**Exhibit 10.53****ADDENDUM TWO****TO LEASE AGREEMENT FOR A GAMMA KNIFE UNIT**     This ADDENDUM TWO TO LEASE AGREEMENT FOR A GAMMA KNIFE UNIT (this “Addendum”) is datedeffective as of January 17, 2007, and is entered into between GK FINANCING, LLC, a Californialimited liability company (“GKF”), and SUNRISE HOSPITAL MEDICAL CENTER, LLC, d/b/a as SunriseHospital Medical Center, [a Nevada corporation] (“Medical Center”), with reference to the followingrecitals:**Recitals****:**     A. On January 8, 2001, GKF and Medical Center executed a Lease Agreement for a Gamma KnifeUnit, which Lease Agreement was amended by a certain Addendum dated June 3, 1999 (such LeaseAgreement, as amended by such Addendum, is referred to herein as the “Lease”);     B. Section 8 of the Lease obligates Medical Center to provide properly trained professional,technical and support personnel (including, without limitation, physicists) for the properperformance of Gamma Knife procedures utilizing the Equipment.     C. Medical Center has requested GKF to provide the services of a medical radiation physicist,and GKF is willing to provide such personnel on the terms and conditions set forth herein.     NOW THEREFORE, in consideration of the mutual covenants and agreements set forth herein, andfor other good and valuable consideration, the receipt and sufficiency of which are herebyacknowledged, the parties agree as follows:**Agreement****:**     1. **Defined Terms****.**Unless otherwise defined herein, the capitalized terms used hereinshall have the same meanings set forth in the Lease.     2. **Provision of a Medical Radiation Physicist****.**          a. For so long as GKF is under contract with a medical radiation physicist (a “Physicist”) toprovide the services set forth in Exhibit A (Specification) attached hereto (the “Services”), andsaid physicist is available to provide the services, GKF shall make available such Physicist toMedical Center to provide the services. The Services shall be performed at the Site. MedicalCenter and the physicians performing the Gamma Knife radiosurgery procedure shall have soleresponsibility to supervise and direct the Physicist.          b. Physicist shall only perform Services as, when and if requested by Medical Center, whichrequest shall be made telephonically or in writing not less than ten (10) days in advance of thedate the Services are requested, unless days of advance notice is mutually agreed to by bothparties.
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          c. Medical Center shall have sole responsibility to credential the Physicist to provide theServices at the Facility, and to verify that Physicist is in compliance with all state andregulatory requirements in connection therewith.          d. Medical Center agrees to reimburse GKF at the per case rates shown in Exhibit B (Rates)attached hereto, which rates shall be subject to increase by the amount of any increase to GKF’scosts. GKF shall submit a detailed invoice to Medical Center on a monthly basis for Servicesrendered, and such invoices shall be payable within ten (10) days following receipt.          e. As GKF is making the Physicist available to Medical Center as provided herein only as anaccommodation to Medical Center, Medical Center shall release, defend, indemnify, protect and holdharmless GKF, its officers, directors, managers, members, affiliates, employees and agents, andeach of them, from any and all liability, obligation, damage, loss, cost, claim or demandwhatsoever of any kind or nature, including reasonable attorney’s fees, and costs arising directlyor indirectly from action taken or omissions made by Physicist in the provision of Services. ThisSection shall survive the termination of this Agreement.          f. Nothing set forth herein shall (i) relieve or release Medical Center of its obligationunder the Lease to provide properly trained professional, technical and support personnel(including, without limitation, physicists) for the proper performance of Gamma Knife proceduresutilizing the Equipment; and/or (ii) obligate GKF to furnish a Physicist to Medical Center excepton the terms set forth herein.     3. **Captions****.**The captions and paragraph headings used herein are for convenience onlyand shall not be used in construing or interpreting this Addendum.     4. **Full Force and Effect****.**Except as amended by this Addendum, all of the terms andprovisions of the Lease, including without limitation, the amount of the Lease Payments, shallremain in full force and effect.     IN WITNESS WHEREOF, the parties have executed this Addendum effective as of the date firstwritten above.           **GK FINANCING, LLC**   **SUNRISE HOSPITAL AND MEDICAL CENTER**             By: /s/ Ernest A. Bates, M.D.   By: /s/ Steve Otto             Name: Ernest A. Bates, M.D.   Name: Steve Otto  Title: Policy Committee Member   Title: Chief Operating Officer and          Interim Chief Executive Officer  
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**Exhibit A**SERVICESGamma Knife radiosurgery: **•** Perform stereotactic treatment planning for Gamma Knife radiosurgeries.  **•** Operate GK unit during treatment. Assure that all treatment parameters are set correctlyand documented.  **•** Calibrate and perform quality assurance on Gamma Knife unit as required by state law andJCAHO (daily, monthly, and annual schedule).  **•** Work with client to select optimum imaging parameters (MRI, CT and/or angiography)appropriate to each case.  **•** Interface with physicians (radiation oncologists and neurosurgeons) to provide necessaryphysics information for their treatment decisions.
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**Exhibit B**RATESThe following fees shall apply: **•** Gamma Knife stereotactic radiosurgery case rate: * per case (multiple fraction caseswill be counted as a single case)  **•** Monthly Gamma Knife calibration is included in the per case rate so long as at least one(1) case is performed in any month.  **•** Annual Gamma Knife calibration and submission of quality controls (one-time annual fee):*The foregoing fees include all expenses and fees associated with procedures, travel andaccommodations during scheduled visits.
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