P13.11 Outcome evaluation of oligometastatic patients with single, large brain metastases treated with gross total resection (GTR) followed by hypofractionated stereotactic radiosurgery (HSRS) on the tumor bed

Abstract

AbstractIntroduction:In case of large brain metastases (BMs), treatment option include whole-brain-radiation-therapy (WBRT), surgery, single dose radiosurgery (SRS) or Hypofractionated stereotactic radiosurgery (HSRS). None of these, when given as a single modality are able to obtain and adequate local control rate. Therefore a combined approach, if feasible, is recommended. The aim of this study was to evaluate the benefit of a combined treatment, gross total resection (GTR) followed by adjuvant hypofractionated-stereotactic-radiosurgery (HSRS) on the tumor bed, in oligometastatic patients with single, large BMs.Methods and Materials:From January 2011 to March 2015, 69 patients with single, large BMs, controlled primary tumor and extracranial disease were treated. All patients underwent gross total resection (GTR) followed by HSRS on the tumor bed with a total dose of 30 Gy in 3 daily fractions. Clinical outcome was evaluated by neurological examination and MRI 2 months after RT and then every 3 months. Local progression was defined as radiographic increase of the enhancing abnormality in the treated brain volume and brain distant progression (BDP) as the presence of new brain metastases or leptomeningeal enhancement outside the treated brain volume. Surgical morbidity and radiation-therapy toxicity, local control (LC), brain distant progression (BDP), and overall survival (OS) were evaluated.Results:The median preoperative volume and maximum diameter of BMS was 18.45 cm3 (range 4.06–64.23 cm3) and 3.6 cm (range 2.1–5.4 cm); the median clinical target volume (CTV) was 29 cm3 (range 4.06–203.10 cm3) and the median planning target volume (PTV) was 55.19 cm3 (range 17.18–282.90 cm3). The median follow-up was 24 months (range 4–33 months). The 1-and 2-year LC in site of treatment was 100%; the median, 1-and 2-year BDP was 11.9 months, 19.6% and 33 %; the median, 1-and 2-year OS was 24 months (range 4–33 months), 91.3% and 73%. No severe postoperative morbidity or radiation toxicity occurred in our series.Conclusions:Multimodal approach, surgery followed by HSRS, can be an effective treatment option for selected patients with single, large brain metastases from different solid tumors.Keywords: brain metastases, surgical resection, hypofractionated-stereotactic-radiosurgery