Clinical practice of image-guided spine radiosurgery - results from an international research consortium

Abstract

BackgroundSpinal radiosurgery is a quickly evolving technique in the radiotherapy and neurosurgical communities. However, the methods of spine radiosurgery have not been standardized. This article describes the results of a survey about the methods of spine radiosurgery at five international institutions.MethodsAll institutions are members of the Elekta Spine Radiosurgery Research Consortium and have a dedicated research and clinical focus on image-guided radiosurgery. The questionnaire consisted of 75 items covering all major steps of spine radiosurgery.ResultsStrong agreement in the methods of spine radiosurgery was observed. In particular, similarities were observed with safety and quality assurance playing an important role in the methods of all institutions, cooperation between neurosurgeons and radiation oncologists in case selection, dedicated imaging for target- and organ-at-risk delineation, application of proper safety margins for the target volume and organs-at-risk, conformal planning and precise image-guided treatment delivery, and close clinical and radiological follow-up. In contrast, three major areas of uncertainty and disagreement were identified: 1) Indications and contra-indications for spine radiosurgery; 2) treatment dose and fractionation and 3) tolerance dose of the spinal cord.ConclusionsResults of this study reflect the current practice of spine radiosurgery in large academic centers. Despite close agreement was observed in many steps of spine radiosurgery, further research in form of retrospective and especially prospective studies is required to refine the details of spinal radiosurgery in terms of safety and efficacy.

Variability in Spine Radiosurgery Treatment Planning -- Results of an International Multi-institutional Study

“…The tolerance dose to the spinal cord is limited to a maximum dose while other institutions limit the dose to different sub-volumes (0.1 cm 3 , 0.4 cm 3 or 0.04 cm 3 ). This disagreement was already stated by Guckenberger et al [17]. Additionally, changes/deviations in beam configuration and optimization goals can lead to different planning results.…”

“…Step 4 delineation of PTV CTV-to-PTV margins ranged between 0 mm and 2 mm according to institutional protocol [17,25]. Margins for generation of the PRV spinal cord ranged between 1 mm and 2 mm.…”

“…An overview of methods of spine radiosurgery for the participating institutions was described by Guckenberger et al [17]. Good agreement was seen for the imaging acquisitioning techniques and safety margins concepts.…”

“…The use of SRS as an alternative treatment to conventional RT has been increasing rapidly. However, there still remains significant variability and little consensus exist regarding target volume contouring and treatment planning [17][18][19].…”

Spinal metastases: From conventional fractionated radiotherapy to single-dose SBRT

“…43 Remarkable consistency has been demonstrated in reported outcomes with durable local control rates in excess of 90% in large retrospective studies. While the perspective of using single dose SBRT in spine metastases is highly promising, the issue of tumor to cord proximity and the associated risk of collateral cord damage continues to represent a hurdle that hinders a wider application of this technique.…”