1. Staff And Patient Radiation Protection
Andrés Sinisterra
Assistant Radiation Safety Officer for Medicine

2. Safety - Suave…....
You are in the driver’s seat, so make it safe….!!!

4. Medical Radiation Doses in the US
Have increased ~ 6 times in past quarter century
Increase use of computed tomography (e.g.: multidetector spiral CT)
Increased Nuclear Medicine procedures
More interventional procedures

6. A wave is a wave & nothing but a wave!

7. Radiation vs. Radioactivity
Energy in transit in the form of high speed particles and electromagnetic waves.
Ionizing Radiation
Radiation with enough energy so that during an interaction with an atom, it can remove tightly bound electrons from their orbits, causing the atom to become charged or ionized.
Radioactivity
Spontaneous transformation of an unstable atom and often results in the emission of radiation. This process is referred to as a transformation, a decay or a disintegration of an atom.

8. External vs. Internal Radiation Exposure
External Exposure – X-rays, Diagnostic Procedures.
Internal Deposition – Contamination from nuclear medicine patient undergoing a diagnostic or therapeutic procedure resulting in an ingestion of radioactive materials by the staff. + =
T E D E

9. Units of Radiation Exposure
Roentgen
Measure of electrical charge produced in air
1,000 mr = 1R
SSD ~3-10 R/min
Measure of energy absorbed, usually in tissue or bone.
200 rad = transient erythema
1 Gray = 100 Rad
Rad (Gray)

10. Units of Radiation Exposure
Rem (Sievert)
Measure of occupational risk (cancer) from radiation exposure
1,000 mrem = 1 Rem
1 Sievert = 100 Rem
5 Rem/yr maximum limit
1 R = 1 Rad = 1 Rem

13. Image Quality Vs Exposure

14. Area of Interest Collimation
Calcification of the vas deferens.
These bilateral asymmetric calcifications occur in the lower to middle portion of the male pelvis

15. A Question of Judgment…?

17. INCIDENT X-RAY
PHOTOELECTRON
Photoelectric effect occurs when an incident x-ray is totally absorbed during the ionization of the inner-shell electron. The incident photon disappears and the k-shell electron, now called a photoelectron, is ejected from the atom.

21. Primary Beam
Scatter Radiation
Leakage Radiation
X-Ray Tube

22. Know Where Your Head Is At……!!!
Caudal

23. Coronal

25. Maximum Scatter plus Leakage
Minimum Scatter

26. Be aware of critically exposed areas
Head
and shoulders
knees
and toes !!!!!

27. The greater the distance the greater the scatter

28. Know Where Your Head Is At……!!!
The greater the distance the greater the scatter

29. Under Normal mode, there is little magnification with the whole beam used to generate a bright image.
Under Mag 1 mode, a smaller beam area is projected to the same II output.  The resulting object size is larger, but the image is dimmer due to the less beam input.
The ABC system would sense the brightness loss and either boost machine X-ray output, increase tube voltage, or a combination of both.

30. Mag Mode (Field-Of-View)
The following Table illustrates the effect of changing Field-Of-View, or magnification modes, for a typical fluoroscopy system
Mag Mode (Field-Of-View)
ESE (R/min)
Increase Factor
Normal (9 inch)
1.2
1.0
Mag 1 (6 inch)
2.9
2.4
Mag 2 (4.5 inch)
5.2
4.3

31. Inverse Square Law (X-Rays & Gamma Rays)
For a point source, the intensity varies inversely as the square of the distance from the source.
Scattered X-rays
X-Ray Tube
1 cm
10,000
2 cm
2,500
5 cm
400
10 cm
100
20 cm 25
Leakage Radiation

32. Control Booth = Background6 5 4 3 7
15 1 m from edge 8 2
m from edge
m from edge
Control Booth = Background

33. Basic Radiation Safety Principles
Time
Distance
Shielding
Contamination Control

34. Radiation Exposure Monitoring
Whole Body Radiation Badge
Worn Underneath Pb Apron
Collar Radiation Badge
Worn Outside Pb Apron At Neck Level
BLACK ICON
RED ICON
Extremity Radiation Badge
Worn on Primary Hand
Closest to Radiation Source

35. Collar Radiation Badge Whole Body Radiation Badge
Worn
Outside
Pb Apron At Neck Level
Whole Body Radiation Badge
Worn
Underneath
Pb Apron

36. Get The Lead Out but Watch Your Back !!
PROTECTIVE EQUIPMENT
Get The Lead Out but Watch Your Back !!

37. ALARA Investigational Level I

38. Reducing Patient Dose During Fluoroscopy (And Yours)
Get off the pedal!! – Fluoro intermittently
Collimate and only expose clinical area
Use larger fields when possible
(Magnification increases patient dose)
Use distance of at least 30 cm for mobile units and 38 cm for fixed installations
Use appropriate mA and KVp

39. Reducing Patient Dose During Fluoroscopy (And Yours)
Remember the egg timer!!!
Be aware of the 5 minute timer (especially in high level mode)
Have sufficient beam filtration
> 90 KVp requires 2.5 mm Al to 3.5 mm 130 KVp
Fluoro only when necessary
Schedule annual QA of equipment

40. As Low Reasonably Achievable ALARA Level I
> 10% of the maximum quarterly exposure limit (125 mrem) As
Low
Reasonably
Achievable
ALARA Level II
> 30% of the maximum quarterly exposure limit (375 mrem)

41. Dose
The amount of energy deposited in any substance by ionizing radiation per unit mass of the substance. It is expressed numerically in rads (traditional units) or grays (SI units).
Absorbed Dose
Dose Equivalent
Deep Dose Equivalent
Eye Dose Equivalent
Shallow Dose Equivalent
Effective Dose Equivalent
Committed Dose Equivalent
Total Effective Dose Equivalent

42. Absorbed Dose - The amount of energy deposited in any substance by ionizing radiation per unit mass of the substance. It is expressed numerically in rads (traditional units) or grays (SI units).
Dose Equivalent - The dose equivalent (H) is the product of the absorbed dose in tissue, the quality factor and all other modifying factors at the location of interest. The unit is the rem (R) or the sievert (Sv).

43. Deep Dose Equivalent (Hd) - Applies to external whole body exposure, means the dose equivalent at a tissue depth of 1 cm or greater.
Eye Dose Equivalent - The external dose equivalent to the lens of the eye at a tissue depth of 0.3 cm.
Shallow Dose Equivalent (Hg) - Applies to the external exposure of the skin or extremity. The dose equivalent at a tissue depth of cm averaged over an area of 1 cm2.

44. Committed Dose Equivalent (HE
Committed Dose Equivalent (HE.50) - The dose equivalent (H) is a given organ or tissue that will be accumulated over 50 years following a single intake of radioactive material.
Effective Dose Equivalent (HE) - The sum of the products of the dose equivalent (HT) to each organ or tissue and the weighting factor (WT) applicable to each of the body organs or tissues that are irradiated (HE = ‡” WTHT).
Total Effective Dose Equivalent - The sum of the deep dose equivalent for external exposures and the committed effective dose equivalent for internal exposures.

45. Biological Effects of Ionizing Radiation Exposure
Cancer (Stochastic Effects, Carcinogenic)
The Radiologist
The Patient
The Fetus
Acute Somatic Effects (Non-Stochastic)
The Radiologist
The Patient
The Fetus ( Teratogenic Effects)
Mutagenic Effects

46. Radiation Exposure Limits
(State of Connecticut Administrative Regulations Sect )
Type of Exposure
Rem Per Calendar Quarter
Whole body; head and trunk; active blood-forming organs; lens of eyes, or gonads.
Hands and forearms; feet and ankles.
Skin of whole body.
1.25
18.75
7.5
(1,250 mrem)
(5.0 rem/yr)
(18,750 mrem)
(75 rem/yr)
(7,500 mrem)
(30 rem/yr)
Fetus
500 mrem Total Gestation
(0.5 rem)

47. Conditions For Exceeding Quarterly Doses To Whole Body
Total Dose For Any Quarter
< 3.0 rem
Total Whole Body Dose
<= 5 (N-18) rem
All Previous Whole Body Doses
Plus
N = Your Age In Years
Prior Dose Must Be On a Clear Record
! ! ! ! ALARA PROGRAM EXISTS ! ! ! !

48. Confidential Declaration of Pregnancy
NRC requires a signed declaration of pregnancy for occupational workers to limit exposures to 500 mrem/9months or 50 mrem in any one month.

