The following information was provided by the
Texas Department of State Health Services (the Department) via phone and email:
On October 3, 2025, the Department received notification from the licensee regarding a treatment error during stereotactic radiosurgery with a gamma knife system for a patient with a brain arteriovenous malformation (AVM). The patient was prescribed a total dose of 20 Gy over 2 fractions. The licensee stated that the event occurred on September 25, 2025, when during the first fraction, a coordinate system error between the stereotactic frame and immobilization masking resulted in radiation being delivered to an incorrect site in the brain, completely missing the AVM target volume. As a result, the prescribed 12 Gy for the first fraction was delivered to non-target brain tissue and 0 Gy reached the intended AVM target. The error was discovered on October 2, 2025, just before the patient was scheduled to undergo the second and final treatment fraction. Treatment was immediately suspended and both the referring physician, who is the surgeon, and the patient were immediately informed.
Additional information will be provided in accordance with SA-300 reporting requirements.
Texas incident number: 10231
A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.