Cancer Research Journal
Volume 4, Issue 6, November 2016, Pages: 90-105

Photon and Electron Beam in the Treatment of Cancer Patient Based on Monitor Unit Compilation

Alamgir Hossain1, *, Dayal Chandra Roy2, Samiron Kumar Saha2, Nazrul Islam3

1Department of Physics, University of Rajshahi, Rajshahi, Bangladesh.

2Department of Physics, Pabna University of Science and Technology, Pabna, Bangladesh

3Department of Radiotherapy, Shaheed Ziaur Rahman Medical college & Hospital, Bogra, Bangladesh

Email address:

(A. Hossain)

*Corresponding author

To cite this article:

Alamgir Hossain, Dayal Chandra Roy, Somiron Kumar Saha, Nazrul Islam. Photon and Electron Beam in the Treatment of Cancer Patient Based on Monitor Unit Compilation. Cancer Research Journal. Vol. 4, No. 6, 2016, pp. 90-105. doi: 10.11648/j.crj.20160406.12

Received: October 11, 2016; Accepted: November 15, 2016; Published: December 2, 2016


Abstract: The aim of this research is to evaluate the precision of the Monitor unit (MU) calculation in radiation therapy to survive the cancerous patient, is the measurement of actual dose required to delivered. An essential key of quality assurance in radiation therapy is verifying the accuracy of monitor unit calculations. Difference between the simpler model calculation and other modifying method calculation assuming a flat water phantom must be required. The accurate measurement of field size is the most important fact since many dosimetric quantities were dependent on field size. Perhaps most commonly used method for determining monitor unit were modified which provide a new formalism.

Keywords: Monitor Unit, Photon, Electron, Cancer


1. Introduction

On the basis of clinical response data the international commission on radiation units(ICRU) and measurement states that dosimetry system must be capable of delivering dose to an accuracy of 5% or 7% [1-2]. More recently Mijnheer et al. [3, 4] and Wambersie et al [3, 5] proposed that the standard deviation of the uncertainty in the delivered dose should not be greater than 3.5%.For more it is need to improve on the treatment technology to get more accuracy. The delivery of therapeutic radiation is a medical procedure and as such requires independent confirmation to ensure correct and accurate delivery [6]. This confirmation is accomplished by a comprehensive calculation and chart review procedure performed both before and throughout patient treatment [6-10]. An evaluation of the incidence of radiotherapy errors over 10 years at a large regional cancer center concluded that treatment plan checks, including MU verification calculations, were very effective in detecting documentation and treatment planning errors [6, 11].Intensity modulated radiation therapy(IMRT) requires an enhanced quality assurance procedure. This applies in particular to the step of MU calculation verification. Because of time constraints, treatment planning systems(TPSs) normally deal only in an approximate manner with the physical processes of the interaction of ionizing radiation in the treatment head and dose deposition inside the patient. Therefore the determination of the absorbed dose needs experimental verification [12].

To get more accuracy many factor should be corrected which take an account for radiation treatment. Some of these are machine set up, patient adjustment exact tumor volume correction, field size determination, monitor unit calculation. All type fractions must included in dose calculation to get more accurate which depend on the monitor unit calculation. To ensure correct dose at any specific tumor cell it must need to know that how many monitor units is required under normalize condition for electron and photon. A small number of studies have already been published on the validity of this commercially available algorithm. The emphasis is generally on the verification of output factors and dose distributions in water [13, 14]. The calculation of monitor units has developed over past several years as treatment planning for the improvement in accuracy but the clinical effect of impact parameter were unclear. The actual distribution of radiation dose accumulated in normal tissues over the complete course of radiation therapy is, in general, poorly quantified [15]. Calibrating the dose per monitor unit (DMU) for individual patients is important to deliver the prescribed dose in radiation therapy [16]. Historically, MUs were determined using a manual calculation process, where the calculations were based on water phantom data gathered at time of machine commissioning. There are a variety of radiation oncology TPSs, from widely used commercial systems to special purpose systems, with limited application to a specific delivery modality [17].Currently, MU settings required to deliver the prescribed dose are often calculated by a computerized treatment planning system using methods and quantities different from those used in manual MU calculations. The verification calculation is not and should not be used as a check of the overall accuracy of the primary TPS; that is the function of commissioning and continual Quality assurance(QA). It is crucial that both the primary and the verification planning systems be properly and thoroughly commissioned so that they are as accurate as possible. Monitoring the agreement between the TPS and the verification system during clinical use can aid in identifying regions where beam models or data may be improved, but such monitoring is not a substitute for the commissioning of either system. Both the TPS and the verification system should be fully tested and commissioned following accepted guidelines [6, 18, 19, 20] prior to clinical use. In France, between 2004 and 2005, 23 patients received an overexposure of radiation resulting from the introduction of the enhanced dynamic wedge into the clinic, a review of the incident pointed to the recent elimination of an independent check of the MU calculation as a major contrib-uting factor [6, 21].

2. Materials and Method

The experiment consists of several parts. We were used VARIAN CLINAC 2100 CD linear accelerator machine at Shaheed Ziaur Rahman Medical college & Hospital(SZMCH), Bogra which provide 6MV,9MV,12MV,15MV photon and electron beam. A water phantom were used which is considered as a measurement body. Output factor(OPF),Percent depth dose(PDD),Tissue maximum ratio(TMR) were measured by using water phantom with electrometer(model Dose-1).The collected beam data were then used for beam modeling on the Pinnacle TPS(Treatment planning system). A set of cylindrical ionization chamber(farmer type FC-65P) were used to measure the radiation dose. The machine was calibrated to ensure that it works properly by comparing different measured data. To calculated monitor unit, we were used a simple model by correcting an impact factor. We were measured output factor in which included phantom scattering factor(Sp) and air scattering factor(Sc). At first we were calculated regular square field size for different irregular field size. We were used 10×10 reference field size. The water phantom were fed to the LINAC machine and measured the output for source axial distance (SAD) & source to surface distance(SSD) technique and also measured the output factor(OPF), Percent depth dose(PDD), Tissue maximum ratio(TMR), wedge factor and other attenuation factor for 6MV & 9MV photon and electron beam. For irregular field size, the output factor were obtained by interpolating neighbors field. The monitor unit was calculated for different field case and comparing with TPS (treatment planning system) calculation i.e. with manual calculation which was showed the better accuracy.

2.1. Calculation Formalism: For Photon Beam

Now-a-days the therapeutic machine has been improved so we need to improve our treatment technique. The equation for calculation of monitor unit (MU) in SSD technique that are used as before is

MU=  (1)

The scattering factor Sc, Sp and ISF(inverse square factor) are included into dose rate and taken as a output factor(OPF) so the equation(1) is reduce to

MU =     (2)

The equation for calculation of monitor unit in SAD technique

MU=     (3)

For Electron Beam: The equation for calculation of monitor unit is

MU=                     (4)

2.2. Calculation of Monitor Unit

(1). Monitor unit calculation for Photon: (Example):

Case-1: Cervix

Calculate how much monitor units required to delivered 50cGy in the anterior field to the isocentre using 6MV photon beam in SAD technique. collimator field size 18.4×17cm2, Depth=8.5cm.

Answer:

Field:1 AP

Technique: SAD

Field size=18.4×1716.67cm2

Depth = 8.5 cm

Energy = 6MV

Dose = 50cGy

Output Factor = 1.0388

Output =1.026cGy/MU

TMR = 0.847

Transmission Factor,TF = 0.998

MU = = = 55.50

The machine calculation is 53

Case-2: Tongue

Calculate how much monitor units required to delivered 50cGy in the lateral face to the isocentre using 6MV photon beam in SAD technique. collimator field size 7.8×10cm2, Depth=8.5cm.

Field: 1 LT Face

Technique: SAD

Equivalent Field size=7.8×108.76,Depth=5cm, Energy=6MV,

Dose = 100cGy, Output Factor = 0.986, Output =1.026 cGy/MU, TMR=0.814

MU = = = 121.43

Where the output factor [OPF] and tissue maximum ratio [TMR] are obtained by interpullating the output factor of field size 8×8,8×9,9×8 and 9×9

The dose per monitor unit is =0.84 cGy

Case-3: Tongue

Calculate how much monitor units required to delivered 100cGy in the right lateral face to the isocentre using 6MV photon beam in SAD technique. Collimator field size 7.2×9.4cm2, Depth=6cm.

Answer:

Field: 1 RT Lateral

Equivalent Technique:SAD

Field size=7.2×9.48.154, Depth=6 cm

Energy=6MV

Dose=100cGy

Output Factor = 0.982

Output=1.045 cGy/MU

TMR=0.920

Wedge=150

Wedge Factor, WF=0.765

MU = = = 138.45

Case-4:Breast

Calculate how much monitor units required to delivered 200cGy in the right lateral face to the isocentre using 6MV photon beam in SSD technique. Collimator field size 7.2×9.4cm2, Depth=6cm,SSD=98cm?

Answer:

Technique:SSD=98cm

Field size=16.2×11.813.65

Depth=2 cm

Energy=6MV

Dose=200cGy

Output Factor=1.024

Output=0.9964 cGy/MU

PDD=97.96%=0.9796

MU = ==200

Case-5: Cervix

Calculate how much monitor units required to delivered 50cGy in the left-lateral face to the isocentre using 15MV photon beam in SAD technique. collimator field size 17.5×11.5cm2, Depth =15cm.

Answer:

Field:1 LT Face

Technique: SAD

Equivalent Field size=17.5×11.513.7514cm2, Depth=15cm, Energy=15MV, Dose=50cGy, Output Factor =1.025, Output =1.125 cGy/MU, TMR=0.776

MU = = = 55.87

(2). Monitor unit calculation for electron:

Eample-1: Calculate the MUs required to deliver 200cGy To a depth of dm 100cm SSD for a 6×6 cm2insert in a 10×10cm2 applicator using 6MeV energy beam?

Answer: For the standard 100 –cm SSD, the monitor unit can be obtained buy using equation (3). Using data from table and square root rule for the output factor, the monitor units are given by.

MU=

Where

Field size, FS=6×6 cm2

OP=1.00cGy/MU

OPF=0.963

And D=200 cGy

Then we get

MU==207.68207

Eample-2: Calculate the MUs required to deliver 300cGy to a depth of dm 100cm SSD for a 9.4×8.6 cm2 insert in a 10×10cm2applicator using 6MeV energy beam?

Answer: For the standard 100 –cm SSD, the monitor unit can be obtained buy using equation (3). Using data from table and square root rule for the output factor, the equivalent square field size is 9×9 cm2, the monitor units are given by

MU=

Where

OP=1.00cGy/MU

OPF=0.99

And D=200 cGy

Then we get

MU= =303

3. Discussions

From above result it was shown that every term in equation (1) & (2) dependent on field size so that it should be correctly measured of field size. Table-1 showed the correct measurement of several square field size from different rectangle size which provides the actual calculation of monitor unit.Table-2&3 were the measurement of output factor of different field size for 6&15MV photon beam.Table-4&5 are measurement of PDD at different depth for different field similarly Table-6&7 were the measurement of TMR for 6&15 photon beam.Figure-1 illustrated that the variation of output factor depending on field size and it was showed that output factor increased exponentially with increasing field size. Figure-2&3illustrated variation of PDD depending on depth and showed that maximum surface dose occurred for high energy photon beam.

Figure 1. Output factor Vs Field size.

Figure 2. Measured PDD Vs depth for 6MV photon beam.

Figure 3. Measured PDD Vs depth for 10 MV photon beam.

Table 1. Field size determination[Equivalent square field size from rectangle field.

1 2 3 4 5 6 7 8 9 10 11 12
2 2.0                    
3 2.4 3.0                  
4 2.7 3.4 4.0                
5 2.9 3.7 4.4 5.0              
6 3.1 4.0 4.8 5.4 6.0            
7 3.3 4.2 5.1 5.8 6.5 7.0          
8 3.4 4.4 5.4 6.2 6.9 7.5 8.0        
9 3.5 4.6 5.6 6.4 7.2 7.8 8.5 9.0      
10 3.6 4.7 5.8 6.7 7.5 8.2 8.9 9.5 10.0    
11 3.7 4.8 6.0 6.9 7.8 8.5 9.2 9.8 10.5 11.0  
12 3.7 4.9 6.1 7.1 8.0 8.8 9.5 10.2 10.9 11.5 12.0
13 3.8 5.0 6.2 7.2 8.2 9.0 9.8 10.5 11.3 11.9 12.5
14 3.8 5.1 6.3 7.4 8.4 9.3 10.1 10.9 11.6 12.3 12.9
15 3.9 5.1 6.4 7.5 8.5 9.4 10.3 11.1 11.9 12.6 13.3
16 3.9 5.2 6.5 7.6 8.6 9.6 10.5 11.4 12.2 13.0 13.7
17 4.0 5.3 6.6 7.7 8.8 9.7 10.7 11.6 12.5 13.2 14.0
18 4.0 5.3 6.6 7.8 8.9 9.9 10.8 11.8 12.7 13.5 14.3
19 4.0 5.3 6.7 7.8 9.0 10.0 11.0 11.9 12.9 13.7 14.5
20 4.0 5.4 6.7 7.9 9.0 10.1 11.1 12.1 13.0 13.9 14.7
21 4.0 5.4 6.8 7.9 9.1 10.1 11.2 12.2 13.2 14.0 14.9
22 4.0 5.4 6.8 8.0 9.1 10.2 11.3 12.3 13.3 14.2 15.1
23 4.1 5.4 6.8 8.0 9.2 10.3 11.4 12.4 13.4 14.3 15.3
24 4.1 5.5 6.8 8.0 9.2 10.4 11.5 12.5 13.5 14.4 15.4
25 4.1 5.5 6.9 8.1 9.3 10.4 11.6 12.6 13.6 14.6 15.6
26 4.1 5.5 6.9 8.1 9.3 10.5 11.6 12.7 13.7 14.7 15.7
27 4.1 5.5 6.9 8.1 9.4 10.5 11.7 12.7 13.8 14.8 15.8
28 4.1 5.5 6.9 8.2 9.4 10.6 11.7 12.8 13.8 14.9 15.9
30 4.1 5.5 6.9 8.2 9.4 10.6 11.7 12.8 13.9 15.0 16.0

Table 1. continued.

1 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 30
2                                  
3                                  
4                                  
5                                  
6                                  
7                                  
8                                  
9                                  
10                                  
11                                  
12                                  
13 13.0                                
14 13.5 14.0                              
15 13.9 14.5 15.0                            
16 14.3 14.9 15.5 16.0                          
17 14.7 15.3 15.9 16.5 17.0                        
18 15.0 15.7 16.3 16.9 17.5 18.0                      
19 15.3 16.0 16.7 17.3 17.9 18.5 19.0                    
20 15.5 16.3 17.0 17.7 18.3 18.9 19.5 20.0                  
21 15.7 16.6 17.3 18.0 18.7 19.3 19.9 20.5 21.0                
22 16.0 16.8 17.6 18.3 19.0 19.7 20.3 20.9 21.5 22.0              
23 16.1 17.0 17.8 18.6 19.3 20.0 20.7 21.3 21.9 22.5 23.0            
24 16.3 17.2 18.0 18.8 19.6 20.3 21.0 21.7 22.3 22.9 23.5 24.0          
25 16.5 17.4 18.2 19.0 19.8 20.6 21.3 22.1 22.7 23.3 23.9 24.5 25.0        
26 16.6 17.5 18.4 19.2 20.1 20.9 21.7 22.4 23.1 23.9 24.3 24.9 25.5 26.0      
27 16.7 17.7 18.5 19.4 20.3 21.1 21.9 22.7 23.4 24.1 24.7 25.3 25.9 26.5 27.0    
28 16.9 17.8 18.7 19.6 20.5 21.3 22.1 22.9 23.7 24.4 25.1 25.7 26.4 27.0 27.5 28.0  
30 17.0 18.0 19.0 19.9 20.8 21.7 22.5 23.3 24.1 24.9 25.7 26.4 27.1 27.7 28.4 29.0 30.0

Table 2. Output Factor For6MV photon beam For SAD Technique output, OP=1.026cGy/MU &SSD output, OP=0.9964 Gy/MU.

  3 4 5 6 7 8 9 10 11 12 13
3 0.909 0.917 0.921 0.926 0.928 0.931 0.932 0.934 0.935 0.936 0.936
4 0.918 0.928 0.933 0.939 0.942 0.945 0.947 0.949 0.950 0.952 0.953
5 0.924 0.935 0.942 0.948 0.952 0.956 0.958 0.961 0.962 0.964 0.965
6 0.930 0.943 0.950 0.957 0.962 0.967 0.969 0.972 0.974 0.976 0.977
7 0.934 0.948 0.956 0.964 0.969 0.974 0.977 0.980 0.982 0.984 0.986
8 0.938 0.952 0.961 0.970 0.976 0.981 0.985 0.988 0.991 0.993 0.995
9 0.941 0.956 0.965 0.975 0.981 0.987 0.990 0.994 0.997 0.999 1.001
10 0.944 0.959 0.969 0.979 0.986 0.992 0.996 1.000 1.003 1.006 1.007
11 0.946 0.962 0.972 0.983 0.989 0.996 1.000 1.004 1.007 1.011 1.013
12 0.948 0.964 0.975 0.986 0.993 1.000 1.004 1.008 1.012 1.016 1.018
13 0.949 0.966 0.977 0.988 0.995 1.002 1.007 1.012 1.015 1.019 1.021
14 0.950 0.968 0.979 0.991 0.998 1.005 1.010 1.015 1.019 1.023 1.025
15 0.951 0.970 0.981 0.993 1.000 1.008 1.013 1.019 1.022 1.026 1.028
16 0.953 0.971 0.983 0.995 1.002 1.010 1.015 1.021 1.024 1.028 1.031
17 0.954 0.972 0.984 0.996 1.004 1.012 1.017 1.023 1.027 1.030 1.033
18 0.955 0.973 0.985 0.998 1.006 1.014 1.019 1.025 1.029 1.033 1.035
19 0.956 0.974 0.987 0.999 1.007 1.015 1.021 1.027 1.031 1.035 1.037
20 0.957 0.974 0.988 1.001 1.009 1.017 1.023 1.029 1.033 1.037 1.040
25 0.960 0.979 0.992 1.005 1.014 1.022 1.029 1.035 1.039 1.044 1.047
30 0.962 0.982 0.996 1.009 1.018 1.027 1.034 1.040 1.045 1.050 1.053
35 0.966 0.985 0.999 1.013 1.022 1.031 1.038 1.045 1.050 1.055 1.058
40 0.967 0.988 1.002 1.016 1.025 1.035 1.042 1.048 1.053 1.058 1.062

Table 2. continued.