49. Are we at risk of danger?

50. Background
Equivalent
Radiation
Time

51. (Adapted From Ipsm Report 53) 5
Typical Effective Doses And Bert Values For Some Common X-Ray Studies To An Adult
(Adapted From Ipsm Report 53) 5
2 years 6
Lower GI series
1.5 years
4.5
Upper GI series
1 year 3
Lumbar spine
6 months
1.5
Thoracic spine
10 days
0.08
Chest x-ray
1 week
0.06
Dental, intra-oral
BERT (time to get same dose from nature)
Effective Dose (mSv)
X-ray Study

52. Other Effective Doses And Bert Values
2 years 6
Lower GI series
1.5 years
4.5
Upper GI series
1 year 3
Lumbar spine
6 months
1.5
Thoracic spine
10 days
0.08
Chest x-ray
1 week
0.06
Dental, intra-oral
BERT (time to get same dose from nature)
Effective Dose (mSv)
X-ray Study

53. Radiation Exposures From ?
Smoking a pack and a half of cigarettes a day will add about 1,300 mrem/year to one's effective dose
Flying from New York to London results in the absorption of an extra
2-3 mrem of cosmic radiation
6-8 mrem from NY to Japan

54. 1,980 mrad to 6,300 mrad for 180 day mission
International Space Station ?
.11 mrad/d to .35 mrad/day
1,980 mrad to 6,300 mrad for 180 day mission

55. Radiation Exposures from Consumer Products 1
1 Adapted from NCRP 95

56. Radiation Exposures from Consumer Products1
1 Adapted from NCRP 95
2 BEDE = Bronchial Epithelial Dose Equivalent; WB = Whole Body; IDF = Ingestion Dose from Foods
BMDE = Bronchial Mucosa Dose Equivalent; CGDE = Corneal Germinal Dose Equivalent; SODE = Selected Organ Dose Equivalent

57. Risks which Increase Chance of Death by 1 in 1 million a
a B.L. Cohen and I.S. Lee, ”Catalog of Risks Extended and Updated”, Health Physics, Vol. 61, Sept

58. More Risks which Increase Chance of Death by 1 in 1 million a
a B.L. Cohen and I.S. Lee, “Catalog of Risks Extended and Updated”, Health Physics, Vol. 61, Sept

59. Estimated Loss of Life Expectancy from Health Risks
Health Risk Average Days of Life Expectancy Lost
Smoking 20 cigarettes/day (6.5 years)
Overweight (by 20%) (2.7 years)
All accidents combined (1.2 years)
Auto accidents
Alcohol consumption
Home accidents
Drowning
Natural background radiation 8
Medical diagnostic x-rays 6
All catastrophes (fire, flood, etc.) 3.5
1,000 mrem (1 rem) occupational radiation dose 1
1,000 mrem (1 rem)/yr for 30 years 30
Note: Average U.S. occupational radiation dose is estimated at rem/year.

60. PROGRAM FOR IMPLEMENTING PATIENT INFORMED CONSENT
AND
FOLLOW UP REGARDING HIGH DOSE SPECIAL
X-RAY PROCEDURES

61. Purpose:
There are certain x-ray guided procedures that could result in the delivery of a radiation dose to an area of a patient’s skin of sufficient magnitude to produce clinical symptoms.
This program was developed to inform patients of this potential risk prior to such procedures, determine if a procedure may lead to a large skin dose and to follow up with the patient if there is a possibility of a skin reaction.

62. Policy:
This program is applicable to personnel involved with the following x-ray guided procedures:
Percutaneous Transluminal Angioplasty
Radiofrequency Cardiac Catheter Ablation
Vascular Embolization
Stent and Filter Placement
Thrombolytic & Fibrinolytic Procedures
Percutaneous Transhepatic Cholangiography and/or Biliary Drainage

63. Policy (continued): Endoscopic Retrograde Cholangiopancreatography
Transjugular Intrahepatic Portosystemic Shunt
Percutaneous Nephrostomy
Urinary/Biliary Stone Removal Or
Any other x-ray guided procedure that could
expose the same area of the skin for more
than 30 minutes

64. Policy (continued):
For such cases, the patient must be informed in writing prior to the procedure of the risks associated with large x-ray skin doses.
Appropriate follow up must be made, if after completion of a procedure, a large skin dose is possible.

