Single-fraction versus multi-fraction (3 x 9 Gy) stereotactic radiosurgery for large (> 2 cm) brain metastases: a comparative analysis of local control and risk of radiation-induced brain necrosis
Menée sur 289 patients présentant des métastases cérébrales de taille supérieure à 2 cm, cette étude évalue, du point de vue du contrôle local des métastases et de la survenue d'une radionécrose cérébrale, l'intérêt d'une radiochirurgie stéréotaxique fractionnée (3 x 9 Gy)
Purpose : to investigate the factors affecting local control and radiation-induced brain necrosis in patients with brain metastases >2 cm in size who received single-fraction or multi-fraction stereotactic radiosurgery (SRS). Factors associated with the clinical outcomes and the development of brain radionecrosis have been assessed. Patients and Methods : Two hundred and eighty-nine consecutive patients with brain metastases >2.0 cm who received SRS as primary treatment at XXXX were analyzed. Cumulative incidence analysis was used to compare local control and radiation-induced brain necrosis between groups from the time of SRS. To achieve a balanced distribution of baseline covariates between treatment groups, a propensity score analysis were used. Results : The 1-year cumulative local control rates were 77% in single-fraction SRS (SF-SRS) group and 91% in multi-fraction SRS (MF-SRS) group (p=0.01). Recurrences occurred in 25 and 11 patients who received SF-SRS or MF-SRS (p=0.03), respectively. Thirty-one (20%) patients undergoing SF-SRS and 11 (8%) subjected to MF-SRS experienced brain radionecrosis (p=0.004); the 1-year cumulative incidence rates of radionecrosis were 18% and 9% (p=0.01), respectively. Significant differences between the two groups in terms of local control and risk of radionecrosis were maintained after propensity score adjustment. Conclusions : In conclusion, MF-SRS at doses of 27 Gy in three daily fractions appears to be an effective treatment modality for large brain metastases associated with better local control and a reduced risk of radiation-induced radionecrosis as compared with SF-SRS.