  14 15 16 17 18 19 20 25 30 35 40
3 0.937 0.937 0.938 0.938 0.939 0.939 0.939 0.941 0.941 0.941 0.942
4 0.953 0.954 0.955 0.955 0.955 0.956 0.956 0.957 0.959 0.959 0.960
5 0.966 0.967 0.967 0.968 0.969 0.969 0.970 0.971 0.972 0.973 0.974
6 0.978 0.980 0.980 0.981 0.982 0.982 0.983 0.985 0.986 0.987 0.987
7 0.987 0.989 0.989 0.990 0.991 0.992 0.993 0.995 0.996 0.997 0.998
8 0.996 0.998 0.999 0.999 1.000 1.001 1.002 1.005 1.006 1.008 1.008
9 1.003 1.004 1.005 1.006 1.007 1.008 1.010 1.012 1.014 1.015 1.016
10 1.009 1.011 1.012 1.013 1.015 1.016 1.017 1.019 1.022 1.023 1.024
11 1.014 1.016 1.018 1.019 1.020 1.021 1.022 1.025 1.028 1.029 1.030
12 1.020 1.022 1.023 1.024 1.025 1.027 1.028 1.032 1.034 1.036 1.037
13 1.023 1.026 1.027 1.028 1.029 1.031 1.032 1.036 1.039 1.040 1.042
14 1.027 1.029 1.031 1.032 1.033 1.035 1.036 1.040 1.043 1.045 1.046
15 1.031 1.033 1.035 1.036 1.037 1.039 1.040 1.045 1.048 1.050 1.050
16 1.033 1.036 1.037 1.038 1.040 1.041 1.042 1.048 1.051 1.053 1.054
17 1.035 1.038 1.039 1.041 1.042 1.043 1.045 1.051 1.054 1.056 1.057
18 1.038 1.040 1.042 1.043 1.045 1.046 1.047 1.053 1.057 1.060 1.061
19 1.040 1.043 1.044 1.046 1.047 1.048 1.050 1.056 1.060 1.063 1.064
20 1.042 1.045 1.047 1.048 1.049 1.051 1.052 1.059 1.063 1.066 1.068
25 1.050 1.053 1.055 1.057 1.058 1.060 1.062 1.069 1.074 1.077 1.079
30 1.056 1.059 1.061 1.063 1.065 1.068 1.070 1.077 1.083 1.086 1.087
35 1.061 1.065 1.067 1.069 1.072 1.074 1.076 1.084 1.090 1.093 1.095
40 1.066 1.069 1.072 1.074 1.076 1.079 1.081 1.089 1.095 1.099 1.101

Table 3. Output Factor For15MV photon beam For SAD Technique output, OP=1.125cGy/MU & SSD OP=0.988 Gy/MU.

  3 4 5 6 7 8 9 10 11 12 13
3 0.897 0.911 0.949 0.988 0.956 0.925 0.927 0.928 0.929 0.930 0.931
4 0.912 0.927 0.933 0.939 0.942 0.945 0.947 0.949 0.950 0.952 0.952
5 0.918 0.935 0.942 0.949 0.953 0.957 0.959 0.961 0.962 0.964 0.965
6 0.925 0.943 0.951 0.959 0.963 0.968 0.970 0.973 0.974 0.976 0.977
7 0.929 0.948 0.956 0.965 0.970 0.975 0.978 0.981 0.982 0.984 0.986
8 0.933 0.953 0.962 0.971 0.977 0.982 0.985 0.989 0.991 0.993 0.994
9 0.935 0.956 0.966 0.976 0.982 0.987 0.991 0.994 0.997 0.999 1.000
10 0.938 0.959 0.970 0.980 0.986 0.993 0.996 1.000 1.002 1.005 1.007
11 0.940 0.962 0.973 0.983 0.990 0.996 1.000 1.004 1.007 1.009 1.011
12 0.942 0.964 0.975 0.987 0.993 1.000 1.004 1.009 1.011 1.014 1.016
13 0.943 0.966 0.9+77 0.989 0.996 1.003 1.007 1.011 1.014 1.017 1.020
14 0.945 0.967 0.979 0.991 0.998 1.005 1.009 1.014 1.017 1.021 1.023
15 0.946 0.969 0.981 0.993 1.000 1.007 1.012 1.016 1.020 1.024 1.026
16 0.947 0.970 0.982 0.995 1.002 1.009 1.014 1.019 1.022 1.026 1.029
17 0.948 0.972 0.984 0.996 1.004 1.011 1.016 1.021 1.025 1.028 1.031
18 0.949 0.973 0.985 0.998 1.005 1.013 1.018 1.023 1.027 1.031 1.033
19 0.951 0.974 0.987 0999. 1.007 1.015 1.020 1.025 1.029 1.033 1.035
20 0.952 0.976 0.988 1.001 1.009 1.017 1.022 1.028 1.031 1.035 1.038
25 0.955 0.980 0.993 1.006 1.014 1.022 1.028 1.034 1.038 1.042 1.045
30 0.959 0.983 0.997 1.010 1.019 1.028 1.033 1.039 1.044 1.048 1.051
35 0.962 0.987 1.001 1.015 1.023 1.032 1.038 1.044 1.049 1.053 1.056
40 0.965 0.990 1.004 1.018 1.027 1.036 1.042 1.048 1.053 1.058 1.061

Table 3. continued.

