title: Skin dose alarm levels in cardiac angiography procedures: is a single DAP value sufficient?
abstract: 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.
authors.affiliation: Department of Medical Physics, Karolinska University Hospital, Stockholm, 171 76, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Karambatsakidou
authors.forename: P
authors.initials: P
authors.lastname: Tornvall
authors.forename: N
authors.initials: N
authors.lastname: Saleh
authors.forename: T
authors.initials: T
authors.lastname: Chouliaras
authors.forename: P-O
authors.initials: PO
authors.lastname: Löfberg
authors.forename: A
authors.initials: A
authors.lastname: Fransson
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects; D015992:Body Mass Index; D017023:Coronary Angiography / Q000009:adverse effects*; D005373:Film Dosimetry; D005471:Fluoroscopy / Q000009:adverse effects; D006801:Humans; D015588:Observer Variation; D011829:Radiation Dosage; D012867:Skin / Q000528:radiation effects*