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Bill Loo

Bill Loo

Co-founder and chief medical advisor of TibaRay, a company developing FLASH radiotherapy technology.

Director
Updated Nov 6, 2026·Latest SEC filing Nov 3, 2026·Suggest an edit

About Bill Loo

Bill Loo co-founded TibaRay, which is developing compact linear accelerators for FLASH radiotherapy, and serves as its chief medical advisor and a board member. He is a physician-scientist in radiation oncology and bioengineering at Stanford Cancer Institute. There he directs the thoracic radiation oncology program, co-directs particle therapy, and leads new technology development in radiation oncology. His clinical work focuses on radiation therapy for lung and thoracic cancers, including stereotactic ablative radiotherapy and four-dimensional image-guided radiation therapy.

He is principal investigator of a research lab that studies the biology of ultra-rapid FLASH radiotherapy and develops new radiation technologies. He conceived the PHASER concept for FLASH cancer therapy and co-leads its research and development. He also serves on National Comprehensive Cancer Network panels that write widely used cancer treatment guidelines.

Experience

This experience comes from official bios and from SEC filings. For roles taken from filings, the years are when the filings name Bill Loo in the role, so the role may have started earlier or lasted longer.

Tibaray, Inc. Current
Co-Founder, Chief Medical Advisor
Member, Board of Directors
2025 – Present · Fremont, CA
TibaRay's Galactica linear accelerator is designed to deliver a full radiotherapy dose in a fraction of a second while sparing healthy tissue.

Key Colleagues at Startups

The people Bill Loo works with at each company, as listed on that company's latest Form D.

Tibaray, Inc. · Form D, Nov 3, 2026
Thinh Tran
Thinh Tran
CEO, Member, Board of Directors
Laird Cagan
Laird Cagan
Member, Board of Directors
Peter Maxim
Peter Maxim
Co-Founder & Member, Board of Directors
James Vetter
James Vetter
Member, Board of Directors
Sami Tantawi
Sami Tantawi
Co-Founder, CTO & Member, Board of Directors

Sources

  1. SECTibaray, Inc. Form D, filed Nov 3, 2026
  2. companyTibaRay — FLASH Effect, Episode 2 transcript (Dr. Bill Loo)