Angeliki Karambatsakidou - Academia.edu (original) (raw)
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Papers by Angeliki Karambatsakidou
The British journal of radiology/British journal of radiology, May 7, 2024
![Research paper thumbnail of [OA221] The dose to the lens of the eye for the heart team performing transcatheter aortic valve implementation (TAVI): Is there any concern for cataract?](https://attachments.academia-assets.com/108044182/thumbnails/1.jpg)
](Physica Medica, Aug 1, 2018
Radiation Protection Dosimetry, Aug 1, 2000
Skin injuries have recently been reported for patients in diagnostic and interventional cardiac p... more Skin injuries have recently been reported for patients in diagnostic and interventional cardiac procedures. Cardiac catheterisation equipment usually has dose monitors showing the dose-area product (DAP) but the DAP value alone is not a suitable indicator for skin dose since the projections vary during the procedures. This work deals with measurements of maximum entrance skin dose, MESD, and effective dose, E, to an anthropomorphic phantom using TL dosemeters placed both on the outside of and inserted in the phantom and simulating a diagnostic and an interventional clinical procedure. DAP values were used for calculating conversion factors: MESD/DAP was 3.8 and 8.1 mSv.Gy -1 .cm -2 and E/DAP was 0.23 and 0.26 mSv.Gy -1 .cm -2 for diagnostic and interventional procedures respectively. Maximum permissible DAP value for preventing skin damage, i.e. MESD <2 Sv, is therefore 530 and 250 Gy.cm -2 respectively for diagnostic and interventional procedures. These results should be used as a local reference level for the patient dose to prevent skin burden. Patient mean DAP was 73, 120 and 170 Gy.cm 2 and effective dose 16, 31 and 41 mSv for diagnostic, interventional and combined procedures respectively.
British Journal of Radiology, Sep 1, 2009
Medical Physics, May 29, 2014
PURPOSE To investigate the potential benefits of automatic monitoring of accumulated patient and ... more PURPOSE To investigate the potential benefits of automatic monitoring of accumulated patient and staff dose indicators, i.e., CAK and KAP, from DICOM Radiation Dose Structured Reports (RDSR) in x-ray angiography (XA). METHODS Recently RDSR has enabled the convenient aggregation of dose indices and technique parameters for XA procedures. The information contained in RDSR objects for three XA systems, dedicated to different types of clinical procedures, has been collected and aggregated in a database for over one year using a system developed with open-source software at the Karolinska University Hospital. Patient weight was complemented to the RDSR data via an interface with the Hospital Information System (HIS). RESULTS The linearly approximated trend in KAP over a time period of a year for cerebrovascular, pelvic/peripheral vascular, and cardiovascular procedures showed a decrease of 12%, 20%, and 14%, respectively. The decrease was mainly due to hardware/software upgrades and new low-dose imaging protocols, and partially due to ongoing systematic radiation safety education of the clinical staff. The CAK was in excess of 3 Gy for 15 procedures, and exceeded 5 Gy for 3 procedures. The dose indices have also shown a significant dependence on patient weight for cardiovascular and pelvic/peripheral vascular procedures; a 10 kg shift in mean patient weight can result in a dose index increase of 25%. CONCLUSION Automatic monitoring of accumulated dose indices can be utilized to notify the clinical staff and medical physicists when the dose index has exceeded a predetermined action level. This allows for convenient and systematic follow-up of patients in risk of developing deterministic skin injuries. Furthermore, trend analyses of dose indices over time is a valuable resource for the identification of potential positive or negative effects (dose increase/decrease) from changes in hardware, software, and clinical work habits.
Radiation Protection Dosimetry, Jan 6, 2016
The aim of this study was to estimate conversion coefficients for maximum entrance skin dose (MES... more The aim of this study was to estimate conversion coefficients for maximum entrance skin dose (MESD) and effective dose (E) for patients undergoing transcatheter aortic valve implantation (TAVI) and to evaluate the risk of exposure-induced cancer death (REID) for prospectively younger patients. Effective doses and risks were estimated for 22 patients using PCXMC whereas MESDs were estimated for a sub-group of 15 patients using Gafchromic film. The estimated conversion coefficients for skin dose [CCS = MESD/dose-area product (DAP)] and E (CCE = E/DAP) were 9.7±1.5 and 0.24±0.02 mSv/Gy cm(2), respectively. The REID ranged from 1:9900 to 1:1400 and by decreasing the age of examination to 40-50 y of age, the REID increased with a factor of 2 for females and 1.5 for males. The organ at risk was the lung. Currently, the patient population is elderly with radiation-induced skin injuries as the main risk. The risk of cancer induction should additionally be considered if younger patient populations are to be treated.
Cardiac radiological interventions often involve long fluo-roscopy times and a high number of cin... more Cardiac radiological interventions often involve long fluo-roscopy times and a high number of cine runs. This results in patient radiation doses that in adults can exceed the threshold level for skin erythema (2 Sv). In children the main concern is instead the increased risk of cancer, related to the relatively high effective doses in children from such interventions. At the Karolinska University Hospital, local alarm levels of DAP values have been established to monitor the skin burden from coronary angiography (CA) and interventional pro-cedures (PCI) in adults. The alarm levels used in the clinic (CA: 350 Gycm2, PCI: 150 Gycm2 and combined procedure: 200 Gycm2) are based on measurements on patients using radiographic film. Dose reports for patients undergoing such procedures and exceeding the threshold DAP value for skin injuries are forwarded to the medical physicist for a skin dose calculation, and the result is returned to the operator for patient follow-up.
British Journal of Radiology, 2005
Maximum estimated skin doses to patients undergoing coronary angiography procedures were obtained... more Maximum estimated skin doses to patients undergoing coronary angiography procedures were obtained using radiographic slow film and diode dosemeters. Conversion factors of maximum entrance skin dose versus dose-area product (MESD/DAP) for diagnostic (coronary angiography (CA); 20 patients; 2 operators) and interventional procedures (percutaneous transluminal coronary angiography (PTCA); 10 patients; 1 operator) were 4.3 (mean value of 10 CA; operator A), 3.5 (mean value of 10 CA; operator B) and 9.7 (mean value of 10 PTCA; operator B) mGy(Gycm2)(-1), respectively. The results emphasise a need for both operator- and procedure-specific conversion factors. Compared with a single, global factor for all cardiac procedures and/or operators that is commonly applied today, such a refinement is expected to improve the accuracy in skin dose estimations from these procedures. Consequently, reference DAP values used in the clinic to define patients who could suffer from a radiation induced skin injury following a cardiac procedure, should be defined for each operator/procedure. The film technique was found to be superior to the diode in defining conversion factors in this study, and allowed for a rapid and accurate estimation of MESD for each patient. With appropriate positioning of the diode, a combined film/diode technique has a potential use in the training of new angiography operators. The patient body mass index (BMI) value was a good indicator of the variation in average lung dose (critical organ) between patients. The highest lung dose/DAP value was obtained for normal sized patients (BMI: 19-26), and was close to 1.5 mGy(Gycm2)(-1) with both CA and PTCA procedures.
OBJECTIVES To estimate risk for exposure-induced cancer death (REID), organ-specific risks of exp... more OBJECTIVES To estimate risk for exposure-induced cancer death (REID), organ-specific risks of exposure-induced cancer death (REIDHT) and associated conversion coefficients (CCREID:KAP=REID/kerma-area product (KAP), CCREIDHT:KAP=REIDHT/KAP) in paediatric cardiac catheterizations using data from radiation dose structured reports (RDSR). A novel risk surveillance tool consisting of age and gender specific risk reference values (RRVs) related to population cancer risk is suggested. METHODS The PCXMC v.2.0 code is used together with exposure-related information from RDSR from a cohort of 238 children to assess cancer risks and related conversion coefficients. The KAP corresponding to 1 in 1000 in increased REID, is used to define age and gender specific KAP-values to monitor risk in such patient cohorts, here denoted as RRVs. RESULTS The REID estimates ranged from below 1 up to 300 in 100000, and the RRV-values for the different age groups and gender ranged from 0.77 Gycm2 and 2.1 Gycm2 ...
![Research paper thumbnail of [OA221] The dose to the lens of the eye for the heart team performing transcatheter aortic valve implementation (TAVI): Is there any concern for cataract?](https://attachments.academia-assets.com/73356308/thumbnails/1.jpg)
](
Radiation Protection Dosimetry, 2016
Radiation Protection Dosimetry, 2000
The British journal of radiology/British journal of radiology, May 7, 2024
Physica Medica, Aug 1, 2018
Radiation Protection Dosimetry, Aug 1, 2000
Skin injuries have recently been reported for patients in diagnostic and interventional cardiac p... more Skin injuries have recently been reported for patients in diagnostic and interventional cardiac procedures. Cardiac catheterisation equipment usually has dose monitors showing the dose-area product (DAP) but the DAP value alone is not a suitable indicator for skin dose since the projections vary during the procedures. This work deals with measurements of maximum entrance skin dose, MESD, and effective dose, E, to an anthropomorphic phantom using TL dosemeters placed both on the outside of and inserted in the phantom and simulating a diagnostic and an interventional clinical procedure. DAP values were used for calculating conversion factors: MESD/DAP was 3.8 and 8.1 mSv.Gy -1 .cm -2 and E/DAP was 0.23 and 0.26 mSv.Gy -1 .cm -2 for diagnostic and interventional procedures respectively. Maximum permissible DAP value for preventing skin damage, i.e. MESD <2 Sv, is therefore 530 and 250 Gy.cm -2 respectively for diagnostic and interventional procedures. These results should be used as a local reference level for the patient dose to prevent skin burden. Patient mean DAP was 73, 120 and 170 Gy.cm 2 and effective dose 16, 31 and 41 mSv for diagnostic, interventional and combined procedures respectively.
British Journal of Radiology, Sep 1, 2009
Medical Physics, May 29, 2014
PURPOSE To investigate the potential benefits of automatic monitoring of accumulated patient and ... more PURPOSE To investigate the potential benefits of automatic monitoring of accumulated patient and staff dose indicators, i.e., CAK and KAP, from DICOM Radiation Dose Structured Reports (RDSR) in x-ray angiography (XA). METHODS Recently RDSR has enabled the convenient aggregation of dose indices and technique parameters for XA procedures. The information contained in RDSR objects for three XA systems, dedicated to different types of clinical procedures, has been collected and aggregated in a database for over one year using a system developed with open-source software at the Karolinska University Hospital. Patient weight was complemented to the RDSR data via an interface with the Hospital Information System (HIS). RESULTS The linearly approximated trend in KAP over a time period of a year for cerebrovascular, pelvic/peripheral vascular, and cardiovascular procedures showed a decrease of 12%, 20%, and 14%, respectively. The decrease was mainly due to hardware/software upgrades and new low-dose imaging protocols, and partially due to ongoing systematic radiation safety education of the clinical staff. The CAK was in excess of 3 Gy for 15 procedures, and exceeded 5 Gy for 3 procedures. The dose indices have also shown a significant dependence on patient weight for cardiovascular and pelvic/peripheral vascular procedures; a 10 kg shift in mean patient weight can result in a dose index increase of 25%. CONCLUSION Automatic monitoring of accumulated dose indices can be utilized to notify the clinical staff and medical physicists when the dose index has exceeded a predetermined action level. This allows for convenient and systematic follow-up of patients in risk of developing deterministic skin injuries. Furthermore, trend analyses of dose indices over time is a valuable resource for the identification of potential positive or negative effects (dose increase/decrease) from changes in hardware, software, and clinical work habits.
Radiation Protection Dosimetry, Jan 6, 2016
The aim of this study was to estimate conversion coefficients for maximum entrance skin dose (MES... more The aim of this study was to estimate conversion coefficients for maximum entrance skin dose (MESD) and effective dose (E) for patients undergoing transcatheter aortic valve implantation (TAVI) and to evaluate the risk of exposure-induced cancer death (REID) for prospectively younger patients. Effective doses and risks were estimated for 22 patients using PCXMC whereas MESDs were estimated for a sub-group of 15 patients using Gafchromic film. The estimated conversion coefficients for skin dose [CCS = MESD/dose-area product (DAP)] and E (CCE = E/DAP) were 9.7±1.5 and 0.24±0.02 mSv/Gy cm(2), respectively. The REID ranged from 1:9900 to 1:1400 and by decreasing the age of examination to 40-50 y of age, the REID increased with a factor of 2 for females and 1.5 for males. The organ at risk was the lung. Currently, the patient population is elderly with radiation-induced skin injuries as the main risk. The risk of cancer induction should additionally be considered if younger patient populations are to be treated.
Cardiac radiological interventions often involve long fluo-roscopy times and a high number of cin... more Cardiac radiological interventions often involve long fluo-roscopy times and a high number of cine runs. This results in patient radiation doses that in adults can exceed the threshold level for skin erythema (2 Sv). In children the main concern is instead the increased risk of cancer, related to the relatively high effective doses in children from such interventions. At the Karolinska University Hospital, local alarm levels of DAP values have been established to monitor the skin burden from coronary angiography (CA) and interventional pro-cedures (PCI) in adults. The alarm levels used in the clinic (CA: 350 Gycm2, PCI: 150 Gycm2 and combined procedure: 200 Gycm2) are based on measurements on patients using radiographic film. Dose reports for patients undergoing such procedures and exceeding the threshold DAP value for skin injuries are forwarded to the medical physicist for a skin dose calculation, and the result is returned to the operator for patient follow-up.
British Journal of Radiology, 2005
Maximum estimated skin doses to patients undergoing coronary angiography procedures were obtained... more Maximum estimated skin doses to patients undergoing coronary angiography procedures were obtained using radiographic slow film and diode dosemeters. Conversion factors of maximum entrance skin dose versus dose-area product (MESD/DAP) for diagnostic (coronary angiography (CA); 20 patients; 2 operators) and interventional procedures (percutaneous transluminal coronary angiography (PTCA); 10 patients; 1 operator) were 4.3 (mean value of 10 CA; operator A), 3.5 (mean value of 10 CA; operator B) and 9.7 (mean value of 10 PTCA; operator B) mGy(Gycm2)(-1), respectively. The results emphasise a need for both operator- and procedure-specific conversion factors. Compared with a single, global factor for all cardiac procedures and/or operators that is commonly applied today, such a refinement is expected to improve the accuracy in skin dose estimations from these procedures. Consequently, reference DAP values used in the clinic to define patients who could suffer from a radiation induced skin injury following a cardiac procedure, should be defined for each operator/procedure. The film technique was found to be superior to the diode in defining conversion factors in this study, and allowed for a rapid and accurate estimation of MESD for each patient. With appropriate positioning of the diode, a combined film/diode technique has a potential use in the training of new angiography operators. The patient body mass index (BMI) value was a good indicator of the variation in average lung dose (critical organ) between patients. The highest lung dose/DAP value was obtained for normal sized patients (BMI: 19-26), and was close to 1.5 mGy(Gycm2)(-1) with both CA and PTCA procedures.
OBJECTIVES To estimate risk for exposure-induced cancer death (REID), organ-specific risks of exp... more OBJECTIVES To estimate risk for exposure-induced cancer death (REID), organ-specific risks of exposure-induced cancer death (REIDHT) and associated conversion coefficients (CCREID:KAP=REID/kerma-area product (KAP), CCREIDHT:KAP=REIDHT/KAP) in paediatric cardiac catheterizations using data from radiation dose structured reports (RDSR). A novel risk surveillance tool consisting of age and gender specific risk reference values (RRVs) related to population cancer risk is suggested. METHODS The PCXMC v.2.0 code is used together with exposure-related information from RDSR from a cohort of 238 children to assess cancer risks and related conversion coefficients. The KAP corresponding to 1 in 1000 in increased REID, is used to define age and gender specific KAP-values to monitor risk in such patient cohorts, here denoted as RRVs. RESULTS The REID estimates ranged from below 1 up to 300 in 100000, and the RRV-values for the different age groups and gender ranged from 0.77 Gycm2 and 2.1 Gycm2 ...
Radiation Protection Dosimetry, 2016
Radiation Protection Dosimetry, 2000