Clinical outcomes of patients with limited brain metastases treated with hypofractionated (5 × 6 Gy) conformal radiotherapy

Abstract

Background and Purpose Hypofractionated conformal radiotherapy (hfCRT) is used for larger brain metastases or metastases near critical structures. We investigated hfCRT outcomes for newly diagnosed brain metastases. Materials and Methods We identified 195 patients with 1–3 brain metastases who underwent 5 × 6Gy hfCRT for 231 lesions from 2007–2013. Associations among clinical factors, local control (LC), distant brain control (DC) and overall survival (OS) were tested using univariate and multivariate (MVA) Cox regression analysis and Kaplan-Meier method. Results Median follow-up was 12.8 months. One hundred forty-three (62%) lesions were treated with hfCRT post-operatively, and 88 (38%) with definitive hfCRT. LC for all lesions was 83% at 1 year. For lesions treated with post-operative hfCRT, tumor size (HR=4.7, p=0.04) and subtotal resection (HR=2.7, p=0.02) were predictive of local failure on MVA. For lesions ≥2.8cm in size, LC was 61% at 12 months for lesions status-post subtotal resection, compared to 84% status-post gross total resection (p=0.004). Extracranial disease presence was associated with worse DC (HR=1.8, p=0.008) and OS (HR=3.1, p<0.001). Conclusions We showed 5 × 6Gy hfCRT provides acceptable LC at 1 year for limited brain metastases. For large lesions not grossly resected, more aggressive strategies can be considered to improve LC.

Focal conformal fractionated radiotherapy vs. radiosurgery for lung cancer patients with limited brain metastases

“…Our results regarding FCFRT were slightly better to the literatures in which 1 year OS around 50% and 2 year OS around 30% were reported (6,7). Our results regarding RS were also slightly better to the literatures in which median OS around seven to nine months was reported (4,5).…”

“…When we searched in PubMed using keywords "(((brain metastases) OR (brain metastasis)) AND (conformal) AND ((radiotherapy) OR (radiation therapy))) NOT (whole brain radiotherapy)" in Nov 2019, we identified two relevant studies providing information regarding definitive FCFRT for LBM. Ohtakara and Hoshi had reported median OS 12 months for 24 patients whereas 13.9 months was reported by Lockney et al for 195 patients (6,7). However, both studies were not limited to neither LC nor definitive setting.…”

The Expanding Role of Radiosurgery for Brain Metastases

“…Table 2 details fifteen series employing 2–7 fractions of radiotherapy where 12 month local control rates ranging between 49% and 96% are reported [ 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ]. Studies were excluded from Table 2 if 12-month LC outcomes were not analysed, or if hypofractionated stereotactic radiotherapy (hfSRT) was performed postoperatively to the tumour cavity, with these patients not being separated in the analysis [ 58 , 59 , 60 , 61 , 62 , 63 , 64 ].…”

Proceedings of the 2018 next-generation Gamma Knife research meeting

“…Many radiosurgeons using linear accelerator (LINAC)-based therapy already use hypofractionation regimens for larger or multiple lesions, especially in the postresection setting. 19,20 In contrast, radiosurgeons performing Gamma Knife therapy at the Cleveland Clinic use 2-stage radiosurgery (2 doses of 15 Gy, or 18 Gy then 12 Gy administered 1 month apart), and Asher et al and Angelov et al have described the successful use of lower-dose GKSRS as neoadjuvant radiosurgery prior to resection. 1,3 As an alternative to Asher et al's protocol, the Cleveland Clinic has an in-house protocol with dose escalation for neoadjuvant radiosurgery.…”