Radiation Biology pt. 2 Flashcards
(51 cards)
Fukushima Daichi,
March 11, 2011
An 8.9 magnitude earthquake and subsequent tsunami
overwhelmed the cooling systems of an aging reactor along
Japan’s northeast coastline. The accident triggered
explosions at several reactors at the complex, forcing a
widespread evacuation in the area around the plant
San Onofre Nuclear Power Plant, San Diego County
San Onofre is at the northwest
corner of San Diego County and
is surrounded by Camp
Pendleton and San Onofre
State Park. Interstate 5 passes
right by.
ACUTE RADIATION SYNDROME
(2)
- A collection of signs and symptoms
following acute whole-body radiation
exposure - Information derived from animal
experiments, patient therapeutic
radiation exposures, atomic bombings
and radiation accidents.
ACUTE RADIATION SYNDROME
* Sub-lethal exposure
* Lethal exposure
* Supralethal exposures
< 2 Gy (200 Rads)
~ 2 –8 Gys (~ 200 to 800 Rads)
> 8 Gys (800 Rads)
Higher dose, — latent period and —
onset of severe symptoms
shorter
rapid
Acute radiation syndrome
periods (4)
- Prodromal period
- Hematopoietic syndrome
- Gastrointestinal syndrome
- Central nervous system and
cardiovascular syndrome
(CNS/CVS syndrome)
- Prodromal period
(<200 R; <2Gy)
- Hematopoietic syndrome
(200- 1,000R; 2-10 Gy)
- Gastrointestinal syndrome
(1,000 – 10,000R; 10 – 100 Gy)
- Central nervous system and
cardiovascular syndrome
(>10,000R; >100 Gy)
PRODORMAL SYNDROME
- Shortly after exposure to whole-body
radiation, an individual may develop
nausea; vomiting;
diarrhea; anorexia;
Causes general malaise, fatigue,
drowsiness and listlessness
Symptoms resolve after several weeks
ACUTE RADIATION SYNDROME
Lethal exposure range
Supralethal exposures
~ 2 – 8 Gys
(~ 200 to 800 Rads)
> 8 Gys
(> 800 Rads)
short latent period and rapid onset of severe symptoms
HEMOPOIETIC SYNDROME
- irreversible injury to the proliferative
capacity of the spleen and bone
marrow with loss of circulating
peripheral blood cells
HEMOPOIETIC SYNDROME
* infection from the
(2)
lymphopenia and
granulocytopenia
* hemorrhage from thrombocytopenia
* anemia from the erythrocytopenia
* Death within 10 - 30 days.
GASTROINTESTINAL SYNDROME
(2)
- extensive damage to the GI system (in
addition to the hemopoietic system) - There is extensive injury to the rapidly
proliferating basal epithelial cells of the
intestinal villi which leads to atrophy and
ulceration.
GASTROINTESTINAL SYNDROME
(5)
- loss of plasma and electrolytes
- hemorrhage and ulceration
- diarrhea, dehydration, weight loss
- Infection
- Death in 3 - 5 days
CARDIOVASCULAR
and
CENTRAL NERVOUS SYSTEM
SYNDROME
(3)
- radiation induced damage to neurons and fine vasculature of brain
- Intermittent stupor, incoordination, disorientation, and convulsions from extensive CNS damage
- irreversible damage with death in a few minutes to 48 hours.
RADIATION TREATMENTS TO THE
ORAL CAVITY
- Combined surgical, radiation and chemotherapy
often provides the optimum treatment
RADIATION TREATMENTS TO THE ORAL
CAVITY
* Oral tissues are subjected to high doses of
radiation during the treatment of malignant
tumors of the (5)
soft palate, tonsils, floor of the
mouth, nasopharynx, and hypopharynx
RADIATION TREATMENTS TO THE ORAL
CAVITY
* Total radiation doses to treat malignant
tumors ranges from
6,000 - 8,000 Rads. Or
60 -80 Gy
Previous Radiation Therapy for Cancer
* Dose
– Solid tumors =
– Lymphomas =
– Intraoral cancer =
- 1 Gy =
60 –80 Gy
20 –40 Gy
50 Gy
1 million μSv
Single intraoral — μSv
FMX (20 images) — μSv
Panoramic radiograph — μSv
1.3
35
9
RADIATION TREATMENTS TO THE ORAL
CAVITY
* Fractionation of the total dose into multiple
small doses provides
greater tumor destruction
than a single large dose
* Fractionation also increases cellular repair of the
normal tissues
Mucosa: -
mucositis
- 20 infections
