The evolution and rise of stereotactic body radiotherapy (SBRT) for spinal metastases

ABSTRACT

Introduction: Owing to improvements in clinical care and systemic therapy, more patients are being diagnosed with, and living longer with, spinal metastases (SM). In parallel, tremendous technological progress has been made in the field of radiation oncology. Advances in both software and hardware are able to integrate three- (and four-) dimensional body imaging with spatially accurate treatment delivery methods. This leads to improved efficacy, shortened treatment schedule, and potentially reduced treatment-related toxicity.

Areas covered: In this review, we will look at the progress made by stereotactic body radiotherapy (SBRT) in the management of SM. We will review the technological factors which have enabled the widespread use of SBRT. The efficacy of SBRT, in various clinical scenarios, and associated toxicities will be reviewed. Lastly, we will discuss about patient selection and provide a five-year roadmap.

Expert commentary: Spine SBRT is a safe and efficacious treatment option. Practice guidelines recommend the use of SBRT in oligometastatic patients especially those with radio-resistant cancer types, and in scenarios involving re-irradiation. SBRT offers patients dose-intensification over a short schedule which may allow less time off systemic therapy. The results of the phase III trials are eagerly awaited.

KEYWORDS:

• Spinal metastases
• radiotherapy
• stereotactic body radiotherapy
• radiosurgery
• oligo-metastases

Declaration of interest

BA Vellayappan is the recipient of a National Cancer Institute Singapore Research Fellowship. M Foote declares receiving a research grant from Elekta. KJ Redmond has received research funding and travel expenses from Accuray, has received research funding from Elekta, has received honorarium from AstraZeneca and acts as a consultant for Medtronic. EL Chang reports receiving honorarium from Brainlab. A Sahgal reports receiving a research grant from Elekta, has received travel expenses from Elekta and Varian, and A Sahgal also belongs to the Elekta MR Linac Research Consortium. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

A reviewer on this manuscript has disclosed that they are on the speaker’s bureau for Varian Medical Systems, BrainLab and Vision RT. Peer reviewers on this manuscript have no other relevant financial or other relationships to disclose.

Additional information

Funding

This manuscript was not funded.