明海大学歯学雑誌　４４‐２☆／４．渡辺

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1 J Meikai Dent Med 44 2, , Quality Assurance IAEA 18 DAP Rando Phantom MSO-S TLD DAP μsv/ cgy cm msv, 0.3 msv 1.5mSv,0.02mSv Quality Assurance in the Dental Radiology Clinical Practice for Radiation Exposure Protection Masayoshi WATANABE, Maki IZAWA, Noriyoshi SHIBA, Naoki KISHIDA, Keisuke SAITO, Tomonori OZAWA and Yasuhiko OKUMURA Division of Dental Radiology, Department of Diagnostic & Therapeutic Science, Meikai University School of Dentistry Abstract : As part of the proceeds of exposure management of training for acquiring imaging technology, we compared dose of training to the dosage limits for occupational exposure for students under age 18 as recommended by the International Atomic Energy Agency IAEA. Our objective was also to establish a consistent method for evaluating safety and protection. We measured the DAP and the dosage absorbed by tissue for intraoral radiography and panoramic radiography. To measure, we used a thermoluminescence dosimeter MSO-S TLD element and a Rando Phantom. We resolved the tissue equivalent dose conversion factor of the DAP and resolved the equivalent dose an average of once per photograph. The results, for each of the tissue samples and the lens, we adopted the equivalent dose conversion factor with the highest value by multiple measurements for evaluating safety : 324 and 72.9 μsv/ cgy cm 2 for intraoral radiography and 3.53 and 225 μsv/ cgy cm 2 for panoramic radiography. The equivalent dose for the tissue samples and the lens was an average of one per 1.4 and 0.3 msv for intraoral radiography and 1.5 and 0.02 for panoramic radiography. The conversion factor arrived at in this study can be used for comparison with the dosage limits to determine the safe dosage range during student training. Key words : mutual shooting, occupational exposure, tissue equivalent dose conversion factor, effective dose conversion factor

2 X ,230 1, X X X International Commission on Radiological Protection, ICRP International Atomic Energy Agency, IAEA IAEA ICRP msv/ msv/ 20 msv/ Heliodent 60 DS Sirona, Germany InSight Film Kodak, USA Veraview epocs Morita Fuji medical Dose Area Product, DAP DAP E Hlens Hskin Table 1 Table Device Heliodent 60 DS Veraview epocs Specification of Helioldent DS and Veraview epocs X Tube voltage kv Tube Current ma Exposure Time s Total Filtration mmal

QA 159 A 1101 2 DAP X 20 cm ThinX RAD Unfors, Sverige X Omat Film Kodak, USA 10 DAP DAPintraoral Kair A 1 DAPintraoral Kair A X X Fig 1 Diamentor E2 PTW, Germany DAP 5 99 1 DAPextraoral 3 DAP

3 QA 159 A DAP X 20 cm ThinX RAD Unfors, Sverige X Omat Film Kodak, USA 10 DAP DAPintraoral Kair A 1 DAPintraoral Kair A X X Fig 1 Diamentor E2 PTW, Germany DAP DAPextraoral 3 DAP 1 TLD TLD MSO-S TLD TMDsystem 3000 Harshow Chemical, Germany Rando Phantom Alderson Research Laboratories, USA TLD 9015/10 X 5-6 Radcal, California ThinX Rad QC X CH-200 M SHIMADZU 70 kv, 2.6 mmal 3.5 mgy/s 10 cm 20 cm TLD X TLD QC 2 Rando Phantom Rando Phantom TLD SOMATOM Emotion 6 Siemens, Germany Image J NIH, USA Rando Phantom 0 X 0, Y 0, Z 0, Fig 2 Z X Y Fig 3 Rando Phantom CT ImageJ XY 1 pixcel 220/ cm Z 1 pixcel 220 / cm Table 2 Rando Phantom 4 Rando Phantom 6 7 Fig 1 Diamentor E2 positioning. Fig 2 Caudo-cranial view of a female Rando phantom s head.

160 44 2015 Fig 3 Frontal view of a female Rando phantom. DAP 70 kv, 6 ma, 16 s Rando Phantom TLD IP Rando Phantom Rando Phantom Z 9 cm 1.

4 Fig 3 Frontal view of a female Rando phantom. DAP 70 kv, 6 ma, 16 s Rando Phantom TLD IP Rando Phantom Rando Phantom Z 9 cm 1.25 cm TLD IP IP 4 Charged Particle Equilibrium, CPE 12 Dair Kair 1 g CPE and g 0 3 Dair g Table 2 TLD locations in the Rando phantom. Site R/L x mm y mm z mm Parotid gl. Right Parotid gl. Left Skin Right Skin Left Lens Right Lens Left Table 3 The exposure times and the patient entrance doses PED and the dose area product DAP in intra-oral radiography. Maxilla Mandibular Site incisor premolar molar incisor premolar molar Exposure time s PED DAP mgy cgy cm TLD Table 3 T TLD CPE air DT Dair μ en/ρ T/ μ en/ρ air 4 CPE and μ en/ρ T/ μ en/ρ air 1 for lens and skin DT μ en/ρ T μ en/ρ air 13 HT/DAP DT, max/dap T lens or skin 5 E/DAP Emax/DAP 6 HT/DAP lens skin DT, max Emax E/DAP 1

5 QA 161 HT DAPav HT/DAP 7 Eintraoral or extraoral DAPav Eintraoral or extraoral/dap 8 HT E DAPav IAEA msv/ 6mSv/ ICRP msv/ 1 DAP Table 3 57 mm Patient Entrance Dose, PED 1 DAP Table 3 10 DAP DAPintraoral 41.8 cgycm 2 99 DAP Table 4 t DAP p 0.01 DAP σ 12.2 DAP σ DAP cgycm 2 2 TLD TLD MSO-S 1 μsv 2 msv Fig kv 70 kv 10 TLD μgy/ μsv Kair μgy μgy/μsv TLDReading B.G. μsv 3 Rando Phantom IP TLD Fig μsv 3.22 μsv μsv μsv μsv μsv 10 4 Fig μsv μsv 1000 Rando Phantom IP Fig 7 IP Fig 8 TLD Rando Phantom No.5 8 Phantom 21 μsv 1,325 μsv 1/100 Table 4 The average height and weight for all training students 99, and the DAP in extra-oral radiography. Gender Number n Height cm Weight kg DAP cgy cm 2 male female Fig 4 Calibration of TLD reader and MSO-S.

162 44 2015 Fig 5 Figure is captured with the wound to phantom face the IP film and the absorbed dose μgy in intra-oral radiography. 1,191 μsv 493 μsv 227 μsv 33.

4 μsv cgy 1 cm 2 1 1/10 10 1/10 5 Hlens, max /DAPintraoral 103.7 μsv cgy 1 cm 2 1 1/10 DAP 5.

6 Fig 5 Figure is captured with the wound to phantom face the IP film and the absorbed dose μgy in intra-oral radiography. 1,191 μsv 493 μsv 227 μsv 33.7 μsv Phantom Fig 9 Fig 6 Absorbed dose of the lens when irradiated by 2.5 cm while moving from the top. 4 DAP 10 Hskin, max 10 Hskin, max /DAPintraoral μsv cgy 1 cm 2 1 1/ /10 5 Hlens, max /DAPintraoral μsv cgy 1 cm 2 1 1/10 DAP 5.89 cgy cm 2 Hskin, max/dapextraoral Fig 7 Figure is captured with the wound to phantom face the IP film and the absorbed dose μgy in extra-oral radiography. 225 μsv cgy 1 cm 2 Hlens, max /DAPextraoral 3.53 μsv cgy 1 cm 2 Looe Table 5

7 QA 163 Fig 8 Figure as taken by installing the occlusal plane IP film and the absorbed dose μgy in extra-oral radiography. Table 6 The dose limit and the effective dose and equivalent dose to the skin and lens, the number of times to reach the dose limit in parentheses. Intraoral radiography Extraoral radiography Dose limit Equivalent dose of lens Hlens msv Equivalent dose of skin Hskin msv Effective dose E msv Fig 9 The dose profile of the phantom surface in extra-oral radiography. Table 5 The effective dose conversion factor and tissue lens and skin equivalent dose conversion factor of DAP per. Tissue Lens Skin Effective Defintion Hlens/DAP Dlens, max/dap Hskin/DAP Dparotid, max/dap Eex/DAP Eex, max/dap Intraoral Extraoral radiography radiography μsv cgy 1 cm 2 μsv cgy 1 cm Table 6 IAEA 16 ICRP 1

8 X X X X IAEA 1 IAEA μsv μsv μsv National Radiological Protection Board, NRPB 15 Entrance Surface Dose, ESD DAP X 5 μsv 10 μsv E-speed 400 ICRP msv msv D-speed film msv 0.01 msv ICRP 1990 Ludlow 18 ICRP msv msv msv msv ICRP Looe 20 ICRP 103 DAP DAP DAP Rando Phantom DAP Looe 3 X Rando Phantom 2.5 cm Rando Phantom

9 QA CT 5mm ImageJ X, Y, Z ICRP X 4 mas 4 20 cm PED mgy/mas TLD 25 cm 5 2 PED μsv cgy 1 cm μsv cgy 1 cm μsv cgy 1 cm μsv cgy 1 cm 2 Looe 1.32 μsv cgy 1 cm μsv cgy 1 cm 2 Fig msv 2.0 msv msv msv 1.5 msv 0.01 msv 1 2, , 7 11 F 1 2, 7 11 IP ICRP IAEA 20 msv 150 msv 6mSv ,000 1, msv 150 msv 1/7 TLD X 1cm 2 1/7 1/

10 msv 20 msv 1/10 6mSv 1/10 1 X DAP μsv/ cgy cm μsv/ cgy cm μsv / cgy cm μsv/ cgy cm msv msv msv msv 2, μsv/ cgy cm μsv/ cgy cm msv 1, msv ICRP IAEA X , , , 31 35, 2004 European Commission : The Safe Use of Radiographs in Dental Practice. In : Radiation Protection 136. European Guidelines on Radiation Protection in Dental Radiology, Luxembourg, Directorate General Environment, Nuclear Safety and Civil Protection, pp53 60, 2004 Brezden, N. A., and S. L. Brooks : Evaluation of panoramic dental radiographs taken in private practice. Oral Surg Oral Med Oral Pathol 63, , 1987 Rushton, V. E., K. Horner, and H. M. Worthington : The Quality of Panoramic Radiographs in General Dental Practice. Br Dent J 186, , 1999 In 22 pp42, 2011 X 79, , 1991 Radiation Protection and Safety of Radiation Sources : Planned exposure situations. In : International Basic Safety Standards Interim Edition IAEA Safety Standards Series GSR Part 3 Interim. pp20 56, 2011 International Commission on Radiological Protection : Recommendations of the International Commission on Radiological Protection. ICRP Publication 60. Ann. ICRP 21, 1 3, 1991 International Commission on Radiological Protection : The 2007 Recommendations of the International Commission on Ra-

11 QA 167 diological Protection. ICRP Publication 103. Ann. ICRP 37, 2 4, 2007 International Commission on Radiological Protection : Statement on Tissue Reactions. ICRP ref , 1 2, 2011 In pp142, 2008 ICRP 90 43, , , 77 78, 1990 Hart D and Wall B F, : Radiation Exposure of the UK Population from Medical and Dental X-ray Examinations. NRPB-W , 2001 NRPB : Guidelines on radiology standards for primary dental care. DOC NRPB 5, 1 57, 1994 Lecomber A and Faulkner K, : Organ absorbed doses in intraoral dental radiography. Br. J Radiol, 66, , 1993 Ludlow JB, Davies-Ludlow LE, White SC. : Patient risk related to common dental radiographic examinations : the impact of 2007 International Commission on Radiological Protection recommendations regarding dose calculation. J Am Dent Assoc 139, , 2008 Tomohiro Okano, Jaideep Sur Review article, : Radiation dose and protection in dentistry. Japanese Dental Science Review 46, , 2010 H. K. Looe, F. Eenboom, N. Chofor, A. Pfaffenberger, M. Steinhoff, A. Rühmann, A. Poplawski, K. Willborn and B. Poppe. : Conversion coefficients for the estimation of effective doses in intraoral and panoramic dentalradiology from dose-area product values. Radiat Prot Dosimetry 131, , 2008 K Iwai, K Hashimoto, K Nishizawa, K Sawada, and K Honda : Evaluation of effective dose from a RANDO phantom in videofluorography diagnostic procedures for diagnosing dysphagia. Dentomaxillofac Radiol 40, , 2011 Nickoloff EL In pp , , 9 16,

J Meikai Dent Med 36 2, , Multi-Dimensional Computed Tomography Multi-Dimensional Computed Tomography MDCT RANDO µsv

J Meikai Dent Med 36 2, , Multi-Dimensional Computed Tomography Multi-Dimensional Computed Tomography MDCT RANDO µsv J Meikai Dent Med 36 2, 187 197, 2007 187 Multi-Dimensional Computed Tomography Multi-Dimensional Computed Tomography MDCT RANDO 1 19691.20 µsv 19678.40 µsv 17325.00 µsv 16408.00 µsv 15360.80 µsv 19185.50

明海大学歯学雑誌 ４４‐２☆／４．渡辺

明海大学歯学雑誌　４４‐２☆／４．渡辺