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26 had adjuvant targeted therapy (7 of whom had undergone metastasectomy). The study noted
improvement in neurologic function and pain relief, while the authors found no improvement in overall
survival amongst patients managed with each modality. However, amongst all patients, there was an overall
[22]
survival benefit for those who received targeted therapy .

Stereotactic body radiation therapy (SBRT) has been employed in the management of osseous metastases
from RCC, both for the treatment of metastases and for palliation. In a study assessing local control of bone
metastases after SBRT or external beam radiation therapy, authors assessed response to 95 bone lesions in
46 patients. They noted significantly improved pain control with SBRT vs. EBRT, 74.9% vs. 39.9%, 74.9%,
and 35.7% experiencing improvement at 12 and 24 months, respectively (P = 0.02). The median time to
[23]
radiolographic failure in both groups was similar (7 months) . Jhaveri et al. demonstrated a dose-
[24]
dependent effect of SBRT on the efficacy (83% vs. 73%) and durability (46% vs. 12% symptom recurrence) of
pain control for patients receiving > 85 Gy vs. < 85 Gy doses.

Liver
[3]
Renal cell carcinoma metastatic to the liver occurs in approximately 20%-40% of patients . These
metastases are difficult to manage as they typically present concurrently with multiple extrahepatic
metastases. Furthermore, only 25% of patients have solitary liver lesions . Ruys et al. reviewed 33
[26]
[25]
patients who underwent intervention for hepatic metastases, with metastasectomy performed in 29 patients.
Overall survival was 79% and 43% at 1 and 5 years after resection. The authors noted that prognostic factors
for improved survival included metachronous metastases and radical resection. Meanwhile, size, solitary
metastases, and the presence of extrahepatic metastases were not associated with an impact on overall
[26]
survival .

[27]
Staehler et al. retrospectively compared 48 patients who underwent liver metastasectomy and 20 patients
who were denied surgery to evaluate overall survival. In this study, nearly 80% of patients received adjuvant
systemic therapy with interleukin therapy. Overall survival at 5 years was 62% in the group who underwent
resection vs. 29% in those who were observed. The survival difference was most substantial amongst patients
with primary tumor low-grade histology (155 months vs. 29 months) in the metastasectomy and
observation cohorts, respectively. Notably, patients with synchronous metastases, ECOG scores > 0 and
[27]
patients with high-grade histology did not benefit from surgical intervention . Although differences were
not statistically significant between cohorts, patients who were denied surgery tended to have higher grade
disease and higher volume metastatic burden.

[28]
In a recent study, Joyce et al. analyzed 34 cases of hepatic metastasectomy. In 17 patients, hepatic
resection was performed for a direct invasion of the liver, while 21 patients underwent simultaneous
nephrectomy and hepatic metastasectomy. Four patients had both locally invasive and separate hepatic
metastases. Amongst these patients, 2-year cancer-specific survival and overall survival were 40% and 29%,
respectively. In a matched cohort of 68 patients undergoing metastasectomy for mRCC to non-hepatic sites,
2-year cancer-specific survival and overall survival were 40% and 28%, respectively .
[28]
Brain
The role of surgical metastasectomy of brain metastases in mRCC remains limited. The surgical approach
typically includes either SBRT, whole-brain radiotherapy, or surgical resection. Analyses of the role of
surgical resection remain limited to case reports and small series. The largest series analyzing the role of
surgical resection for brain metastases in mRCC retrospectively analyzed 50 patients with metachronous
brain metastases after primary treatment. The median overall survival from the time of craniotomy was
approximately 13 months, with a 10% postoperative mortality rate. Twenty-two patients received additional