title: CyberKnife robotic image-guided stereotactic radiotherapy for oligometastic cancer : A prospective evaluation of 95 patients/118 lesions.
abstract: OBJECTIVE
  To evaluate the outcome of robotic CyberKnife (Accuray Inc. Sunnyvale, USA)-based stereotactic radiotherapy (CBK-SRT) for oligometastic cancer patients.
  
  
  METHODS
  Between May 2007 and December 2009, 95 patients with a total of 118 lesions underwent CBK-SRT (median dose 24 Gy in 3 fractions).
  
  
  METHODS
  adult patients with limited volume cancer; suitability for SRT but not for other local therapies. Primary diagnoses included breast, lung, head and neck, gastrointestinal and other malignancies. Prostate cancer patients were excluded. Concomitant systemic therapy was given in 40 % of cases and median follow-up was 12 months. Toxicity and tumor response were evaluated using the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer (RTOG/EORTC) Scale and Response Evaluation Criteria in Solid Tumors RECIST.
  
  
  RESULTS
  Toxicity was rare and observed mainly in patients with comorbidities or uncontrolled cancer. Out of 87 evaluable lesions, complete radiological response, partial response, stabilization and progressive disease were observed in 15 (17 %), 25 (29 %), 34 (39 %) and 13 (15 %) lesions, respectively. Upon restricting the analysis to lesions treated with CBK-SRT alone (no concomitant therapy), response- and local control (LC) rates remained similar. Actuarial 3-year in-field progression-free survival- (i.e. LC), progression-free survival- (PFS) and overall-survival (OS) rates were 67.6, 18.4, and 31.2 %, respectively. LC was reduced in cases of early recurrence. OS- and cause-specific survival (CSS) rates were significantly lower in patients treated for visceral lesions. Failures were predominantly out-field.
  
  
  CONCLUSIONS
  CBK-SRT is a feasible therapeutic approach for oligometastastic cancer patients that provides long-term in-field tumor control with a low toxicity profile. Further investigations should focus on dose escalation and optimization of the combination with systemic therapies.
authors.affiliation: Department of Radiotherapy, European Institute of Oncology, via Ripamonti 435, Milan, Italy. barbara.jereczek@ieo.it
authors.forename: B A
authors.initials: BA
authors.lastname: Jereczek-Fossa
authors.forename: I
authors.initials: I
authors.lastname: Bossi-Zanetti
authors.forename: R
authors.initials: R
authors.lastname: Mauro
authors.forename: G
authors.initials: G
authors.lastname: Beltramo
authors.forename: L
authors.initials: L
authors.lastname: Fariselli
authors.forename: L C
authors.initials: LC
authors.lastname: Bianchi
authors.forename: C
authors.initials: C
authors.lastname: Fodor
authors.forename: P
authors.initials: P
authors.lastname: Fossati
authors.forename: G
authors.initials: G
authors.lastname: Baroni
authors.forename: R
authors.initials: R
authors.lastname: Orecchia
mesh_terms: D000206:Actuarial Analysis; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D003198:Computer Simulation; D018572:Disease-Free Survival; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000473:pathology; D009369:Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D011446:Prospective Studies; D016634:Radiosurgery / Q000379:methods*; D012371:Robotics / Q000379:methods*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult