NucMed Flashcards
What length of time should a lactating female who undergoes 18F-FDG PET scanning wait before resuming breast-feeding?
(a)4 h
(b) 24 h
(c) 1 week
(d) Breast-feeding should be discontinued
(b) With a physical half-life of 109 min and a biologic half-life of 6 h, the effective half-life for 18F is approximately 1.4 h. Nonetheless, many imaging departments recommend that nursing mothers refrain from nursing for 24 h following a PET study with this isotope, although this varies greatly among labs. Some laboratories recommend as little as 6-h interruption after imaging, so it is completely eliminated from the body in 14 h.
Why is it important to know if a patient has an inflammatory condition before performing an 18F-FDG PET scan?
(a)18F-FDG and certain anti-inflammatory medications cause severe reactions when used simultaneously
(b) 18F-FDG can exacerbate inflammatory conditions
(c) Some inflammatory conditions cause areas of increased uptake of 18F-FDG
(c) Areas of inflammation often show increased activity on 18F-FDG images.
Which of the following has the shortest half-life?
(a)82Rb
(b) 13N
(c) 15O
(d) 18F
(a) 82Rb has a half-life of 1.3 min, 13N has a half-life of 10 min, 15O has a half-life of 122.2 s, and 18F has a half-life of 109 min.
Which dose and route of administration are the best choices when performing a whole body PET scan with 18F-FDG and a dedicated PET scanner?
(a)2-4 mCi IV
(b) 2-4 mCi IM
(c) 10-20 mCi IV
(d) 10-20 mCi IM
(e) 30-35 mCi IV
(c) The dose recommended by the Society of Nuclear Medicine Procedure Guideline for whole-body FDG PET scanning is 10-20 mCi injected intravenously (370 to 740 MBq).
Fill in the blank. High blood glucose levels may _____ 18F-FDG uptake in tumors.
(a)Decrease
(b)Increase
(a) Increased glucose level can decrease tumor uptake so many institutions reschedule a patient’s PET scan if their blood glucose level exceeds 200 mg/dL.
Parenteral nutrition should be discontinued for several hours prior to 18FDG imaging.
(a)True
(b)False
(a) Regardless of how a patient receives his or her nutrition, increased glucose level may decrease tumor uptake because glucose will compete with FDG for cellular uptake. Of course, the decision to remove nutrition is up to the clinician.
Which of the following is NOT a scintillation crystal found in PET cameras:
(a)Lutetium oxyorthosilicate (LSO)
(b) Bismuth germanate (BGO)
(c) Lead sulfate (PbSO4)
(d) Gadolinium oxyorthosilicate (GSO)
(c) Scintillation crystals that have been used in PET cameras include NaI(Tl), LSO, BGO, and GSO. Lead sulfate, PbSo4, is the white powder often seen on the electrodes of car batteries.
In the event of a spill of 99mTc to clothes, one should immediately:
(a)Enter a shower fully clothed.
(b) Remove and store the clothes until they decay to background.
(c) Wash the clothes in hot water and then survey them to determine remaining activity.
(d) Remove and destroy the clothing.
(b) The first priority in event of a spill is to contain the contamination, i.e., to keep it from being spread. In this case, that would be accomplished by removing the clothing and storing it until the activity has decayed to background level.
What is the best way to decrease the radioactive dose to visitors if a patient is surveyed to emit 3 mR/h at bedside?
(a)Have the patient wear lead aprons.
(b) Keep the patient well hydrated and encourage frequent voiding.
(c) Have the visitor sit or stand as far as possible from bedside.
(d) Have the visitor wear lead shielding.
(c) The best and simplest way to decrease exposure to a visitor would be to increase the distance form the patient. If the exposure rate is 3 mrem/h at bedside, we can estimate 1 ft. from the patient and we move the visitor to 2 ft. from the patient, the exposure rate at the new distance would be 0.75 merm/h. (The equation in solution to question 5 of this chapter is rearranged to read (I1)(d1)^2 = (I2)(d2)^2 and solved for the new intensity.)
A spill of 99mTc increases the exposure rate in a room from 1.7 to 3.15 mR/h. The room is posted with a sign reading “Caution-Radioactive Materials.” What would be the ideal solution?
(a)Change the sign to one reading “Caution-Radiation Area.”
(b) Call the NRC.
(c) Decontaminate the floor with water and cleanser.
(d) Place absorbent paper over the spill and close the room until the activity has decayed.
(d) A sign reading “Caution Radioactive Materials” is required wherever radioisotopes are used. The sign reading “Caution Radiation Area” sign is required if the dose rate exceeds 5 mrem/h, so no change in sign posting is needed. However, the spill should be contained, so restricting access to the area until the activity has decayed to background is the best course of action.
A technologist has 500 mrem registered on his ring badge in 1 month. What should be done to decrease exposure in the future?
(a)Use lead pigs and syringe shields when preparing radiopharmaceuticals.
(b) Have another technologist elute the generator.
(c) Wear lead aprons.
(a) All technologists should use lead vials and syringe shields when working with radiopharmaceuticals.
Which of the following is the most effective means of measuring low levels of removable radiation?
(a)By performing an area survey
(b) By performing a wipe test
(c) With a pocket dosimeter
(d) With a TLD
(b) Wipe tests are used to detect removable contamination from surfaces such as packages, floors and counters and are achieved by wiping the area in question with a dry wipe and then counting the wipes along with a background sample in a well counter.
