Hypofractionated stereotactic radiotherapy for brain metastases

• Published in: Cancer radiothérapie Vol. 14; no. 2; p. 119
• Main Authors: Schlienger, M, Nataf, F, Huguet, F, Pene, F, Foulquier, J-N, Orthuon, A, Roux, F-X, Touboul, E
• Format: Journal Article
• Language: French
• Published: France 01.04.2010
• Subjects: Brachytherapy - methods; Brain Neoplasms - pathology; Brain Neoplasms - secondary; Brain Neoplasms - surgery; Humans; Necrosis; Neoplasm Metastasis - radiotherapy; Radiotherapy Dosage; Survival Rate; Time Factors
• ISSN: 1769-6658
• DOI: 10.1016/j.canrad.2009.10.004

A survey of the literature has been performed to find arguments in order to help the choice between radiosurgery and hypofractionated stereotactic radiotherapy in the treatment of brain metastases. A comparison of two groups of brain metastases treated with hypofractionated stereotactic radiotherapy or radiosurgery, with or without WBRT was performed. Hypofractionated stereotactic radiotherapy: there were eight series including 448 patients published from 2000 to 2009; treated with 5-6 MV X-Rays, non invasive head immobilization, a margin 2 to 10mm; 24 to 40Gy in three to five fractions; a 5 to 8 days duration in six series and 15-16 days in two other series. WBRT (30%) ; radiosurgery: there were 12 series (1994 to 2005) including 2157 patients; an invasive head immobilization, no margin; doses from 10 to 25 Gy; six series over 12 had Gamma Knife radiosurgery and six had Linacs X-Rays. WBRT (30 Gy/10 F/12 days) associated to radiosurgery in several series. The following parameters were compared: median GTV, median survival, 1-year survival rate, local control rate, necrosis and WBRT rates. Hypofractionated stereotactic radiotherapy series: the parameters were respectively: 0,52-4,47 cm(3) (median 2,8 cm(3)); 5-16 months (median 8,7 months); 68,2-93% (median 82,5%); necrosis rate 3,1%; associated WBRT 30%. Radiosurgery series: the parameters were respectively: 1,3 to 5,5 cm(3) (median 2 cm(3)); 5,5 to 22 months (median 11 months); 71 to 95% (median 85%); 0,5 to 6% (median 2,4%); associated WBRT 58%. Results seem similar in the two groups: Hypofractionated stereotactic radiotherapy with non invasive immobilization could theoretically treat all brain metastases sizes except lesions<10 mm (500 mm(3)). In large volumes,>4200 mm(3) GTV, the toxicity of hypofractionated stereotactic radiotherapy was not reported, thus it was difficult to compare its results with the published reports of radiosurgery toxicity. WBRT was a confusing parameter. Obviously, this initial survey has important limitations, specifically its methodology. Radiosurgery and hypofractionated stereotactic radiotherapy could be used to treat brain metastases with GTV>500 mm(3) and < or = 4200 mm(3) (Ø 20mm); for GTV<500 mm(3) (Ø 10mm) an invasive procedure with radiosurgery is necessary. For GTV>4200 mm(3) (Ø 20mm), hypofractionated stereotactic radiotherapy could be proposed, provided further studies, using 4 to 6 Gy fractions, a duration less or equal to 10-12 days and a margin of 2mm will be performed.