1. Beam Directed Radiotherapy – Principles and practice

2. Definition Exact Calculations Beam Directing devices Advance Planning Beam directed radiotherapy

3. Need for Beam direction Homogenous Tumor Dose Low normal tissue dose Best therapeutic ratio

4. Steps Positioning Immobilization Localization Field Selection Dose distribution Calculations Verification Execution

6. Examples

9. Positioning aids… Pituitary Board Prone Support 3 way support

11. Breast boards… Modern Breast Board Indexed Arm supports Indexed wrist support Head rest Carbon fiber tilt board Wedge to prevent sliding

13. Belly boards & leg immobilizer`

14. Mould making

15. Mould making : Contd..

16. Mould making : Contd..

18. Thermoplastics : Principle

29. Lateral height method H 1 H 2 d d H 1 + H 2 2 d =

31. Tube shift principles Marker d 2 y f S Tumor x 1 x 2 d 1

32. Calculation d 1 f y d 2 x 1 x 2 x 1 S = d 1 f – d 1 S x 2 S = d 2 f – d 2 y = d 2 – d 1 = f x 2 + S x 2 - x 1 + S x 1 Tumor Marker

38. Contour Plotter

48. SAD calculations Total Tumor dose Number of fields x Number of #s = T Incident dose = T x 100 TMR/TAR Time = ID Output

54. Electronic Portal Imaging

63. Applicators: Design Lead Sheet Box Plastic Cap Metal Plate with hole

66. Jaws: Disadvantages A Perspex box may be applied to the head Compression not possible SSD indicator used. Patient to source distance unknown Light beam shining through the jaws Size and shape of field remain unknown Remedy Disadvantages

67. Front & Back Pointers

71. Pin & Arc Pin Arc Bubble

72. Pin & Arc: Principle

73. Pin & Arc : Method d D d D D This is the isocenter

76. Principle of Isocentric mounting

81. Conclusion Team Work Precision Quality Assurance

82. Thank You