Fractionated Stereotactic Radiation Therapy Using Volumetric Modulated Arc Therapy in Patients with Solitary Brain Metastases

Abstract

Purpose. To analyze retrospectively the clinical efficacy and safety for patients treated with fractionated stereotactic radiation therapy (FSRT) using volumetric modulated arc therapy. Methods. Between 2016 and 2017, 46 patients with solitary brain metastasis who underwent FSRT consisting of 25-40 Gy/5 fractions were recruited in this study. All targets within the same course received different prescriptions according to size. Toxicities were graded according to the Common Terminology Criteria for Adverse Events version 4.0. Results. The median follow-up was 11 months (3-53 months). The 6-month and 12-month local control rate calculated by Kaplan-Meier estimate was, respectively, 95% and 86%. Tumor diameter<2.5 cm obtained 100% improved 12-month local control rate compared with 66% in those with ≥2.5 cm (P<0.001). The 12-month local control calculated by Kaplan-Meier estimate was 95% in tumors with >30 Gy treatment and only 60% in tumors with ≤30 Gy treatment (P=0.001). Multivariate analysis revealed that the prescription dose≤30 Gy resulted in increased local failure (hazard ratio (HR), 0.14 (range, 0.019-0.95; P=.046)). Grade 3 or worse toxic effects were found in 5 (11%) patients, and no patient experienced surgical resection for symptomatic radioactive necrosis. Conclusions. FSRT for solid brain metastasis appears to have the advantages of a high rate of local control with a minimal risk of severe toxicity and deserves application in the clinical practice.

Hypofractionated stereotactic radiotherapy for brain metastases in lung cancer patients: Dose‒response effect and toxicity

“…However, we observed an improvement in LC when treating with > 30 Gy/5 fractions, with a 1year cumulative incidence of local failure of 11.2%. Similar results have also been reported [17][18][19]. Sten Myrehaug's study showed that local failure at 1 year was 33% for patients treated with < 30 Gy/5 fractions versus 19% for patients treated with ≥ 30 Gy/5 fractions, with a total dose of < 30 Gy as opposed to ≥ 30 Gy (HR, 1.68, P = 0.03) as a signi cant predictor of local failure [18].…”

Outcomes in Patients with Intact and Resected Brain Metastasis Treated with 5-Fraction Stereotactic Radiosurgery

“…Time to LP (eg, LC) observed in this study compares favorably to those of prior HF-SRS reports, which typically range from 70 to 90% ≥12 months following SRS. 8 , 11 , 13 , 15 , 16 , 17 , 23 , 31 Prior HF-SRS series have demonstrated associations between improved LC and smaller tumor size, 15 , 17 surgical resection, 15 and greater HF-SRS dose. 16 , 17 , 23 , 31 We similarly identified significant association between greater total GTV (cc) and LP; however, we found no association to SRS dose or surgical resection among a population with a larger number of BMs of similar size, with >99 and 69% BMs receiving 5-fraction HF-SRS total doses <30 and 25 Gy, respectively.…”

“… 8 , 11 , 13 , 15 , 16 , 17 , 23 , 31 Prior HF-SRS series have demonstrated associations between improved LC and smaller tumor size, 15 , 17 surgical resection, 15 and greater HF-SRS dose. 16 , 17 , 23 , 31 We similarly identified significant association between greater total GTV (cc) and LP; however, we found no association to SRS dose or surgical resection among a population with a larger number of BMs of similar size, with >99 and 69% BMs receiving 5-fraction HF-SRS total doses <30 and 25 Gy, respectively. Comparatively, in a recent 5-fraction HF-SRS series with just 38% patients who received <6 Gy per fraction, a total radiation therapy dose of ≥30 Gy prescribed to 99% PTV coverage was associated with superior LC.…”

Recurrence of Glioblastoma Multiforme (GBM) Treated in a Radiotherapy Institution in Chile

“…on September 22, 2020 with excellent tolerance and low doses of corticosteroids (4mg of dexamethasone every day) a 90% KPS and ECOG 1; Therefore, the benefit of H-SRS in the treatment of relapses or remnants due to GBM is supported [13,14]. Treatment monitoring is based on brain MRI and monthly clinical evaluations.…”