65. 1. Document the total x-ray “ON” time, not the duration of the procedure
2. For procedures with total x-ray “ON” time exceeding 30 minutes, determine what body area may have been exposed for the greatest duration and ESTIMATE the maximum fraction of the total “ON” time this occurred.
3. If the total x-ray “ON” time exceeded 30 minutes and the same area of the skin was irradiated for 30 minutes or longer, notify the Radiation Safety Office (2250).

66. 4. The Radiation Safety Officer (or delegate) will estimate the maximum skin dose for the procedure.
5. The Radiation Safety Officer will provide a report to the interventionalist indicating the maximum estimated skin dose.
6. The interventionalist, upon receiving the RSO’s report, shall notify the patient or the patient’s referring physician if the possibility of a skin reaction exists.
7. The referring physician and/or interventionalist will provide treatment instructions to the patient as is medically necessary.

67. Prior to a procedure, the patient should be asked about previous fluoroscopic interventions.
Connective tissue diseases (e.g. scleroderma, lupus erythematosus, mixed connective tissue disease), diabetes mellitus, hyperthyroidism and the homozygous form of ataxia telangiectasia have been associated with an increased sensitivity to radiation [9].  Some chemotherapy agents are also known to increase radiation effects.  The history should include these risk factors. The patient should be advised about the potential higher risk .
To avoid injuries when using an oblique or lateral beam projection, the patient's arm must be secured away from the primary beam.  Direct exposure of the female breast, especially entrance-beam exposure, must also be avoided.

69. Radiation Biology

70. Radiosensitivity of Cells 1
As cells mature they become less sensitive to radiation
As metabolic rate increases cells become more sensitive to radiation
As reproductive rate increases cells become more sensitive to radiation
Cell types that are most sensitive to radiation include lymphocytes and stem cells
Cell types that are least sensitive to radiation include muscle and ganglion cells
1 Adapted from The 1906 Law of Bergonie and Tribondeau

71. Various degrees of sensitivity to radiation exist due to the type of tissue which receives the exposure
Radiosensitive
Radioresistant
Breast tissue
Heart tissue
Bone marrow cells
Large arteries
Mucosa lining of small intestines
Large veins
Sebaceous (fat) glands of skin
Mature blood cells
Immune response cells
Neurons
All stem cell populations
Muscle cells
Lymphocytes

72. Radiation Induced Skin Injuries
TABLE 1.
REPORTS RECEIVED BY FDA OF SKIN INJURY FROM FLUOROSCOPY
Type of Procedure with Injury Report
Number of Injuries
RF Cardiac Ablation 13
Catheter Placement for Chemotherapy 1
Transjugular Intrahepatic Portosystemic Shunt (TIPS) 3
Coronary Angioplasty 4
Renal Angioplasty 2
Multiple Hepatic/Biliary Procedures
Percutaneous Cholangiogram with Multiple Embolizations
* Food and Drug Administration, USA, Internet Site.

73. Radiation Induced Skin Injuries
TABLE 2.
EXAMPLES OF SKIN INJURIES FROM FLUOROSCOPY *
Patient
Sex
Age
Procedure
Injury A
Male 40
Coronary angiography & PTCA, followed by 2nd coronary angiography
Skin necrosis requiring 12x10 cm skin graft B
Female
nag
RF catheter ablation
Second degree burn (7.5x12.5 cm) C 25
Skin breakdown 3 weeks post procedure D 34
Draining skin lesions on back 3 weeks after procedure E 62
Balloon ablation bile duct
Burn-like injury on back
Anastomosis requiring a skin graft F 61
Renal angioplasty
Skin necrosis requiring graft
* Food and Drug Administration, USA, Internet Site.

