Introduction: Intensity-Modulated Radiotherapy (IMRT) is becoming the standard of practice since it delivers precision radiotherapy to the planning target volumes (PTV) and minimizes dose to Organs-At-Risk (OARs). Two planning methodologies exist i.e. Preselected Beam Optimization (PSBO) or Beam Angle Optimization (BAO) which are selected by the physicist and the treatment planning system respectively. Both methods aim to achieve prescription to planning target volume (PTV) with maximal sparing of organs at risk (OARs). The present study aims to compare the dosimetric parameters between the Beam angle optimization (BAO) with preselected beam angle orientation (PSBO) in brain tumour patients. Materials and Methods: Present study was conducted in the department of Radiation Oncology. Twenty patients of brain tumour planned by PSBO were randomly selected. A new plan was created for each patient with BAO method. Dosimetric parameters of PTV (V95%, Dmax, Dmean, D2, D50, D98, HI, CI, and MUs) and OAR (brainstem, eyes, lenses, optic nerves, cochleae, hippocampi, and normal brain tissue) were compared. Results: The dosimetric parameters of PTV in PSBO and BAO plans are almost similar and none of the parameters have shown a statistically significant difference. There was a difference of >1Gy in various OARs like brainstem Dmax, optic nerves Dmax, lenses Dmax, Dmin Dmax of right hippocampus and left hippocampus Dmin, though it was not statistically significant. Rest of the OARs like, both eyes, cochleae and normal brain had a difference of <1Gy and not statistically significant. Conclusion: Dosimetric parameters of PSBO patient planning method are equivalent to BAO method. PSBO may be more useful since it is an individualized planning and may further utilise less time with growing experience of the medical physicist.

Introduction: Intensity-Modulated Radiotherapy (IMRT) is becoming the standard of practice since it delivers precision radiotherapy to the planning target volumes (PTV) and minimizes dose to Organs-At-Risk (OARs). Two planning methodologies exist i.e. Preselected Beam Optimization (PSBO) or Beam Angle Optimization (BAO) which are selected by the physicist and the treatment planning system respectively. Both methods aim to achieve prescription to planning target volume (PTV) with maximal sparing of organs at risk (OARs). The present study aims to compare the dosimetric parameters between the Beam angle optimization (BAO) with preselected beam angle orientation (PSBO) in brain tumour patients. Materials and Methods: Present study was conducted in the department of Radiation Oncology. Twenty patients of brain tumour planned by PSBO were randomly selected. A new plan was created for each patient with BAO method. Dosimetric parameters of PTV (V95%, Dmax, Dmean, D2, D50, D98, HI, CI, and MUs) and OAR (brainstem, eyes, lenses, optic nerves, cochleae, hippocampi, and normal brain tissue) were compared. Results: The dosimetric parameters of PTV in PSBO and BAO plans are almost similar and none of the parameters have shown a statistically significant difference. There was a difference of >1Gy in various OARs like brainstem Dmax, optic nerves Dmax, lenses Dmax, Dmin Dmax of right hippocampus and left hippocampus Dmin, though it was not statistically significant. Rest of the OARs like, both eyes, cochleae and normal brain had a difference of <1Gy and not statistically significant. Conclusion: Dosimetric parameters of PSBO patient planning method are equivalent to BAO method. PSBO may be more useful since it is an individualized planning and may further utilise less time with growing experience of the medical physicist.