title: Phase II study of helical tomotherapy for oligometastatic colorectal cancer.
abstract: BACKGROUND
  To evaluate the efficacy and toxicity of helical tomotherapy in the treatment of oligometastatic colorectal cancer (CRC) patients who were not amenable for metastasectomy and/or (further) systemic treatment.
  
  
  METHODS
  CRC patients with five or less metastases were enrolled. No limitations concerning dimension or localization of the metastases were imposed. Patients were treated with intensity-modulated and image-guided radiotherapy using helical tomotherapy, delivering a total dose of 40 Gy in fractions of 4 Gy. Positron emission tomography-computed tomography (PET-CT) was carried out at baseline and 3 months after the initiation of radiotherapy to evaluate the metabolic response rate according to PET Response Criteria in Solid Tumors (PERCIST) version 1.0. Side-effects were scored using National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTC AE) version 3.0.
  
  
  RESULTS
  Twenty-three patients were enrolled. A total of 52 metastases were treated. One patient (4%) experienced grade 3 vomiting; two patients (9%) grade 2 diarrhea and dysphagia, respectively. Twenty-two patients were evaluated by post-treatment PET-CT. Five (23%) and seven patients (32%) achieved a complete and partial metabolic response, respectively, resulting in an overall metabolic response rate of 55%. The actuarial 1-year local control, progression-free survival, and overall survival were 54%, 25% and 86%, respectively.
  
  
  CONCLUSIONS
  The use of helical tomotherapy in oligometastatic CRC patients resulted in a promising metabolic response rate of 55%.
authors.affiliation: Department of Radiation Oncology, UZ Brussel, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Engels
authors.forename: H
authors.initials: H
authors.lastname: Everaert
authors.forename: T
authors.initials: T
authors.lastname: Gevaert
authors.forename: M
authors.initials: M
authors.lastname: Duchateau
authors.forename: B
authors.initials: B
authors.lastname: Neyns
authors.forename: A
authors.initials: A
authors.lastname: Sermeus
authors.forename: K
authors.initials: K
authors.lastname: Tournel
authors.forename: D
authors.initials: D
authors.lastname: Verellen
authors.forename: G
authors.initials: G
authors.lastname: Storme
authors.forename: M
authors.initials: M
authors.lastname: De Ridder
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D049268:Positron-Emission Tomography; D011879:Radiotherapy Dosage; D014057:Tomography, X-Ray Computed