SEMINAR 1. Radiological Protection Of Patients. Radiation Protection in Paediatric Cardiology. Dra. Patricia Miranda González

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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 Pediatric patients have special features, they are not small adults.

3 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 Mean values of P ka for different procedures Type of examination P ka 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 A PILOT PROGRAMME ON PATIENT DOSIMETRY ON PAEDIATRIC INTERVENTIONAL CARDIOLOGY IN CHILE

5 2. Children have especially radiosensitive tissues

6 Estocastic (Probabilistic) Deterministic efect Efect Rx Cancer and Genetic efects Probability dosis Cataratas Esterility Eritema Epilation Fetal Malformations Dosis

7 3. Their have longer life span makes the stochastic effect manifest 674 childrens undergoing cardiac catheterization due to congenital heart desease between The expected number of cancer was 4.75, but the real number was 11.0

8 Estocastic (Probabilistic) Deterministic efect Efect Rx Cancer and genetic efects Probability dosis Cataratas Esterility Eritema Epilation Fetal Malformations Dosis

9 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 por Sievert (Sv) 0,16 0,12 0,08 Female Male 0,04 0, Edad de exposicion

10 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 kkerma area product KAP (cgycm^ kerma area product v/s body weight y = 78,531e 0,4495x R² = 0,8974, R=0,9473 < > 40 Weight (kg) A PILOT PROGRAMME ON PATIENT DOSIMETRY ON PAEDIATRIC INTERVENTIONAL CARDIOLOGY IN CHILE

11 Kerma area product per minute fluoroscopy versus body weight 25 FLUOROSCOPY kerma area product / time fluoroscopy (cgycm^2min y = e x R 2 = < > 40 Weight (kg) Kerma area product per cine frame versus body weight kerma area product / fram e (cgycm ^2) CINE ACQUISITION y = e x R 2 = < > 40 Weight (kg) A PILOT PROGRAMME ON PATIENT DOSIMETRY ON PAEDIATRIC INTERVENTIONAL CARDIOLOGY IN CHILE

12 A PILOT PROGRAMME ON PATIENT DOSIMETRY ON PAEDIATRIC INTERVENTIONAL CARDIOLOGY IN CHILE

13 HDO Biplane A 11Nov04 paediatric microgy/frame Cine 25 cm Cine 20 cm Cine 16 cm cm PMMA

14 RADIATION DOSE AND IMAGE QUALITY FOR PAEDIATRIC ITERVENTIONAL CARDIOLOGY E. Vañó. C. Ubeda. F Leyton and P. Miranda Published 8 july 2008

15 PART 2 Paediatric Interventional Cardiology (PIC) has a challenge How to reduce the doses in PIC? 1. Formation in RP

16 Support Programs of the IAEA Regional Workshops in Chile 2006 and Costa Rica Attending cardiologist from all Latinamerica. Several works at the workshop to evaluate patient dose in interventional Cardiology in Latin America.

17 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 Biplane Siemens Flat panel Biplane Siemens with image itensifiers

19 Dose rate reaching the patient is meassured or calculated (usually expresed in mgy/min)

20 Flat Panel sistem Dose rate reaching the metacrilatpatient is meassured or calculated (usually expressed in mgy/min)

21 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 RADIATION DOSE AND IMAGE QUALITY FOR PAEDIATRIC ITERVENTIONAL CARDIOLOGY E. Vañó. C. Ubeda. F Leyton and P. Miranda Published 8 july 2008

23 RADIATION DOSE AND IMAGE QUALITY FOR PAEDIATRIC ITERVENTIONAL CARDIOLOGY E. Vañó. C. Ubeda. F Leyton and P. Miranda Published 8 july 2008

24 50 Scatter dose rate (msv/h) low med high cine PMMA thickness (cm)

25 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 HDO Biplane A 11Nov04 paediatric mgy/min Fluoro low 25 cm Fluoro med 25 cm Fluoro high 25 cm cm PMMA

27 HDO Biplane A 11Nov04 paediatric vs adult Fluoro low 25 cm mgy/min Fluoro med 25 cm Fluoro high 25 cm Fluoro low adult Fluoro med 25 cm adult Fluoro high 25 cm adult cm PMMA

28 CD-1 1 fluoro

29 CD-1 4 cine

30 Comparison between median KAP (Gy.cm 2 ) for paediatric cardiology procedures reported by different authors (figures adapted by the authors of this paper). Age bands (years) Boothroy d et al. [10] (1997) Rassow et al. [11] (2000) (Gycm²) Bacher et al. [12] (2005) (Gycm² ) Martinez et al. [7] (2007) (Gycm²) *This paper (2008) (Gycm²) < < < < *A PILOT PROGRAMME ON PATIENT DOSIMETRY ON PAEDIATRIC INTERVENTIONAL CARDIOLOGY IN CHILE

31 Pediatric interventional cardiologyst dose HDO Biplane A 11Nov04 paediatric 6 5 msv/h Fluoro low 20 cm Fluoro med 20 cm Fluoro high 20 cm cine 30f/s 20 cm cm PMMA

32 Different C-arm angulations can modify the disperse dose in a 5 factor

33 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 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 Efficacy and Radiation Safety in Interventional Radiology. WHO Geneva. Suggested action levels in staff exposure in interventional radiology (Joint WHO/IRH/CE workshop 1995) SUGGESTED ACTION LEVELS FOR STAFF DOSE Body Eyes Hands/Extremities 0.5 msv/month 5.0 msv/month 15.0 msv/month

35 Radiation protection measures Image intensifier Patient Lens dose, optional Finger dose, optional Second dosemeter outside and above the apron at the neck, optional 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 tube Anual equivalent dose in the lens of the eye 150 msv skin 500 msv hands and feet 500 msv

36 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 mm lead. Tactile gloves, typically equivalent to 0.03 mm lead. Typical reduction > 15-55%.

37 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 Avoid more than 90% of the scatter radiation THYROID PROTECTOR

39 Sometimes, hands in the direct beam!!

40 Vañó et al. Br J Radiol 1998; 71: Mean values (µsv) per procedure (using protection tools) Interventional radiologist Interventional cardiologist

41 Give me a break!!!