Tu Dan, MD
Radiation Oncology · Dallas, TXNPI 1902192123
Payments from drug & device makers
What this record shows
This record is dominated by travel and lodging: $433 of the $715 with a category attached, or 60.6%. Varian Medical Systems, Inc. accounts for 60.6% of it on its own, with 2 other manufacturers making up the rest. Reporting peaked in 2019 at $433 and has fallen 63.7% since, to $157 in 2024.
Across 4 payments — averaging $178.71 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Varian Medical Systems, Inc.$433
- AstraZeneca$157
- Novocure Inc.$124
Across 17 payments — averaging $16,275 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.
- Reflexion Medical, Inc.$216K
- Incyte Corporation$61K
What the payments were for
- Travel & lodging$43361%
- Food & beverage$28139%
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 |
|---|---|---|
| Varian Medical Systems, Inc. | 1 | $433 |
| AstraZeneca | 2 | $157 |
| Novocure Inc. | 1 | $124 |
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.
- Radiation Oncology$433
- Optune$124
How this compares
$715 in reported general payments places this provider in the 55th percentile of 418 radiation oncology providers in Texas.
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.
Most prescribed under Part D
| Drug | Claims | Cost to plans & patients |
|---|---|---|
| Dexamethasone | 92 | $1,072 |
| Memantine Hcl | 15 | $125 |
| Prednisone | 11 | $27 |
Paid to pharmacies, not to this prescriber.
Other radiation oncology in Dallas
- Hak ChoyDallas$119K
- Robert TimmermanDallas$77K
- Puneeth IyengarDallas$60K
- Assal RahimiDallas$43K
- Neil DesaiDallas$29K
- Kiran KumarDallas$29K
- Kenneth WestoverDallas$24K
- Jonathan VermaDallas$6K
- James WelshHouston$421K
- Stephen ChunHouston$344K
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.