Radiotherapy and nuclear medicine basics: salivary toxicity of radioiodine: practice question

A Radiology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Radiology · Radiotherapy and nuclear medicine basics: salivary toxicity of radioiodine

Sample item

A patient who received a therapeutic dose of I-131 for thyroid cancer has painful swelling of the parotid glands two days later. What is the cause and the usual measure to reduce it?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

D. Radiation sialadenitis, reduced by hydration and sialogogues such as lemon candies

Salivary glands concentrate iodine, so radioiodine causes sialadenitis. Hydration and sialogogues increase salivary flow and clear activity from the ducts. The other conditions have different causes and treatments.

Option by option

  • A. Suppurative parotitis, treated by drainage

    Suppurative parotitis needs antibiotics, not sialogogues.

  • B. Calculus obstruction, treated by lithotripsy

    Calculus obstruction is not related to the radioiodine dose.

  • C. Viral parotitis, treated by isolation

    Viral parotitis is not caused by the isotope and does not need isolation after I-131.

  • D. Radiation sialadenitis, reduced by hydration and sialogogues such as lemon candies (correct)

    Correct. Salivary glands take up iodine and become inflamed after radioiodine.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

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Questions about this Radiology question

What is the answer to this Radiology question?

The best answer is D, Radiation sialadenitis, reduced by hydration and sialogogues such as lemon candies. Salivary glands concentrate iodine, so radioiodine causes sialadenitis.

Why is "Suppurative parotitis, treated by drainage" not the answer?

Suppurative parotitis needs antibiotics, not sialogogues.

Why is "Calculus obstruction, treated by lithotripsy" not the answer?

Calculus obstruction is not related to the radioiodine dose.

Why is "Viral parotitis, treated by isolation" not the answer?

Viral parotitis is not caused by the isotope and does not need isolation after I-131.

What concept does this question test?

It tests Radiotherapy and nuclear medicine basics: salivary toxicity of radioiodine in Radiology. Hydration and sialogogues increase salivary flow and clear activity from the ducts. The other conditions have different causes and treatments.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Radiotherapy and nuclear medicine basics: salivary toxicity of radioiodine?

Learn signs with the image, and the disease they point to. Then use the flashcards and the other Radiology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.