SAbR For Oligometastatic Renal Cell Carcinoma

Hypothesis:

Stereotactic ablative body radiation (SAbR) prolongs progression-free survival for patients with oligometastatic kidney cancer (RCC) and delays the initiation of systemic therapy.

Primary Objectives:

• To evaluate the delay in time to start of systemic therapy (TTST) as a surrogate of progression free survival (PFS), defined as the time from the first day of SAbR to start of systemic therapy.

Secondary Objective:

* To evaluate the modified progression-free survival (mPFS) for patients with oligometastatic renal cell carcinoma who are treated with SAbR.
* To evaluate the overall survival (OS)
* To evaluate the cancer specific survival (CSS)
* To evaluate the local control rate of irradiated lesions.
* To measure the health-related quality of life (HRQOL).

The study is a prospective single institution phase II single-arm open-label trial evaluating SAbR in patients with newly diagnosed oligometastatic RCC.

Problem Statements:

* Can local therapy (SAbR) safely delay the start of systemic therapy?
* Safely delaying the start of systemic therapy can have significant quality of life benefits for patients since systemic therapy has significant side effects.
* Can SAbR be curative in truly oligometastatic RCC patients?

Primary Endpoint:

• Time to start of systemic therapy (TTST) defined as the time from the first day of SAbR to start of systemic therapy.

Secondary Endpoint:

* Modified progression-free survival (mPFS) is defined as the survival interval without development of \>3 sites of new metastasis, new sites of metastases that are not amenable to SAbR treatment, a total of \>6 sites of metastasis that required SAbR, local failure at SAbR-treated site, or development of brain metastasis.
* Overall Survival
* Local control
* Toxicity
* HRQOL

Sample Size: 23 Patients will be enrolled.

Statistical Analysis: Time to event will be estimated using the Kaplan-Meier approach along with the 95% confidence interval.

Eligibility Criteria:
Inclusion Criteria:

* Metastatic renal cell carcinoma with limited measurable extracranial metastases (Limited metastases, or oligometastases, defined as ≤3 sites of metastasis).
* Radiographic evidence of metastatic disease. CT should be performed within 30 days of registration.
* Pathology confirmation of Renal cell carcinoma.
* Prior surgery, or radiation is permitted.
* Age ≥ 18 years.
* Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, and for 90 days after Radiation treatment has been completed . Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.

A female of child-bearing potential is any woman (regardless of sexual orientation, having undergone a tubal ligation, or remaining celibate by choice) who meets the following criteria:

* Has not undergone a hysterectomy or bilateral oophorectomy; or
* Has not been naturally postmenopausal for at least 12 consecutive months (i.e., has had menses at any time in the preceding 12 consecutive months).

  * Ability to understand and the willingness to sign a written informed consent and agrees to undergo image studies and follow up

Exclusion Criteria:

* Subjects with brain metastasis as assessed by contrast MRI or contrast CT scans(contrast recommended).
* Subjects with previous history of brain metastasis.
* Subjects that received prior systemic therapy for kidney cancer in the past 1 year, except one line of immuno- or cytokine therapy (e.g. prior IL-2); systemic therapy for other cancers does not apply to this exclusion criteria
* Subjects with ≥3 unfavorable prognostic factors defined by Motzer et al. (1999), (KPS \<80% or ECOG\>1, Hgb \< LLN, LDH \>1.5x normal, corrected serum calcium \>10mg/dl and absence of prior nephrectomy), Patients with 0, 1-2, and ≥3 factors had time to death of 20 months, 10 months and 4 months.
* Subjects with life expectancy \< 6 months.
* Subjects receiving any other investigational agents
* Subjects must not be pregnant due to the potential for congenital abnormalities and the potential of this regimen to harm nursing infants.