title: Stereotactic radiotherapy with real-time tumor tracking for non-small cell lung cancer: clinical outcome.
abstract: OBJECTIVE
  To report the clinical outcome of treatment using real-time tumor tracking for 70 patients with inoperable stage I non-small cell lung cancer (NSCLC).
  
  
  METHODS
  Seventy inoperable patients with peripherally located early-stage NSCLC were treated with 45 or 60 Gy in three fractions using CyberKnife. Pathology was available in 51% of patients. Thirty-nine patients had a T1-tumor and 31 had a T2-tumor. Markers were placed using the vascular, percutaneous intra-, or extra-pulmonary approach, depending on the risk of pneumothorax.
  
  
  RESULTS
  The actuarial 2-year local control rate for patients treated with 60 Gy was 96%, compared to 78% for patients treated with a total dose of 45 Gy (p=0.197). All local recurrences (n=4) occurred in patients with T2-tumors. Overall survival for the whole group at two years was 62% and the cause specific survival was 85%. The median follow-up was 15 months. Grade 3 toxicity occurred in two patients (3%) after marker placement. Treatment-related late grade 3 toxicity occurred in 7 patients (10%). No grade > or = 4 toxicity occurred.
  
  
  CONCLUSIONS
  Excellent local control of 96% at 1- and 2-years was achieved using 60 Gy in three fractions for NSCLC patients treated with the real-time tumor tracking. Toxicity was low.
authors.affiliation: Radiation Oncology Department, Daniel den Hoed-Erasmus Medical Center, Rotterdam, The Netherlands. n.vandervoortvanzyp@erasmusmc.nl
authors.forename: Noëlle C
authors.initials: NC
authors.lastname: van der Voort van Zyp
authors.forename: Jean-Briac
authors.initials: JB
authors.lastname: Prévost
authors.forename: Mischa S
authors.initials: MS
authors.lastname: Hoogeman
authors.forename: John
authors.initials: J
authors.lastname: Praag
authors.forename: Bronno
authors.initials: B
authors.lastname: van der Holt
authors.forename: Peter C
authors.initials: PC
authors.lastname: Levendag
authors.forename: Robertus J
authors.initials: RJ
authors.lastname: van Klaveren
authors.forename: Peter
authors.initials: P
authors.lastname: Pattynama
authors.forename: Joost J
authors.initials: JJ
authors.lastname: Nuyttens
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000601:surgery*; D015897:Comorbidity; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D011832:Radiation Injuries / Q000209:etiology; D016634:Radiosurgery / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome