might contribute substantially to annual doses, although they are relatively rarely performed. The results revealed that considerable progress has been made in the use of radiation protection tools. While their use in electrophysiology procedures is not generic, the situation in haemodynamic procedures is rather encouraging, as ceiling-suspended shields are used in 90% of cases, while the combination of ceiling shield and lead glasses is noted in more than 40% of the procedures. However, we find that still 7% of haemodynamic procedures are performed without any radiation protection tools.
Collapse
|
22
|
Teles P, Costa J, Costa D, Matela N, Vaz P. Activity estimation and biokinetic analysis of 99mTc-DMSA in renal infant patients using a gamma camera. Phys Med 2018; 52:9-17. [PMID: 30139615 DOI: 10.1016/j.ejmp.2018.06.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 06/08/2018] [Accepted: 06/09/2018] [Indexed: 10/28/2022] Open
Abstract
Biokinetic data from the administration of radiopharmaceuticals is essential in nuclear medicine dosimetry. It has particular significance in children, as their metabolism is very different from adults. Biokinetic models for paediatric patients could therefore need to be adapted to better reflect their absorption, retention and excretion functions, when compared to adults. Obtaining quality in vivo infant or paediatric biokinetic data is then essential to improve the available reference models, which in turn can lead to the optimization of paediatric procedures and protocols in clinical practice. This study analyses the biokinetic behaviour of 99mTc-dimercaptosuccinic acid (DMSA), in 8 infants aged 4 months to 2 years old, through an imaging study using a gamma camera, and compares the obtained values with those obtained with the reference ICRP biokinetic model. The in vivo data was treated using an adapted methodology from the MIRD 16 pamphlet. Activity curves for the liver, the kidney and the whole body, were built, and new effective absorption, retention and excretion half-lives were estimated, and compared with the reference biokinetic parameters of ICRP 128. The obtained residence time in the kidneys of 2.56 h, has a deviation of 30.8% to the ICRP 128 value of 3.70 h. The obtained maximum uptake in the kidneys was of 0.22/A0, which compares to the value of 0.31/A0 for ICRP. The obtained biokinetic parameters were used to estimate the absorbed dose. The obtained dose values are smaller than the reference ICRP 128 ones by 32.1% in the kidneys, and 18.4% in the liver.
Collapse
Affiliation(s)
- P Teles
- Grupo de Protecção e Segurança Radiológica, Centro de Ciências e Tecnologias Nucleares (C2TN), CTN/IST, Pólo de Loures. Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal.
| | - J Costa
- Grupo de Protecção e Segurança Radiológica, Centro de Ciências e Tecnologias Nucleares (C2TN), CTN/IST, Pólo de Loures. Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal; Departamento de Física, Faculdade de Ciências e Tecnologias da Universidade Nova de Lisboa, Quinta da Torre, Campus Universitário, 2829-516 Caparica, Portugal
| | - D Costa
- Serviço de Medicina Nuclear, Champalimaud Centre for the Unknown, Av. Brasília, 1400-038 Lisboa, Portugal
| | - N Matela
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências da Universidade de Lisboa, Campo Grande 1749-016 Lisboa, Portugal
| | - P Vaz
- Grupo de Protecção e Segurança Radiológica, Centro de Ciências e Tecnologias Nucleares (C2TN), CTN/IST, Pólo de Loures. Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| |
Collapse
|
23
|
Teles P, Maria SD, Pinto M, Delaunay F. [OA074] Fano theory validation of the MCNP6.0 Monte Carlo code for medical applications. Phys Med 2018. [DOI: 10.1016/j.ejmp.2018.06.146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
24
|
Teles P, Nikodemová D, Bakhanova E, Becker F, Kneževic Ž, Pereira MF, Sarmento S. A Review of Radiation Protection Requirements and Dose Estimation for Staff and Patients in CT Fluoroscopy. Radiat Prot Dosimetry 2017; 174:518-534. [PMID: 27522054 DOI: 10.1093/rpd/ncw231] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 07/06/2016] [Indexed: 06/06/2023]
Abstract
The combination of fluoroscopically guided interventional procedures with computed tomography (CTF) has become widespread around the world. The benefits of CTF include the ability to obtain a real-time visualization of the entire body, increased target accuracy and improved visualization of biopsy needles. Modern CTF units work with variable frame rates for image selection, and therefore the dose distributions for patients and staff can considerably vary, creating growing concern in terms of the occupational exposure of interventionists and the drawback of a higher exposure of the patient. A literature review of the latest CTF publications is summarized in this article. A wide range of CTF studies reveal different treatment methods used in clinical practice, and therefore the differences in the exposures between them; as well as in the radiation protection tools and dose monitoring. Further optimization of radiation protection methods, harmonization of exposure patterns as well as training and education of CTF staff on the basis of the information in the survey, are strongly recommended.
Collapse
Affiliation(s)
- P Teles
- Grupo de Proteção e Segurança Radiológica, Centro de Ciências e Tecnologias Nucleares (C2TN), Instituto Superior Técnico, Universidade de Lisboa, Pólo de Loures. Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - D Nikodemová
- Slovak Medical University, Limbová 14, 83301 Bratislava, Slovakia
| | - E Bakhanova
- National Research Center for Radiation Medicine, NAMS Ukraine, Melnikova 53, Kiev 04050, Ukraine
| | - F Becker
- Institute for Nuclear Waste Disposal, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Ž Kneževic
- Ruder Boškovic Institute, Bijenicka 54, 10000 Zagreb, Croatia
| | - M F Pereira
- Grupo de Proteção e Segurança Radiológica, Centro de Ciências e Tecnologias Nucleares (C2TN), Instituto Superior Técnico, Universidade de Lisboa, Pólo de Loures. Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
- Laboratório de Proteção e Segurança Radiológica (LPSR), Instituto Superior Técnico, Universidade de Lisboa, Pólo de Loures. Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - S Sarmento
- Medical Physics, Radiobiology and Radiation Protection Group, IPO Porto Research Center (CI-IPOP), Portuguese Oncology Institute of Porto (IPO Porto), Porto, Portugal
| |
Collapse
|
25
|
Teles P, Mendes M, Zankl M, de Sousa V, Santos AI, Vaz P. Assessment of the Absorbed Dose in the Kidney of Nuclear Nephrology Paediatric Patients using ICRP Biokinetic Data and Monte Carlo Simulations with Mass-Scaled Paediatric Voxel Phantoms. Radiat Prot Dosimetry 2017; 174:121-135. [PMID: 27103650 DOI: 10.1093/rpd/ncw096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 03/11/2016] [Indexed: 06/05/2023]
Abstract
The aim of this work is to use Monte Carlo simulations and VOXEL phantoms to estimate the absorbed dose in paediatric patients (aged from 2 weeks to 16 y), with normal renal function, to whom technetium-99m-dimercaptosuccinic acid (99mTc-DMSA) was administered, for diagnostic renal scintigraphy purposes; and compare them with values obtained using the International Commission on Radiological Protection (ICRP) methodology. In the ICRP methodology, the cumulated absorbed dose in the kidneys is estimated by multiplying the administered activity with the corresponding given dose coefficients. The other methods were based on Monte Carlo simulations performed on two paediatric voxel phantoms (CHILD and BABY), and another three phantoms, which were modified to suit the mass of the patients' kidneys, and other anatomical factors. Different S-values were estimated using this methodology, which together with solving the ICRP biokinetic model to determine the cumulated activities, allowed for the estimation of absorbed doses different from those obtained with the ICRP method, together with new dose coefficients. The obtained values were then compared. The deviations suggest that the S-values are strongly dependent on the patient's total body weight, which could be in contrast with the ICRP data, which is provided by age, regardless of other anatomical parameters.
Collapse
Affiliation(s)
- P Teles
- Grupo de Protecção e Segurança Radiológica, Centro de Ciências e Tecnologias Nucleares (C2TN), CTN/IST, Pólo de Loures. Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - M Mendes
- Grupo de Protecção e Segurança Radiológica, Centro de Ciências e Tecnologias Nucleares (C2TN), CTN/IST, Pólo de Loures. Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - M Zankl
- Helmholtz Zentrum München - German Research Center for Environmental Health (HMGU), Department of Radiation Sciences, Research Unit Medical Radiation Physics and Diagnostics, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany
| | - V de Sousa
- Grupo de Protecção e Segurança Radiológica, Centro de Ciências e Tecnologias Nucleares (C2TN), CTN/IST, Pólo de Loures. Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - A I Santos
- Serviço de Medicina Nuclear, Hospital Garcia de Orta, E.P.E. Av. Torrado da Silva, 2801-951 Almada, Portugal
| | - P Vaz
- Grupo de Protecção e Segurança Radiológica, Centro de Ciências e Tecnologias Nucleares (C2TN), CTN/IST, Pólo de Loures. Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| |
Collapse
|
26
|
Ferrari P, Becker F, Carinou E, Chumak V, Farah J, Jovanovic Z, Krstic D, Morgun A, Principi S, Teles P. Monte Carlo study of the scattered radiation field near the eyes of the operator in interventional procedures. J Radiol Prot 2016; 36:902-921. [PMID: 27861170 DOI: 10.1088/0952-4746/36/4/902] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Interventional radiology and cardiology guarantee high benefits for patients, but are known to be associated with a high level of radiation exposure of medical staff. The recently suggested decrease of the annual dose limit for the eye lens, from 150 to 20 mSv, caused a need for a reconsideration of practices ensuring sufficient protection for the lens of the eyes of medical staff. In such context the study of the scattered radiation around the operator's head could help in finding the best solutions to be adopted for the ceiling-suspended shield and lead glasses in the most common situations in interventional practices. MCNPX Monte Carlo code was employed with anthropomorphic mathematical phantoms to simulate interventional practice projections. For each projection the effect of changing selected parameters on the evaluated scattered radiation towards the operator's head has been calculated. The variety of modelled situations provides plentiful material regarding the spatial distribution of the scattered radiation, useful to improve eye lens radiation protection, such as the following: (a) Glasses, which provide shielding from both lateral and bottom-up scattered radiation, can reduce by ten times the exposure to the most exposed eyes; (b) The ceiling-suspended shield offers valuable protection, but such effectiveness can diminish by 90% if the shielding is not correctly positioned; (c) The transition from femoral to radial access usually intensifies the scattered radiation toward the operator head (a factor of 1.5 for AP projection), but for RAO projections, a reduction of the order by two to three times, in the case of radial access, can be seen, due to the protection provided by the image receptor. The detailed fluence outcomes show that there is a preferential direction of the impinging scattered radiation that should be considered when radiation protection options are evaluated or when a dedicated eye lens dosemeter is used for monitoring.
Collapse
Affiliation(s)
- Paolo Ferrari
- ENEA- Radiation Protection Institute, 4 Via Martiri di Monte Sole, 40129 Bologna (BO), Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Vrba T, Broggio D, Caldeira M, Capello K, Fantínová K, Franck D, Gómez-Ros JM, Hunt J, Kinase S, Leone D, Lombardo PA, Manohari M, Marzocchi O, Moraleda M, Nogueira P, Ośko J, Arron S, Suhl S, Takahashi M, Teles P, Tremblay M, Tymińska K, Lopez MA, Tanner R. EURADOS intercomparison exercise on MC modelling for the in-vivo monitoring of AM-241 in skull phantoms (Part II and III). Radiat Phys Chem Oxf Engl 1993 2015. [DOI: 10.1016/j.radphyschem.2015.04.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
28
|
Teles P, Barros S, Cardoso S, Facure A, da Rosa LAR, Santos M, Pereira P, Vaz P, Zankl M. A dosimetric study of prostate brachytherapy using Monte Carlo simulations with a voxel phantom, measurements and a comparison with a treatment planning procedure. Radiat Prot Dosimetry 2015; 165:482-487. [PMID: 25870437 DOI: 10.1093/rpd/ncv055] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In prostate brachytherapy treatments, there is an initial swelling of the prostate of the patient due to an oedema related to the insertion of the seeds. The variation of the prostate volume can lead to variations in the final prescribed dose in treatment planning procedures. As such, it is important to understand their influence for dose optimisation purposes. This work reports on a dosimetric study of the swelling of the prostate in prostate brachytherapy using Monte Carlo simulations. Dosimetric measurements performed on a physical anthropomorphic tissue-equivalent prostate phantom and thermoluminescent dosimeters (TLDs) were used to validate the MC model. Finally the MC model was also used to simulate prostate swelling in a real treatment planning procedure. The obtained results indicate that the parameters mentioned above represent a source of uncertainty in dose assessment in prostate brachytherapy, and can be detrimental to a correct dose evaluation in treatment plannings, and that these parameters can be accurately determined by means of MC simulations with a voxel phantom.
Collapse
Affiliation(s)
- P Teles
- CTN Pólo de Loures, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela, LRS, Portugal
| | - S Barros
- CTN Pólo de Loures, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela, LRS, Portugal
| | - S Cardoso
- Universidade Federal do Rio de Janeiro, Av. Pedro Calmon, 550, Rio de Janeiro 21941-901, Brazil
| | - A Facure
- Comissão Nacional de Energia Nuclear, Rua Gal Severiano, 90, Rio de Janeiro 22290-901, Brazil
| | - L A R da Rosa
- Instituto de Radioproteção e Dosimetria, Av. Salvador Allende, Rio de Janeiro 22780-160, Brazil
| | - M Santos
- Instituto de Radioproteção e Dosimetria, Av. Salvador Allende, Rio de Janeiro 22780-160, Brazil
| | - P Pereira
- Dosimetrika, Avenida Olegário Maciel, 231 - Barra da Tijuca, Rio de Janeiro, 22621-200, Brazil
| | - P Vaz
- CTN Pólo de Loures, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela, LRS, Portugal
| | - M Zankl
- Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| |
Collapse
|
29
|
Baptista M, Figueira C, Teles P, Cardoso G, Zankl M, Vaz P. Assessment of the occupational exposure in real time during interventional cardiology procedures. Radiat Prot Dosimetry 2015; 165:304-309. [PMID: 25848113 DOI: 10.1093/rpd/ncv052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Interventional cardiology (IC) procedures can be complex, requiring the operators to work near the patient, during long exposure times. Owing to scattered radiation in the patient and the fluoroscopic equipment, the medical staff are exposed to a non-uniform radiation field and can receive high radiation doses. In this study, it is proposed to analyse staff doses obtained in real time, during IC procedures. A system for occupational dosimetry in real time was used. In order to identify some parameters that may affect the staff doses, Monte Carlo (MC) calculations, using MCNPX v.2.7.0 code and voxel phantoms, were performed. The data obtained from measurements, together with MC simulations, allowed the identification of actions and behaviours of the medical staff that could be considered a risk under routine working conditions. The implementation of this monitoring system for exposure of personnel may have a positive effect on optimisation of radiological protection in fluoroscopically guided cardiac procedures.
Collapse
Affiliation(s)
- M Baptista
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, km 139,7, 2695-066 Bobadela LRS, Portugal
| | - C Figueira
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, km 139,7, 2695-066 Bobadela LRS, Portugal
| | - P Teles
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, km 139,7, 2695-066 Bobadela LRS, Portugal
| | - G Cardoso
- Hospital Garcia de Orta, EPE, Av. Torrado da Silva, 2801-951 Almada, Portugal
| | - M Zankl
- Helmholtz Zentrum München-German Research Center for Environmental Health, Medical Radiation Physics and Diagnostics, 85758 Neuherberg, Germany
| | - P Vaz
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, km 139,7, 2695-066 Bobadela LRS, Portugal
| |
Collapse
|
30
|
Mendes M, Costa F, Figueira C, Madeira P, Teles P, Vaz P. Assessment of patient dose reduction by bismuth shielding in CT using measurements, GEANT4 and MCNPX simulations. Radiat Prot Dosimetry 2015; 165:175-181. [PMID: 25813483 DOI: 10.1093/rpd/ncv059] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This work reports on the use of two different Monte Carlo codes (GEANT4 and MCNPX) for assessing the dose reduction using bismuth shields in computer tomography (CT) procedures in order to protect radiosensitive organs such as eye lens, thyroid and breast. Measurements were performed using head and body PMMA phantoms and an ionisation chamber placed in five different positions of the phantom. Simulations were performed to estimate Computed Tomography Dose Index values using GEANT4 and MCNPX. The relative differences between measurements and simulations were <10 %. The dose reduction arising from the use of bismuth shielding ranges from 2 to 45 %, depending on the position of the bismuth shield. The percentage of dose reduction was more significant for the area covered by the bismuth shielding (36 % for eye lens, 39 % for thyroid and 45 % for breast shields).
Collapse
Affiliation(s)
- M Mendes
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - F Costa
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - C Figueira
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - P Madeira
- Serviço de Radiologia, Hospital de São José, Centro Hospitalar Lisboa Central, EPE, Rua José António Serrano, 1150-199 Lisboa, Portugal
| | - P Teles
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - P Vaz
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| |
Collapse
|
31
|
Costa F, Teles P, Nogueira A, Barreto A, Santos A, Carvalho A, Martins B, Oliveira C, Gaspar C, Barros C, Neves D, Costa D, Rodrigues E, Godinho F, Alves F, Cardoso G, Cantinho G, Conde I, Vale J, Santos J, Isidoro J, Pereira J, Salgado L, Rézio M, Vieira M, Simãozinho P, Almeida P, Castro R, Parafita R, Pintão S, Lúcio T, Reis T, Vaz P. Estimation of the collective ionizing dose in the Portuguese population for the years 2011 and 2012, due to nuclear medicine exams. Rev Esp Med Nucl Imagen Mol 2015; 34:1-8. [DOI: 10.1016/j.remn.2014.03.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 03/28/2014] [Accepted: 03/31/2014] [Indexed: 10/25/2022]
|
32
|
Costa F, Teles P, Nogueira A, Barreto A, Santos A, Carvalho A, Martins B, Oliveira C, Gaspar C, Barros C, Neves D, Costa D, Rodrigues E, Godinho F, Alves F, Cardoso G, Cantinho G, Conde I, Vale J, Santos J, Isidoro J, Pereira J, Salgado L, Rézio M, Vieira M, Simãozinho P, Almeida P, Castro R, Parafita R, Pintão S, Lúcio T, Reis T, Vaz P. Estimation of the collective ionizing dose in the Portuguese population for the years 2011 and 2012, due to nuclear medicine exams. Rev Esp Med Nucl Imagen Mol 2015. [DOI: 10.1016/j.remnie.2014.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
33
|
Baptista M, Teles P, Cardoso G, Vaz P. Assessment of the dose distribution inside a cardiac cath lab using TLD measurements and Monte Carlo simulations. Radiat Phys Chem Oxf Engl 1993 2014. [DOI: 10.1016/j.radphyschem.2014.03.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
34
|
Palmans H, Rabus H, Belchior AL, Bug MU, Galer S, Giesen U, Gonon G, Gruel G, Hilgers G, Moro D, Nettelbeck H, Pinto M, Pola A, Pszona S, Schettino G, Sharpe PHG, Teles P, Villagrasa C, Wilkens JJ. Future development of biologically relevant dosimetry. Br J Radiol 2014; 88:20140392. [PMID: 25257709 DOI: 10.1259/bjr.20140392] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Proton and ion beams are radiotherapy modalities of increasing importance and interest. Because of the different biological dose response of these radiations as compared with high-energy photon beams, the current approach of treatment prescription is based on the product of the absorbed dose to water and a biological weighting factor, but this is found to be insufficient for providing a generic method to quantify the biological outcome of radiation. It is therefore suggested to define new dosimetric quantities that allow a transparent separation of the physical processes from the biological ones. Given the complexity of the initiation and occurrence of biological processes on various time and length scales, and given that neither microdosimetry nor nanodosimetry on their own can fully describe the biological effects as a function of the distribution of energy deposition or ionization, a multiscale approach is needed to lay the foundation for the aforementioned new physical quantities relating track structure to relative biological effectiveness in proton and ion beam therapy. This article reviews the state-of-the-art microdosimetry, nanodosimetry, track structure simulations, quantification of reactive species, reference radiobiological data, cross-section data and multiscale models of biological response in the context of realizing the new quantities. It also introduces the European metrology project, Biologically Weighted Quantities in Radiotherapy, which aims to investigate the feasibility of establishing a multiscale model as the basis of the new quantities. A tentative generic expression of how the weighting of physical quantities at different length scales could be carried out is presented.
Collapse
Affiliation(s)
- H Palmans
- 1 Acoustics and Ionising Radiation Division, National Physical Laboratory (NPL), Teddington, Middlesex, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Oliveira SM, Teixeira NJ, Fernandes L, Teles P, Vieira G, Vaz P. Tissue composition and density impact on the clinical parameters for (125)I prostate implants dosimetry. Phys Med 2014; 30:799-808. [PMID: 25239870 DOI: 10.1016/j.ejmp.2014.06.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 06/18/2014] [Accepted: 06/20/2014] [Indexed: 10/24/2022] Open
Abstract
The MCNPX code was used to calculate the TG-43U1 recommended parameters in water and prostate tissue in order to quantify the dosimetric impact in 30 patients treated with (125)I prostate implants when replacing the TG-43U1 formalism parameters calculated in water by a prostate-like medium in the planning system (PS) and to evaluate the uncertainties associated with Monte Carlo (MC) calculations. The prostate density was obtained from the CT of 100 patients with prostate cancer. The deviations between our results for water and the TG-43U1 consensus dataset values were -2.6% for prostate V100, -13.0% for V150, and -5.8% for D90; -2.0% for rectum V100, and -5.1% for D0.1; -5.0% for urethra D10, and -5.1% for D30. The same differences between our water and prostate results were all under 0.3%. Uncertainties estimations were up to 2.9% for the gL(r) function, 13.4% for the F(r,θ) function and 7.0% for Λ, mainly due to seed geometry uncertainties. Uncertainties in extracting the TG-43U1 parameters in the MC simulations as well as in the literature comparison are of the same order of magnitude as the differences between dose distributions computed for water and prostate-like medium. The selection of the parameters for the PS should be done carefully, as it may considerably affect the dose distributions. The seeds internal geometry uncertainties are a major limiting factor in the MC parameters deduction.
Collapse
Affiliation(s)
- Susana Maria Oliveira
- Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo Mártires da Pátria, 130, 1169-056 Lisbon, Portugal; Quadrantes Faro - Unidade de Radioterapia do Algarve, Rua da Associação Oncológica do Algarve, 8000-316 Faro, Portugal; MedicalConsult, SA, Campo Grande, 56-8°A, 1700-093 Lisbon, Portugal.
| | - Nuno José Teixeira
- Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo Mártires da Pátria, 130, 1169-056 Lisbon, Portugal; Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Av. D. João II, lote 4.69.01, 1900-096 Lisbon, Portugal
| | - Lisete Fernandes
- Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Av. D. João II, lote 4.69.01, 1900-096 Lisbon, Portugal; Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal; Centro de Biodiversidade, Genómica Integrativa e Funcional, Faculdade de Ciências, Universidade de Lisboa, Edifício ICAT, Campus FCUL, Campo Grande, 1740-016 Lisbon, Portugal
| | - Pedro Teles
- IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, Estrada Nacional 10, 2695-006 Bobadela LRS, Portugal
| | - Guy Vieira
- Quadrantes Faro - Unidade de Radioterapia do Algarve, Rua da Associação Oncológica do Algarve, 8000-316 Faro, Portugal
| | - Pedro Vaz
- IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, Estrada Nacional 10, 2695-006 Bobadela LRS, Portugal
| |
Collapse
|
36
|
Rabus H, Palmans H, Hilgers G, Sharpe P, Pinto M, Villagrasa C, Nettelbeck H, Moro D, Pola A, Pszona S, Teles P. Biologically Weighted Quantities in Radiotherapy: an EMRP Joint Research Project. EPJ Web of Conferences 2014. [DOI: 10.1051/epjconf/20147700021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
37
|
Oliveira SM, Teixeira NJ, Fernandes L, Teles P, Vaz P. Dosimetric effect of tissue heterogeneity for (125)I prostate implants. Rep Pract Oncol Radiother 2014; 19:392-8. [PMID: 25337412 DOI: 10.1016/j.rpor.2014.03.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 11/26/2013] [Accepted: 03/19/2014] [Indexed: 11/29/2022] Open
Abstract
AIM To use Monte Carlo (MC) together with voxel phantoms to analyze the tissue heterogeneity effect in the dose distributions and equivalent uniform dose (EUD) for (125)I prostate implants. BACKGROUND Dose distribution calculations in low dose-rate brachytherapy are based on the dose deposition around a single source in a water phantom. This formalism does not take into account tissue heterogeneities, interseed attenuation, or finite patient dimensions effects. Tissue composition is especially important due to the photoelectric effect. MATERIALS AND METHODS The computed tomographies (CT) of two patients with prostate cancer were used to create voxel phantoms for the MC simulations. An elemental composition and density were assigned to each structure. Densities of the prostate, vesicles, rectum and bladder were determined through the CT electronic densities of 100 patients. The same simulations were performed considering the same phantom as pure water. Results were compared via dose-volume histograms and EUD for the prostate and rectum. RESULTS The mean absorbed doses presented deviations of 3.3-4.0% for the prostate and of 2.3-4.9% for the rectum, when comparing calculations in water with calculations in the heterogeneous phantom. In the calculations in water, the prostate D 90 was overestimated by 2.8-3.9% and the rectum D 0.1cc resulted in dose differences of 6-8%. The EUD resulted in an overestimation of 3.5-3.7% for the prostate and of 7.7-8.3% for the rectum. CONCLUSIONS The deposited dose was consistently overestimated for the simulation in water. In order to increase the accuracy in the determination of dose distributions, especially around the rectum, the introduction of the model-based algorithms is recommended.
