Nuke MA Flashcards
I-131
- Beta particles. beta emission decay
- t1/2: 8 D. Gamma photons: 364 KeV.
Both Beta and long t1/2 > high rad
I-123
- Decay by Electron capture
- Gamma Kev: 159. t1/2: 13 Hr
- no alpha or beta particles
RAIU thyriod N uptake
4HR: 6-15%
24 HR: 15-30%
decreased thyroid RAIU DDX
- 1ry, 2ry hypoT
- excess T4 2/2 meds, strumi ovari, factitious
- amiodarone tox
- subacute thyroditis»_space; PAINFUL
- postpartum thyroditis
I131 doses:
Graves: 10-15 mCI T MNG ot T nodule: 15-30 mCI thyriod ca local: 30-100 mCI LAD: 100-200 mCI mets > 200 mCI
postpartum I2 Rx
- start 6 wk after delivery to decrease concen of I2 in the br
- give Dop agonist to decrease I2 dose to the br
I2 WBS - ve. +ve TG next?
FDG only if TG > 10
TG < 2 less likely recurrance
FDG for thyroid ca
+ve: De-differ PTC, FTC. anaplastic, hurthle cell, MTC
-ve: DIFFER. PTC, FTC
+ve MTC ( FDG, In111-Oct (not the best but 1st line), Ga67-Dotatate, I2 if DE-DIFFER)
MIBG med interaction
CCB labetolol ( other BB r ok) TCA. sympatho ( -ephidrine, phenylephrine) reserpine Insulin cocaine
aplha blocker is ok
In-OCT negative in
insulinoma. less SN in MTC
+ve
meningoma, glioma, RCC, BCA, SCLC
Tc99-MDP and NaF attach to
Ca hydroxypetiate
STx calc ( myositis) attach to CaPO4
Ewing sarcoma mets on BS
no positive uptake on BS. but OS does
mmc 3 sites Pagets
Pelvis > spine > skull
Hyperostosis frontalis
- inner table expansion
- Women»_space;» Male
- +ve in BS
Hypertrophic Osteoarthopathy DDX ?
- LCa: mcc
- COPD
- IBD
- Li. diz
- CHF
- Hypoexia
Both periosteal reaction + cortical thickening
SOC for posible infected prosthesis
In111-WBC + TC99-SC
Mets calc sites & DDx
- thyroid, lung, GI, GU, heart. DDx: - CRF - MM - parathyriod tum - high vit D.
Free pertchn: only thyriod and stomch
BMD
- T score: compare 2 young, same sex, ethic ( done in old pt )
- Z score:compare to same age, sex sex & ethnic ( done in young pt)
- most reproducible site adult: spine > total hip > NON dominat radius
- most reproducible site children: PA spine, total body less head
DDx of increased renal uptake on BS
CTX ATN SCA high Ca 2/2 PTH necrosis iron
When do u use Z or T score.
Z score for young pt < 50 YO, pre- M W
T score: > 50. Post-M W.
ab Z score < 2 for expected age
BMD response to Rx & hip fracture risk
1 - Rx: spine
2- Hip fracture risk : total hip measurement
most Sen study to eval NB mets
MIBG > BS
MIBG + BS > MIBG alone
Radium-223
Alpha particle
< 100 um
decrease bone pain + increase survival
GI excretion > diarrhea
Stonium-89
beta particle
7.2 mm
urine exc
