Status of NRC Permanent Implant Brachytherapy Medical Event Definition: An Update Michael Fuller Team Leader Medical Radiation Safety Team U.S. NRC

Purpose To provide an overview and an update of the proposed changes to the Medical Event definition (criteria) as it relates to Permanent Implant Brachytherapy. 2

Changes to Medical Event Definition In August 2010, The Commission Directed NRC Staff to: Work closely with the Advisory Committee for the Medical Uses of Isotopes (ACMUI), the Agreement States, and the medical community to develop medical event (ME) definitions that would: Protect the interests of patients, Allow physicians the flexibility to take actions that they deem medically necessary, Preserve the NRC’s ability to detect misapplications of radioactive material and failures in process, procedure and training. 3

Workshops ACMUI Meeting in Rockville, April 2011 First Workshop in New York, June 2011 Second Workshop in Houston, August

Key Messages Received During the Workshops Among the Agreement States - fairly consistent with NRC regulations, but wide variance in the interpretation and implementation of the regulations. ME definition for permanent implant brachytherapy needs to be revised, and should be based upon total source strength (activity) not absorbed dose. 5

Key Messages Received During the Workshops If ME definition is based upon total source strength, a tolerance of + 20% is reasonable. The term “Medical Event” should be reserved for those instances where there is real harm to the patient or a potential for same (clinically significant). 6

Licensee staff should be trained in the policies and procedures for identifying MEs. Patient’s rights should be protected. Authorized Users should be required to attest in writing, that the distribution of seeds, within the target was implanted as intended. Post-implant imaging should be required. Key Messages Received During the Workshops 7

Recent Developments In February 2012, the ACMUI held a public teleconference and provided NRC staff with recommendations for changes to the ME definition for permanent implant brachytherapy. In April 2012, NRC staff provided the Commission with the staff’s recommendations for changes to the ME definition for permanent implant brachytherapy. 8

NRC Staff’s Recommendations Define separate ME criteria for permanent implant brachytherapy utilizing radioactive sources. For treatment site, a ME occurs when 20% or more of implanted sources are outside the intended implant location. 9

For normal tissue in neighboring structures, a ME occurs when the dose to at least 5 contiguous cc exceeds 150% of the dose prescribed for the treatment site. For normal tissue structures within treatment site, a ME occurs when the dose to at least 5 contiguous cc exceeds 150% of the expected dose for that tissue. NRC Staff’s Recommendations 10

NRC Staff’s Recommendations A ME occurs when the treatment is administered: using wrong radionuclide; or using wrong source strength (+/- 20%) as specified in the written directive; or to the wrong patient; or with implantation directly into the wrong site or body part; or with delivery using the wrong modality; or using leaking sources. 11

NRC Staff’s Position All of the recommended ME criteria reflect circumstances in which there is actual or potential harm to patients being treated. Patient interests will be protected. Physicians will be able to take medically necessary actions. 12

NRC Staff’s Position NRC will be able to continue detecting failures in process, procedures, and training plus misapplications by Authorized Users. Key Stakeholder input is reflected in these recommendations. 13

WHAT’S NEXT? On August 13, 2012 The Commission Approved the NRC Staff’s Recommendations for Changes to the ME Definition for Permanent Implant Brachytherapy Staff Develops a Regulatory Basis for a Proposed Rule Proposed Rule 14

QUESTIONS? 15