To Evaluate Stereotactic Body Radiotherapy for Treatment of Primary Renal Cell Carcinoma Tumors

There is a need for a non-invasive treatment modality in renal cell carcinoma (RCC) patients
who are medically or technically inoperable or refuse surgery. The primary tumor in patients
with RCC is generally managed surgically or with a non-surgical ablative modality, but there
is significant toxicity and invasiveness associated with current surgical and percutaneous
treatment modalities. Stereotactic radiotherapy was first developed to treat brain
metastases and other intracranial tumors by giving a single high-dose treatment delivered
with a precision of less than 1 mm. This treatment requires immobilization of the tumor and
precise imaging to guide the treatment. The brain is particularly amenable to this approach
since there is no internal brain motion, the skull is easily fixed in position, and
excellent imaging is available. Recent developments in immobilization and image guidance now
permit precise tumor targeting of extracranial sites, such as the liver and lung.
Stereotactic radiotherapy used at extracranial sites is called stereotactic body
radiotherapy (SBRT). Because of the great precision of SBRT, a high dose per treatment is
possible. Early work evaluating SBRT in primary and metastatic liver and lung tumors has
shown excellent results in tumor control and toxicity. Based on this, we propose expanding
the use of this technique to RCC.

In this study, the investigators seek to evaluate the safety and efficacy of SBRT for the
treatment of the primary tumor in renal cell carcinoma (RCC). One goal of this study is to
establish the maximum tolerated dose (MTD) of renal SBRT by determining the dose-volume
relationship and toxicity for the kidney when high dose per fraction SBRT is used. In order
to ensure proper immobilization and tumor localization, the investigators will use abdominal
compression, 4D CT scanning at the time of simulation, and cone beam CT scanning at the time
of treatment. The investigators propose to perform Tc-99m glucoheptonate renal scans before
and after SBRT to assess renal tissue at the periphery of the lesion, as well as baseline
and follow-up serum chemistry evaluation, creatinine, complete blood count, urinalysis, and
creatinine clearance.

Inclusion Criteria:

- Any patient with a primary renal cell carcinoma (RCC) tumor who is inoperable for
technical (i.e surgical) or medical reasons

- Patient must be screened by a urologic surgeon to verify eligibility on the above
basis

- Biopsy proof of RCC is preferred; however, in current practice the diagnosis is often
clinical based on characteristic imaging. If there are compelling clinical reasons
not to proceed with biopsy, the clinical diagnosis will suffice.

- Patient with metastases are eligible if in the opinion of the treating physicians the
patient could benefit from treatment of the primary renal tumor.

- ECOG performance status 0-2

- Age ≥18 years

- Signed informed consent

Exclusion Criteria:

- Inadequate renal function, as measured by creatinine clearance calculated from 24
hour urine collection. Creatinine clearance values of at least 50 ml/min are required

- Prior attempt at curative treatment of this primary kidney tumor

- Inability to lie still for approximately 1 hour in immobilization device

- Presence of a connective tissue disorder other than rheumatoid arthritis.

- Pregnancy

- Inability to develop a radiation treatment plan that adheres to the dose constraints
described below in Radiotherapy Treatment Planning section.