title: Radical stereotactic radiosurgery with real-time tumor motion tracking in the treatment of small peripheral lung tumors.
abstract: BACKGROUND
  Recent developments in radiotherapeutic technology have resulted in a new approach to treating patients with localized lung cancer. We report preliminary clinical outcomes using stereotactic radiosurgery with real-time tumor motion tracking to treat small peripheral lung tumors.
  
  
  METHODS
  Eligible patients were treated over a 24-month period and followed for a minimum of 6 months. Fiducials (3-5) were placed in or near tumors under CT-guidance. Non-isocentric treatment plans with 5-mm margins were generated. Patients received 45-60 Gy in 3 equal fractions delivered in less than 2 weeks. CT imaging and routine pulmonary function tests were completed at 3, 6, 12, 18, 24 and 30 months.
  
  
  RESULTS
  Twenty-four consecutive patients were treated, 15 with stage I lung cancer and 9 with single lung metastases. Pneumothorax was a complication of fiducial placement in 7 patients, requiring tube thoracostomy in 4. All patients completed radiation treatment with minimal discomfort, few acute side effects and no procedure-related mortalities. Following treatment transient chest wall discomfort, typically lasting several weeks, developed in 7 of 11 patients with lesions within 5 mm of the pleura. Grade III pneumonitis was seen in 2 patients, one with prior conventional thoracic irradiation and the other treated with concurrent Gefitinib. A small statistically significant decline in the mean % predicted DLCO was observed at 6 and 12 months. All tumors responded to treatment at 3 months and local failure was seen in only 2 single metastases. There have been no regional lymph node recurrences. At a median follow-up of 12 months, the crude survival rate is 83%, with 3 deaths due to co-morbidities and 1 secondary to metastatic disease.
  
  
  CONCLUSIONS
  Radical stereotactic radiosurgery with real-time tumor motion tracking is a promising well-tolerated treatment option for small peripheral lung tumors.
authors.affiliation: Department of Radiation Medicine, Georgetown University Hospital, Washington, DC, USA. collinsb@gunet.georgetown.edu
authors.forename: Brian T
authors.initials: BT
authors.lastname: Collins
authors.forename: Kelly
authors.initials: K
authors.lastname: Erickson
authors.forename: Cristina A
authors.initials: CA
authors.lastname: Reichner
authors.forename: Sean P
authors.initials: SP
authors.lastname: Collins
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Gagnon
authors.forename: Sonja
authors.initials: S
authors.lastname: Dieterich
authors.forename: Don A
authors.initials: DA
authors.lastname: McRae
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shadi
authors.initials: S
authors.lastname: Yousefi
authors.forename: Elliot
authors.initials: E
authors.lastname: Levy
authors.forename: Thomas
authors.initials: T
authors.lastname: Chang
authors.forename: Carlos
authors.initials: C
authors.lastname: Jamis-Dow
authors.forename: Filip
authors.initials: F
authors.lastname: Banovac
authors.forename: Eric D
authors.initials: ED
authors.lastname: Anderson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000532:radiotherapy; D019583:Dose Fractionation, Radiation; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000532:radiotherapy*; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D018579:Patient Selection; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome