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Microsoft PowerPoint - 5- patricia miranda.ppt [Sólo lectura]

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Microsoft PowerPoint - 5- patricia miranda.ppt [Sólo lectura]

  1. 1. SEMINAR 1 Radiological Protection Of Patients Radiation Protection in Paediatric Cardiology Dra. Patricia Miranda González CARDIOVASCULAR DEPARTMENT , CALVO MACKENNA’S HOSPITAL SANTIAGO CHILE
  2. 2. Radiation Protection in Paediatric Cardiology Pediatric patients have special features, they are not small adults.
  3. 3. Radiation Protection in Paediatric Cardiology PART 1 1. They have congenital diseases of the heart Paediatric cardiology is absolutely different from the adult cardiology not only in the age of the patients (newborns until fifteen years old) but also because of the diversity of structural anomalies in congenital heart diseases • This is important to understand because paediatric procedures are longer than procedures in adults (Lock 2000). • In certain times need to be studied before each surgery, even up to three times before the age of two years old. • More complex congenital heart diseases have the possibility of cardiac surgery, complex diagnostic studies are necessary including several biplane angiographic recordings, measurement of local pressure curves and oxygen saturation (with and without oxygen), before and after cardiac surgery.
  4. 4. Radiation Protection in Paediatric Cardiology Mean values of Pka for different procedures Type of examination Pka Gycm² mean Pulmonary angioplasty with stent 8.10 Diagnostic complex (D) 6.47 Closure atrial septal defect 5.14 Other 4.54 Aortic valvuloplasty 3.63 Pulmonary angioplasty 3.56 Diagnostic “normal” (d) 3.46 Therapeutic (global) 3.44 Aortic angioplasty 2.98 Diagnostic (global) 2.44 Pulmonary valvuloplasty 2.00 Patent ductus arteriosus closure. 1.27 A PILOT PROGRAMME ON PATIENT DOSIMETRY ON PAEDIATRIC INTERVENTIONAL CARDIOLOGY IN CHILE
  5. 5. Radiation Protection in Paediatric Cardiology 2. Children have especially radiosensitive tissues
  6. 6. Radiation Protection in Paediatric Cardiology Estocastic Deterministic (Probabilistic) efect Efect Cancer and Cataratas Genetic efects Esterility Eritema Probability ∝ dosis Epilation Fetal Malformations Rx Dosis
  7. 7. Radiation Protection in Paediatric Cardiology 3. Their have longer life span makes the stochastic effect manifest 674 childrens undergoing cardiac catheterization due to congenital heart desease between 1950-1970 The expected number of cancer was 4.75, but the real number was 11.0
  8. 8. Radiation Protection in Paediatric Cardiology Estocastic Deterministic (Probabilistic) efect Efect Cancer and Cataratas genetic efects Esterility Eritema Probability ∝ dosis Epilation Rx Fetal Malformations Dosis
  9. 9. Radiation Protection in Paediatric Cardiology According to the International Commission Radiological ptrotection (ICRP) the probability of cancer iduction by ionizig radiation is a factor 2-3 higher for infants and children in comparision with adults (ICRP 1991). 0,20 Muerte 0,16 Female por Sievert Male 0,12 (Sv) 0,08 0,04 0,00 0 15 30 45 60 75 90 Edad de exposicion
  10. 10. Radiation Protection in Paediatric Cardiology 4. The age of the patients is very different (newborns until fifteen years of age) even their weight. Air kerma area product retains a strong dependence on patient weight kerma area product v/s body weight 900 0,4495x kkerma area product KAP (cGycm^2 800 y = 78,531e R² = 0,8974, R=0,9473 700 600 500 400 300 200 100 0 < 10 10 ‐ 20 20 ‐ 30 30 ‐ 40 > 40 Weight (kG) A PILOT PROGRAMME ON PATIENT DOSIMETRY ON PAEDIATRIC INTERVENTIONAL CARDIOLOGY IN CHILE
  11. 11. Radiation Protection in Paediatric Cardiology Kerma area product per minute fluoroscopy versus body weight FLUOROSCOPY 25 0.4386x y = 2.3857e fluoroscopy (cGycm ^2m in‐1 kerm a area product / tim e 2 20 R  = 0.9994 15 10 5 CINE ACQUISITION 0 0.6 < 10 10 ‐ 20 20 ‐ 30 30 ‐ 40 > 40 0.5386x y = 0.0356e Weight (kG) ke rm a are a product / fram e 0.5 2 R  = 0.9863 0.4 (cGycm ^ 2 ) Kerma area product per cine frame versus 0.3 body weight 0.2 0.1 0 < 10 10 ‐ 20 20 ‐ 30 30 ‐ 40 > 40 Weight (kG) A PILOT PROGRAMME ON PATIENT DOSIMETRY ON PAEDIATRIC INTERVENTIONAL CARDIOLOGY IN CHILE
  12. 12. Radiation Protection in Paediatric Cardiology A PILOT PROGRAMME ON PATIENT DOSIMETRY ON PAEDIATRIC INTERVENTIONAL CARDIOLOGY IN CHILE
  13. 13. Radiation Protection in Paediatric Cardiology HDO Biplane A 11Nov04 paediatric 250 200 microGy/frame 150 Cine 25 cm Cine 20 cm 100 Cine 16 cm 50 0 4 8 12 16 20 cm PMMA
  14. 14. Radiation Protection in Paediatric Cardiology RADIATION DOSE AND IMAGE QUALITY FOR PAEDIATRIC ITERVENTIONAL CARDIOLOGY E. Vañó. C. Ubeda. F Leyton and P. Miranda Published 8 july 2008
  15. 15. Radiation Protection in Paediatric Cardiology PART 2 Paediatric Interventional Cardiology (PIC) has a challenge ¿ How to reduce the doses in PIC? 1. Formation in RP
  16. 16. Radiation Protection in Paediatric Cardiology Support Programs of the IAEA • Regional Workshops in Chile 2006 and Costa Rica 2007. • Attending cardiologist from all Latinamerica. • Several works at the workshop to evaluate patient dose in interventional Cardiology in Latin America.
  17. 17. Radiation Protection in Paediatric Cardiology 2. The equipment ¿What is the best Image intesifier or Flat Panel? Both sistems are adecuated, but flat panel have became the most “popular” because the market offers a better image quality and dose reduction, nevertheless the experince show that at least at this “inicial point” is different.
  18. 18. Radiation Protection in Paediatric Cardiology Biplane Siemens Flat panel Biplane Siemens with image itensifiers
  19. 19. Radiation Protection in Paediatric Cardiology Dose rate reaching the patient is meassured or calculated (usually expresed in mGy/min)
  20. 20. Radiation Protection in Paediatric Cardiology Flat Panel sistem Dose rate reaching the metacrilatpatient is meassured or calculated (usually expressed in mGy/min)
  21. 21. Radiation Protection in Paediatric Cardiology 3. Operation modes Sometimes, interventionists do not have clear criteria to select the different operation modes. Thus, the characterization of the systems in dose and image quality using test objects offers a set of useful data to help cardiologists to select the most appropriate operation modes for the different procedures and patient sizes.
  22. 22. Radiation Protection in Paediatric Cardiology RADIATION DOSE AND IMAGE QUALITY FOR PAEDIATRIC ITERVENTIONAL CARDIOLOGY E. Vañó. C. Ubeda. F Leyton and P. Miranda Published 8 july 2008
  23. 23. Radiation Protection in Paediatric Cardiology RADIATION DOSE AND IMAGE QUALITY FOR PAEDIATRIC ITERVENTIONAL CARDIOLOGY E. Vañó. C. Ubeda. F Leyton and P. Miranda Published 8 july 2008
  24. 24. Radiation Protection in Paediatric Cardiology 50 Scatter dose rate (mSv/h) 40 low 30 med high 20 cine 10 0 16 20 24 28 PMMA thickness (cm)
  25. 25. Radiation Protection in Paediatric Cardiology Important factors in the dose rate for fluoroscopy • Number of pulses per second (pulsed fluoroscopy). • Dose per puls (o dose per “frame”). • Added Filter (normaly the low dose modes use cupper filters of 0,4 to 0,8 mm).
  26. 26. Radiation Protection in Paediatric Cardiology HDO Biplane A 11Nov04 paediatric 20.0 17.3 18.0 16.0 14.0 12.0 mGy/min Fluoro low 25 cm 10.0 Fluoro med 25 cm 7.4 6.7 8.0 Fluoro high 25 cm 6.0 3.4 3.1 2.8 4.0 1.5 1.4 1.3 0.7 0.5 0.6 2.0 0.3 0.2 0.3 0.0 4 8 12 16 20 cm PMMA
  27. 27. Radiation Protection in Paediatric Cardiology HDO Biplane A 11Nov04 paediatric vs adult 25.0 21.6 20.0 17.3 Fluoro low 25 cm Fluoro med 25 cm 15.0 mGy/min 11.7 Fluoro high 25 cm Fluoro low adult 10.0 7.4 Fluoro med 25 cm adult Fluoro high 25 cm adult 4.5 5.0 3.4 0.0 20 cm PMMA
  28. 28. Radiation Protection in Paediatric Cardiology CD-1 1 fluoro 5860895
  29. 29. Radiation Protection in Paediatric Cardiology CD-1 4 cine 5861107
  30. 30. Radiation Protection in Paediatric Cardiology Comparison between median KAP (Gy.cm2) for paediatric cardiology procedures reported by different authors (figures adapted by the authors of this paper). Age Boothroy Rassow Bacher Martinez *This bands d et al. et al. et al. et al. [7] paper (years) [10] [11] [12] (2007) (2008) (1997) (2000) (2005) (Gycm²) (Gycm²) (Gycm²) (Gycm² ) <1 12 3 1.9 1.0 1-<5 24 5 4.1 2.9 1.6 5 - < 10 48 10 4.5 1.8 10 - <16 98 18 15.4 5.1 *A PILOT PROGRAMME ON PATIENT DOSIMETRY ON PAEDIATRIC INTERVENTIONAL CARDIOLOGY IN CHILE
  31. 31. Radiation Protection in Paediatric Cardiology Pediatric interventional cardiologyst dose HDO Biplane A 11Nov04 paediatric 6 5 4 Fluoro low 20 cm mSv/h Fluoro med 20 cm 3 Fluoro high 20 cm cine 30f/s 20 cm 2 1 0 4 8 12 16 20 cm PMMA
  32. 32. Radiation Protection in Paediatric Cardiology Different C-arm angulations can modify the disperse dose in a 5 factor
  33. 33. Radiation Protection in Paediatric Cardiology Operation modes tips 1. Use of fluoroscopy runs instead of cine 2. Use of “one shot” instead of cine 3. Use one projections instead of two if it is possible (PDA closure with coil)
  34. 34. Radiation Protection in Paediatric Cardiology 4. Reduce the operator doses References: • Radiation Safety in Interventional Radiology: BfS ISH 178/97. Proceedings of the 1995 Joint WHO/ISH Workshop. October 9- 13; Munich-Neuherberg. Bundesamt für Starhlenschutz, Germany. 1997. • Efficacy and Radiation Safety in Interventional Radiology. WHO 2000. Geneva. Suggested action levels in staff exposure in interventional radiology (Joint WHO/IRH/CE workshop 1995) SUGGESTED ACTION LEVELS FOR STAFF DOSE Body 0.5 mSv/month Eyes 5.0 mSv/month Hands/Extremities 15.0 mSv/month
  35. 35. Radiation Protection in Paediatric Cardiology Radiation Lens dose, optional protection measures Finger dose, optional Second dosemeter Image outside and above the apron intensifier at the neck, optional Patient Personal dose dosemeter behind the lead apron Dose limits of occupational exposure (ICRP 60) Effective dose 20 mSv in a year averaged over a period of 5 years X-ray Anual equivalent dose in the tube lens of the eye 150 mSv skin 500 mSv hands and feet 500 mSv
  36. 36. Radiation Protection in Paediatric Cardiology Reduction in operator doses with the use of radiation protection tools • Lead apron of 0.5; 0.35 or 0.25 mm lead equivalent (weight of the apron to be taken into account). Typical reduction 90% (or more). • Thyroid protector. 0.5 mm lead equivalent • Suspended ceiling screens, typically equivalent to 1 mm lead. Typical reduction > 90%. • Under table lead equivalent protection • Protective goggles, typically 0.5-0.75 mm lead. • Tactile gloves, typically equivalent to 0.03 mm lead. Typical reduction > 15-55%.
  37. 37. Radiation Protection in Paediatric Cardiology Attenuation measured at the San Carlos University Hospital (lead aprons) 0.50 mm lead 60 kV; 100% <1% 100 kV; 100% 3-7% But, X ray beam filtration has a great influence!!
  38. 38. Radiation Protection in Paediatric Cardiology Avoid more than 90% of the scatter radiation THYROID PROTECTOR
  39. 39. Radiation Protection in Paediatric Cardiology Sometimes, hands in the direct beam!!
  40. 40. Radiation Protection in Paediatric Cardiology Vañó et al. Br J Radiol 1998; 71:954-960 Mean values (µSv) per procedure (using protection tools) Interventional Interventional radiologist cardiologist
  41. 41. Radiation Protection in Paediatric Cardiology Give me a break !!!

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