Artikel
Robotic radiosurgery of intraspinal and intramedullary metastases
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Veröffentlicht: | 28. April 2011 |
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Gliederung
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Objective: To analyze the outcome of frameless radiosurgery for intraspinal and intramedullary metastases.
Methods: Eligibility was approved by an interdisciplinary tumor board. Clinical status, treatment parameters, local tumor control, pain level (visual analogue scale) and adverse effects have been recorded prospectively. Patients were treated with a single irradiation fraction utilizing the CyberKnife® system (Accuray Inc. Sunnyvale CA). Clinical and MRI follow-up were done every three months after treatment.
Results: From 2005 to 2009 22 patients with 24 metastases of various primary cancers (mamma 6, renal 4, lung 2, melanoma 2, others 8) were treated. The median age was 54 years (range 24–80). Eleven intramedullary, four intradural and nine intraspinal extradural lesions were located at six cervical, twelve thoracic and six lumbar levels. All but three patients had initial neurological symptoms and 60% of the patients suffered from mild or severe paraparetic deficits (ASIA scale B, C and D). Median prescription dose was 16.5 Gy (95%C.I. 16.0–17.0) to the 70% isodose, median target volume was 1.4 cm3 (95%C.I. 0.8–2.0). During a mean follow-up of nine months, two lesions showed a local progression, resulting in an actuarial local tumor control rate of 95% after six and 83% after 12 months. Three lesions resolved completely, seven showed a partial remission and 12 lesions were unchanged on MRI controls. Initial neurological deficits improved in four of 16 patients and remained stable in 10. Pain was reduced in three of 10 patients and remained stable in seven. No adverse effects, apart from mild nausea in three cases, have been observed.
Conclusions: Robotic radiosurgery for intraspinal and intramedullary metastases is a feasible and safe treatment option for selected patients. Neurological deficits improved or remained unchanged in most patients. Therefore radiosurgery may offer a non-invasive treatment to control neurological symptoms and pain.