title: Alternative treatment of stereotactic cyst aspiration and radiosurgery for cystic brain metastases.
abstract: BACKGROUND
  Surgical removal is the first choice of treatment for large cystic brain metastases. However, some patients cannot undergo surgical resection due to their general condition and/or the tumor location.
  
  
  OBJECTIVE
  In this study, we investigated the feasibility and safety of stereotactic cyst aspiration and gamma knife radiosurgery (GKR) as an alternative treatment for these lesions and followed the volumetric changes in cystic and solid portions.
  
  
  METHODS
  Between February 2005 and March 2012, a total of 24 patients underwent GKR after cyst aspiration for 29 cystic metastatic brain tumors. The median age was 60 years (range, 18-81). The number of male patients was 18 and that of female patients 6. Most of the patients were in class II (87.5%) based on the data of the Radiation Therapy Oncology Group using recursive partitioning analysis. We analyzed the changes in tumor volume, the local control rate, intracranial progression-free survival (PFS) and overall survival (OS).
  
  
  RESULTS
  Before aspiration, the mean total tumor volume was 32.7 cm(3) (range, 12.1-103.3) and cystic volume was 18.6 cm(3) (range, 8-72.3). The mean duration of cyst drainage was 1 day (range, 1-2). The mean amount of aspiration was 16.8 cm(3) (range, 6-67.4). After aspiration, the total mean volume was 12.4 cm(3) (range, 3.7-38.1) and cystic volume was 2.0 cm(3) (range, 0.1-9.5). The nature of the cyst was serous in 18, serous and hemorrhagic in 3, and serous and necrotic in 8. The median prescription dose was 16 Gy (range, 14-20). There was no treatment-related complication. The local control rate was 58.6% (17/29). The median survival to local recurrence was 6.0 (±1.42) months. During the follow-up period, an Ommaya reservoir was placed in 3 patients. Insertion of an Ommaya reservoir and whole-brain radiotherapy (WBRT) or GKR were done in 2 patients, WBRT in 2, GKR in 1 and operation in 1. The median intracranial PFS and OS after intracranial metastasis was 5.2 (±0.42) and 6.8 (±0.38) months.
  
  
  CONCLUSIONS
  Cyst aspiration and GKR were feasible and safe but not very efficient, which could be an alternative option for large cystic metastases in patients who could not expect longer survival time.
authors.affiliation: Department of Neurosurgery, Chonnam National University Medical School and Hwasun Hospital, Gwangju, Republic of Korea.
authors.forename: Tae-Young
authors.initials: TY
authors.lastname: Jung
authors.forename: In-Young
authors.initials: IY
authors.lastname: Kim
authors.forename: Shin
authors.initials: S
authors.lastname: Jung
authors.forename: Woo-Youl
authors.initials: WY
authors.lastname: Jang
authors.forename: Kyung-Sub
authors.initials: KS
authors.lastname: Moon
authors.forename: Seung-Jin
authors.initials: SJ
authors.lastname: Park
authors.forename: Sa-Hoe
authors.initials: SH
authors.lastname: Lim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D001932:Brain Neoplasms / Q000556:secondary* / Q000601:surgery / Q000628:therapy; D002277:Carcinoma / Q000556:secondary* / Q000601:surgery / Q000628:therapy; D003131:Combined Modality Therapy; D016371:Cranial Irradiation; D003560:Cysts / Q000601:surgery*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007276:Injections, Intraventricular / Q000295:instrumentation; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000532:radiotherapy; D016634:Radiosurgery / Q000379:methods*; D012509:Sarcoma / Q000556:secondary / Q000601:surgery / Q000628:therapy; D013238:Stereotaxic Techniques; D013396:Suction / Q000379:methods*; D016019:Survival Analysis; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents