FRCR FRCR Clinical Oncology 3

Question 1

In the 4Rs of radiobiology, which process refers to cells moving from a radiation-resistant phase to a more sensitive phase?

Accepted Answer

Reassortment (redistribution)

Answer

Reassortment (redistribution) describes the movement of cells through the cell cycle so that cells in the resistant S-phase progress to more radiosensitive G2/M phases between fractions.

Question 2

Palliative radiotherapy for painful bone metastases most commonly uses which fractionation schedule in the US?

Accepted Answer

Single fraction 8 Gy

Answer

Multiple randomized trials and meta-analyses confirm that a single 8 Gy fraction provides equivalent pain relief to multi-fraction schedules for uncomplicated bone metastases.

Question 3

Which imaging modality is most commonly used for radiation therapy treatment planning?

Accepted Answer

CT simulation

Answer

CT simulation provides accurate electron density data required for dose calculation algorithms used in treatment planning systems.

Question 4

The Gleason grading system is used to characterize which malignancy treated with radiotherapy?

Accepted Answer

Prostate cancer

Answer

The Gleason score grades prostate adenocarcinoma based on glandular architecture, guiding decisions about radiation dose, field design, and androgen deprivation therapy.

Question 5

Radiation-induced spinal cord injury (myelopathy) is most closely associated with exceeding which dose constraint?

Accepted Answer

45–50 Gy in conventional fractionation

Answer

The maximum spinal cord dose is typically limited to 45–50 Gy in 1.8–2 Gy fractions to keep the risk of radiation myelopathy below 0.2%.

FRCR - Fellow of the Royal College of Radiologists Practice Test

FRCR - Fellow of the Royal College of Radiologists Practice Test

FRCR FRCR Clinical Oncology 3