# Daily versus weekly prostate cancer image guided radiation therapy: phase 3 multicenter randomized trial

Source: https://onco.cc/key-papers/paper-de-crevoisier-daily-weekly-igrt-ijrobp-2018/  
OnCo record `paper-de-crevoisier-daily-weekly-igrt-ijrobp-2018` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A French trial of 470 men compared checking the prostate's position with imaging before every radiotherapy session against checking weekly. Daily imaging lowered rectal side effects and PSA-defined progression, but the main endpoint, recurrence-free survival, did not differ, and overall survival was worse in the daily group.

## Summary

De Crevoisier and colleagues randomised 470 men with node-negative localised prostate cancer at 21 centres between 2007 and 2012 to daily image guidance or weekly image guidance (days 1, 2 and 3 and then weekly), with prostate doses of 70 to 80 Gy. At a median follow-up of 4.1 years, recurrence-free survival, the primary outcome, did not differ significantly (hazard ratio 0.81, P = .330). Overall survival was worse in the daily group (hazard ratio 2.12, 95 per cent confidence interval 1.03 to 4.37, P = .042), as was the post hoc other-cancer-free interval (hazard ratio 2.21). Acute rectal bleeding was lower with daily imaging (6 against 11 per cent), late rectal toxicity was lower (hazard ratio 0.71), and the post hoc biochemical progression-free interval was better (hazard ratio 0.45).

## Fields

- Kind: Key paper
- Last checked: 2026-10-20
- Tags: precision; radiation
- Journal: International Journal of Radiation Oncology, Biology, Physics
- Year: 2018
- DOI: 10.1016/j.ijrobp.2018.07.2006
- Authors: de Crevoisier R, Bayar MA, Pommier P, et al.
- Findings: Recurrence-free survival, the primary outcome, did not differ (hazard ratio 0.81, P = .330).; Late rectal toxicity grade 1 or worse was lower with daily imaging (hazard ratio 0.71, 95 per cent confidence interval 0.53 to 0.96).; Biochemical progression-free interval was better with daily imaging (hazard ratio 0.45), a post hoc analysis.; Overall survival was worse in the daily group (hazard ratio 2.12, 95 per cent confidence interval 1.03 to 4.37), and the post hoc other-cancer-free interval was also worse (hazard ratio 2.21).
- What it means: Imaging the prostate before every session is now standard, and this trial supports it for rectal side effects and PSA control. It also shows how hard it is to turn a physical gain in accuracy into a survival result, and that a randomised trial can throw up an unexplained difference that should be reported rather than smoothed over.
- Caveats: The primary endpoint was not met; the biochemical and clinical progression results are post hoc.; The abstract does not explain the overall survival difference; the worse other-cancer-free interval in the daily group points to causes other than prostate cancer, but that is not established.; Doses of 70 to 80 Gy over several weeks; many men are now treated with fewer, larger fractions, which this trial did not test.

## Sources

- IJROBP 2018: https://doi.org/10.1016/j.ijrobp.2018.07.2006
- PubMed 30071296: https://pubmed.ncbi.nlm.nih.gov/30071296/

## Connected records

- cancers: [Prostate cancer](https://onco.cc/cancers/prostate/)
- fronts: [Radiation Therapy](https://onco.cc/fronts/radiation/)
- technologies: [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/)
- terms: [Fiducial markers](https://onco.cc/terms/fiducial-markers/), [GTV, CTV and PTV (target volumes)](https://onco.cc/terms/planning-target-volume/)
- journals: [International Journal of Radiation Oncology, Biology, Physics](https://onco.cc/journals/ijrobp/)

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