NMTCB Pharmaceutical & Radiopharmaceutical Agents 5

Question 1

Which radiopharmaceutical is used to image somatostatin receptor-positive neuroendocrine tumors (NETs)?

Accepted Answer

Ga-68 DOTATATE

Answer

Ga-68 DOTATATE binds with high affinity to somatostatin receptor subtype 2 (SSTR2), which is overexpressed on most neuroendocrine tumors.

Question 2

What is the primary mechanism of Tc-99m tetrofosmin (Myoview) myocardial uptake?

Accepted Answer

Passive redistribution driven by mitochondrial membrane potential

Answer

Tc-99m tetrofosmin is a lipophilic cationic complex that accumulates in mitochondria of viable myocardial cells driven by the large negative mitochondrial membrane potential.

Question 3

Tc-99m DMSA (dimercaptosuccinic acid) is most commonly used for imaging of the:

Accepted Answer

Renal cortex to detect scarring or functional cortical mass

Answer

Tc-99m DMSA binds to renal tubular cells and provides a static image of the renal cortex, making it ideal for detecting cortical scars and measuring differential renal function.

Question 4

Which statement about In-111 pentetreotide (OctreoScan) is correct?

Accepted Answer

It is a somatostatin analogue that images neuroendocrine tumors expressing SSTR

Answer

In-111 pentetreotide is a radiolabeled octreotide analogue that binds somatostatin receptors (primarily SSTR2) on neuroendocrine tumors for planar/SPECT imaging.

Question 5

What is the maximum recommended number of Tc-99m MAA particles to inject for a lung perfusion scan in a patient with severe pulmonary hypertension?

Accepted Answer

100,000 particles or fewer

Answer

In severe pulmonary hypertension, the number of MAA particles should be reduced to 100,000 or fewer to minimize the risk of further compromising the reduced pulmonary capillary bed.

(NMTCB) Nuclear Medicine Technology Certification Board Practice Test

(NMTCB) Nuclear Medicine Technology Certification Board Practice Test

NMTCB Pharmaceutical & Radiopharmaceutical Agents 5