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FIRST AMENDATORY AGREEMENT
TO CREDIT AGREEMENT

     THIS FIRST AMENDATORY AGREEMENT TO CREDIT AGREEMENT made as of the 30th of
September, 2001 by and among IMPATH INC., a Delaware corporation with its chief
executive office at 521 West 57th Street, New York, New York 10019, and IMPATH
PREDICTIVE ONCOLOGY, INC., a Delaware corporation with its chief executive
office at 521 West 57th Street, New York, New York 10019 and IMPATH-BIS INC., a
Delaware corporation with its chief executive office at 521 West 57th Street,
New York, New York 10019, and MEDICAL REGISTRY SERVICES, INC., a Delaware
corporation with its chief executive office at 521 West 57th Street, New York,
New York 10019, and IMPATH-BCP., a Delaware corporation with its chief executive
office at 521 West 57th Street, New York, New York 10019, and IMPATH-PCRL INC.,
a Delaware corporation with its chief executive office at 521 West 57th Street,
New York, New York 10019, and IMPATH-HDC, INC., a Delaware corporation with its
chief executive office at 521 West 57th Street, New York, New York 10019, and
IMPATH INFORMATION SERVICES, INC., a Delaware corporation with its chief
executive office at 521 West 57th Street, New York, New York 10019 (each the
foregoing, a “Borrower” and collectively the “Borrowers”), and each of the
financial institutions identified as Lenders on Schedule 1 annexed to the Credit
Agreement and made a part hererof (together with each of their successors and
assigns, referred to individually as a “Lender” and, collectively, as the
“Lenders”), and FLEET NATIONAL BANK, a national banking association with an
office at 1185 Avenue of the Americas, New York, New York 10036 (the “Bank”),
acting in the manner and to the extent described in Article IX of the Credit
Agreement (in such capacity, the “Agent”

W I T N E S S E T H:

     WHEREAS, the Borrowers and the Agent and the Lenders entered into a certain
Credit Agreement dated June 4, 2000 (the “Credit Agreement”); and

     WHEREAS, the Borrowers and the Agent and Lenders desire to amend the Credit
Agreement as hereinafter set forth.

     NOW, THEREFORE, in consideration of the mutual covenants and conditions
hereinafter contained, the Borrowers and the Lenders hereby agree as follows:

     1. All capitalized terms not otherwise defined herein shall have the
meaning ascribed to them in the Credit Agreement.

     2. The definition of “EBITDA” is hereby amended to read in its entirety as
follows:

     “EBITDA” means income from continuing operations before interest, taxes,
depreciation and amortization determined in accordance with GAAP. For the
purpose only of testing compliance with any financial covenant hereunder,
“EBITDA” means income from continuing operations before interest, taxes,
depreciation and amortization determined in accordance with GAAP, plus (a) up to
Three Million Two Hundred Thousand Dollars ($3,200,000) directly related to the
settlement of certain litigation in the fourth quarter of 2000, and (b) up to
Nine Million Dollars ($9,000,000) expensed in the third quarter of 2001 in
connection with the Company’s settlement with the United States Department of
Justice.

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     3. All other sections of the Credit Agreement remain unchanged and in full
force and effect.

4. Borrowers hereby reaffirm all covenants, representations, warranties, and
agreements contained in the Credit Agreement and certify that except as
otherwise specifically indicated herein, all representations made in the Credit
Agreement remain correct and accurate.

     Except as herein amended, the Credit Agreement shall remain unmodified and
in full force and effect and binding upon the parties thereto.

[Signature page follows]

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     IN WITNESS WHEREOF, the parties have caused this Agreement to be duly
executed and delivered by the proper and duly authorized officers as of the date
and year first above written.

AGENT:

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Fleet National Bank

By: /s/ Christian J. Covello
——————————————
      Name: Christian J. Covello
      Title:   Vice President

BORROWERS:

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IMPATH Inc.

By: /s/ Richard C. Rosenzweig
——————————————
      Name: Richard C. Rosenzweig
      Title:   Vice President and General Counsel

IMPATH Predictive Oncology, Inc.

By: /s/ Richard C. Rosenzweig
——————————————
      Name: Richard C. Rosenzweig
      Title:   Vice President and General Counsel

IMPATH-BIS, Inc.

By: /s/ Richard C. Rosenzweig
——————————————
      Name: Richard C. Rosenzweig
      Title:   Vice President and General Counsel

Medical Registry Services, Inc.

By: /s/ Richard C. Rosenzweig
——————————————
      Name: Richard C. Rosenzweig
      Title:   Vice President and General Counsel

IMPATH-BCP, Inc.

By: /s/ Richard C. Rosenzweig
——————————————
      Name: Richard C. Rosenzweig
      Title:   Vice President and General Counsel

IMPATH-PCRL, Inc.

By: /s/ Richard C. Rosenzweig
——————————————
      Name: Richard C. Rosenzweig
      Title:   Vice President and General Counsel

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IMPATH-HDC, Inc.

By: /s/ Richard C. Rosenzweig
——————————————
      Name: Richard C. Rosenzweig
      Title:   Vice President and General Counsel

IMPATH Information Services, Inc.

By: /s/ Richard C. Rosenzweig
——————————————
      Name: Richard C. Rosenzweig
      Title:   Vice President and General Counsel

LENDERS:

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Fleet National Bank

By: /s/ Christian J. Covello
——————————————
      Name: Christian J. Covello
      Title:   Vice President

The Bank of New York

By: /s/ Gina Beyer
——————————————
      Name: Gina Beyer
      Title:   Vice President

Key Corporate Capital Inc.

By: /s/ James R. Lynch, Jr.
——————————————
      Name: James R. Lynch, Jr.
      Title:   Vice President