title: Patient dose during carotid artery stenting with embolic-protection devices: evaluation with radiochromic films and related diagnostic reference levels according to factors influencing the procedure.
abstract: OBJECTIVE
  To measure the maximum entrance skin dose (MESD) on patients undergoing carotid artery stenting (CAS) using embolic-protection devices, to analyze the dependence of dose and exposure parameters on anatomical, clinical, and technical factors affecting the procedure complexity, to obtain some local diagnostic reference levels (DRLs), and to evaluate whether overcoming DRLs is related to procedure complexity.
  
  
  METHODS
  MESD were evaluated with radiochromic films in 31 patients (mean age 72 ± 7 years). Five of 33 (15 %) procedures used proximal EPD, and 28 of 33 (85 %) procedures used distal EPD. Local DRLs were derived from the recorded exposure parameters in 93 patients (65 men and 28 women, mean age 73 ± 9 years) undergoing 96 CAS with proximal (33 %) or distal (67 %) EPD. Four bilateral lesions were included.
  
  
  RESULTS
  MESD values (mean 0.96 ± 0.42 Gy) were <2 Gy without relevant dependence on procedure complexity. Local DRL values for kerma area product (KAP), fluoroscopy time (FT), and number of frames (NFR) were 269 Gy cm(2), 28 minutes, and 251, respectively. Only simultaneous bilateral treatment was associated with KAP (odds ratio [OR] 10.14, 95 % confidence interval [CI] 1-102.7, p < 0.05) and NFR overexposures (OR 10.8, 95 % CI 1.1-109.5, p < 0.05). Type I aortic arch decreased the risk of FT overexposure (OR 0.4, 95 % CI 0.1-0.9, p = 0.042), and stenosis ≥ 90 % increased the risk of NFR overexposure (OR 2.8, 95 % CI 1.1-7.4, p = 0.040). At multivariable analysis, stenosis ≥ 90 % (OR 2.8, 95 % CI 1.1-7.4, p = 0.040) and bilateral treatment (OR 10.8, 95 % CI 1.1-109.5, p = 0.027) were associated with overexposure for two or more parameters.
  
  
  CONCLUSIONS
  Skin doses are not problematic in CAS with EPD because these procedures rarely lead to doses >2 Gy.
authors.affiliation: Department of Medical Physics, Fondazione IRCCS Policlinico San Matteo, 27100, Pavia, Italy. l.dercole@smatteo.pv.it
authors.forename: Loredana
authors.initials: L
authors.lastname: D'Ercole
authors.forename: Pietro
authors.initials: P
authors.lastname: Quaretti
authors.forename: Nicola
authors.initials: N
authors.lastname: Cionfoli
authors.forename: Catherine
authors.initials: C
authors.lastname: Klersy
authors.forename: Milena
authors.initials: M
authors.lastname: Bocchiola
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Rodolico
authors.forename: Andrea
authors.initials: A
authors.lastname: Azzaretti
authors.forename: Francesco
authors.initials: F
authors.lastname: Lisciandro
authors.forename: Tommaso
authors.initials: T
authors.lastname: Cascella
authors.forename: Federico
authors.initials: F
authors.lastname: Zappoli Thyrion
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D016893:Carotid Stenosis / Q000601:surgery*; D057505:Embolic Protection Devices; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D020766:Intracranial Embolism / Q000209:etiology / Q000517:prevention & control; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D015641:Radiography, Interventional; D011874:Radiometry / Q000295:instrumentation*; D012867:Skin / Q000528:radiation effects*; D015607:Stents; D016896:Treatment Outcome