Diagnosis ,Treatment and Medical Effects of Radiation Contamination Albert L. Wiley,MD,PhD,USNR(RET) Dir., REAC/TS and WHO REMPAN Ctr.,Oak Ridge - PowerPoint PPT Presentation

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Diagnosis ,Treatment and Medical Effects of Radiation Contamination Albert L. Wiley,MD,PhD,USNR(RET) Dir., REAC/TS and WHO REMPAN Ctr.,Oak Ridge

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Title: Diagnosis ,Treatment and Medical Effects of Radiation Contamination Albert L. Wiley,MD,PhD,USNR(RET) Dir., REAC/TS and WHO REMPAN Ctr.,Oak Ridge


1
Diagnosis ,Treatment and Medical Effects of
Radiation ContaminationAlbert L.
Wiley,MD,PhD,USNR(RET)Dir., REAC/TS and WHO
REMPAN Ctr.,Oak Ridge
Oak Ridge Regional Emergency Management
Forum Emergency Management-Preparing the
Community October18,2007
2
OBJECTIVES
  • Discuss external contamination and the bodys
    mechanisms for the internalization of
    radionuclides.
  • Discuss the procedures for diagnosis ,treatment
    and effects of internal contamination with
    radionuclides.

3
External Contamination
  • Most contamination will be on clothes. At least
    outer clothing should be removed before transport
    of patient to hospital (to minimize spread of
    contamination to ambulance and ED).
  • Send victims identification (in plastic baggie)
    to the ED with the victim.
  • As much as possible, leave contaminated materials
    (including the clothes that were removed) at the
    incident scene.

4
Patient Arrival
  • Determine priorities
  • Is patient stable?
  • Manage life threatening problems first.
  • Is patient contaminated?
  • Remove patients clothing, blankets, sheets.
  • Place in plastic bag.
  • Change gloves.

5
Collect Samples from
  • Nose
  • Mouth
  • Wounds
  • Also Baseline urine, then 24-hour samples of
    urine and feces

6
V. Decontamination
  • Determine priorities
  • Consider
  • Medical needs of patient
  • Chemical nature of contaminant
  • Seriousness and extent of contamination
  • Presence of wounds
  • Key Issues
  • Clothing removal if not accomplished
  • Radiological survey documentation
  • Collection of samples specimens
  • Prioritize decon effort
  • open wounds
  • body orifices
  • intact skin
  • Type of decon procedure documentation
  • Radiological reassessment documentation

7
Decontamination Intact Skin
  • 1. Wash with water.
  • 2. Use the mechanical action of flushing and/or
    friction of cloth, sponge or soft brush.
  • 3. Begin with the least aggressive techniques and
    the mildest agents.
  • 4. For showering, begin with the head and proceed
    to the feet.
  • 5. Keep materials out of eyes, nose, mouth and
    wounds. Use waterproof draping to limit spread.
  • 6. Avoid causing mechanical, chemical or thermal
    damage to skin.
  • Helpful hints
  • Drape clean areas.
  • Wipe toward center
  • Blot to dry.
  • Provide privacy for patient.
  • Remember GRAVITY.

8
Whole-body Absorption Fractions of 58CoCl2
through mechanically wounded and damaged skin
9
DOE Summary of Dose Limits for Radiation
Workers
  • Whole Body (int ext) - 5 rem/yr
  • occupational exposure
  • Lens of Eye -15 rem
  • Extremities - 50 rem
  • Organ, tissue, skin - 50 rem
  • Declared pregnant - 0.5 rem
  • gestational period
  • Minors under 18 yrs - 0.1 rem
  • General public - 0.1 rem

10
Internal Contamination Defined
  • The presence of radioactive material inside the
    body.
  • Excludes normal background levels of
    radioactivity in the body
  • Usually considered of medical urgency, but seldom
    acutely life-threatening (stochastic risk is the
    usual dominant risk, although deterministic risk
    can occur and even be lethal ,as in recent
    Polonium 210 incident in UK.)
  • Treatment can be effective, but is ELEMENT
    specific (so,need early isotope identification)

11
Common Routes of Entry
  • Inhalation (usually most important)
  • Ingestion
  • Injection (wound)
  • Absorption through intact or abraded skin
  • Intact skin is an effective barrier against
    almost all radionuclides
  • burned skin may be more permeable to
    radionuclides than intact skin

12
There is inhalation risk from a variety of
incidents causing a radionuclide plume.
13
Estimate of total cancer risks for a population
(European Union/US) exposed to high dose/dose
rate Low-LET radiation -- Risks/100
persons/Sv (data abstracted from Table 38 UNSCEAR
2000)
e
Elicited Risk 1 10
BEIR V 2 8
ICRP 60 12
UNSCEAR 1994 12
UNSCEAR 20003 9
1Elicited estimate from poll of experts 2A-Bomb
follow-up through 1985 3A-Bomb follow-up through
1990 (for low dose/dose rate exposures, risk is
lower by 1/2)
14
ICRP 26 Dose Limits(1977--1985)
  • Three principles of radiation protection
  • justification, limitation, optimization
  • Recommended Limits
  • stochastic effects 50 mSv (5 rem) per year
  • non-stochastic effects 500 mSv (50 rem) per
    year, but 150 mSv to eye lens (3 mm)
  • declared pregnant woman 5 mSv
  • Also recommended Q 20 for neutrons

15
Internal dosimetry necessary for medical
management
  • Disciplines
  • Physics
  • Chemistry
  • Mathematics
  • Anatomy
  • Physiology
  • Radiobiology
  • Industrial Hygiene

16
Annual Limit on Intake (ALI)Used to Acess Risk--
and ? Decision for Start/Stop Treatment
  • Defined as the dose limit divided by the dose
    conversion factor
  • Dose limit may be either stochastic (SALI) or
    non-stochastic (NALI)
  • Different ALIs for inhalation and ingestion
  • Only one significant figure
  • Example Cs-137
  • 0.05 Sv/8.6 x 10-9 Sv/Bq 6 x 108 Bq

17
Some ALIs of Interest in Microcuries
  • Radionuclide ALI (inhalation) ALI (ingestion)
  • H-3 80,000 80,000
  • P-32 400 600
  • Co-60 30 200
  • Sr-90 4 400
  • Cs-137 200 100
  • Ra-226 0.6 2
  • U-238 0.8 200
  • Pu-239 0.006 0.8

18
Methods for Assessing Intakes
  • Whole Body Counting
  • Feasible for nuclides that emit penetrating x or
    gamma rays.
  • Useful also for nuclides emitting energetic beta
    particles - can be detected by their
    bremsstrahlung radiation.
  • Bioassay
  • Urine - most widely used.
  • Feces.
  • Excised material from wounds.
  • Chromosome aberration analysis.

19
Immediate Diagnosis/Emergency Intake Estimates
  • Nasal Swabs
  • Facial surveys
  • Sputum
  • Spot urine (Sometimes useful,ie,Cs)
  • ? Deployable lung counters
  • When all else fails - get a good history!

20
Bioassay Is Necessary for Diagnosis/Monitoring,bu
t Has Limitations
  • 1. Slow
  • 2. Usually need collections of both urine and
    feces
  • 3. May overestimate uptakes
  • 4. Expensive

21
Methods for Assessing Intakes
  • Whole Body or Lung Counting
  • Feasible for nuclides that emit penetrating x or
    gamma rays.
  • Useful also for nuclides emitting energetic beta
    particles - can be detected by their
    bremsstrahlung radiation.
  • Bioassay
  • 24 hr Urine collections - most widely
    used(liquid scintillation and spectroscopy)
  • 24 hr Feces collections
  • Excised material from wounds.
  • Cytogenetic Biodosimetry

22
Lung Counting with Phoswich Detector Used to
Dx/Monitor IC
23
Inhalation Pathway(Importance of Particle Size
and Chemical Form)
  • Particle size of the aerosol particles determine
    region of the respiratory tract where most are
    deposited.
  • Fate of inhaled particles is dependent on their
    physico-chemical properties.
  • Highly insoluble particles remain in the lung for
    longer periods of time than soluble compounds.
  • A small fraction will be transported to the
    tracheo-bronchial lymph nodes by pulmonary
    macrophages.
  • Some are cleared through the airways, swallowed,
    and excreted in the feces.

