title: Toward the complete control of brain metastases using surveillance screening and stereotactic radiosurgery.
abstract: OBJECTIVE The incidence of brain metastases is increasing with improved systemic therapies, many of which have a limited impact on intracranial disease. Stereotactic radiosurgery (SRS) is a first-line management option for brain metastases. The purpose of this study was to determine if there is a threshold tumor size below which local control (LC) rates approach 100%, and to relate these findings to the use of routine surveillance brain imaging. METHODS From a prospective registry, 200 patients with 1237 brain metastases were identified who underwent SRS between December 2012 and May 2015. The median imaging follow-up duration was 7.9 months, and the median margin dose was 18 Gy. The maximal diameter and volume of tumors were measured. Histological analysis included 96 patients with non-small cell lung cancers (NSCLCs), 40 with melanoma, 35 with breast cancer, and 29 with other histologies. RESULTS Almost 50% of brain metastases were NSCLCs and commonly measured less than 6 mm in maximal diameter or 70 mm3in volume. Thirty-three of 1237 tumors had local progression at a median of 8.8 months. The 1- and 2-year actuarial LC rates were 97% and 93%, respectively. LC of 100% was achieved for all intracranial metastases less than 100 mm3in volume or 6 mm in diameter. Patients whose tumors at first SRS were less than 10 mm maximal diameter or a volume of 250 mm3had improved overall survival. CONCLUSIONS SRS can achieve LC rates approaching 100% for subcentimeter metastases. The earlier initial detection and prompt treatment of small intracranial metastases may prevent the development of neurological symptoms and the need for resection, and improve overall survival. To identify tumors when they are small, routine surveillance brain imaging should be considered as part of the standard of care for lung, breast, and melanoma metastases. ■ CLASSIFICATION OF EVIDENCE Type of question: prognostic; study design: retrospective cohort; evidence: Class II.
authors.affiliation: Departments of1Neurosurgery.
authors.forename: Amparo
authors.initials: A
authors.lastname: Wolf
authors.affiliation: Departments of1Neurosurgery.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Kvint
authors.affiliation: 2Medical Oncology, and.
authors.forename: Abraham
authors.initials: A
authors.lastname: Chachoua
authors.affiliation: 2Medical Oncology, and.
authors.forename: Anna
authors.initials: A
authors.lastname: Pavlick
authors.affiliation: 2Medical Oncology, and.
authors.forename: Melissa
authors.initials: M
authors.lastname: Wilson
authors.affiliation: 3Radiation Oncology, Laura and Isaac Perlmutter Cancer Center, NYU Langone Medical Center, New York University, New York, New York.
authors.forename: Bernadine
authors.initials: B
authors.lastname: Donahue
authors.affiliation: Departments of1Neurosurgery.
authors.forename: John G
authors.initials: JG
authors.lastname: Golfinos
authors.affiliation: 3Radiation Oncology, Laura and Isaac Perlmutter Cancer Center, NYU Langone Medical Center, New York University, New York, New York.
authors.forename: Joshua
authors.initials: J
authors.lastname: Silverman
authors.affiliation: Departments of1Neurosurgery.
authors.forename: Douglas
authors.initials: D
authors.lastname: Kondziolka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000532:radiotherapy* / Q000556:secondary; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D016634:Radiosurgery / Q000009:adverse effects; D012189:Retrospective Studies; D016019:Survival Analysis; D047368:Tumor Burden
keywords: CI = confidence interval; DS-GPA = diagnosis-specific graded prognostic assessment; FDG = fluorodeoxyglucose; HR = hazard ratio; KPS = Karnofsky Performance Scale; LC = local control; LMD = leptomeningeal disease; NCCN = National Comprehensive Cancer Network; NSCLC = non–small cell lung cancer; SRS = stereotactic radiosurgery; WBRT = whole-brain radiation therapy; brain metastasis; local control; maximal diameter; oncology; overall survival; stereotactic radiosurgery; tumor volume