Comparison of dosimetric parameters of SBRT plans made on brain metastasis patient treatment plans

COMPARISON OF DOSIMETRIC PARAMETERS OF SBRT PLANS MADE ON BRAIN METASTASIS PATIENT TREATMENT PLANS In this study, dosimetric comparison was made by making virtual treatment plans with VMAT and CyberKnife treatment planning systems with SRS / SBRT technique for 9 patients who received radiotherapy treatment with a diagnosis of brain metastasis. Bursa Uludag University School of Medicine Department of Radiation Oncology Department received treatment in patients with brain metastases obtained 9 of archival material was made retrospectively and virtual treatment plan. In the plans made, 18 Gy dose was determined to be given to the patient in fraction. PTV, brain-PTV, lenses, eyes, optic nerves, optic chiasm, brain stem, hippocampus, pituitary, cochlea, lacrimal glands were contoured by a radiation oncologist and neuroradiologist for virtual plans. In the plans, attention was paid to the isodose covering 95% of the target volume and protecting critical organs. Dose distributions were obtained with the DVHs in the created plans and statistical analysis was performed using the Independent-Samples T Test and Mann Whitney U tests with the SPSS program. As a result, a significant difference was found in dosimetric comparisons of both lenses and lacrimal gland, right eye, HI, CI and MU, while a significant difference was found in PTV, brain-PTV, left eye, optic nerve, optic chiasma, brainstem, hippocampus, pituitary, cochleas and lacrimals. no difference was found. Although no significant difference was found in most critical organs, the lowest values of many were obtained from the CyberKnife plans. Looking at the values of HI, CI and MU, the lowest values were obtained from the VMAT planning system. Keywords: Brain Metastasis, Stereotactic Radiosurgery, CyberKnife, VMAT