24
Particle Size Distribution in the Respiratory Tree
Particle Size (Micron, Mass Median Diameter)
18-20 15-18 7-12 4-6 (bronchioles) 1-5
(alveoli)
25
Clearance Time - Nasopharynx
  • Time to Swallowing
  • Anterior Nares 60 min.
  • Nasopharynx 10 min.
  • (10 mm/min)

26
Clearance Time of Respiratory Tract
  • Hours
  • Trachea .1
  • Bronchi 1.0
  • Bronchioles 4.0
  • Terminal Bronchioles 10.0
  • Alveoli 100.0 Days

27
Uptake of Actinides(Pu,Am,Cf,etc) May Be
Remarkably Rapid
100
80
Percent Deposited
Bone Deposition
60
40
20
0
0
1
2
Time (Hours)
28
Dose Inhalation Pu-239
  • Type S material
  • Lung highly irradiated organ
  • Effective dose reflects lung dose
  • Dose rate for systemic tissues increase to broad
    maximum value at about 6000 d

29
Pu-239 Inhalation
  • Integrated dose rate as a function of time
  • Integral converged for lung and effective dose
  • Bone surface and liver integral not converged

30
Saturate the Critical Organ with the Stable
Isotope
131I
131I
I
THYROID
131I
131I
31
Prompt KI Treatment of 131I Intake is Highly
Effective
0
Thyroid Uptake,
15
30
6
12
18
24
Time of administration post-exposure, hours
32
Health EffectChildhood Thyroid Cancer near
Chernobyl from I-131
  • In Gomel region of Belarus, north of Chernobyl,
    children were screened for thyroid cancer by
    physical examination, ultrasound imaging of the
    thyroid, and by thyroid function tests.
  • Prior to the accident, thyroid cancer rate
    0.5/million. In the period 1991-1994, rate
    96.4/million. This represents almost a 200-fold
    increase.
  • Reference BMJ, vol 310, p 801, March 25, 1995.

33
FDA Recommendations for Potassium Iodide
  • A daily dose of
  • 16 mg of KI for infants lt1 month
  • 32 mg of KI for children 1 month to 3 years
  • 65 mg of KI for children and teenagers 3 years to
    18 years
  • 130 mg of KI for adults including pregnant and
    lactating women and adolescents over 150 pounds
  • Daily dosing should continue until the risk of
    exposure has passed and/or until other measures
    (evacuation, sheltering, control of the food and
    milk supply) have been successfully implemented

34
Clearance Time of Gastrointestinal Tract
  • Occupancy Time
  • (Hours)
  • Stomach 6
  • Small Intestine 14
  • Upper Large Intestine 18
  • Lower Large Intestine 22

35
Absorption of Ingested Radionuclides
  • GROUP RADIOACTIVE ABSORBED
  • ELEMENTS OF
  • Alkali Metals Na, K, High 90
  • Rb, Cs
  • Group VIII Fe 10
  • Metals Co 30-90
  • Ru 3

36
Absorption of Ingested Radionuclides
  • GROUP ELEMENTS ABSORBED
  • Lanthanides Ce, Pm, lt0.1
  • Eu, Tb
  • Actinides Th, U, lt0.1
  • Np, Pu

37
Reduction of Absorption From Gastrointestinal
Tract
  • 1. Antacid
  • 2. Precipitation into insoluble salt
  • 3. Catharsis

