Pilot Study of Preoperative Stereotactic Radiosurgery for Brain Metastases

Both Stereotactic Radiosurgery (SRS) and Neurosurgery (NS) are routinely used to treat brain metastases (BM) detected via magnetic resonance imaging (MRI) scanning. Cancer patients recruited to this trial will receive current standard treatment interventions available (SRS and NS) delivered in a different sequence or order. All trial participants with confirmed BM will be treated with preoperative SRS, followed by neurosurgery within 1-3 days of SRS completion. The purpose of this study is to find out how well tumours in the brain are controlled by using SRS before NS and the side effects related. SRS & NS treatment delivery occurs over a 1-2 week period approximately. Trial participants will also be offered the the option of contributing their tissue and blood samples for laboratory testing related to this study and 'banking' or storage of left over samples for future research. Stereotactic Radiosurgery (SRS): SRS is a standard non-surgical radiation therapy used to treat small tumours of the brain, using many precisely focused radiation beams. Stereotactic radiosurgery is not surgery, in the ordinary sense, because there is no incision involved and general anesthesia is not required for adults. SRS can deliver precisely-targeted radiation in fewer high-dose treatments, which can help preserve healthy tissue. SRS is also used to treat the space or cavity left in the brain after the removal of a brain metastasis by surgery. SRS works by distorting and destroying the DNA of tumor cells. SRS is a specialised type of external beam radiation therapy using focused radiation beams targeting a well-defined tumour. SRS is customised to the individual patient via treatment planning. SRS is planned using specialised radiotherapy planning computer technology according to standard hospital procedure. Patients routinely attend an SRS planning session performed to acquire CT imaging required to plan treatment. This session is performed within 1 week prior to SRS treatment and usually takes 1 hour to complete. In addition a planning MRI will be acquired which also takes about 1 hour. The images from planning CT and MRI scans routinely acquired, are imported into a radiation planning computer. This computer precisely measures the tumour/s identified for treatment with radiation. Using this technology the radiation oncologist and a team of radiation therapists, create a unique computerised three-dimensional treatment plan specific to a patients individual radiation therapy requirements. The treatment plan created is used to guide precise treatment set-up each time a patient attends for SRS and also to deliver the radiation dose with extreme accuracy. Treatment is given face to face in the radiotherapy department; the duration of each session is up to 1 hour covering initial treatment set-up through to treatment delivery. The number of radiotherapy treatments will depend on the size, location and number of brain metastasis or surgical cavities. The number of treatments can range between 1 and 5 sessions delivered over a maximum of 7 days. Treatment is delivered using radiotherapy machines operated by radiation therapists under the supervision of a specialist radiation oncology doctor. SRS is monitored throughout the treatment course and is routinely documented in the electronic medical record and treatment planning / delivery system. Neurosurgery (NS): NS a an operation performed by a neurosurgeon on the nervous system, especially the brain to remove brain metastastases. Trial participants will receive NS with-in 1-3 days after completing SRS treatment. The approximate duration of the procedure is up to 4-6 hours. Patients undergoing NS require hospital admission; the length of stay is dependent on the amount of post surgery recovery time required by each patient. Patients are anaesthetised and surgery performed in a hospital operating room. During the hospital stay patient's are monitored regularly by the neurosurgeon and hospital staff. An MRI scan is routinely performed 2 days after NS, to assess the outcome of the operation. The NS procedure and post-op management is routinely documented in the patient’s electronic medical record. Patient records will be accessed to source NS data for analysis. After Treatment: Trial participants will be reviewed at 1 month and 3 months after treatment completion. Follow-up visits will continue 3 monthly during the first year after completing SRS and NS treatment, followed by regular 6 monthly visits until two years after surgery. This follow-up schedule is standard for all cancer patients having SRS and NS treatments. Optional Translational Sub-Study: Trial participants consenting to the optional translational sub-study will have blood and tissue collected for molecular/laboratory evaluation before treatment, during SRS, after treatment completion and at the time of post treatment disease progression. Tissue will be accessed from the archived diagnostic sample, the neurosurgery operation sample and where feasible tissue collected at the time of post treatment progression. After the sub-study is completed, any remaining blood and tissue samples collected, will be 'banked' or stored for future approved research.