The table below is for data of PDD against depth and for various field sizes for an 18 MV beam. (Figure 1) a) Plot PDD against depth for the following fields in the same graph the SSD is 100 cm. Note: the fields are on the surface. 6x6cm 12x12cm 30x30 cm Present your graphs and discuss the curves in each. (15 marks) moxo 4x46x6x8 10X10 12x12 15x15 20x20 25X25 DO 30 Depth os 0 730 70 10 OS NO 55 20 1000 100 TO 725 7 NON 3 7222 223 535 150 170 520 5 SO SE b) Using the same data from figure 1, calculate the PDD values at the depths of: lcm (for fields: 6x6, 12x12, and 30x30 cm). 10cm (for fields: 6x6, 12x12, and 30x30 cm). 24cm (for fields: 6x6, 12x12, and 30x30 cm). Calculate the depth dose values for the above fields if the SSD is increased to 120 cm. Compare the results at two different SSD values (part a vs part b) and discuss your results. (ensure you include your graphs) (10 marks) c) At the depth of 11 cm plot PDD across all fields against field sizes (6x6cm, 12x12cm, and 30x30 cm). Discuss the results and give reasons for the variations of PDD values, at the same depths, with field sizes (ensure you show your graphs) (15 marks) The table below is for data of PDD against depth and for various field sizes for an 18 MV beam. (Figure 1) a) Plot PDD against depth for the following fields in the same graph the SSD is 100 cm. Note: the fields are on the surface. 6x6cm 12x12cm 30x30 cm Present your graphs and discuss the curves in each. (15 marks) moxo 4x46x6x8 10X10 12x12 15x15 20x20 25X25 DO 30 Depth os 0 730 70 10 OS NO 55 20 1000 100 TO 725 7 NON 3 7222 223 535 150 170 520 5 SO SE b) Using the same data from figure 1, calculate the PDD values at the depths of: lcm (for fields: 6x6, 12x12, and 30x30 cm). 10cm (for fields: 6x6, 12x12, and 30x30 cm). 24cm (for fields: 6x6, 12x12, and 30x30 cm). Calculate the depth dose values for the above fields if the SSD is increased to 120 cm. Compare the results at two different SSD values (part a vs part b) and discuss your results. (ensure you include your graphs) (10 marks) c) At the depth of 11 cm plot PDD across all fields against field sizes (6x6cm, 12x12cm, and 30x30 cm). Discuss the results and give reasons for the variations of PDD values, at the same depths, with field sizes (ensure you show your graphs) (15 marks)