Billy Loo, MD
Radiation Oncology · Stanford, CANPI 1720167711
Payments from drug & device makers
What this record shows
This record is dominated by speaking fees: $7,019 of the $10,908 with a category attached, or 64.3%. Mevion_medical_systems_inc accounts for 71.2% of it on its own, with 7 other manufacturers making up the rest. Reporting peaked in 2024 at $6,703 and has fallen 97.8% since, to $144 in 2025. Among radiation oncology clinicians in CA with any reported payments, this total sits in the top 10% — high for the specialty, which is a reason to read the composition above rather than the number alone.
Across 29 payments — averaging $376.14 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Mevion_medical_systems_inc$8K
- Reflexion Medical, Inc.$2K
- Novocure Inc.$685
- AstraZeneca$144
- Siemens Medical Solutions USA, Inc.$125
- Varian Medical Systems, Inc.$119
- plus $140 from 2 others
Across 1 payment — averaging $125,000 each. Payments tied to a research study. These frequently flow through the physician to a hospital or research institution rather than to the physician personally.
- Varian Medical Systems, Inc.$125K
What the payments were for
- Consulting fees$6856%
- Speaking & faculty fees$7,01964%
- Travel & lodging$2,00718%
- Food & beverage$1,19711%
General payments by program year
Who reported the general payments
Companies are grouped under their corporate parent — a single manufacturer often files under several CMS reporting entities. Research and ownership payments are counted separately and are not in this table.
| Company | Payments | Total |
|---|---|---|
| Mevion_medical_systems_inc | 13 | $7,766 |
| Reflexion Medical, Inc. | 4 | $1,929 |
| Novocure Inc. | 1 | $685 |
| AstraZeneca | 5 | $144 |
| Siemens Medical Solutions USA, Inc. | 2 | $125 |
| Varian Medical Systems, Inc. | 2 | $119 |
| Genentech USA, Inc. | 1 | $116 |
| Elekta, Inc. | 1 | $24 |
What the payments were tied to
Products named in the reported payments. Only payments of $100 or more are attributed here — the typical reported payment nationally is a meal worth about $16, and listing those product-by-product would be noise.
- PTS250$7,620
- REFLEXION MEDICAL RADIOTHERAPY SYSTEM$1,911
- TECENTRIQ$116
How this compares
$10,908 in reported general payments places this provider in the 90th percentile of 627 radiation oncology providers in California.
Medicare billing
What this is not: this is the amount Original Medicare Part B allowed for services this provider billed in 2024. It is not their income. It excludes Medicare Advantage — now more than half of all Medicare enrollment — along with Medicaid and all commercial insurance, and it is gross practice revenue before staff, rent, supplies and malpractice premiums. CMS also suppresses any figure covering ten or fewer patients, so low-volume providers appear smaller than they are.
Other radiation oncology in Stanford
- Maximilian DiehnStanford$73K
- Yushen QianStanford$47K
- Anusha KalbasiStanford$37K
- Rishabh ChaudhariStanford$35K
- Quynh-Thu leStanford$23K
- Scott SoltysStanford$19K
- Noah Kastelowitz-LiebermanStanford$17K
- Rakesh PatelLos Gatos$1.3M
- Amir LavafPalm Springs$411K
- Albert ChangLos Angeles$290K
Where these figures come from
- Payments: CMS Open Payments, program years 2019–2025 (publication P06302026_06032026).
- Billing: Medicare Physician & Other Practitioners, data year 2024. Original Medicare Part B only.
- Identity: NPPES NPI Registry, July 2026.