To evaluate role of Ga68-dotatate PET-CT for radiation therapy planning in meningioma - preliminary workup

To Evaluate Role Of Ga68-dotatate PET-CT For Radiation Therapy Planning in meningioma - Preliminary Workup Human meningioma cell strongly express somatostatin receptor .we retrospectively analysed 27 patients data as to how far Ga68 dotatate PET-CT imaging is helpful to improve target volume delineation for radiotherapy planning compare to MRI. After validation of localization, volumetric accuracy and images registration Dicom images were transferred to radio therapy centre. 27 patients were scanned on flat bed with personalized rigid radiotherapy mould covering region of interest to prevent positioning differences. Data were exported to nucletron oncentra treatment planning contouring system. Target delineations were done using PET-CT data and spy Glass. After biological target and critical volume definition, data were sent to plato sunrise TPS for IMRT planning. Using dose volume histogram dose determined for tumors and critical organs. Plan is exported to Siemensprimus linac using lantis software for IMRT execution or using eclipse data were sent to Novalis Tx in some cases. Results and SRS imaging can be reliably used for tailoring radiation therapy planning.Technique allows better discrimination between SR2 expressing meningioma and tumor free tissue, more useful in skull base lesions. Radiation oncologist can better contour involved tumor volume with greater precision.PET provided additional information concerning tumor extension and planning target volume was modified in 50 % of cases. (author)