United States Nuclear Regulatory Commission - Protecting People and the Environment

U.S. Nuclear Regulatory Commission

Technical Assistance Request, Evaluation of Comments on NRC Information Not ice for Ophthalmic Applicators (NRC IN 90-59)

HPPOS-273 PDR-9306100107

Title: Technical Assistance Request, Evaluation of

Comments on NRC Information Notice for Ophthalmic

Applicators (NRC IN 90-59)

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

February 20, 1992. As requested in a Region II memorandum

from William Cline to J. E. Glenn, dated March 13, 1991

(Enclosure 1), the staff has reviewed the comments

presented by the Navy Radiation Safety Committee (Enclosure

2) concerning NRC Information Notice 90-58, "Improper

Handling of Ophthalmic Strontium-90 Beta Radiation

Applicators" (Enclosure 3). The following comments were

offered in response to the Navy Radiation Safety

Committee's concerns as denoted by NRC Region II (Enclosure

1).

Comment 2a: Issue of holding the eye open with tape during

the procedure.

NRC consultants tell us that tape is not an optimal means

of securing a patient's eyelid. The current medical

practice calls for the use of eyelid retractors. In order

to prevent Bremsstrahlung radiation, retractors made of low

atomic weight materials are preferred.

Comment 2b: Number of treatments per year versus use of

fingertips.

The number of treatments stated in case 2 was used as an

example and should not become the focus of the

illustration. The case emphasizes that a physician using

his/her fingers to secure the eyelid while administering

the treatment is improper procedure. Regardless of the

number of treatment applications, attention surrounding the

illustration should be directed towards ALARA guidelines

and the use of passive restraints such as eyelid retractors

to immobilize the eyelid.

Comment 2c: Interpretation of "extremity" limits.

Contrary to the Navy's criticism, contact with the source

tip of the applicator could indeed result in a radiation

dose in excess of NRC limits. We do not agree with the

concept that exposure with the Sr-90 eye applicator source

is tantamount to "hot particle" exposure because of

differences in geometry and dosimetry. In particular, the

area irradiated by a "hot particle" is substantially less

than one square centimeter, whereas the area irradiated by

a strontium-90 (Sr-90) eye applicator is greater than one

square centimeter. As defined in 10 CFR 20.1003, the

shallow-dose equivalent for skin or extremities applies to

tissue at a depth of 0.007 centimeters averaged over an

area of one square centimeter. Therefore this criteria

applies to Sr-90 eye applicators.

Comment 2d: Rules requiring personnel monitors.

The requirements for personal dosimeters discussed in the

information notice are in keeping with minimally accepted

ALARA guidelines.

The Navy's data indicates that their exposures do not

approach 10 CFR Part 20 minimum requirements for personnel

monitoring devices. However, it would be prudent health

physics practice to wear personal dosimeters because of

unanticipated exposures as well as planned exposures. Once

an individual has demonstrated sufficient knowledge and

skill using an applicator, exceptions might be considered.

If a licensee can clearly demonstrate that (1) the

radioactive material used is limited to the Sr-90 eye

applicator and (2) the resulting exposures did not reach

the limits set forth in 20.202 or 20.1502 (a), NRC would

consider licensee procedures without requirements for the

use of personal dosimeter devices on a case-by-case basis.

Comment 2e: Sterilizing agents.

Further review of the sterilization processes revealed that

the typical manufacturer's directions for sterilizing the

device are inconsistent with the Centers for Disease

Control's (CDC) recommendations. While this may be an

important point, the information provided in Item 1 of the

typical manufacturer's instructions was designed to call

the licensee's attention to the need for sterilization of

the Sr-90 eye applicators. The manufacturers may

ultimately modify their sterilization procedures to

coincide with those of the CDC.

Comments 2f and 2g: Corrosion and Calibration.

The information of concern in comments 2f and 2g was not

discussed in NRC IN 90-58. We are currently planning to

develop an information notice covering both the calibration

and possible corrosion of the device.

Comment 2h: Seventy years of use without an incident.

The three uses cited in the information notice represent

examples of significant potential exposures and, as such,

warrant notification of the licensees.

Regulatory references: 10 CFR 20.1, 10 CFR 20.202, 10 CFR

20.1101, 10 CFR 20.1502

Subject codes: 8.1, 8.3, 8.5

Applicability: Byproduct Material

Page Last Reviewed/Updated Thursday, March 29, 2012