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                                                                   EXHIBIT 99.4

                               US ONCOLOGY, INC.

                            IS OFFERING TO EXCHANGE
                                      its
                   9 5/8% Senior Subordinated Notes due 2012
               pursuant to its Prospectus, dated         , 2002,
                        for all issued and outstanding
                   9 5/8% Senior Subordinated Notes due 2012

To: Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees:

  US Oncology, Inc., a corporation organized under the laws of Delaware
("USON"), is offering, subject to the terms and conditions set forth in its
prospectus, dated          , 2002 (the "Prospectus"), relating to the offer
(the "Exchange Offer") of USON to exchange an aggregate principal amount of up
to $175,000,000 of its 9 5/8% Senior Subordinated Notes due 2012 (the "New
Notes"), the issuance of which has been registered under the Securities Act of
1933, as amended (the "Securities Act"), for a like principal amount of its
issued and outstanding 9 5/8% Senior Subordinated Notes due 2012 (the "Old
Notes"). The Old Notes were issued in offerings under Rule 144A and Regulation
S of the Securities Act that were not registered under the Securities Act. The
Exchange Offer is being extended to all holders of the Old Notes in order to
satisfy certain obligations of USON contained in the Registration Rights
Agreement, dated as of February 1, 2002, by and among USON and UBS Warburg
LLC, Deutsche Banc Alex. Brown Inc. and First Union Securities, Inc. The New
Notes are substantially identical to the Old Notes, except that the transfer
restrictions and registration rights applicable to the Old Notes do not apply
to the New Notes.

  Please contact your clients for whom you hold Old Notes regarding the
Exchange Offer. For your information and for forwarding to your clients for
whom you hold Old Notes registered in your name or in the name of your
nominee, or who hold Old Notes registered in their own names, we are enclosing
the following documents:

    1. A Prospectus dated        , 2002;

    2. A Letter of Transmittal for your use and for the information of your
  clients;

    3. A Notice of Guaranteed Delivery to be used to accept the Exchange
  Offer if: (a) certificates for the Old Notes are not immediately available,
  (b) time will not permit the certificates for the Old Notes or other
  required documents to reach the Exchange Agent before the expiration of the
  Exchange Offer or (c) the procedure for book-entry transfer cannot be
  completed prior to the expiration of the Exchange Offer;

    4. A form of letter which may be sent to your clients for whose accounts
  you hold Old Notes registered in your name or in the name of your nominee,
  with space provided for obtaining such clients' instructions with regard to
  the Exchange Offer;

    5. Guidelines for Certification of Taxpayer Identification Number on
  Substitute Form W-9; and

  Your prompt action is requested. The Exchange Offer will expire at 5:00
P.M., New York City time on         , 2002, unless the Exchange Offer is
extended (as it may be extended, the "Expiration Date"). Old Notes tendered
pursuant to the Exchange Offer may be withdrawn at any time before the
Expiration Date.
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  Unless a holder of Old Notes complies with the procedures described in the
Prospectus under the caption "The exchange offer--Guaranteed delivery
procedures," the holder must do one of the following on or prior to the
Expiration Date to participate in the Exchange Offer:

  . tender the Old Notes by sending the certificates for the Old Notes, in
    proper form for transfer, a properly completed and duly executed Letter
    of Transmittal, with any required signature guarantees, and all other
    documents required by the Letter of Transmittal, to JPMorgan Chase Bank,
    as Exchange Agent, at one of the addresses listed in the Prospectus under
    the caption "Exchange Agent"; or

  . tender the Old Notes by using the book-entry procedures described in the
    Prospectus under the caption "The exchange offer--Book-entry transfer"
    and transmitting a properly completed and duly executed Letter of
    Transmittal, with any required signature guarantees, or an Agent's
    Message (described below) instead of the Letter of Transmittal, to the
    Exchange Agent.

  In order for a book-entry transfer to constitute a valid tender of Old Notes
in the Exchange Offer, the Exchange Agent must receive a confirmation of book-
entry transfer (a "Book-Entry Confirmation") of the Old Notes into the
exchange Agent's account at The Depository Trust Company in accordance with
The Depository Trust Company's Automated Tender Offer Program prior to the
Expiration Date. The term "Agent's Message" means a message, transmitted by
The Depository Trust Company and received by the Exchange Agent and forming a
part of the Book-Entry Confirmation, which states that The Depository Trust
Company has received an express acknowledgment from the tendering holder of
Old Notes that the holder has received and has agreed to be bound by the
Letter of Transmittal.

  If a registered holder of Old Notes wishes to tender the Old Notes in the
Exchange Offer, but (a) the certificates for the Old Notes are not immediately
available, (b) time will not permit the certificates for the Old Notes or
other required documents to reach the Exchange Agent before the expiration of
the Exchange Offer or (c) the procedure for book-entry transfer cannot be
completed before the Expiration Date, a tender of Old Notes may be effected by
following the Guaranteed Delivery Procedures described in the Prospectus under
the caption "The exchange offer--Guaranteed delivery procedures."

  USON will, upon request, reimburse brokers, dealers, commercial banks, trust
companies and other nominees for reasonable and necessary costs and expenses
incurred by them in forwarding the Prospectus and the related documents to the
beneficial owners of Old Notes held by them as nominee or in a fiduciary
capacity. USON will pay or cause to be paid all stock transfer taxes
applicable to the exchange of Old Notes in the Exchange Offer, except as set
forth in Instruction 13 of the Letter of Transmittal.

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  Any inquiries you may have with respect to the Exchange Offer should be
directed to JPMorgan Chase Bank, the Exchange Agent for the Exchange Offer, at
its address and telephone number set forth on the front of the Letter of
Transmittal. Any requests for additional copies of the enclosed materials
should be directed to US Oncology, Inc. at the following address and telephone
number:

                               US Oncology, Inc.
                           Attention: B. Scott Aitken
                             16825 Northchase Drive
                                   Suite 1300
                              Houston, Texas 77060
                           Telephone: (832) 601-6178

                                          Very truly yours,

                                          US ONCOLOGY, INC.

NOTHING CONTAINED HEREIN OR IN THE ENCLOSED DOCUMENTS SHALL CONSTITUTE YOU OR
ANY PERSON AS AN AGENT OF USON OR THE EXCHANGE AGENT, OR AUTHORIZE YOU OR ANY
OTHER PERSON TO USE ANY DOCUMENT OR MAKE ANY STATEMENT ON BEHALF OF EITHER OF
THEM IN CONNECTION WITH THE EXCHANGE OFFER, EXCEPT FOR STATEMENTS EXPRESSLY
MADE IN THE PROSPECTUS OR THE LETTER OF TRANSMITTAL.

Enclosures

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