Exhibit 10.55

                       SECOND AMENDMENT TO LOAN DOCUMENTS

         THIS SECOND AMENDMENT TO LOAN DOCUMENTS (this  "Amendment") is made and
entered into as of this 30th day of June,  2009,  by and among  INTRAOP  MEDICAL
CORPORATION,  a Nevada  corporation  (the  "Company"),  and the investors of the
Company set forth on the signature pages hereto (the  "Investors").  Capitalized
terms used but not defined  herein shall have the meanings  assigned  thereto in
the Loan Documents (as defined below).

                                    RECITALS

         WHEREAS,  pursuant to that certain Debenture Purchase Agreement,  dated
as of  September  30,  2008  and  amended  as of April 9,  2009  (the  "Purchase
Agreement"),  the  Company  has  issued  to the  Investors  10%  Senior  Secured
Debentures (as the same may have been amended and restated, the "Debentures");

         WHEREAS, to secure the Company's obligations under the Debentures,  the
Company and the Investors  have entered into a Security  Agreement,  dated as of
September  30,  2008 and amended as of April 9, 2009 (the  "Security  Agreement"
and,  together  with  the  Purchase  Agreement  and the  Debentures,  the  "Loan
Documents"); and

         WHEREAS,  the Company and the Investors  wish to amend certain terms of
the Loan Documents as described below.

                                    AGREEMENT

         NOW,  THEREFORE,  in consideration of these premises and for other good
and  valuable  consideration,  the receipt and  sufficiency  of which are hereby
acknowledged, the parties hereto agree as follows:

         1.       AMENDMENT.

                   1.1      Amendment to Loan Documents.

                           (a) The Debentures are hereby amended by changing the
references  to "June  30,  2009" in (i) the  second  paragraph  of the  preamble
thereto and (ii) the  definition of "Monthly  Payment Date" in Section 1 thereof
to "December 31, 2009".

                           (b) The Debentures are hereby amended by amending and
restating in its entirety the  definition of "Original  Issue Date" set forth in
Section 1 thereof as follows:

         ""Original  Issue Date" shall mean the date on which this Debenture was
         originally  issued   (notwithstanding   any  subsequent  amendment  and
         restatements hereof)."

                           (c) The Debentures are hereby amended by amending and
restating  in its entirety  clause (ii) of the second  paragraph of the preamble
thereto as follows:


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         "(ii) the date the Company closes an issuance,  or series of issuances,
         of promissory  notes  convertible  into shares of its Common Stock with
         gross  aggregate  proceeds  received  by the  Company  of not less than
         $6,000,000 (other than pursuant to the Purchase Agreement)"

                           (d) The  Purchase  Agreement  is hereby  amended such
that the form of the Debenture  attached thereto as Exhibit A is consistent with
the amendments to the Debentures  set forth in Sections  1.1(a),  (b) and (c) of
this Amendment.

                           (e) The  Purchase  Agreement  is  hereby  amended  by
changing  the  references  to "June  30,  2009"  and  "$2,000,000"  in the first
sentence  of  Section  2.4  thereof to  "December  31,  2009" and  "$3,500,000",
respectively.

                           (f) The  Security  Agreement  is  hereby  amended  by
changing the reference to "$3,500,000" in the preamble thereof to "$5,000,000".

                   1.2      Amendment  to  Warrants.  As  further  consideration
for the agreements of E.U.  Capital Venture Inc.  ("E.U.  Capital") set forth in
this Amendment,  the Company hereby agrees that the "Warrant Price" set forth in
Section 1 of (i) those certain Warrants to Purchase Common Stock of the Company,
issued on or around  August 17,  2007,  providing  for the  purchase of up to an
aggregate  of  1,083,515  shares  of  the  Company's  Common  Stock  (the  "2007
Warrants"),  and (ii) that  certain  Warrant  to  Purchase  Common  Stock of the
Company, issued on or around August 1, 2008, providing for the purchase of up to
1,350,000 shares of the Company's Common Stock (the "2008 Warrant" and, together
with the 2007  Warrants,  the  "Warrants"),  is hereby  amended to two cents and
eight  tenths of a cent  ($0.028),  subject to  adjustment  as  provided  in the
Warrants.

                   1.3      Effect on Agreements.

                           (a) Except as expressly set forth in Sections 1.1 and
1.2 of this  Amendment,  the Loan Documents and the Warrants shall be and remain
in full force and effect in accordance with their terms.  The Loan Documents and
the Warrants,  as amended by Sections 1.1 and 1.2 of this Amendment,  are hereby
ratified and confirmed in all respects.

