U.S. Nuclear Regulatory Commission

Technical Assistance Request, Medical College of Virginia, Richmond, VA, Policy Guidance Concerning Use of Xenon-133 in Saline

HPPOS-319 PDR-9307060010

Title: Technical Assistance Request, Medical College of

Virginia, Richmond, VA, Policy Guidance Concerning Use of

Xenon-133 in Saline

See the memorandum from J. E. Glenn to D. M. Collins dated

June 25, 1993. This memo responds to a technical assistance

request from Region I, dated May 29, 1992, concerning a

request from the Medical College of Virginia for policy

guidance. The licensee requested clarification whether

xenon-133 (Xe-133) in saline should be considered a gas and

the subsequent applicability requirements of 10 CFR 35.205.

The licensee intended to administer Xe-133 in saline

intravenously to patients for cerebral blood flow studies.

These patients cannot be moved into a room at negative

pressure for the studies without creating a potential

health risk.

Xe-133 dissolved in saline is technically not a gas.

Therefore, the licensee does not need to adhere to the

requirement to administer radioactive gases only in rooms

that are at negative pressure compared to surrounding rooms

as stipulated in 10 CFR 35.205 (b). However, in case of a

spill of the saline solution before administration, the

xenon will be released from the suspension as a gas. The

licensee should indicate if the xenon is dissolved in

saline under pressure. If so, additional precautions may

be necessary if the vial containing the Xe-133 is

inadvertently punctured. The rebreathing system should

recapture all exhaled xenon. It will be essential for the

licensee to post spilled gas clearance times and have

adequate safety precautions to ensure minimal exposure of

personnel and patients in the Neuroscience Intensive Care

Unit.

Therefore, the requirements of 10 CFR 35.205 (a), (c), (d),

and (e), that stipulate air concentrations be within 10 CFR

Part 20 limits, calculation and posting of spilled gas

clearance times, monthly checks of the operation of the

reusable collection systems, and measurement of ventilation

rates in the area each six month, should be instituted as

part of the licensee's protocol for use of Xe-133 in

cerebral blood flow studies.

Regulatory references: 10 CFR 35.205

Subject codes: 12.19, 9.1, 11.2, 11.3

Applicability: Byproduct Material