PURPOSE: The purpose of the present analysis was to assess whether adding a 1 mm margin to the gross @entity5 volume (GTV) improves the control rate of brain @entity3 treated with radiosurgery (RS). @entity1 AND METHODS: All the @entity1 had one or two brain metastases, 30 mm or less in diameter, and only one isocentre was used for RS. There were 23 females and 38 males. The median age was 54 years (34-76). The median Karnofsky performance status was 80 (60-100). At the time of RS, 23 @entity1 had no evidence of @entity85 and 38 had a progressive @entity262 . Thirty-eight @entity1 were treated up-front with only RS. Twenty-three @entity1 were treated for relapse or progression more than 2 months after whole brain radiotherapy. From January 1994 to July 1995, clinical target volume (CTV) was equal to GTV without any margin (33 metastases). From August 1995 to August 2000, CTV was defined as GTV plus a 1 mm margin (45 metastases). A dose of 20Gy was prescribed to the isocentre and 14Gy at the margin of CTV. RESULTS: The median follow-up was 10.5 months (1-45). The mean minimum dose delivered to GTV was 14.6Gy in the group without a margin and 16.8Gy in the group with a 1 mm margin (P<0.0001). The response of 11 metastases was never assessed because @entity1 died before the first follow-up. Ten metastases recurred, eight in the group treated without a margin and two in the group treated with a 1 mm margin (P=0.01). Two-year local control rates were 50.7+/-12.7% and 89.7+/-7.4% (P=0.008), respectively. Univariate analysis showed that the treatment group (P=0.008) and the @entity5 volume (P=0.009) were prognostic factors for local control. In multivariate analysis, only the treatment group with a 1 mm margin was an independent prognostic factor for local control (P=0.04, RR: 5.8, 95% CI [1.08-31.13]). There were no significant differences, either in overall survival rate or in early and late side effects, between the two groups. CONCLUSION: Adding a 1 mm margin to the GTV in @entity1 treated with RS significantly improves the probability of @entity3 control without increasing the side effects.

Radiosurgery for brain XXXX : impact of CTV on local control.

@entity1 :: ('9606', 'Species') :: ['patients', 'PATIENTS'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumour'] @entity262 :: ('MESH:D034721', 'Disease') :: ['systemic disease'] @entity3 :: ('MESH:D009362', 'Disease') :: ['metastasis'] @entity85 :: ('MESH:D009140', 'Disease') :: ['extracranial disease']
@entity3 :: (MESH:D009362,Disease) :: ['metastasis']
