Current status of cranial stereotactic raDiosurgery in the UK

Objective: To investigate and benchmark the current clinical and dosimetric practices in stereotactic raDiosurgery (SRS) in the UK. Methods: A detailed questionnaire was sent to 70 radiotherapy centres in the UK. 97% (68/70) of centres replied between June and December 2014. Results: 21 centres stated that they are practising SRS, and a further 12 centres plan to start SRS by the end of 2016. The most commonly treated indications are brain metastases and acoustic neuromas. A large range of prescription isodoses that range from 45% to 100% between different radiotherapy centres was seen. Ionization chambers and solid-water phantoms are used by the majority of centres for patient-specific quality assurance, and thermoplastic masks for patient immobilization are more commonly used than fixed stereotactic frames. The majority of centres perform orthogonal kilovoltage X-rays for localization before and during delivery. The acceptable setup accuracy reported ranges from 0.1 to 2mm with a mean of 0.8mm. Conclusion: SRS has been increasing in use in the UK and will continue to increase in the next 2 years. There is no current consensus between SRS centres as a whole, or even between SRS centres with the same equipment, on the practices followed. This indicates the need for benchmarking and standardization in SRS practices within the UK. Advances in knowledge: This article outlines the current practices in SRS and provides a benchmark for reference and comparison with future research in this technique.