ABSTRACT
Objective:To determine the peak skin dose (PSD) to patients from neuro-interventional procedures and evaluate the risk of the deterministic effect.Methods:Gafchromic XR RV3 films were used in a level A tertiary hospital in Beijing to measure the patients′ PSD from neuro-interventional procedures, mainly three common types of procedures, including vascular embolization, vascular angioplasty and vascular angiography. The films were scanned by Epson Expression 10000XL, read by ImageJ software, and analyzed by Film QA Pro?2014 software.Results:PSD was measured in 23 embolizations, 14 stentings and 12 arteriography. There were 20 patients whose PSD were equal or greater than 2 Gy, including 15 in vascular embolization and 5 in angioplasty. The PSDs to patients in cerebral arteriography were all below 2 Gy. The PSDs to some of the patients were higher than the threshold for deterministic effect recommended by ICRP Publication 118.Conclusions:There is a risk of deterministic effect in neurointerventional procedures. It is suggested that the patients be followed up to observe their radiation injury as well as to know in time the subsequent diagnosis and treatment.
ABSTRACT
Objective To measure the peak skin dose (PSD) in two cardiovascular interventional procedures,including coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA) using radiochromic film.Methods Gafchromic XR-RV3 film was selected to measure PSD in two hospitals.The films were placed on the table underneath the patient during interventional surgery.The kV,mA,fluoroscopy time,dose-area product (DAP),and cumulative dose at reference point and other relevant information were recorded for all cases.Using the Epson V750 flatbed scanner for scanning and analyzing film,FilmQA software was chosen to analyze the pixel value of red,green and blue color channels.The PSD was determined using red channel data.The correlation and linear regression analysis between PSD and device-displayed parameters was carried out.Results PSD were measured using XR-RV3 film for 26 CA and 19 CA + PTCA procedures.For CA procedures,maximum fluoroscopy time,cumulative dose and DAP were 17.62 min,1 498.50 mGy and 109.68 Gy · cm2,respectively.The maximum PSD was 361.20 mGy.However,for CA + PTCA procedures,maximum fluoroscopy time,cumulative dose and DAP were 64.48 min,6 976.20 mGy and 5 336.00 Gy· cm2,respectively.One patient with CA + PTCA procedures was found to have received the PSD value more than 2 Gy,up to 2 195.70 mGy.DAP was found to be a good indicator (R2 =0.815,P ＜0.05) of PSD for CA procedure,and correlated with cumulative dose (R2 =0.916,P ＜ 0.05) for CA + PTCA procedures.Conclusions The PSD value of some patients in cardiac interventional procedures would exceed 2 Gy,the threshold of deterministic effects recommended by ICRP.The dose-related parameters value showed on DSA device can only used to estimate PSD roughly.Using XR-RV3 film accurate measurement of the PSD in interventional projects is a very fast and effective method.
ABSTRACT
Objective To study the dosimetric characteristics of two different radiochromic films used to estimate peak skin dose(PSD) of patients.The characteristics of these two films were investigated and compared after exposure to ionizing radiation in the diagnostic energy range,including post-exposure gray growth,sensitivity,energy dependence and dose response.Methods GafChromic XR-RV3 film and KODAK EDR2 film were exposed to air kerma 800 mGy free-in-air using five X-ray beam qualities (60,80,100,120 and 140 kVp) in a SSDL.The measurement for each energy was normalized to 80 kV to analyze energy dependence of films.The films were calibrated to different dose level (0.025-10 Gy) onphantom by 80 kV X-rays.The response curve were plotted to analyze sensitivity and dose response.The films were scanned with Epson V750 commercial flatbed scanner.Color channel analysis was performed.Results The post-exposure gray growth of XR-RV3 film was found to be fairly stable.The change were 2％,4％,6％ at 24 h,72 h and 6 weeks after exposure respectively.EDR2 film was found to be more sensitivity than XR-RV3 film in low dose.The energy response of the XR-RV3 film and EDR2 film were within 9％ and 23％ over the clinical diagnostic x-ray energies,respectively.In the dose range of 0.025-10 Gy,for the XR-RV3 film,the red channel with the dose response curve was most obvious.For EDR2 film,the pixel value of three color channels was coincident.The EDR2 film appeared to be saturated when receiving doses greater than 500 mGy.Conclusions The XR-RV3 film is superior to EDR2 film in gray growth,energy dependence,dose-response and other aspects.This film is very suitable for measuring and analyzing PSD of patients in interventional radiology procedures.
ABSTRACT
Objective To collect information of patient doses of interventional radiology in Beijing Xuanwu Hospital,and investigate correlation between the peak skin dose(PSD) and dose-area product(DAP).Methods Radiation doses from 135 patients have been studied including 84 coronary angiographies(CAG) and 51 percutaneous transluminal coronary angioplasties(PCI).Dose-area product(DAP) values,cumulative dose(CD) at interventional reference points,fluoroscopy times,total number of cine frames were collected for each patient.Skin dose measurements were made with thermoluminescent dosimeters(TLD) placed as a 10 ? 9 arrays of TLDs on the body.The grid of TLDs arrays was 5 ? 4 cm.Results Mean values for dose-area product were 2690.84 ?Gym2 for CAG and 7946.91 ?Gym2 for PCI.Mean values for CD were 431.6 mGy cm2 for CAG and 1395.3 mGy for PCI.Mean fluoroscopy times were 2.9 min for CAG and 10.9 min for PCI and mean number of frames were 544 and 945 for CAG and PCI,respectively.PSD values ranged from 26.18 to 120.37 mGy for CAG and 38.91 to 184.79 mGy for PCI.The relationship between DAP and PSD was r = 0.52 for CAG and r = 0.54 for PCI.The correlation of PSD with CD was r = 0.45 for CAG and r = 0.53 for PCI.Conclusion Comparison shows that patients DAP,CD and fluoroscopy time values were comparable with other publications.Skin dose values of investigated patients are below the threshold dose for radiation skin injury(2 Gy).There is no good relationship between DAP and PSD.So calculation of individual maximum skin dose based on DAP data is not reliable and needs to find a new reference value for skin dose.(J Intervent Radiol,2007,16:222-225)