title: Stereotactic radiotherapy following surgery for brain metastasis: Predictive factors for local control and radionecrosis.
abstract: OBJECTIVE
  To evaluate local control and adverse effects after postoperative hypofractionated stereotactic radiosurgery in patients with brain metastasis.
  
  
  METHODS
  We reviewed patients who had hypofractionated stereotactic radiosurgery (7.7Gy×3 prescribed to the 70% isodose line, with 2mm planning target volume margin) following resection from March 2008 to January 2014. The primary endpoint was local failure defined as recurrence within the surgical cavity. Secondary endpoints were distant failure rates and the occurrence of radionecrosis.
  
  
  RESULTS
  Out of 95 patients, 39.2% had metastatic lesions from a non-small cell lung cancer primary tumour. The median Graded Prognostic Assessment score was 3 (48% of patients). One-year local control rates were 84%. Factors associated with improved local control were no cavity enhancement on pre-radiation MRI (P<0.00001), planning target volume less than 12cm3(P=0.005), Graded Prognostic Assessment score 2 or above (P=0.009). One-year distant cerebral control rates were 56%. Thirty-three percent of patients received whole brain radiation therapy. Histologically proven radionecrosis of brain tissue occurred in 7.2% of cases. The size of the preoperative lesion and the volume of healthy brain tissue receiving 21Gy (V21) were both predictive of the incidence of radionecrosis (P=0.010 and 0.036, respectively).
  
  
  CONCLUSIONS
  Adjuvant hypofractionated stereotactic radiosurgery to the postoperative cavity in patients with brain metastases results in excellent local control in selected patients, helps delay the use of whole brain radiation, and is associated with a relatively low risk of radionecrosis.
authors.affiliation: Service de radiothérapie, institut de cancérologie de l'Ouest René-Gauducheau, 2, boulevard Jacques-Monod, 44805 Saint-Herblain, France. Electronic address: melaniedore.pro@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Doré
authors.affiliation: Service de neurochirurgie, centre hospitalier universitaire Laënnec, boulevard Jacques-Monod, 44805 Saint-Herblain, France.
authors.forename: S
authors.initials: S
authors.lastname: Martin
authors.affiliation: Service de physique médical, institut de cancérologie de l'Ouest René-Gauducheau, 2, boulevard Jacques-Monod, 44805 Saint-Herblain, France.
authors.forename: G
authors.initials: G
authors.lastname: Delpon
authors.affiliation: Service de radiothérapie, institut de cancérologie de l'Ouest René-Gauducheau, 2, boulevard Jacques-Monod, 44805 Saint-Herblain, France.
authors.forename: K
authors.initials: K
authors.lastname: Clément
authors.affiliation: Département de biostatistique, institut de cancérologie de l'Ouest René-Gauducheau, 2, boulevard Jacques-Monod, 44805 Saint-Herblain, France.
authors.forename: L
authors.initials: L
authors.lastname: Campion
authors.affiliation: Service de radiothérapie, institut de cancérologie de l'Ouest René-Gauducheau, 2, boulevard Jacques-Monod, 44805 Saint-Herblain, France.
authors.forename: F
authors.initials: F
authors.lastname: Thillays
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D001930:Brain Injuries / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary* / Q000601:surgery*; D002277:Carcinoma / Q000000981:diagnostic imaging / Q000556:secondary* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging / Q000556:secondary / Q000601:surgery; D008875:Middle Aged; D009336:Necrosis; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000517:prevention & control; D059906:Neuroimaging; D011183:Postoperative Complications / Q000209:etiology*; D011379:Prognosis; D011832:Radiation Injuries / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D016634:Radiosurgery / Q000009:adverse effects*; D012189:Retrospective Studies; D016896:Treatment Outcome; D047368:Tumor Burden
keywords: Brain; Cerveau; Chirurgie; Metastasis; Métastase; Stereotactic; Stéréotaxique; Surgery