If a radiopharmaceutical is spilled on the floor, the first priority is to:
(a)Contact the Radiation Safety Officer.
(b) Pour a chelating solution over the area of the spill.
(c) Cover the area with absorbent paper and restrict access around it
(d) Call the housekeeping department to arrange for cleaning.
(c) The contamination must be contained as a first priority. Using a chelating agent may change the chemical structure of the substance spilled but will not affect the radioactivity of it. The Radiation Safety Officer should be notified, but first access to the area of the spill must be restricted.
Gaseous radiopharmaceuticals may only be used in rooms that:
(a)Have at least one window
(b) Contain an oxygen supply
(c) Are at a positive pressure compared to surrounding rooms
(d) Are at a negative pressure compared to surrounding rooms
(d) Airborne radiation, such as aerosols or gases, should be administered in rooms that are at negative pressure to surrounding areas. Depending on the amount of activity and the length of time it is present, special posting may be required (10 CFR 20.1902)
A technologist discovers that a patient in the room next to a radioiodine therapy will receive 2.5 mrem/h when lying in his bed which is against the shared wall. What should be done?
(a)Move the bed to the other side of the room.
(b) Discharge the therapy patient.
(c) Discharge the non-therapy patient.
(d) Calculate how long visitors to the non-therapy patient can stay.
(e) Calculate how long the patient may stay in bed each hour.
(a) Time, distance, and shielding are the most important factors in reducing exposure; in this case, the simplest solution is to employ an increase in distance to the source of the radiation.
Which of the following is not a misadministration?
(a)When a dose of 400 μCi of 99mTc MAA is given rather than 4 mCi
(b) When the correct dose of 111In oxine for cisternogram is injected intravenously
(c) When a patient who should have been injected with 20 mCi of 99mTc HDP for a bone scan receives a capsule containing 250 μCi of 123I intended for a thyroid patient
(d) When a patient who should have received 50 mCi of 131I receives 35 mCi instead
(e) None of the above
(e) A misadministration can involve the wrong patient, the wrong radiopharmaceutical, the wrong route of administration, or a dose that differs by more than 20% of the prescribed dose or falls outside the prescribed dose range. Doses that differ from the prescribed dose by more than 5 rem effective dose equivalent, 50 rem to an organ or tissue, or 50 rem shallow dose equivalent to the skin are also misadministrations.
What is the dose rate limit at the surface of a package bearing a DOT Class I White label?
(a)0.5 mR/h
(b) 2 mR/h
(c) 50 mR/h
(d) 100 mR/h
(e) 200 mR/h
(a) A package with such a label may have an exposure rate that does not exceed 0.5 mR/h at the package surface, and there must be no detectable radiation at 1 m from the package.
The doorway to the nuclear medicine reception area should be posted with:
(a)Caution: Radiation Area
(b) Caution: High Radiation Area
(c) Grave Danger: Very High Radiation Area
(d) Caution: Radioactive Materials
(e) None of the above
(e) The sign “Caution Radioactive Area” is posted wherever radioactive materials are used or stored. Unless patients are being injected in the reception area, a sign is not needed.
Which of the following bodies regulates the use of investigational pharmaceuticals?
(a)NRC
(b) DOT
(c) IRB
(d) FDA
(d) All the use of investigational pharmaceuticals is regulated by the Food and Drug Administration.
What is the best choice for disposal of a vial containing 27 mCi of 99mTc in 2 ml of liquid?
(a)Transfer to an authorized recipient
(b) Incinerate
(c) Bury
(d) Store until decayed to background
(e) Release to the atmosphere through evaporation
(d) If the radioactive material has a half-life of 120 days, the material can be disposed of as ordinary trash after decaying in storage. Before disposal, the material must be surveyed and not be greater than background radiation (10 CFR 35.92). Records must be kept of this for 3 years (10 CFR 35.2092) and must include the radionuclide, the date of disposal, the equipment used to survey the material, the background dose rate, and the dose rate at the surface of the container used for disposal, as well as the name of the person disposing of the material.
Reports of area surveys must include all of the following except:
(a)A diagram of the areas surveyed
(b) Equipment that was used to perform the survey
(c) Date performed
(d) Initials of the person who performed the survey
(e) List of isotopes used in the area
(e) NRC licensees are required to prepare and maintain reports of area surveys for 3 years. A list of isotopes used in the area is not a required part of the report.
Which of the following must be kept for 5 years?
(a)Records of misadministrations
(b) Records of dose calibrator linearity
(c) Records of doses assayed before administration
(d) Area survey records
(e) Records of instructions to breast-feeding women who received radiopharmaceuticals
(a) Misadministration records must be kept for 5 years. Records of patient dosage, area survey records, and records of instructions given to lactating females must be kept for 3 years.
A pregnant technologist receives 350 mrem during her pregnancy according to a film badge worn at waist level. Has the NRC dose limit for the fetus been exceeded?
(a)Yes
(b)No
(b) The total dose limit for a fetus is 0.5 rem (10 CFR 20.1208)
Which of the following must be done during disposal of a carton in which a shipment of 131I was received?
(a)RSO must be notified.
(b) Carton must be stored for ten half-lives before disposal.
(c) Radioactive labels must be removed or obliterated.
(d) Carton must be discarded with biohazardous waste.
(e) (b) and (c).
(c) Cartons that have been used toe ship radioactive material must have radiation labels removed before disposal. If wipe tests show contamination, it must be regarded as radioactive waste and disposed according to the relevant regulations.