MAUDE Adverse Event Report: SIRTEX MEDICAL, INC. SIR-SPHERES MICROSPHERES; Y90 RESIN MICROSPHERES

Model Number	SIR-Y002
Medical Device Problem Code	No Apparent Adverse Event (3189)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	02/20/2026
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
The treating physician stated the patient received only 41% of the prescribed activity due to stasis.The proctor at the case believed this to be inaccurate.This mdr is being filed out of an abundance of caution should an under dose had occurred which has the potential to cause or contribute the serious injury of the untreated tumor leading to tumor progression.The batch record review found the device to be manufactured in accordance with the approved specifications.The following is a technical assessment of the post-administration exposure-rate measurements associated with the february 20 sir-spheres y-90 procedure conducted by sirtex's radiation safety manager: the february 20 measurements identified that the pre- and post-administration exposure-rate readings were collected under non-standardized conditions, including differences in detector type, measurement geometry, shielding, and lack of documented background correction.For y-90, bremsstrahlung radiation fields are highly dependent on measurement geometry and instrumentation.As a result, exposure-rate readings obtained under differing conditions cannot be reliably converted to activity or used for quantitative residual determination.Variability of this nature is well-documented and does not indicate a device-related issue.To provide a more reliable assessment, subsequent measurements obtained on february 23 using a shielded configuration and controlled geometry consistent with published methodologies (lopez, et.Al., 90y sir-spheres activity measurement with siros, j.Nucl.Med.Technol.2024) were reviewed.These measurements support that only a minimal amount of residual activity remained in the delivery system following the procedure.When considered alongside the immediate post-procedure patient exposure-rate measurements, which are consistent with expected findings following successful y-90 administration, the totality of available data supports that the prescribed activity was delivered as intended.There is no evidence to suggest a device malfunction, product quality issue, or use error related to the sir-spheres y-90 device.The observed variability in exposure-rate measurements is attributable to non-standardized measurement conditions rather than actual retained activity.This assessment supports the proctor's clinical determination that the dose was successfully administered.Sirtex medical affairs has stated based on the available clinical, procedural, and technical information, there is no evidence to support that a clinically meaningful underdose occurred or that the device malfunctioned.The reported ~41% delivered activity is derived from non-standardized post-procedure exposure measurements, which are inherently unreliable for quantitative assessment of y-90 activity due to variability in geometry, detector type, and shielding conditions.Subsequent controlled assessments and overall procedural context support that the intended dose was delivered.There were no reported adverse clinical consequences, and no device deficiency or use error has been identified.From a medical and safety standpoint, this event is best characterized as a measurement/interpretation artifact rather than a true dosing issue, with no impact on patient safety and no causal relationship to the device.
Event or Problem Description
The physician called stasis and only 41% of prescribed activity delivered that was determined using post radiation measurements by the nuc med tech.The proctor at the case does not believe this is not accurate and believes the patient got the full dose.

• Brand Name: SIR-SPHERES MICROSPHERES
• Common Device Name: Y90 RESIN MICROSPHERES
• Manufacturer (Section D): SIRTEX MEDICAL, INC.; 300 unicorn park dr.; fl. 2; woburn MA 01801
• Manufacturer Contact: melissa sanchez ; 300 unicorn park drive; fl. 2; woburn, MA 01801
• MDR Report Key: 24675016
• Report Number: 9710358-2026-00008
• Device Sequence Number: 21369701
• Product Code: NAW
• UDI-Device Identifier: 00850014612146
• UDI-Public: (01)00850014612146(17)260222(11)260222(10)UB038
• Combination Product (Y/N): N
• Initial Reporter State: GA
• Initial Reporter Country: US
• PMA/510(K) Number: P990065
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): N
• Reporter Type: Manufacturer
• Initial Reporter Occupation: Physician
• Type of Report: Initial
• Report Date (Section B): 03/24/2026

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Operator of Device: Health Professional
• Device Expiration Date: 02/22/2026
• Device Model Number: SIR-Y002
• Device Lot Number: UB038
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Was the Report Sent to FDA?: No
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 02/22/2026
• Initial Report FDA Received Date: 03/24/2026
• Was Device Evaluated by Manufacturer? (Y/N): Device Not Returned to Manufacturer
• Date Device Manufactured: 02/16/2026
• Is the Device Labeled for Single Use? (Y/N): Yes
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Initial
• Patient Sequence Number: 1
• Patient Sex: Unknown