Single-fraction versus hypofractionated stereotactic radiosurgery for medium-sized brain metastases of 2.5 to 3 cm

• Published in: Journal of neuro-oncology Vol. 145; no. 1; pp. 49 - 56
• Main Authors: Chon, Haemin, Yoon, KyoungJun, Lee, Doheui, Kwon, Do Hoon, Cho, Young Hyun
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.10.2019; Springer Nature B.V
• Subjects: Aged; Brain cancer; Brain Neoplasms - secondary; Brain Neoplasms - surgery; Clinical Study; Dose Fractionation, Radiation; Female; Follow-Up Studies; Humans; Male; Medicine; Medicine & Public Health; Metastases; Metastasis; Neoplasms - pathology; Neoplasms - surgery; Neurology; Oncology; Prognosis; Prospective Studies; Radiation therapy; Radiosurgery; Radiosurgery - mortality; Retrospective Studies; Survival Rate; Toxicity; Hypofractionation; Stereotactic radiosurgery; Brain metastases; Radiation necrosis
• ISSN: 0167-594X; 1573-7373
• DOI: 10.1007/s11060-019-03265-1

Purpose Given recently suggested utility of hypofractionated stereotactic radiosurgery (SRS) in treating large brain metastases (BMs) > 3 cm, we sought to prospectively control tumor size variable to investigate the efficacy and safety of hypofractionated SRS for medium-sized BMs (2.5 to 3 cm) compared with single-fraction SRS. Methods Between 2011 and 2015, a total of 100 patients with newly diagnosed BMs (n = 105) of 2.5 to 3 cm had been treated with either single-fraction (n = 67; median dose 20 Gy) or hypofractionated SRS (n = 38; median cumulative dose 35 Gy in 5 daily fractions). No patients received any prior or upfront whole brain radiotherapy. In each patient, treatment outcome was measured by local tumor control (LTC), overall and progression-free survival (OS and PFS), and the occurrence of radiation necrosis (RN). Results With a median follow-up of 14 months, significant differences were observed between the single-fraction versus hypofractionated SRS groups in the incidence of RN (29.9% vs. 5.3%, P  < 0.001) and LTC (1-year LTC rates 66.6% vs. 92.4%, P  = 0.028). There were no differences in PFS (median 6 months vs. 6 months, P  = 0.381) and OS (median 13 months vs. 18 months, P  = 0.239). Treatment-related adverse events ( ≥ grade 2 toxicity by CTCAE ver. 4.0) occurred more frequently in single-fraction group, although the difference did not reach statistical significance (56.3% vs. 36.1%, P  = 0.084). Conclusions Our results suggest a better safety and efficacy profile of hypofractionated SRS for medium-sized BMs compared with single-fraction SRS. Further prospective studies are needed to confirm these results.