# Timothy J. Whelan

Source: https://onco.cc/people/timothy-whelan/  
OnCo record `timothy-whelan` (Person). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Led the Canadian trials that established three-week breast radiotherapy and defined when nodal radiotherapy helps.

## Summary

Timothy Whelan led the Ontario hypofractionation trial showing 16 fractions over three weeks matches 25 fractions for breast conservation, which with the UK START trials moved the world to shorter schedules, and MA.20, which showed regional nodal irradiation reduces recurrence in node-positive disease. He led the LUMINA study showing radiotherapy can be omitted in low-risk luminal A breast cancer and chairs the CCTG breast site.

## Fields

- Kind: Person
- Last checked: 2026-09-10
- Tags: radiotherapy; breast; canada
- Role: Professor of Oncology, McMaster University; Radiation Oncologist, Juravinski Cancer Centre
- Specialisms: Breast radiotherapy; Hypofractionation; Regional nodal irradiation; Radiotherapy omission

## Sources

- PubMed: https://pubmed.ncbi.nlm.nih.gov/?term=Whelan%20TJ%5BAuthor%5D%20breast%20radiotherapy

## Connected records

- cancers: [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/)
- technologies: [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/)
- institutions: [Juravinski Cancer Centre / Escarpment Cancer Research Institute](https://onco.cc/institutions/juravinski/)

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