{"entity":{"id":"paper-kirkpatrick-srs-margin-trial-ijrobp-2015","kind":"paper","name":"Defining the optimal planning target volume in image-guided stereotactic radiosurgery of brain metastases: results of a randomized trial","aka":[],"tldr":"Brain metastases treated with radiosurgery were randomly given a 1 millimetre or a 3 millimetre margin. Control of the treated tumours was similar, the larger margin irradiated more healthy brain, and five of the six biopsy-proven cases of radiation damage were in the 3 millimetre group.","summary":"Kirkpatrick and colleagues randomised individual brain metastases in adults with one to three lesions under 4 cm to a 1 mm or a 3 mm uniform expansion of the gross tumour volume drawn on contrast MRI, treated on a linear accelerator with image guidance. Between 2010 and 2012, 49 patients with 80 metastases were treated. The 3 mm group had a significantly higher ratio of treated to visible volume and a larger volume receiving 12 Gy or more. Local recurrence occurred in only 3 lesions (2 in the 1 mm group, P = .51), 6.7 per cent at 12 months. Biopsy-proven radionecrosis alone occurred in 6 lesions, 5 of them in the 3 mm group (P = .10). No significant change in neurocognition or quality of life was seen at three months. The authors concluded that a 1 mm expansion is more appropriate.","asOf":"2026-10-20","links":[{"label":"IJROBP 2015","url":"https://doi.org/10.1016/j.ijrobp.2014.09.004"},{"label":"PubMed 25442342","url":"https://pubmed.ncbi.nlm.nih.gov/25442342/"}],"tags":["precision","radiation"],"related":[],"cancers":["secondary-brain-tumours","metastatic-cancer"],"sections":["radiation"],"technologies":["radiosurgery-srs","imrt-igrt"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["stereotactic-radiosurgery","radiation-necrosis","planning-target-volume"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":["ijrobp"],"dependsOn":[],"notes":[],"journal":"International Journal of Radiation Oncology, Biology, Physics","year":2015,"doi":"10.1016/j.ijrobp.2014.09.004","pmid":"25442342","authors":"Kirkpatrick JP, Wang Z, Sampson JH, et al.","paperType":"rct","findings":["49 patients with 80 brain metastases were randomised lesion by lesion to a 1 mm or 3 mm margin.","Local recurrence was seen in 3 lesions (2 in the 1 mm group, P = .51); 6.7 per cent at 12 months.","Biopsy-proven radionecrosis occurred in 6 lesions, 5 in the 3 mm group (P = .10).","The volume receiving 12 Gy or more was significantly higher with the 3 mm margin."],"whatItMeans":"With image guidance, a larger safety margin around a brain metastasis did not buy better tumour control and added healthy brain to the high-dose region. It is one of the few randomised tests of a margin itself.","caveats":["Small, single centre, and randomised by lesion rather than by patient.","The radionecrosis difference was not statistically significant (P = .10).","Median overall survival was 10.6 months, which limits how long late effects could be observed."],"participants":49},"route":"/key-papers/paper-kirkpatrick-srs-margin-trial-ijrobp-2015/","neighbours":{"cancer":[{"id":"secondary-brain-tumours","kind":"cancer","name":"Brain metastases (secondary brain tumours)","route":"/cancers/secondary-brain-tumours/"},{"id":"metastatic-cancer","kind":"cancer","name":"Metastatic cancer (cancer that has spread)","route":"/cancers/metastatic-cancer/"}],"section":[{"id":"radiation","kind":"section","name":"Radiation Therapy","route":"/fronts/radiation/"}],"technology":[{"id":"imrt-igrt","kind":"technology","name":"IMRT / IGRT (modern external beam)","route":"/technologies/imrt-igrt/"},{"id":"radiosurgery-srs","kind":"technology","name":"Stereotactic radiosurgery (Gamma Knife, CyberKnife, linac SRS)","route":"/technologies/radiosurgery-srs/"}],"term":[{"id":"planning-target-volume","kind":"term","name":"GTV, CTV and PTV (target volumes)","route":"/terms/planning-target-volume/"},{"id":"radiation-necrosis","kind":"term","name":"Radiation necrosis (brain)","route":"/terms/radiation-necrosis/"},{"id":"stereotactic-radiosurgery","kind":"term","name":"Stereotactic radiosurgery (SRS)","route":"/terms/stereotactic-radiosurgery/"}],"journal":[{"id":"ijrobp","kind":"journal","name":"International Journal of Radiation Oncology, Biology, Physics","route":"/journals/ijrobp/"}]}}