                           (b) Nothing  contained herein shall in any way impair
the  Debentures now held for the  Obligations,  nor affect or impair any rights,
powers, or remedies under the Loan Documents, it being the intent of the parties
hereto that this Amendment  shall not constitute a novation of the Debentures or
an accord and satisfaction of the  Obligations.  The Company hereby ratifies and
reaffirms  the  validity  and  enforceability  of all of the liens and  security
interests  heretofore  granted  pursuant to the Loan  Documents,  as  collateral
security  for the  Obligations,  and  acknowledges  that all of such  liens  and
security  interests,  and all Collateral  heretofore pledged as security for the
Obligations, continues to be and remains Collateral for the Obligations from and
after the date hereof.

         2.       MISCELLANEOUS.


<PAGE>

                   2.1 Governing  Law. This  Amendment  shall be governed by and
  construed  under the internal  laws of the State of Delaware in all  respects,
  without giving effect to conflict of law principles thereof.

                   2.2 Entire Agreement.  This Amendment and the other documents
  delivered  pursuant hereto  constitute the full and entire  understanding  and
  agreement between the parties with regard to the subjects hereof.

                   2.3 Severability.  In the event one or more of the provisions
  of this Amendment should,  for any reason,  be held to be invalid,  illegal or
  unenforceable in any respect, such invalidity,  illegality or unenforceability
  shall not affect any other  provisions of this  Amendment,  and this Amendment
  shall be construed as if such invalid,  illegal or unenforceable provision had
  never been contained herein.

                   2.4 Titles and  Subtitles.  The  titles of the  sections  and
  subsections  of this  Amendment are for  convenience of reference only and are
  not to be considered in construing this Amendment.

                   2.5  Counterparts.  This  Amendment  may be  executed  in any
  number of counterparts,  each of which shall be an original,  but all of which
  together shall constitute one instrument.

                   2.6  Additional  Purchaser.  By execution of this  Amendment,
  each  of VMG  Holdings  II,  LLC  and  Lacuna  Hedge  Fund  LLLP  hereby:  (a)
  acknowledges  receipt  of a  copy  of the  Purchase  Agreement,  the  Security
  Agreement and the other Loan  Documents;  and (b) agrees to become a party to,
  and be bound by, (i) the terms and conditions of the Purchase Agreement,  as a
  "Purchaser" under the Purchase Agreement as if it were an original "Purchaser"
  party thereto, and (ii) the terms and conditions of the Security Agreement, as
  a "Secured  Party"  under the  Security  Agreement  as if it were an  original
  "Secured  Party" party  thereto,  in each case with respect to all  Debentures
  previously  issued to it or that may be issued to it in the future pursuant to
  the terms of the Purchase Agreement.

                      [THIS SPACE INTENTIONALLY LEFT BLANK]


<PAGE>

         IN WITNESS  WHEREOF,  the undersigned  have caused this Amendment to be
duly executed as of the day and year first written above.

                                        COMPANY:

                                        INTRAOP MEDICAL CORPORATION


                                        By:  /s/ John Powers
                                             -----------------------------------
                                              Name:  John Powers
                                              Title: Chief Executive Officer

                                        INVESTORS:


                                        E.U. CAPITAL VENTURE, INC.


                                        By:  /s/ Hans Morkner
                                             -----------------------------------
                                              Name:
                                              Title:


                                        ENCYCLOPEDIA EQUIPMENT LLC


                                        By:  /s/ Oliver Janssen
                                             -----------------------------------
                                              Name:
                                              Title:


                                        LACUNA VENTURE FUND LLLP


                                          By:  Lacuna Hedge GP LLLP, its general
                                          partner

                                          By:  Lacuna, LLC, its general partner

                                        By: /s/ Richard O'Leary
                                            ------------------------------------
                                             Name:
                                             Title:


                                        VMG HOLDINGS II, LLC


                                        By: /s/ Gregory S. Koonsman
                                            ------------------------------------
                                             Name:  Gregory S. Koonsman
                                             Title:  Managing Partner

                                          /s/ Rawleigh Ralls
                                        ----------------------------------------
                                           RAWLEIGH RALLS


<PAGE>

                                        LACUNA HEDGE FUND LLLP


                                          By:  Lacuna Hedge GP LLLP, its general
                                          partner

                                          By:  Lacuna, LLC, its general partner


                                        By: /s/ Richard O'Leary
                                            ------------------------------------
                                             Name:
                                             Title: