Need to Know Flashcards
Protons have a ____ charge
Positive
Neutrons have a _____ charge
No Charge
Electrons have a ______ charge
Negative
Half life order from least to most:
Y, Au, I131, Pd, Sr-89, I125, Ir, Co, Sr-90, C, Ra
-Yttrium (Y-90)
-Gold (Au-198)
-Iodine (I-131)
-Palladium (Pd-103)
-Strontium (Sr-89)
-Iodine (I-125)
-Iridium (Ir-192)
-Cobalt (Co-60)
-Strontium (Sr-90)
-Cesium (C-137)
-Radium (Ra-226)
Half life order from least to most (numbers): Y, Au, I131, Pd, Sr-89, I125, Ir, Co, Sr-90, C, Ra
-2.67 days (Y-90)
-2.7 days (Au-198)
-8 days (I-131)
-17 days (Pd-103)
-50.5 days (Sr-89)
-59.4 days (I-125)
-73.8 days (Ir-192)
-5.26 years (Co-60)
-28 years (Sr-90)
-30 years (C-137)
-1,622 years (Ra-226)
Tx area for: Y-90 (Yttrium) =
Liver and lymphoma tx
Tx area for: Au-198 (Gold) =
Prostate seeds
Tx area for: I-131 (Iodine) =
Thyroid
Tx area for: Pd-103 (Palladium) =
Prostate implants
Tx area for: Sr-89 (Strontium) =
Bone met pain
Tx area for: I-125 (Iodine) =
Prostate implants
Tx area for: Ir-192 (Iridium) =
HDR tx, nylon ribbons w seeds
Tx area for: Co-60 (Cobalt) =
External beam tx
Tx area for: Sr-90 (Strontium) =
Cancers in the eye
Tx area for: C-137 (Cesium) =
Brachytherapy for cervix or uterus
Radium is the ____ isotope
Original
4 R’s of Radiation
-Repopulation
-Redistribution
-Repair
-Reoxygenation
Repopulation is:
Remaining cells undergo mitosis to repopulate tissues
Redistribution is:
Cells transition into a more radiosensitive cell cycle (easier destruction)
Repair is:
Healthy tissues use O2 to repair, malignant cells are hypoxic and cannot repair
Reoxygenation is:
Malignant (hypoxic) cells become radiosensitive by O2
Linear energy transfer (LET):
Rate of energy deposited into material as radiation travels through it
Hounsfield Units in tissue:
-1000 = air
-400/-600 = lung
-50/-100 = fat
0 = water
+15 = CSF
+30/+45 = blood
+50 = muscle
+1000 = dense bone
2 types of electron interactions:
Bremsstrahlung, Characteristic
Bremsstrahlung Interaction:
electron interacts near nucleus by slowing, but never directly interacts with it, instead changes direction creating brem x-ray
Characteristic interaction:
electron interacts with orbiting electron from either the K, L, M shell. K shell creates the highest energy photon and can be used for diagnostic X-rays, not therapeutic
Photon interactions:
Coherent scatter, Compton scatter, photoelectric effect, pair production, photodisintegration (photonuclear)