Sandra Hopkins Final Report.pdf - University of Surrey

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6. ConclusionPatient dose was measured in two cardiac catheterisation labs using calibrated dose area product(DAP) meters. These systems were virtually identical from a technical perspective but wereinstalled approximately five years apart. Measured DAP determined that the newer lab had higherpatient doses compared with the old lab and they were also above the Diagnostic Reference Level.This was despite a reduction in the screening time and the number of acquisition runs. The reasonfor this higher dose was attributed to manufacturer’s setting higher detector doses in the new laband also dose saving copper pre-filtration not being automatically utilised for acquisition runs.Users need to work with Medical Physics and applications specialists to lower doses whilstmaintaining adequate image quality to ensure that doses are as low as reasonable practicable.A Matlab programme was adapted for the local cardiac systems to record the skin dose distributionfor coronary angiography procedures and to provide a value and position for the region ofmaximum skin dose for each procedure. Skin dose measurements using thermoluminescentdosimeters (TLDs) determined that indicated skin dose did not include any contribution fromscattered radiation from nearby runs so would always be an under estimate. This is worthy of moredetailed study but the current programme was considered sufficient to determine whether a patientneeded to be followed up for any signs of skin damage. Tests using the Matlab programmedetermined that skin effects are not likely to be seen for routine coronary angiography proceduresbut complex interventional procedures should be analysed on a case by case basis to determinewhether follow up is required. The accuracy of the programme to display the correct region ofirradiation requires further refinement. Additionally, the programme does not take into account anytranslational movement of the patient table. This information is not currently available in thepatient’s dose record. This should be investigated further as the information is available in the x-rayroom on the TV monitor.41
References1. NRPB W4 – Radiation exposure of the UK population from medical and dentalexaminations, March 20022. Fulkner K and Werduch A, ‘An estimate of the collective dose to the European populationfrom cardiac x-ray procedures’, The British Journal of Raidology, 81 (2008), 955-9623. US Food and Drug Administration. Avoidance of serious x-ray induced skin injuries topatients during fluoroscopy guided procedures. Med Bull 1994; 24:7-174. International Commission on Radiological Protection. The biological basis for doselimitation in the skin. ICRP publication 59. Ann ICRP 1991, 22(2)5. International Commission on Radiological Protection 1990. Recommendations of the ICRP.ICRP Publication 60. Ann ICRP 1991; 21:1-36. International Commission on Radiological Protection, ‘Aviodance of radiation injuries frommedical interventional procedures, ICRP publication 85, Pergamon press7. Vano E, Gonzalez L, Ten J, Fernandez J, Guibelalde E and Macaya C, ‘Skin dose and doseareaproduct values for Interventional Cardiology procedures’, British Journal of Radiology,74 (2001), 48-558. Morrell R, ‘Dosimetry and Optimisation in High Dose Fluoroscopic and FluorographicProcedures’, Thesis submitted to the University of Nottingham for the degree of Doctor ofPhilosophy, March 20069. Morrell R, Rogers A, ‘A mathematical model for patient skin dose assessment in cardiaccatheterization procedures’, British Journal of Radiology 79 (2006), 756-76110. Coulden R A, Readman L P, ‘Coronary angiography: an analysis of radiographic practice inthe UK’, The British Journal of Radiology, 66 (1993), 327-33111. Betsou S, Efstathopoulos E, Katritsis D, Faulkner K and Panayiotakis G, ‘Patient radiationdoses during cardiac catheterisation procedures’, British Journal of Radiology, 71 (1998)634-63912. Leung K and Martin C, ‘Effective doses in Coronary Angiography’, British Journal ofRadiology, 69 (1996), 426-43113. International Commission on Radiological Protection, ‘The 2007 Recommendations of theInternational Commission on Radiological Protection, ICRP publication 103’. (Annals ofICRP Volume 37 No 2-4)14. Vano E, Goicolea J, Galvan C, Gonzalez L, Meiggs L, Ten J and Macaya V, ‘Skin radiationinjuries in patients following repeated Coronary Angioplasty procedures’, British Journal ofRadiology (2001) 74, 1023-103142
Page 1 and 2: Calculation, verification and monit
Page 3 and 4: AcknowledgementsI would like to exp
Page 5 and 6: 4.3.2 Simulated Patient Skin Absorb
Page 7: These types of interventional proce
Page 12 and 13: 2.3.3 Equipment configurationFigure
Page 14 and 15: Skin injuries can occur when skin d
Page 16 and 17: couch height position when the cent
Page 18 and 19: This formula provides the idealised
Page 20 and 21: 3. Method3.1 Verification of Patien
Page 22 and 23: The field size was set to Mag 1 (20
Page 24 and 25: Further combined orientations were
Page 26 and 27: 70 183 67 60.7 +10.3%102 205 175 15
Page 28 and 29: Method 3 - Thermo Luminescent Dosim
Page 30: 13172125293337414549535761656973778
Page 33 and 34: 4.3.2 Simulated patient Skin Absorb
Page 35 and 36: However, a second set of orientatio
Page 37 and 38: further analysis work. An excerpt o
Page 39 and 40: Figure 29 : Intervention coronary e
Page 41 and 42: maximum skin dose to average dose 3
Page 43 and 44: of 29% 42 . Image quality assessmen
Page 45: always resulted in a reduction in d
Page 49 and 50: 30. Theodorakou C and Horrocks J A,

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