Collapse
Key Words
- AAPM TG, American Association of Physicists in Medicine Task Group
- Brachytherapy
- CT, computerized tomography
- DVH, dose–volume histogram
- EBRT, external beam radiotherapy
- EUD, equivalent uniform dose
- HT, heterogeneous
- LDRBT, low dose-rate brachytherapy
- MBDCA, model-based dose calculation algorithm
- MC, Monte Carlo
- Model-based calculation algorithms
- Monte Carlo
- NTCP, normal tissue complication probability
- OAR, organ at risk
- PS, planning system
- Prostate cancer
- TCP, tumor control probability (TCP)
- Tissue heterogeneity
- W, water
- dDVH, differential dose–volume histogram
Collapse
Affiliation(s)
- Susana Maria Oliveira
- Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo Mártires da Pátria, 130, 1169-056 Lisbon, Portugal ; Quadrantes Faro - Unidade de Radioterapia do Algarve, Rua da Associação Oncológica do Algarve, 8000-316 Faro, Portugal ; MedicalConsult, SA, Campo Grande, 56-8°A, 1700-093 Lisbon, Portugal
| | - Nuno José Teixeira
- Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo Mártires da Pátria, 130, 1169-056 Lisbon, Portugal ; Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Av. D. João II, lote 4.69.01, 1900-096 Lisbon, Portugal
| | - Lisete Fernandes
- Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Av. D. João II, lote 4.69.01, 1900-096 Lisbon, Portugal ; Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal ; Centro de Biodiversidade, Genómica Integrativa e Funcional, Faculdade de Ciências, Universidade de Lisboa, Edifício ICAT, Campus FCUL, Campo Grande, 1740-016 Lisbon, Portugal
| | - Pedro Teles
- IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, Estrada Nacional 10, 2695-006 Bobadela LRS, Portugal
| | - Pedro Vaz
- IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, Estrada Nacional 10, 2695-006 Bobadela LRS, Portugal
| |
Collapse
|
38
|
Figueira C, Becker F, Blunck C, DiMaria S, Baptista M, Esteves B, Paulo G, Santos J, Teles P, Vaz P. Medical staff extremity dosimetry in CT fluoroscopy: an anthropomorphic hand voxel phantom study. Phys Med Biol 2013; 58:5433-48. [DOI: 10.1088/0031-9155/58/16/5433] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
39
|
Teles P, Carmen de Sousa M, Paulo G, Santos J, Pascoal A, Cardoso G, Lança I, Matela N, Janeiro L, Sousa P, Carvoeiras P, Parafita R, Santos AI, Simãozinho P, Vaz P. Estimation of the collective dose in the Portuguese population due to medical procedures in 2010. Radiat Prot Dosimetry 2013; 154:446-458. [PMID: 23045717 DOI: 10.1093/rpd/ncs258] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In a wide range of medical fields, technological advancements have led to an increase in the average collective dose in national populations worldwide. Periodic estimations of the average collective population dose due to medical exposure is, therefore of utmost importance, and is now mandatory in countries within the European Union (article 12 of EURATOM directive 97/43). Presented in this work is a report on the estimation of the collective dose in the Portuguese population due to nuclear medicine diagnostic procedures and the Top 20 diagnostic radiology examinations, which represent the 20 exams that contribute the most to the total collective dose in diagnostic radiology and interventional procedures in Europe. This work involved the collaboration of a multidisciplinary taskforce comprising representatives of all major Portuguese stakeholders (universities, research institutions, public and private healthcare providers, administrative services of the National Healthcare System, scientific and professional associations and private service providers). This allowed us to gather a comprehensive amount of data necessary for a robust estimation of the collective effective dose to the Portuguese population. The methodology used for data collection and dose estimation was based on European Commission recommendations, as this work was performed in the framework of the European wide Dose Datamed II project. This is the first study estimating the collective dose for the population in Portugal, considering such a wide national coverage and range of procedures and consisting of important baseline reference data. The taskforce intends to continue developing periodic collective dose estimations in the future. The estimated annual average effective dose for the Portuguese population was of 0.080±0.017 mSv caput(-1) for nuclear medicine exams and of 0.96±0.68 mSv caput(-1) for the Top 20 diagnostic radiology exams.
Collapse
Affiliation(s)
- Pedro Teles
- Instituto Superior Técnico/Instituto Tecnológico e Nuclear, Estrada Nacional 10, Sacavém 2686-953, Portugal.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Louro A, Peralta L, Soares S, Pereira A, Cunha G, Belchior A, Ferreira L, Monteiro Gil O, Louro H, Pinto P, Rodrigues AS, Silva MJ, Teles P. Human exposure to indoor radon: a survey in the region of Guarda, Portugal. Radiat Prot Dosimetry 2013; 154:237-244. [PMID: 22899215 DOI: 10.1093/rpd/ncs166] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Radon ((222)Rn) is a radioactive gas, abundant in granitic areas, such as the city of Guarda at the northeast of Portugal. This gas is recognised as a carcinogenic agent, being appointed by the World Health Organization as the second leading cause of lung cancer after tobacco smoke. Therefore, the knowledge of radon concentrations inside the houses (where people stay longer) is important from the point of view of radiological protection. The main goal of this study was to assess the radon concentration in an area previously identified with a potentially high level of residential radon. The radon concentration was measured using CR-39 detectors, exposed for a period of 2 months in 185 dwellings in the Guarda region. The radon concentration in studied dwellings, ranged between 75 and 7640 Bq m(-3), with a geometric mean of 640 Bq m(-3) and an arithmetic mean of 1078 Bq m(-3). Based on a local winter-summer radon concentration variation model, these values would correspond to an annual average concentration of 860 Bq m(-3). Several factors contribute to this large dispersion, the main one being the exact location of housing construction in relation to the geochemical nature of the soil and others the predominant building material and ventilation. Based on the obtained results an average annual effective dose of 15 mSv y(-1) is estimated, well above the average previously estimated for Portugal.
Collapse
Affiliation(s)
- Alina Louro
- Laboratório de Instrumentação e Física Experimental de Partículas, Lisboa, Portugal
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Bento J, Martins B, Teles P, Neves M, Colarinha P, Alves F, Teixeira N, Vaz P, Zankl M. Performance assessment and uncertainty evaluation of a portable NaI-based detection system used for thyroid monitoring. Radiat Prot Dosimetry 2012; 151:252-261. [PMID: 22345216 DOI: 10.1093/rpd/ncs011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This work aims at assessing the performance of a portable detection system, equipped with an NaI(Tl) scintillation detector for in vivo thyroid monitoring, which was properly calibrated using an anthropomorphic neck phantom. The anthropomorphic physical phantoms commonly used for the efficiency calibration of in vivo counters often present certain limitations regarding the geometry and the activity distribution. Therefore, the feasibility of these detection systems for in vivo monitoring should be assessed whenever possible. To accomplish this assessment, patients to whom (99m)Tc and (123)I marked radiopharmaceuticals have been administered in the framework of nuclear medicine diagnostic procedures were monitored. As the biokinetic models of the administered radiopharmaceuticals are known, the time-dependent activity functions in the critical organs after administration are easily quantified. The measured activities in the thyroid using the NaI(Tl) scintillation detector were compared with the estimated activities using the biokinetic models, in order to reach conclusion about the applicability of the portable scintillation counter for in vivo thyroid monitoring. The state-of-the-art Monte Carlo computer program PENELOPE and two voxel phantoms (male and female) were used to evaluate the overall uncertainties influencing the thyroid monitoring. A computational parametric study was performed to quantify the influence of several parameters in the activity quantification (neck-detector distance, thyroid shape, thyroid size and overlying tissue thickness), which allowed one to gain insight and to better understand the discrepancies between the calculated and measured activities.
Collapse
Affiliation(s)
- J Bento
- Instituto Tecnológico e Nuclear, Sacavém, Portugal.
| | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Broggio D, Bento J, Caldeira M, Cardenas-Mendez E, Farah J, Fonseca T, Konvalinka C, Liu L, Perez B, Capello K, Cowan P, Cruzate JA, Freire L, Gómez-Ros JM, Gossio S, Heide B, Huikari J, Hunt J, Kinase S, Kramer G, Kurihara O, Kyrieleis A, Lebacq AL, Leone D, Li C, Li J, Mihailescu LC, Moraleda M, Navarro JF, Oliveira C, Puerta N, Reichelt U, Simões C, Sommer D, Takahashi M, Teles P, Vanhavere F, Vrba T, Franck D, Gualdrini G, Lopez MA. Monte Carlo modelling for the in vivo lung monitoring of enriched uranium: Results of an international comparison. RADIAT MEAS 2012. [DOI: 10.1016/j.radmeas.2012.04.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
43
|
Bento J, Teles P, Neves M, Santos AI, Cardoso G, Barreto A, Alves F, Guerreiro C, Rodrigues A, Santos JAM, Capelo C, Parafita R, Martins B. Study of nuclear medicine practices in Portugal from an internal dosimetry perspective. Radiat Prot Dosimetry 2012; 149:438-443. [PMID: 21795254 DOI: 10.1093/rpd/ncr319] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Nuclear medicine practices involve the handling of a wide range of pharmaceuticals labelled with different radionuclides, for diagnostic and therapeutic purposes. This work intends to evaluate the potential risks of internal contamination of nuclear medicine staff in several Portuguese nuclear medicine services and to conclude about the requirement of a routine internal monitoring. A methodology proposed by the International Atomic Energy Agency (IAEA), providing a set of criteria to determine the need, or not, for an internal monitoring programme, was applied. The evaluation of the risk of internal contaminations in a given set of working conditions is based on the type and amount of radionuclides being handled, as well as the safety conditions with which they are manipulated. The application of the IAEA criteria showed that 73.1% of all the workers included in this study should be integrated in a routine monitoring programme for internal contaminations; more specifically, 100% of workers performing radioimmunoassay techniques should be monitored. This study suggests that a routine monitoring programme for internal exposures should be implemented in Portugal for most nuclear medicine workers.
Collapse
Affiliation(s)
- J Bento
- Instituto Tecnológico e Nuclear, Sacavém, Portugal.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Bento J, Barros S, Teles P, Neves M, Gonçalves I, Corisco J, Vaz P. Monte Carlo simulation of the movement and detection efficiency of a whole-body counting system using a BOMAB phantom. Radiat Prot Dosimetry 2012; 148:403-413. [PMID: 21525044 DOI: 10.1093/rpd/ncr201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This study reports on the computational analysis and experimental calibration of the whole-body counting detection equipment at the Nuclear and Technological Institute (ITN) in Portugal. Two state-of-the-art Monte Carlo simulation programmes were used for this purpose: PENELOPE and MCNPX. This computational work was undertaken as part of a new set of experimental calibrations, which improved the quality standards of this study's WBC system. In these calibrations, a BOMAB phantom, one of the industry standards phantoms for WBC calibrations in internal dosimetry applications, was used. Both the BOMAB phantom and the detection system were accurately implemented in the Monte Carlo codes. The whole-body counter at ITN possesses a moving detector system, which poses a challenge for Monte Carlo simulations, as most codes only accept static configurations. The continuous detector movement was approximately described in the simulations by averaging several discrete positions of the detector throughout the movement. The computational efficiency values obtained with the two Monte Carlos codes have deviations of less than 3.2 %, and the obtained deviations between experimental and computational efficiencies are less than 5 %. This work contributes to demonstrate the great effectiveness of using computational tools for understanding the calibration of radiation detection systems used for in vivo monitoring.
Collapse
Affiliation(s)
- Joana Bento
- Instituto Tecnológico e Nuclear, Estrada Nacional 10, 2686-953 Sacavém, Portugal.
| | | | | | | | | | | | | |
Collapse
|
45
|
Di Maria S, Ottolini M, Sarotto M, Martin-Fuertes F, Vazquez M, Mbala E, Teles P, Vaz P, Castelliti D, Reale M, Mansani L, Baeten P. Neutronic Assessment and Criticality Analysis of the In-Vessel Fuel Storage Facilities in the CDT Project. Fusion Science and Technology 2012. [DOI: 10.13182/fst12-a13436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- S. Di Maria
- Instituto Tecnòlogico e Nuclear, EN 10, 2686-953 Sacavém, Portugal
| | - M. Ottolini
- Ansaldo Nucleare S.p.A., c.so Perrone 25, 16161 Genova, Italy
| | - M. Sarotto
- ENEA, via Martiri di Monte Sole 4, 40129 Bologna, Italy
| | | | - M. Vazquez
- CIEMAT, Avda Complutense 22, 28040 Madrid, Spain
| | | | - P. Teles
- Instituto Tecnòlogico e Nuclear, EN 10, 2686-953 Sacavém, Portugal
| | - P. Vaz
- Instituto Tecnòlogico e Nuclear, EN 10, 2686-953 Sacavém, Portugal
| | | | - M. Reale
- Ansaldo Nucleare S.p.A., c.so Perrone 25, 16161 Genova, Italy
| | - L. Mansani
- Ansaldo Nucleare S.p.A., c.so Perrone 25, 16161 Genova, Italy
| | - P. Baeten
- SCK-CEN, Boeretang 200, Mol B-2400, Belgium
| |
Collapse
|
46
|
Di Maria S, Barros S, Bento J, Teles P, Figueira C, Pereira M, Vaz P, Paulo G. TLD measurements and Monte Carlo simulations for glandular dose and scatter fraction assessment in mammography: A comparative study. RADIAT MEAS 2011. [DOI: 10.1016/j.radmeas.2011.06.072] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
47
|
Nogueira P, Silva L, Teles P, Bento J, Vaz P. Monte Carlo simulation of the full energy peak efficiency of a WBC. Appl Radiat Isot 2009; 68:184-9. [PMID: 19819154 DOI: 10.1016/j.apradiso.2009.09.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Accepted: 09/09/2009] [Indexed: 10/20/2022]
Abstract
A whole body counting system is in operation at the Nuclear and Technological Institute, in Portugal. Computational methods were used to determine the detection efficiency; a well-known source of bias in modelling the behaviour of a HPGe detector is the insufficient knowledge regarding the thickness of the lithium dead layer. In order to accurately simulate the detection system and to achieve agreement between the Monte Carlo results and the performed measurements, the value for the dead layer thickness was optimized.
Collapse
Affiliation(s)
- P Nogueira
- Instituto Tecnológico e Nuclear Unidade de Protecção e Segurança Radiológica E.N. 10, Apartado 21, 2686-953 Sacavem, Portugal.
| | | | | | | | | |
Collapse
|
48
|
|