Stereotactic Ablative Radiation for Systemic Therapy-naïve Oligometastatic Kidney Cancer

Area of Science:

• Oncology
• Radiation Oncology
• Medical Physics

Background:

• Systemic therapy-naïve oligometastatic renal cell carcinoma (RCC) lacks evidence-based management guidelines.
• Oligometastatic disease represents an intermediate state between localized and widespread metastatic cancer.

Purpose of the Study:

• To evaluate stereotactic ablative radiotherapy (SAbR) for longitudinal disease control in systemic therapy-naïve oligometastatic RCC.
• To assess SAbR's impact on patient quality of life (QOL).

Main Methods:

• Prospective phase II single-arm trial involving 23 RCC patients with ≤3 extracranial metastases.
• SAbR administered longitudinally to all initial and subsequent metastases.
• Primary endpoint: freedom from systemic therapy >1 year; secondary endpoints: PFS, QOL, LC, toxicity, CSS, OS.

Main Results:

• Freedom from systemic therapy at 1 year was 91.3%, exceeding the 60% benchmark.
• One-year progression-free survival (PFS) was 82.6% with 100% local control (LC).
• Quality of life (QOL) was largely unaffected; no grade 3/4 toxicities observed.

Conclusions:

• SAbR provides meaningful longitudinal disease control for oligometastatic RCC while preserving QOL.
• These findings support further investigation of SAbR in this patient population.