38
Medical Countermeasures Are Generally Element
Specific
Nuclide Medication Comments
Am-241 Ca and Zn DTPA by IV, aerosol,?IM Clelation,Works on liver even after long deposition
Cf-252 Ca and Zn DTPA
Cs-137 Prussian Blue Binds Cs,hepato-enteric cycle
Co-60 penicillamine Gastric lavage,?DTPA
Fission Products Depends on mixture Spectroscopic identificationnuclides isotope,specific RX
H-3 Forced H2O Isotopic dilution
I-131 KI or SSKI Give in first 1-6 hours
P-32 Phosphates Isotopic dilution
Pu-239 Ca and Zn DTPA EDTA less effective
Sr-89/90 Sr,Ca gluconate,iv Consider alginates
39
Isotopically Dilute
BEER
Men
TRITIUM
40
Displace
  • USE CALCIUM TO COMPETE WITH RADIOSTRONTIUM
  • USE STABLE IODIDE TO COMPETE WITH RADIOTECHNETIUM

41
Uranium
  • Chemical toxicity to kidney is usually the main
    issue. Radiotoxicity is significant only with
    enriched U-235.
  • TREATMENT
  • Sodium bicarbonate to alkalinize urine
  • Oral dosageAdults Initially, 4 g PO then 1-2 g
    every 4 hours. Titrate dosage based on urinary
    pH.Children 1-10 mEq/kg/day (84-840 mg/kg/day)
    PO, given in divided doses every 4-6 hours.
    Titrate dosage based on urinary pH.
  • May need renal dialysis until renal recovery from
    injury.

42
V. Decontamination
  • Determine priorities
  • Consider
  • Medical needs of patient
  • Chemical nature of contaminant
  • Seriousness and extent of contamination
  • Presence of wounds
  • Key Issues
  • Clothing removal if not accomplished
  • Radiological survey documentation
  • Collection of samples specimens
  • Prioritize decon effort
  • open wounds
  • body orifices
  • intact skin
  • Type of decon procedure documentation
  • Radiological reassessment documentation

43
Excretion of Inhaled Uranium
44
Chelators
  • DTPA - Diethylenetriaminepentaacetic Acid
  • EDTA - Versene
  • BAL - Dimercaprol
  • DFOA - Deferoxamine
  • PCA - Penicillamine

45
Prompt DTPA Treatment of 239Pu Intake is Highly
Effective
  • Retention ( of Uptake)
  • Control DTPA Treated
  • Liver 14.0 0.47
  • Skeleton 57.0 5.9

46
How to Administer DTPA
  • IV injection of DTPA (1 gm/4ml) with 6 ml saline
    over 5-10 minutes
  • IV Piggyback (1 gm DTPA in 100ml saline) over 20
    minutes
  • Aerosol 1 gram undiluted via hand-held
    nebulizer inhalation takes 10-15 minutes
  • IM injection (painful)
  • Under 18 YOA, use zinc-DTPA
  • Monitor magnesium and other electrolytes
    routinely
  • Complete package information available at
  • www.orau.gov/reacts/resources.htm

47
REAC/TS DTPA Program
  • Maintain Registries of DTPA and PB use in US
  • Provide a stock of pharmaceuticals at REAC/TS and
    with co- investigators for treatment of internal
    contamination
  • Ca- and Zn-DTPA
  • Prussian Blue (Radiogardase)

48
REAC/TS Deployment Teams SPECIAL Medical
Responsibilities
  • REACTS provides 24/7 response for on site
    medical care to NNSA assets (FRMAC, etc.) with
    additional special responsibility/capability to
    provide rapid deployment for radiation dose
    estimate and emergency treatment of INTERNAL
    contaminations with DTPA, Prussian Blue.

49
Prussian Blue is Effective in Rx of Radio-Cesium
or Thallium Uptake
  • Binds ions in gut
  • Reduces biological half life and may avert Cs137
    dose(CEDE) to approx one third of untreated value
  • Not absorbed,relatively non-toxic-monitor K
  • Reduces recycling
  • Need to monitor urine,feces during Rx
  • First used effectively for Cs in Brazil
    accident,1987.
  • Complete package information available at
    www.orau.gov/reacts/resources.htm

50
Who/When to Treat?(Guidelines for Industrial
Accidents)
  • ALI (annual limit of intake) is that CEDE
    necessary to give 5 rem 0.05 Sv.
  • For intake lt 1 ALI, no treatment.
  • For 1lt intake lt 5 ALI, possibly no treatment,
    with physician discretion.
  • For 5 lt intake lt 10 ALI, consider treatment.
  • For intake gt 10 ALI, probably treat ,with
    patient consent.
  • We need consenus on a mass casualty plan!
    management plan.

51
Cs-137 Inhalation INTAKEWHAT IS THE DOSE
(CEDE)?
Step 1) Estimate the Intake Using Intake
Retention Fractions.
At 190 days about 18 of Cs-137 Remains in whole
body.
52
ExampleAssume Lung Counts Measured 1.48 MBq
40 uCi of Cs-137 at 190 Days
Intake (Inhalation) 1.48 MBq/0.18 8.2 MBq 40
uCi/0.18 222 uCi
Step 2) Compare to Annual Limit on Intake
(ALI). ALI 7.4 MBq 200 uCi for Cs-137
(Gives 0.05 Sv 5 rem CEDE) So individual has
110 of ALI and Dose of 0.55 Sv 5.5
rem! TREAT???
53
Bioassay Example of Urine Data Used to Decide on
Rx
  • A worker spends some time in an area where Co-60
  • (T1/2 5.271 y) oxide is present. At the end
    of the quarter (70 days later), activity is
    detected in his routine urine sample. Follow-up
    samples reveal the following excretion pattern
  • Days after
    24-hour urine
  • suspected exposure activity (Bq)
  • 70
    60
  • 100
    50
  • 130
    45
  • A lung count on day 70 revealed 0.25 MBq of
    Co-60.
  • Using IRF and DCF ,can calculate organ
    doses--then,based on regulations and patients
    risk perception, MD can decide on Rx.

54
ExampleOne Data-Point Organ Dose Estimates for
UK Po210 Incident
  • Per ICRP 68, 10 of soluble Po-210 is absorbed
    from the GI tract (of that 30 gt liver, 10 gt
    kidney, 10 gt red marrow, 10 gt spleen, remainder
    distributed in soft tissue)
  • Hypothetical Data point Suppose a bioassay on
    Nov 22 suggested 1 GBq (27 mCi) of Po-210 in the
    whole body. Correcting for the effective(bio and
    physical) half-life, this would have been 1.5
    GBq on Nov. 1, resulting from an estimated intake
    of 15 GBq, or 0.09 mg.

55
One Data-Point Po210 Organ Dose Estimate,
Example(cont)
  • The initial dose rate to red marrow would be
  • (1.5 GBq x 0.1 x 5.3 MeV x 1.609E-13 J/MeV)/1.5
    kg 8.5 mGy/sec
  • 8.5 mGy/sec x 3600 x 24 74 Gy (7400cGy) per
    day. After 22 days, this would have decreased to
    49 Gy/d. The integrated dose to red marrow would
    be 1300 Gy.
  • Similarly, the initial dose rates to liver would
    be 185 Gy/d, to kidney 335 Gy/d, and to spleen
    306 Gy/d. The integrated doses to these organs
    would be 3220, 5830, and 5320 Gy, respectively.
  • Sometimes Treatment Decision is Clear!

56
Internal Contamination Summary
  • Intakes of radionuclides can be treated
    successfully
  • The appropriate treatment is element-specific, so
    the contaminant must be identified
  • The sooner treatment is begun, the better
  • Reference NCRP Pub. 65, Management of Persons
    Accidentally Contaminated with Radionuclides

57
Good References!
  • NCRP 65 Management of Persons Accidentally
    Contaminated with Radionuclides (April, 1980)
  • EPA Federal Guidance Report 11 Limiting Values
    of Radionuclide Intake and Air Concentration and
    Dose Conversion Factors for Inhalation,
    Submersion and Ingestion (EPA-520/1-88-020,
    Sept., 1988)

58
More Good References
  • www.orau.gov/REACTS (Detailed video demonstration
    of external decontamination)
  • Ca/Zn DTPA Package Insert,FDA website
  • Prussian Blue Package Insert,FDA website
  • KI Package Insert,FDA website

59
Thank you!wileya_at_orau.gov
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