title: Characterisation of grids of point detectors in maximum skin dose measurement in fluoroscopically-guided interventional procedures.
abstract: OBJECTIVE
  Point detectors are frequently used to measure patient's maximum skin dose (MSD) in fluoroscopically-guided interventional procedures (IP). However, their performance and ability to detect the actual MSD are rarely evaluated. The present study investigates the sampling uncertainty associated with the use of grids of point detectors to measure MSD in IP.
  
  
  METHODS
  Chemoembolisation of the liver (CE), percutaneous coronary intervention (PCI) and neuroembolisation (NE) procedures were studied. Spatial dose distributions were measured with XR-RV3 Gafchromic(®) films for 176 procedures. These distributions were used to simulate measurements performed using grids of detectors such as thermoluminescence detectors, with detector spacing from 1.4 up to 10 cm.
  
  
  RESULTS
  The sampling uncertainty was the highest in PCI and NE procedures. With 40 detectors covering the film area (36 cm × 44 cm), the maximum dose would be on average 86% and 63% of the MSD measured with Gafchromic(®) films in CE and PCI procedures, respectively. In NE procedures, with 27 detectors covering the film area (14 cm × 35 cm), the maximum dose measured would be on average 82% of the MSD obtained with the Gafchromic(®) films.
  
  
  CONCLUSIONS
  Thermoluminescence detectors show good energy and dose response in clinical beam qualities. However the poor spatial resolution of such point-like dosimeters may far outweigh their good dosimetric properties. The uncertainty from the sampling procedure should be estimated when point detectors are used in IP because it may lead to strong underestimation of the MSD.
authors.affiliation: Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, BE-2400 Mol, Belgium. Electronic address: jeremie.dabin@sckcen.be.
authors.forename: J
authors.initials: J
authors.lastname: Dabin
authors.affiliation: Medical Physics Department,Veneto Institute of Oncology IOV-IRCCS, Via Gattamelata 64, 35128 Padova, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Negri
authors.affiliation: Institut de Radioprotection et de Sûreté Nucléaire (IRSN), BP17, 92262 Fontenay-aux-Roses Cedex, France.
authors.forename: J
authors.initials: J
authors.lastname: Farah
authors.affiliation: VINCA Institute of Nuclear Sciences (VINCA), University of Belgrade, P.O. Box 522, 11001 Belgrade, Serbia.
authors.forename: O
authors.initials: O
authors.lastname: Ciraj-Bjelac
authors.affiliation: Institut de Radioprotection et de Sûreté Nucléaire (IRSN), BP17, 92262 Fontenay-aux-Roses Cedex, France.
authors.forename: I
authors.initials: I
authors.lastname: Clairand
authors.affiliation: Istituto Superiore di Sanità (ISS), Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: De Angelis
authors.affiliation: Nofer Institute of Occupational Medicine, 8 Sw. Teresy, Str., 91-348 Łódź, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Domienik
authors.affiliation: Radiation and Nuclear Safety Authority (STUK), P.O. Box 14, 00881 Helsinki, Finland.
authors.forename: H
authors.initials: H
authors.lastname: Jarvinen
authors.affiliation: Institute of Nuclear Physics (IFJ - PAN), ul Radzikowskiego 152, PL-31-342 Kraków, Poland.
authors.forename: R
authors.initials: R
authors.lastname: Kopec
authors.affiliation: Ruđer Bošković Institute (RBI), Bijenička c. 54, 10000, Zagreb, Croatia.
authors.forename: M
authors.initials: M
authors.lastname: Majer
authors.affiliation: Centre Hospitalier Universitaire de Liège (CHUL)/Zephyra scrl, Avenue de l'Hôpital, 4000 Liège, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Malchair
authors.affiliation: National Radiation Protection Institute (NRPI), Bartoškova 28, 140 00 Prague 4, Czech Republic.
authors.forename: L
authors.initials: L
authors.lastname: Novák
authors.affiliation: Radiation and Nuclear Safety Authority (STUK), P.O. Box 14, 00881 Helsinki, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Siiskonen
authors.affiliation: Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, BE-2400 Mol, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Vanhavere
authors.affiliation: Udine University Hospital (AOUD), pl S. Maria della Misericordia, 15, 33100 Udine, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Trianni
authors.affiliation: Ruđer Bošković Institute (RBI), Bijenička c. 54, 10000, Zagreb, Croatia.
authors.forename: Ž
authors.initials: Ž
authors.lastname: Knežević
mesh_terms: D016461:Chemoembolization, Therapeutic / Q000379:methods*; D005471:Fluoroscopy; D062645:Percutaneous Coronary Intervention / Q000379:methods*; D011829:Radiation Dosage; D012867:Skin / Q000528:radiation effects*; D013819:Thermoluminescent Dosimetry; D035501:Uncertainty
keywords: Fluoroscopically-guided procedures; Maximum skin dose; Point detectors; Sampling uncertainty; TLD