74. Radiation Induced Skin Injuries
TIME TO THRESHOLD
EFFECT
THRESHHOLD DOSE, Rad
NORMAL R/MIN
HIGH R/MIN
TIME TO ONSET
Early Transient Erythema
200
0.7 hr
0.17 hr
Hours
Temporary Epilation
300
1.0 hr
0.25 hr
3 Weeks
Main Erythema
600
2.0 hr
0.50 hr
10 Days
Permanent Epilation
700
2.3 hr
0.58 hr
Dry Desquamation
1,000
3.3 hr
0.83 hr
4 Weeks
Moist Desquamation
1,500
5.0 hr
1.25 hr
Late Erythema
6 – 10 Weeks
Dermal Necrosis
1,800
6.0 hr
1.50 hr
> 10 Weeks

75. Radiation Induced Skin Injuries
TIME TO THRESHOLD
EFFECT
THRESHHOLD DOSE (Gy)
NORMAL R/MIN
HIGH R/MIN
TIME TO ONSET
Early Transient Erythema
200
0.7 hr
0.17 hr
Hours
Temporary Epilation
300
1.0 hr
0.25 hr
3 Weeks
Main Erythema
600
2.0 hr
0.50 hr
10 Days
Permanent Epilation
700
2.3 hr
0.58 hr
Dry Desquamation
1,000
3.3 hr
0.83 hr
4 Weeks
Moist Desquamation
1,500
5.0 hr
1.25 hr
Late Erythema
6 – 10 Weeks
Dermal Necrosis
1,800
6.0 hr
1.50 hr
> 10 Weeks

76. Free Radical Production from Irradiated Water
H2O H2O e -
H2O H OH
H2O + e H2O -
H2O H + OH -
OH + OH H2O2

77. Stochastic Effects (by chance)
Health effects that occur randomly. Effects that occur by chance, generally occurring without a threshold level of dose, whose probability is proportional to the dose and whose severity is independent of the dose. .
(examples: cancer incidence and genetic effects)

78. Stochastic Effects (by chance)
1,000,000 persons buy a lottery ticket for $1,00 each.
999,999 persons will not get the large prize. Only one will win the BIG ONE.
Return on scratch tickets is not certain.

79. Nonstochastic (Deterministic) Effects
Health effects that can be induced upon reaching an apparent threshold, and their severity varies with the radiation dose.
examples:
cataract in the lens of the eye, non- malignant damage to the skin

80. Nonstochastic (Deterministic) Effects
100 persons invest $1,000 at 5% interest
Each person will receive $1,050.00
Return is certain

81. So....., how really dangerous is this so called “RADIATION??”

82. Industrial Radiation Accident

83. An example of a skin injury attributable to x-rays from fluoroscopy is shown in Figure 2.
This case, patient A in Table 2, is that of a 40-year-old male who underwent coronary angiography, coronary angioplasty and a second angiography procedure due to complications, followed by a coronary artery by-pass graft, all on March 29, 1990.
Source:
Thomas B. Shope, Ph.D. (HFZ-140) FDA/Center for Devices and Radiological Health

84. Figure 2(a).
Condition of patient's back six to eight weeks following multiple coronary angiography and angioplasty procedures
Source:
Thomas B. Shope, Ph.D. (HFZ-140) FDA/Center for Devices and Radiological Health

85. Figure 2(b).
Appearance of skin injury approximately 16 to 21 weeks following the procedures with small ulcerated area present.
Source:
Thomas B. Shope, Ph.D. (HFZ-140) FDA/Center for Devices and Radiological Health

86. Figure 2(c).
Appearance of skin injury approximately 18 to 21 months following procedures, evidencing tissue necrosis.
Source:
Thomas B. Shope, Ph.D. (HFZ-140) FDA/Center for Devices and Radiological Health

87. Close-up view of lesion shown in 2(c).
Figure 2(d).
Close-up view of lesion shown in 2(c).
Source:
Thomas B. Shope, Ph.D. (HFZ-140) FDA/Center for Devices and Radiological Health

88. Appearance of patient's back following skin grafting procedure.
Figure 2(e).
Appearance of patient's back following skin grafting procedure.
Source:
Thomas B. Shope, Ph.D. (HFZ-140) FDA/Center for Devices and Radiological Health

89. Transjugular Intrahepatic Portosystemic Shunt
6 month
23 month
10 month
22 month
This patient received 3 TIPS procedures within a week
7.5 month
Source:
Koening, Wagner, et al., University of Texas Health Science Center

90. Radiofrequency Cardiac Catheter Ablation
Tissue necrosis 5 months after procedure, and deep ulceration with exposure of the humerus at 6.5 months
Source:
Koening, Wagner, et al., University of Texas Health Science Center

91. Following Proper Protection Procedures Minimizes Unnecessary Exposures
Remember ....!!!
Following Proper Protection Procedures
Minimizes Unnecessary Exposures

92. The End