FRCR VAULT

Breast: FAST-Forward 5-fraction radiotherapy

Free question published 30 July 2026

BreastFAST-Forward 5-fraction radiotherapy

A 67-year-old woman has had breast-conserving surgery for a 12 mm, grade 1, ER-positive, HER2-negative invasive carcinoma with negative sentinel nodes and clear margins. She lives a long distance from the cancer centre and would prefer the shortest possible whole-breast radiotherapy course. No regional nodal irradiation is planned. Which radiotherapy schedule is most appropriate?

  1. A30 Gy in 5 fractions over 5 weeks (once weekly)
  2. B28.5 Gy in 5 fractions over 5 weeks (once weekly)
  3. C26 Gy in 5 fractions over 1 week
  4. D20 Gy in 5 fractions over 1 week
  5. E36 Gy in 6 fractions over 2 weeks

Why C is correct

FAST-Forward demonstrated that 26 Gy in 5 fractions over 1 week is non-inferior to 40 Gy in 15 fractions for ipsilateral breast tumour relapse (5-year IBTR 1.4% vs 2.1%) and is as safe for normal tissue effects up to 5 years. It is recommended as a standard of care for whole-breast radiotherapy without regional nodal irradiation.

And why the others are not

  • AIncorrect. 30 Gy in 5 weekly fractions was a FAST trial (not FAST-Forward) regimen and was not the FAST-Forward standard; it is not a 1-week schedule.
  • BIncorrect. 28.5 Gy in 5 once-weekly fractions derives from the FAST trial, not from FAST-Forward, and is given over 5 weeks rather than 1 week.
  • DIncorrect. 20 Gy in 5 fractions is an underdose and was not a FAST-Forward arm.
  • EIncorrect. 36 Gy in 6 fractions was not a FAST-Forward arm and is not an evidence-based whole-breast standard.

Source FAST-Forward - 26 Gy in 5 fractions over 1 week (5-year results) — Murray Brunt A, Haviland JS, Wheatley DA, et al. Hypofractionated breast radiotherapy for 1 week versus 3 weeks (FAST-Forward): 5-year efficacy and late normal tissue effects results from a multicentre, non-inferiority, randomised, phase 3 trial. Lancet. 2020;395(10237):1613-1626.

More free breast questions

2,500+ cited questions like this one are waiting in the vault.

See plans and pricing