Stereotactic body radiotherapy for cervical cancer (score): systematic review and meta-analysis

Introduction: Locally advanced cervical cancer (LACC) remains a critical global health issue, disproportionately impacting low- and middle-income countries despite advancements in prevention and early detection. For LACC, treatment typically involves external beam radiotherapy (EBRT) with chemotherapy followed by brachytherapy (BCT). However, due to resource challenges, anatomical limitations, and patients’ comorbidities or preferences, Stereotactic Body Radiotherapy (SBRT) is being considered an alternative to BCT due to its high precision and potential to reduce side effects.

Objective: To evaluate the efficacy and safety of SBRT boost as an alternative for patients without conditions to receive traditional BCT.

Methods: A systematic review and meta-analysis, registered with PROSPERO and adhering to PRISMA guidelines, focused on studies of women with LACC treated with SBRT as an alternative to BCT. A comprehensive literature search was conducted in PubMed, Embase, and Cochrane databases. The analysis included retrospective and prospective studies, excluding those with fewer than five participants or a follow-up of less than 12 months. Due to study heterogeneity, a random-effects model was used for statistical analysis. The review measured outcomes such as local control (LC), overall survival (OS) rates and late toxicity, with meta-regression analyses examining correlations between treatment parameters and the primary endpoints.

Results: The meta-analysis reviewed 11 studies from 2012 to 2022 across various regions. Median ages ranged from 52 to 80 years, with sample sizes between 6 and 55 patients. The pooled LC rate was 92.3% (CI 95% 88–96%), and the OS rate was 56% (CI 95% 48–63%), both with no heterogeneity. LC rates at 1, 3, and 5 years were 94%, 90%, and 88%, respectively; OS rates were 76%, 62%, and 59%. Meta-regression analyses found no significant correlation between treatment parameters and LC or OS. The rate of late grade 3 or higher genitourinary toxicity was 2%, and gastrointestinal toxicity was 3.3%. Only the SBRT boost interval of 24 hours or less was linked to increased late GI toxicity (p = 0.009).

Conclusion: SBRT emerges as a promising boost therapy for cervical cancer patients with no anatomical or clinical condition or who refuse to receive BCT. SBRT produced robust LC and low rates of late severe toxicity. Further investigations to optimize SBRT treatment regimens and validate long-term clinical outcomes are warranted.

Corresponding author: Jessé Lopes da Silva (e-mail: jessejeu@yahoo.com.br).