Exhibit
10.21A





AMENDMENT
TO


PERFORMANCE
RESTRICTED STOCK RIGHTS AGREEMENT


PURSUANT
TO THERAGENICS CORPORATION


2000
STOCK INCENTIVE PLAN





THIS AMENDMENT (this “Amendment”) is
made on December ___, 2008, by THERAGENICS CORPORATION, a Delaware corporation
(the “Company”) and ________________ (the “Recipient”).





INTRODUCTION:





The Company previously granted to the
Recipient on February __, 2006, Performance Restricted Stock Rights pursuant to
that certain Performance Restricted Stock Rights Agreement pursuant to the
Theragenics Corporation 2000 Stock Incentive Plan (the
“Agreement”).  The parties now desire to amend the Agreement to comply
with Section 409A of the Internal Revenue Code of 1986, as amended.





NOW, THEREFORE,the Company
and the Recipient hereby amend the Agreement as follows:





1. By
deleting the existing language of Item C of Exhibit 1 and inserting in lieu
thereof the following:





“Except if a Change in Control occurs
before December 31, 2008, if the Recipient ceases to perform services before
December 31, 2008 as an employee of the Company or an Affiliate due to the
Recipient’s death, Disability, or termination of employment by the Company or an
Affiliate without Cause (each, a ‘Payment Event’), the number of shares of
Common Stock to be issued to the Recipient will be determined as of the end of
the year in which the Payment Event occurs based on the following methodology:
Cumulative Revenue and Cumulative Earnings Per Share will be projected by
assuming that cumulative revenue and cumulative earnings per share for the
period from January 1, 2006 through the end of the year in which the
Payment Event occurs continues at the same average rate through
December 31, 2008.  The number of shares of Common Stock to which
the participant is entitled shall be then prorated in the same proportion that
the number of days elapsed from January 1, 2006 through the date the
Participant ceases to be an employee of the Company or an Affiliate bears to the
total number of days in the period beginning January 1, 2006 through
December 31, 2008 (provided that in any such event, the Committee may, in its
sole discretion, provide by written resolution that a greater portion of the
shares shall be issued).  Fractional shares will be disregarded and
will not be issued.”





2. By
deleting the existing language of Item D of Exhibit 1 and inserting the
following in lieu thereof:









“If a
Change in Control occurs before December 31, 2008, then neither Item A nor Item
C will apply, and (1) if the Recipient remains an employee of the Company or an
Affiliate until the occurrence of the Change in Control, then one (1) share of
Common Stock will be issuable as of the date of the Change in Control for each
Performance Restricted Stock Right and the Performance Restricted Stock Rights
will terminate as of such date, and (2) in the case of a Recipient who before
the date of the Change in Control has ceased to perform services as an employee
of the Company or an Affiliate due to Recipient’s death, Disability, or
termination of employment by the Company or an Affiliate without Cause, then a
fraction, the numerator of which is the number of days of the Recipient’s
employment by the Company and its Affiliates from and including January 1,
2006 through the date of death, Disability or termination of employment by the
Company or an Affiliate without Cause, and the denominator of which is the
number of days from and including January 1, 2006 through December 31, 2008, of
one (1) share of Common Stock will be issuable as of the date of the Change in
Control for each Performance Restricted Stock Right (provided that in any such
event, the Committee may, in its sole discretion, provide by written resolution
that a greater portion of the shares shall be issued) and the Performance
Restricted Stock Rights will terminate as of such date.”




3. By
deleting the existing language of Item F of Schedule 1 and inserting in lieu
thereof the following:




“If a Recipient is entitled to shares
of Common Stock pursuant to Item A, a share certificate shall be issued in 2009
as soon as reasonably practicable after the Company determines the number of
shares to be issued, but in no event shall such share certificate be issued
later than March 15, 2009.  If a Recipient is entitled to shares of
Common Stock pursuant to Item C, a share certificate shall be issued as soon as
reasonably practicable after the end of the year in which the Payment Event
occurs and after the Company determines the number of shares to be issued,
provided, however, that in no event will the certificate be issued later than
the fifteenth day of the third calendar month following the end of the year in
which the Payment Event occurs.”




4. By
deleting the existing language of Item G of Schedule 1 and inserting in lieu
thereof the following:




“If a Recipient is entitled to shares
of Common Stock pursuant to Item D, a share certificate shall be issued as soon
as reasonably practicable, but in no event later than ten (10) business days
following the date of the Change in Control.”




Except as specifically amended hereby,
the Agreement shall remain in full force and effect as prior to this
Amendment.




-2-




IN WITNESS WHEREOF, the Company and the
Recipient have executed this Amendment as of the date set forth
above.





RECIPIENT:
            
            THERAGENICS
      CORPORATION:By:Title:








-3-