SBRT & SABR
SBRT and SABR are a type of specialised technique called stereotactic radiotherapy. This is the delivery of radiotherapy in highly focussed, concentrated doses of radiation, delivered over 1 – 5 fractions compared to the more conventional 20 to 35 fractions delivered every day for a number of weeks.
SBRT (stereotactic body radiotherapy) typically delivers 3-5 fractions to organs outside of the brain, such as the lungs, spine, liver and pancreas.
SABR (stereotactic ablative radiotherapy) delivers 1 – 5 fractions typically every other day, depending on the exact tumour site and size. It has potential for treatment of sites such as the bones, lungs, liver and brain for oligometastatic lesions ie. malignant tumours where the primary tumour is under control and not progressing, but where there are remote areas of tumour spread, but that are well localised and only few in number.
The use of SBRT is expanding
"Outcomes of early clinical experience in medically inoperable patients are very encouraging and thus the use of SBRT is expanding.
"With an increase in diagnosis of Stage 1 lung cancer and improvements in the delivery of SBRT, it can be anticipated that more patients will receive SBRT with good outcomes."
Fuss, Martin. Lung SBRT Clinical White Paper.
Patient positioning is essential
"Accurate patient positionng and tumor relocalization are essential for SBRT use in the liver and other abdominal and retroperitoneal sites, as at other tumor sites."
Kavanagh, Brian D; Tracey E. Schefter; Peter J Wersall. Liver, Renal, and Retroperitoneal Tumors: Stereotactic Radiotherapy.
Safer delivery of high doses
"Advances in stereotactic radiaton techniques have resulted in safer delivery of high doses to extracranial sites with reduced toxicity and improved outcomes.
"Lung SBRT has been associated with local control rates of over 90%."
Dilling, Thomas J; Sarah Hoffe. Stereotactic Body Radiation Therapy: transcending the Conventional to Improve Outcomes.