Acute Radiation Syndrome And Its Management

Dr. K. L. Chakraborti, MBBS, M.D, PDCC (Rad)Head, Department of Radiological Imaging,Institute of Nuclear Medicine and Allied Sciences,Timarpur, Delhi-11054drklchakraborti@gmail.com

“Radiation is an energy in the form of electro-magnetic waves or particulate matter, traveling in the air.”

Definition of Radiation

Radiation is classified into:

◦Ionizing radiation◦Non-ionizing radiation

Types of Radiation

Ionizing Versus Non-ionizing Radiation

Ionizing Radiation– Higher energy electromagnetic waves

(gamma) or heavy particles (beta and alpha).

– High enough energy to pull electron from orbit.

Non-ionizing Radiation– Lower energy electromagnetic waves.– Not enough energy to pull electron

from orbit, but can excite the electron.

Primary Types of Ionizing Radiation

Alpha particlesBeta particlesGamma rays (or photons)X-Rays (or photons)Neutrons

Types or Products of Ionizing Radiation

or X-

rayneutron

Sources Of Radiation

Response During Emergencies

Management

Phases of Acute Radiation Syndrome

ProdromalStage

LatentStage

ManifestIllness

Recovery or Death

Time (days to years)

Exposure

Prodromal Phase - 48 to 72 hours ◦ nausea, vomiting, and anorexia.

Latent Phase - 2 to 2 ½ weeks.◦ leukocytes, platelets are decreasing as a

result of bone marrow insult Manifest Illness Phase

◦ Hematopoietic, GI, CNS Recovery Phase or Death

◦ may take weeks or months

ARS - Phases

1. Neurovegetative Syndrome (< 1 Gy)

Vomiting in 5%

Reduced lymphocytes

Chromosomal Aberrations (>100 mSv) 

Forms of ARS

2. Haematopoietic Syndrome (1-8 Gy)

Blood forming system is affected

Vomiting in 1 hr. (> 3Gy)

Erythema(redness), Epilation (loss of hair)

Forms of ARS

3. Gastrointestinal syndrome (8-30 Gy)

The lining of the intestines is damaged

Vomiting and diarrhoea in less than 1 hr.

Lymphocytes less than 100/cubic mm in 48 hrs.

Forms of ARS

4.Neurovascular syndrome (>30 Gy)

The brain is affected

Vomiting within minutes

Drowsiness, Tremors, Convulsions, Coma 

Forms of ARS

Acute Radiation Syndrome (A Spectrum of Disease)

Treatment options

Accident dosimetryPHYSICAL

DOSIMETRYBIOLOGICALDOSIMETRY

CLINICALDOSIMETRY

DOSE RECONSTRUCTION,Personal Dosimeters

CYTOGENETIC DOSIMETRY

Dicentrics, FISH, PCC, MNA

NAUSEA, VOMITING,

CELL COUNTS, SKIN REACTIONS

OTHER BIOINDICATORS

Guidelines for management of radiation injuries on the basis of early symptoms

Symptom Dose Action requiredNo vomiting < 1 Gy Outpatient with 5-week

surveillanceVomiting in 2-3 h 1-2 Gy Surveillance in a general hospital

(or outpatient for 3 weeks) followed by hospitalization

Vomiting in 1-2 h 2-4 Gy  Hospitalization in a haematological department 

Vomiting in < 1 hDiarrhoeaErythema

> 4 Gy Hospitalization in a well equipped haematological or surgical department with transfer to a specialized centre for GFs / BMT

Definitive 1. Prevention of Infections

• Isolation, Gut sterilization2. Treatment of Infections

• Antibiotics, Antiviral, Antifungal3. Haematological Support

• Packed cells, Platelet transfusion4. Regeneration of Bone-Marrow

• Growth factors (4-8 Gy), BMT (>9 Gy)

Treatment:

Barrier nursing / reverse isolation

◦ Laminar flow isolation with microbial filters◦ Strict hand washing before and after patient care ◦ Surgical scrubs for staff ◦ Gowns, caps, gloves, masks for staff ◦ Double bagging of all disposables

Prevention of Infections

Reduction of microbial acquisition

◦ Low-microbial content food (Cooked food only, avoid salads/fruits)

◦ Acceptable water supply◦ Air filtration to reduce aspergillus infection◦ Avoid invasive procedures

(e.g. nasogastric tubes, catheters)

Prevention of Infections

Suppression of micro-organisms

◦ Physiological interventions like Maintenance of gastric acidity Avoidance of antacids and H2 blockers Use of Sucralfate for stress ulcer prophylaxis when

indicated to reduce gastric colonization and pneumonia

Early oral enteral nutrition (when feasible)

Prevention of Infections

Hematological support◦ Platelets maintained at > 20 000/L.

If surgery > 75 000/L◦ Transfusion of packed red blood cells (PRBCs) to

maintain Hb > 8 g/dl◦ All blood products should receive 15-20 Gy of

radiation before infusion to prevent graft-versus-host disease through infusion of mononuclear cells present in the products

Hematological Support

Consider allo-BMT if◦ Fully matched sibling donor available◦ Patient has absolute lymphocyte count (ALC)

<100/l◦ Radiation dose unknown or likely to be 8-12 Gy ◦ No other injuries preclude survival or

transplantation (e.g. severe burns)◦ Irradiation is not continuing from an internal

contamination

BMT

Combined Injuries

For long term effects surveillance and screening at regular intervals are required and if any body found to be suffering from cancer then the management will be done by a cancer specialist.

30