Akademik Veri Yönetim Sistemi
JOURNAL OF CANCER RESEARCH AND CLINICAL ONCOLOGY, cilt.151, sa.266, ss.1-8, 2025 (SCI-Expanded, Scopus)
Purpose This study aims to investigate the influence of Gamma Knife dose rate on treatment outcomes, in conjunction with
tumor-specific factors of composition, size, and primary tumor location.
Methods This retrospective cohort study analyzed 173 patients with 451 brain metastases treated between 2011 and 2015.
Radiosurgery was performed using the Leksell Gamma Knife System, with dose rates categorized into four groups based
on cobalt-60 decay: 2.9–2.7, 2.7–2.5, 2.5–2.3, and 2.3–2.1 Gy/min. Tumors were further classified according to dose rate
into a simplified high/low classification (cutoff: 2.5 Gy/min) for clinical applicability. The Response Assessment in Neuro-
Oncology Brain Metastases Group (RANO-BM) criteria were employed to evaluate treatment response. Statistical analyses
were conducted to assess associations between dose rate, tumor characteristics, and outcomes.
Results No significant association was identified between dose rates and treatment response (p = 0.35), indicating effective
tumor control even at lower dose rates. Tumor composition and size had a significant impact on outcomes; cystic tumors
demonstrated poorer responses compared to solid tumors, and larger tumors exhibited reduced efficacy. Specific primary
tumor sites, particularly renal cell carcinoma and malignant melanoma, were linked to less favorable responses, confirming
their radioresistant characteristics.
Conclusion This study highlights that dose rate does not significantly impact treatment outcomes in Gamma Knife radiosurgery
for brain metastases, indicating that effective tumor control can be achieved even at lower dose rates. These findings
provide reassurance regarding the efficacy of treatments utilizing decaying cobalt-60 sources and highlight the importance
of patient- and tumor-specific factors in predicting radiosurgical outcomes.