Radiotherapy: hypofractionation: 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: hypofractionation

Sample item

Why can prostate cancer be treated with fewer, larger fractions of radiotherapy?

AIt has no repair capacityBIts alpha/beta ratio is low, so it is more sensitive to fraction size, like late-responding tissuesCIts alpha/beta ratio is very high so it needs larger fractionsDIt is hypoxic and therefore radioresistant

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

The answer and the reasoning

B. Its alpha/beta ratio is low, so it is more sensitive to fraction size, like late-responding tissues

Tumours with a low alpha/beta ratio, as estimated for prostate cancer, respond more to higher dose per fraction, which allows shorter schedules. The key is that the therapeutic ratio must be preserved for nearby organs, requiring accurate delivery. Breast cancer is similarly treated with moderate hypofractionation.

Option by option

A. It has no repair capacity
Repair capacity exists in all cells.
B. Its alpha/beta ratio is low, so it is more sensitive to fraction size, like late-responding tissues (correct)
Correct. A low alpha/beta ratio favours larger fractions.
C. Its alpha/beta ratio is very high so it needs larger fractions
A high ratio would favour conventional fractionation.
D. It is hypoxic and therefore radioresistant
Hypoxia lowers sensitivity and is not the rationale.

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.

Questions about this Radiology question

What is the answer to this Radiology question?

The best answer is B, Its alpha/beta ratio is low, so it is more sensitive to fraction size, like late-responding tissues. Tumours with a low alpha/beta ratio, as estimated for prostate cancer, respond more to higher dose per fraction, which allows shorter schedules.

Why is "It has no repair capacity" not the answer?

Repair capacity exists in all cells.

Why is "Its alpha/beta ratio is very high so it needs larger fractions" not the answer?

A high ratio would favour conventional fractionation.

Why is "It is hypoxic and therefore radioresistant" not the answer?

Hypoxia lowers sensitivity and is not the rationale.

What concept does this question test?

It tests Radiotherapy: hypofractionation in Radiology. The key is that the therapeutic ratio must be preserved for nearby organs, requiring accurate delivery. Breast cancer is similarly treated with moderate hypofractionation.

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: hypofractionation?

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.