The following is a summary of “Dose-response of localized renal cell carcinoma after stereotactic body radiation therapy: A meta-analysis,” published in the March 2024 issue of Oncology by Huang et al.
Stereotactic ablative radiation therapy (SBRT) represents a promising modality for managing primary renal cell carcinoma (RCC), particularly among patients deemed ineligible for surgical intervention. This review aims to comprehensively evaluate the impact of escalating the biologically equivalent dose (BED) through diverse radiation fractionation schemes on clinical outcomes in this patient population.
PubMed (Medline), EMBASE, and the Cochrane Library were systematically searched to identify relevant studies published up to October 2023. Studies focusing on patients with localized RCC undergoing SBRT were included to assess its efficacy in local control, progression-free survival, and overall survival. Meta-regression analyses, employing a random-effects model, were performed to evaluate clinical outcomes relative to the BED for each study, with heterogeneity assessed using I2 statistics.
The analysis encompassed 724 RCC patients from 22 studies, with a mean age of 72.7 years (range: 44.0–81.0). Exceptional rates of local control were observed, with estimates of 99% (95% CI: 97–100%, I2 = 19%), 98% (95% CI: 96–99%, I2 = 8%), and 94% (95% CI: 90–97%, I2 = 11%) at one year, two years, and five years, respectively. However, no definitive correlation between escalating BED and local control, progression-free survival, or overall survival was discerned. Furthermore, no evidence of publication bias was identified.
This review underscores the absence of a discernible dose-response relationship between oncological outcomes and biologically effective doses in SBRT for RCC. Notably, excellent local control outcomes were consistently observed across a spectrum of doses. Pending further evidence, current recommendations discourage routine dose escalation beyond thresholds of 25–26 Gy in one fraction or 42–48 Gy in three fractions. Instead, considerations for de-escalation or adjustments to target coverage should be weighed to ensure safe organ-at-risk doses are maintained, thereby optimizing treatment outcomes.
Source: sciencedirect.com/science/article/pii/S0167814024001385