  14 15 16 17 18 19 20 25 30 35 40
3 0.932 0.932 0.932 0.933 0.933 0.933 0.933 0.935 0.9937 0.937 0.938
4 0.953 0.9544 0.954 0.955 0.955 0.956 0.956 0.958 0.960 0.961 0.963
5 0.966 0.967 0.967 0.968 0.968 0.969 0.969 0.972 0.974 0.975 0.976
6 0.978 0.979 0.980 0.981 0.981 0.982 0.982 0.985 0.988 0.988 0.989
7 0.987 0.988 0.989 0.990 0990. 0.991 0.992 0.995 0.997 0.998 0.999
8 0.996 0.997 0.998 0.999 1.000 1.000 1.001 1.005 1.007 1.009 1.008
9 1.002 1.004 1.005 1.006 1.007 1.007 1.008 1.012 1.014 1.016 1.016
10 1.009 1.011 1.012 1.013 1.014 1.014 1.015 1.018 1.021 1.023 1.023
11 1.013 1.016 1.017 1.018 1.019 1.020 1.021 1.024 1.027 1.029 1.029
12 1.018 1.021 1.022 1.023 1.024 1.025 1.026 1.030 1.033 1.035 1.035
13 1.022 1.024 1.025 1.026 1.027 1.029 1.030 1.034 1.037 1.039 1.039
14 1.025 1.027 1.029 1.030 1.031 1.032 1.034 1.038 1.041 1.043 1.044
15 1.029 1.031 1.032 1.034 1.035 1.036 1.038 1.042 1.045 1.047 1.048
16 1.031 1.033 1.035 1.036 1.037 1.039 1.040 1.045 1.048 1.050 1.051
17 1.033 1.036 1.037 1.039 1.040 1.042 1.043 1.048 1.051 1.053 1.054
18 1.036 1.038 1.040 1.041 1.043 1.044 1.046 1.050 1.054 1.056 1.057
19 1.038 1.041 1.042 1.044 1.045 1.047 1.048 1.053 1.057 1.059 1.061
20 1.040 1.043 1.045 1.046 1.048 1.049 1.051 1.056 1.060 1.062 1.064
25 1.048 1.051 1.052 1.054 1.056 1.058 1.059 1.069 1.070 1.073 1.074
30 1.054 1.057 1.059 1.061 1.063 1.065 1.066 1.073 1.078 1.081 1.082
35 1.060 1.063 1.065 1.067 1.069 1.071 1.073 1.080 1.085 1.088 1.090
40 1.064 1.068 1.070 1.072 1.074 1.076 1.078 1.085 1.091 1.094 1.095

Table 4. Normalization percent depth doses(PDD)(d=10cm) for 6-MV x-rays,SSD-100cm.

Dsepth[mm] Field size[mm]
40.0 60.0 80.0 100.0 120.0 150.0 200.0 250.0 300.0 350.0 400.0
115.0 56.671 58.55 60.500 61.950 62.629 63.850 65.200 66.043 66.330 67.085 67.500
120.0 54.750 56.99 59.013 60.025 60.975 62.471 63.750 65.000 64.837 65.720 65.945
125.0 53.075 55.143 57.337 58.525 59.600 60.400 62.025 63.050 63.385 64.195 64.271
130.0 51.467 53.714 55.567 57.037 57.875 59.000 60.500 61.725 61.935 62.400 63.138
135.0 50.125 52.317 53.987 55.233 56.413 57.688 58.850 60.112 60.585 61.275 61.510
140.0 48.600 50.44 52.200 53.775 55.100 56.000 57.500 58.933 58.935 60.016 60.425
145.0 47.067 48.886 51.050 52.287 53.700 54.667 56.425 57.500 57.671 58.620 58.875
150.0 45.550 47.725 49.700 50.950 51.929 53.250 54.813 56.100 56.520 57.225 57.625
155.0 44.200 46.600 48.056 49.586 50.775 52.000 53.333 54.925 55.065 55.920 56.265
160.0 42.950 45.125 47.025 48.300 49.300 50.500 52.100 53.650 53.630 54.725 54.930
165.0 41.771 43.850 45.675 46.800 48.087 49.100 50.725 52.300 52.610 53.530 53.830
170.0 40.425 42.056 44.383 45.600 46.443 47.871 49.833 50.750 51.357 52.225 52.630
175.0 39.213 40.943 43.100 44.500 45.457 46.900 48.600 49.813 50.032 51.020 51.430
180.0 38.086 40.138 41.800 42.800 44.300 45.612 47.400 48.914 49.115 49.925 50.135
185.0 36.900 39.000 40.500 41.800 43.000 44.400 45.914 47.400 47.920 48.675 49.030
190.0 35.500 37.600 39.500 40.611 41.786 43.200 44.900 46.037 46.615 47.520 48.020
195.0 34.550 36.457 38.100 39.725 40.662 42.214 43.556 45.114 45.410 46.400 46.830
200.0 33.650 35.433 37.300 38.871 39.700 41.150 42.600 44.075 44.610 45.300 45.600
205.0 32.700 34.131 36.250 37.388 38.713 39.800 41.537 43.100 43.475 44.168 44.665
210.0 31.713 33.583 35.125 36.275 37.350 38.800 40.643 42.000 42.419 43.214 43.619
215.0 30.850 32.500 34.100 35.571 36.550 37.678 39.500 40.888 41.352 42.252 42.650
220.0 29.967 31.567 33.167 34.650 35.325 37.050 38.575 40.100 40.410 41.315 41.724
225.0 29.100 30.600 32.000 33.500 34.643 36.100 37.667 38.971 39.411 40.263 40.720
230.0 28.163 29.800 31.367 32.638 33.625 34.867 36.600 37.900 38.230 39.300 39.700
235.0 27.171 28.900 30.625 31.667 32.500 33.900 35.633 37.000 37.375 38.420 38.820
240.0 26.400 28.100 29.700 30.878 31.933 33.300 34.650 36.086 36.615 37.415 38.014
245.0 25.550 27.100 28.717 29.825 30.950 32.217 34.086 35.500 35.757 36.675 37.065
250.0 24.914 26.520 28.100 29.180 30.157 31.450 33.200 34.400 34.800 35.600 36.200
255.0 24.250 25.633 27.300 28.287 29.329 30.686 32.200 33.443 33.920 34.850 35.253
260.0 23.675 25.100 26.614 27.750 28.600 29.713 31.267 32.750 33.100 34.000 34.415
265.0 22.843 24.300 25.800 26.700 27.800 29.000 30.300 31.971 32.405 33.150 33.665
270.0 22.250 23.600 25.025 26.188 27.113 28.388 29.744 31.300 31.614 32.410 32.915
275.0 21.688 23.000 24.300 25.400 26.286 27.500 29.100 30.500 30.900 31.750 32.110
280.0 21.100 22.337 23.667 24.844 25.800 26.833 28.300 29.700 30.310 30.815 31.315
285.0 20.525 21.800 23.037 24.071 25.125 26.263 27.843 29.000 29.305 30.150 30.500
290.0 19.900 21.000 22.500 23.400 24.300 25.600 27.100 28.400 28.500 29.400 29.815
295.0 19.157 20.600 21.900 22.712 23.788 24.825 26.300 27.588 28.000 28.850 29.100
300.0 18.517 20.000 21.217 22.200 0.000 24.117 0.000 26.800 27.214 28.015 28.500

Table 5. Normalization percent depth doses(PDD)(d=10cm) for 15-MV x-rays,SSD-100cm.Values: Dose [%].

Depth[cm] Field size[cm]
4 5 6 7 8 9 10 11
0.0 24.6 25.9 27.1 28.7 30.3 31.6 32.8 34.0
1 78.4 77.1 77.7 78.7 79.7 80.7 81.0 82.3
2 96.5 96.7 96.9 96.9 96.9 97.2 97.5 97.9
3 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0
4 98.7 98.5 98.2 98.5 98.6 98.3 97.7 97.6
5 96.0 95.0 95.0 95.0 94.9 94.7 94.6 94.5
6 90.5 90.8 91.1 91.2 91.2 91.2 91.1 91.0
7 86.7 87.1 87.4 87.3 87.1 87.2 87.3 77.6
8 83.0 83.2 83.3 83.6 83.9 83.6 83.7 83.8
9 79.3 79.7 80.0 80.2 80.4 80.3 80.1 80.3
10 75.3 75.5 76.0 76.4 78.8 76.8 76.8 76.9
11 71.7 71.0 70.2 71.9 73.5 73.7 73.8 74.1
12 68.6 69.1 69.6 70.0 70.3 70.5 70.7 70.9
13 65.2 65.9 66.6 66.9 67.2 67.4 67.6 68.0
14 62.3 62.9 63.5 63.9 64.3 64.5 64.6 65.0
15 58.9 59.8 60.7 61.1 61.4 61.8 62.1 62.2
16 56.9 57.4 57.9 58.5 59.1 59.3 59.5 59.8
17 54.0 54.8 55.6 56.0 56.3 56.6 56.8 57.2
18 51.7 52.3 52.9 53.4 53.9 54.1 54.2 54.7
19 49.2 50.0 50.7 51.2 51.6 51.8 52.0 52.5
20 45.9 47.6 48.2 48.7 49.2 49.5 49.8 50.3
21 45.0 45.6 46.1 46.5 46.9 47.4 47.9 48.2
22 42.8 43.4 44.0 44.6 45.1 45.4 45.6 46.1
23 40.0 41.5 42.0 42.6 43.1 43.5 43.8 44.2
24 39.1 39.6 40.1 40.7 41.2 41.6 42.0 42.2
25 37.4 37.9 38.4 39.0 39.6 39.9 40.1 40.5
26 35.7 38.2 36.6 37.3 38.0 38.3 38.5 38.8
27 33.9 34.5 35.1 38.7 36.2 36.5 36.8 37.2
28 32.6 33.2 33.7 34.2 34.6 35.1 35.6 35.9
29 31.1 31.0 32.1 32.6 33.1 33.5 33.9 34.3
30 29.7 30.2 30.7 31.2 31.6 32.0 32.4 32.6

Table 5. continued.

Depth[cm] Field size[cm]
12 13 14 15 16 17 18 20 25
  35.1 36.2 37.4 38.5 39.6 40.7 41.8 44.0 48.8
0.0 83.0 83.6 84.1 84.6 85.2 85.8 86.5 87.7 90.1
1 98.7 98.6 98.7 99.0 99.1 99.2 99.3 99.5 99.9
2 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0
3 97.4 97.6 97.5 97.6 97.4 97.2 97.0 96.5 96.3
4 94.4 94.4 94.3 94.3 94.1 93.9 93.6 93.2 93.3
5 90.9 90.7 90.6 90.4 90.3 90.2 90.1 89.9 90.4
6 87.6 74.1 80.7 87.2 87.1 87.0 87.0 86.8 86.9
7 83.8 83.0 83.8 83.8 83.6 83.8 83.7 83.7 83.5
8 80.5 80.5 80.6 80.6 72.6 64.5 58.8 40.4 81.0
9 76.9 77.1 77.4 77.6 77.8 77.6 77.7 77.7 77.7
10 74.3 74.2 74.2 74.1 74.2 74.2 74.3 74.4 74.8
11 71.0 71.1 71.3 71.4 71.4 71.4 71.4 71.4 72.0
12 68.3 68.4 68.4 68.5 68.6 68.6 68.7 68.8 69.4
13 65.3 65.5 65.7 65.9 66.0 66.1 66.2 68.4 66.6
14 62.3 62.6 62.8 63.1 63.2 63.3 63.3 63.5 64.0
15 60.0 60.2 60.3 60.5 60.6 60.7 60.9 61.1 61.5
16 57.5 57.7 57.8 58.0 58.2 58.3 58.5 58.8 59.2
17 55.2 55.4 55.6 55.6 55.9 56.0 56.2 56.4 56.9
18 52.9 53.0 53.2 53.3 53.4 53.6 53.7 54.0 55.0
19 50.7 50.8 51.0 51.1 51.3 51.5 51.6 52.0 52.9
20 48.5 48.7 49.0 49.2 49.3 49.5 49.6 49.9 50.7
21 46.5 46.7 47.0 47.2 47.3 47.5 47.6 47.9 48.6
22 44.6 44.9 45.1 45.4 45.5 45.6 45.8 46.0 45.7
23 42.4 42.7 43.1 43.4 42.8 42.1 41.5 40.2 45.0
24 40.8 41.1 41.3 41.6 41.8 42.0 42.3 42.7 43.3
25 49.3 39.4 39.7 40.0 41.0 42.0 42.9 44.9 41.8
26 37.5 37.8 38.0 38.2 38.4 38.5 38.7 39.0 39.9
27 36.1 36.3 36.5 38.7 38.9 37.1 37.3 37.7 38.4
28 34.6 34.0 35.1 35.3 36.5 35.7 35.8 36.2 36.0
29 33.2 33.4 33.7 33.0 34.1 34.3 34.4 34.8 35.0
30                  

Table 6. Measured Tissue Maximum Ratio[TMR](6 MV)Values: Ratio [%].

Depth[mm] Field size[cm]
1 2 3 4 5 6 7 8
0.0 0.382 0.393 0.404 0.414 0.425 0.436 0.442 0.448
10.0 0.911 0.917 0.923 0.929 0.935 0.940 0.942 0.944
20.0 0.999 0.999 0.998 0.998 0.998 0.998 0.998 0.998
30.0 0.963 0.966 0.968 0.970 0.973 0.975 0.976 0.976
40.0 0.920 0.925 0.929 0.934 0.938 0.942 0.946 0.950
50.0 0.877 0.883 0.889 0.895 0.901 0.908 0.913 0.918
60.0 0.825 0.835 0.846 0.856 0.866 0.877 0.884 0.888
70.0 0.794 0.804 0.815 0.825 0.836 0.846 0.853 0.857
80.0 0.753 0.764 0.775 0.7895 0.796 0.807 0.818 0.828
90.0 0.718 0.730 0.741 0.753 0.764 0.776 0.786 0.793
100.0 0.691 0.701 0.712 0.722 0.732 0.743 0.753 0.763
110.0 0.664 0.674 0.683 0.693 0.703 0.713 0.723 0.732
120.0 0.619 0.632 0.645 0.957 0.670 0.683 0.695 0.705
130.0 0.588 0.601 0.615 0.628 0.641 0.655 0.667 0.675
140.0 0.571 0.582 0.593 0.604 0.615 0.626 0.637 0.645
150.0 0.535 0.548 0.561 0.574 0.587 0.600 0.613 0.622
160.0 0.511 0.524 0.537 0.550 0.563 0.576 0.589 0.598
170.0 0.498 0.508 0.517 0.527 0.537 0.548 0.558 0.569
180.0 0.466 0.478 0.491 0.503 0.515 0.528 0.541 0.549
190.0 0.437 0.450 0.463 0.475 0.488 0.501 0.514 0.524
200.0 0.426 0.437 0.448 0.459 0.470 0.481 0.492 0.502
210.0 0.404 0.415 0.427 0.438 0.450 0.462 0.473 0.482
220.0 0.392 0.402 0.412 0.421 0.431 0.442 0.452 0.461
230.0 0.371 0.381 0.391 0.402 0.412 0.422 0.433 0.442
240.0 0.349 0.360 0.371 0.381 0.392 0.403 0.414 0.423
250.0 0.335 0.345 0.355 0.365 0.375 0.386 0.396 0.405
260.0 0.326 0.335 0.344 0.353 0.362 0.371 0.381 0.389
270.0 0.311 0.319 0.328 0.337 0.345 0.354 0.363 0.371
280.0 0.300 0.308 0.316 0.324 0.332 0.340 0.349 0.356
290.0 0.289 0.296 0.304 0.311 0.318 0.325 0.333 0.340
300.0 0.261 0.271 0.280 0.290 0.300 0.309 0.319 0.328
310.0 0.249 0.258 0.267 0.277 0.286 0.295 0.305 0.314
320.0 0.237 0.246 0.255 0.264 0.273 0.282 0.291 0.300
330.0 0.226 0.235 0.243 0.252 0.260 0.279 0.278 0.286
340.0 0.216 0.224 0.232 0.240 0.248 0.257 0.265 0.273
350.0 0.206 0.214 0.221 0.229 0.237 0.245 0.253 0.261
360.0 0.196 0.204 0.211 0.219 0.226 0.234 0.242 0.249
370.0 0.187 0.194 0.201 0.209 0.216 0.223 0.231 0.238
380.0 0.178 0.185 0.192 0.199 0.206 0.213 0.220 0.227
390.0 0.170 0.176 0.183 0.190 0.196 0.203 0.210 0.216
400.0 0.162 0.168 0.174 0.181 0.187 0.194 0.200 0.207

Table 6. continue.

Depth[mm] Field size[cm]
9 10 11 12 13 14 15 16 17
0.0 0.457 0.467 0.477 0.486 0.495 0.504 0.513 0.519 0.524
10.0 0.946 0.948 0.949 0.950 0.952 0.955 0.958 0.969 0.960
20.0 0.999 0999. 0.999 0.999 0.999 1.000 1.000 0.999 0.998
30.0 0.978 0.980 0.980 0.978 0.978 0.979 0.980 0.980 0.979
40.0 0.953 0.956 0.956 0.955 0.955 0.956 0.958 0.958 0.958
50.0 0.923 0.927 0.929 0.929 0.929 0.932 0.935 0.937 0.936
60.0 0.892 0.896 0.898 0.900 0.901 0.906 0.909 0.913 0.912
70.0 0.861 0.865 0.870 0.873 0.876 0.879 0.882 0.884 0.884
80.0 0.835 0.839 0.843 0.847 0.851 0.854 0.857 0.860 0.861
90.0 0.800 0.808 0.815 0.818 0.821 0.826 0.830 0.833 0.835
100.0 0.771 0.778 0.785 0.789 0.794 0.798 0.803 0.808 0.810
110.0 0.741 0.750 0.759 0.763 0.764 0.771 0.775 0.780 0.783
120.0 0.714 0.720 0.726 0.732 0.737 0.743 0.749 0.755 0.760
130.0 0.684 0.692 0.701 0.707 0.712 0.716 0.721 0.726 0.730
140.0 0.653 0.662 0.671 0.680 0.687 0.693 0.697 0.701 0.705
150.0 0.632 0.639 0.647 0.654 0.659 0.665 0.670 0.676 0.761
160.0 0.607 0.615 0.623 0.630 0.636 0641. 0.646 0.651 0.656
170.0 0.581 0.590 0.597 0.604 0.609 0.614 0.620 0.626 0.631
180.0 0.557 0.564 0.570 0.577 0.586 0.594 0.600 0.606 0.611
190.0 0.534 0.542 0.549 0.556 0.563 0.569 0.576 0.581 0.587
200.0 0.511 0.521 0.530 0.540 0.545 0.550 0.555 0.561 0.567
210.0 0.490 0.497 0.504 0.512 0.518 0.524 0.531 0.537 0.542
220.0 0.469 0.477 0.486 0.496 0.501 0.505 0.510 0.517 0.524
230.0 0.450 0.458 0.466 0.474 0.480 0.486 0.492 0.497 0.502
240.0 0.431 0.440 0.447 0.455 0.462 0.468 0.474 0.480 0.485
250.0 0.414 0.422 0.429 0.436 0.443 0.449 0.454 0.460 0.465
260.0 0.397 0.405 0.413 0.420 0.427 0.432 0.437 0.442 0.446
270.0 0.379 0.387 0.394 0.402 0.409 0.415 0.420 0.426 0.431
280.0 0.363 0.371 0.378 0.386 0.393 0.399 0.405 0.410 0.414
290.0 0.348 0.357 0.364 0.370 0.376 0.381 0.387 0.392 0.398
300.0 0.335 0.342 0.348 0.355 0.361 0.367 0.373 0.378 0.382
310.0 0.320 0.327 0.334 0.340 0.346 0.352 0.358 0.363 0.367
320.0 0.306 0.313 0.320 0.325 0.331 0.337 0.343 0.349 0.352
330.0 0.293 0.300 0.306 0.311 0.317 0.323 0.329 0.335 0.338
340.0 0.280 0.287 0293. 0.298 0.303 0.309 0.315 0321. 0.325
350.0 0.268 0.274 0.281 0.285 0.290 0.296 0.302 0.308 0.312
360.0 0.256 0.262 0.269 0.273 0.278 0.283 0.289 0.295 0.299
370.0 0.244 0.251 0.257 0.261 0.266 0.270 0.276 0.282 0.287
380.0 0.233 0.240 0.246 0.250 0.254 0.258 0.265 0.270 0.275
390.0 0.223 0.229 0.236 0.240 0.243 0.247 0.253 0.259 0.264
400.0 0.213 0.219 0.225 0.229 0.233 0.236 0.242 0.248 0.253

Table 6. continue.

Depth[mm] Field size[cm]
18 19 20 21 22 23 24 25 26 27
0.0 0.530 0.536 0.541 0.550 0.559 0.568 0.577 0.586 0.598 0.609
10.0 0.960 0.961 0.962 0.963 0.965 0.967 0.970 0.972 0.974 0.976
20.0 0.997 0.996 0.995 0.996 0.996 0.997 0.998 0.999 0.999 0.999
30.0 0.979 0.978 0.978 0.978 0.979 0.979 0.980 0.980 0.980 0.980
40.0 0.957 0.957 0.957 0.958 0.959 0.961 0.962 0.963 0.964 0.963
50.0 0.935 0.934 0.934 0.933 0.935 0.937 0.938 0.939 0.940 0.940
60.0 0.911 0.911 0.911 0.911 0.914 0.916 0.919 0.921 0.923 0.923
70.0 0.885 0.885 0.886 0.888 0.890 0.893 0.896 0.899 0.901 0.902
80.0 0.861 0.861 0.861 0.862 0.865 0.868 0.871 0.874 0.876 0.878
90.0 0.836 0.838 0.840 0.842 0.845 0.848 0.850 0.852 0.854 0.855
100.0 0.811 0.812 0.813 0.815 0.818 0.821 0.824 0.826 0.828 0.830
110.0 0.784 0.786 0.788 0.791 0.793 0.797 0.801 0.804 0.806 0.808
120.0 0.762 0.763 0.766 0.769 0.772 0.776 0.779 0.782 0.784 0.786
130.0 0.732 0.735 0.737 0.741 0.745 0.749 0.752 0.755 0.757 0.759
140.0 0.707 0.709 0.712 0.716 0.719 0.723 0.728 0.731 0.734 0.736
150.0 0.684 0.686 0.689 0.693 0.697 0.701 0.705 0.708 0.711 0.713
160.0 0.659 0.862 0.665 0.669 0.673 0.677 0.681 0.685 0.689 0.691
170.0 0.635 0.639 0.643 0.647 0.652 0.658 0.661 0.664 0.666 0.667
180.0 0.615 0.618 0.622 0.626 0.630 0.635 0.640 0.644 0.647 0.650
190.0 0.592 0.595 0.598 0.602 0.605 0.611 0.615 0.619 0.621 0.623
200.0 0.573 0.575 0.578 0.581 0.585 0.589 0.593 0.597 0.600 0.603
210.0 0.548 0.551 0.555 0.559 0.564 0.569 0.574 0.578 0.581 0.584
220.0 0.530 0.534 0.537 0.541 0.545 0.549 0.553 0.557 0.561 0.264

Table 6. continue.

Depth[mm] Field size[cm]
28 29 30 31 32 33 34
0.0 0.620 0.632 0.643 0.648 0.654 0.660 0.666
10.0 0.978 0.980 0.982 0.983 0.984 0.985 0.985
20.0 0.999 0.999 0.999 0.999 0.999 0.998 0.998
30.0 0.980 0.980 0.980 0.980 0.980 0.981 0.981
40.0 0.963 0.962 0.961 0.961 0.962 0.963 0.964
50.0 0.940 0.939 0.939 0.940 0.941 0.942 0.944
60.0 0.923 0.923 0.923 0.923 0.924 0.924 0.924
70.0 0.900 0.899 0.899 0.899 0.899 0.900 0.902
80.0 0.877 0.877 0.877 0.877 0.878 0.879 0.880
90.0 0.855 0.855 0.855 0.856 0.856 0.857 0.858
100.0 0.831 0.830 0.831 0.831 0.833 0.834 0.835
110.0 0.810 0.809 0.810 0.810 0.811 0.812 0.814
120.0 0.788 0.788 0.788 0.788 0.789 0.790 0.792
130.0 0.761 0.762 0.762 0.764 0.765 0.764 0.769
140.0 0.738 0.740 0.740 0.740 0.742 0.743 0.744
150.0 0.715 0.716 0.717 0.719 0.721 0.723 0.725
160.0 0.684 0.696 0.696 0.697 0.698 0.699 0.700
170.0 0.668 0.670 0.671 0.673 0.675 0.678 0.680
180.0 0.653 0.655 0.657 0.658 0.659 0.661 0.662
190.0 0.625 0.627 0.628 0.630 0.632 0.635 0.637
200.0 0.606 0.608 0.611 0.613 0.615 0.617 0.619
210.0 0.586 0.589 0.591 0.593 0.595 0.596 0.599
220.0 0.567 0.570 0.573 0.575 0.576 0.578 0.580

Table 7. Measured Tissue maximum Ratio[TMR] for 15mv.Values: Ratio [%].

Depth[cm] Field size[cm]
1 2 3 4 5 6 7 8
0.0 0.193 0.206 0.218 0.231 0.244 0.257 0.271 0.286
1.0 0.708 0.717 0.725 0.733 0.741 0.749 0.758 0.767
2.0 0.935 0.938 0.942 0.945 0.949 0.953 0.952 0.952
3.0 1.007 1.006 1.005 1.004 1.003 1.003 1.003 1.003
4.0 1.008 1.007 1.006 1.005 1.004 1.003 1.004 1.006
5.0 0.983 0.984 0.985 0.986 0.987 0.988 0.988 0.987
6.0 0.941 0.946 0.950 0.955 0.959 0.964 0.966 0.965
7.0 0.919 0.924 0.928 0.932 0.937 0.942 0.942 0.940
8.0 0.901 0.903 0.906 0.909 0.912 0.915 0.918 0.920
9.0 0.869 0.874 0.879 0.883 0.888 0.893 0.897 0.898
10.0 0.840 0.844 0.849 0.853 0.858 0.863 0.867 0.871
11.0 0.801 0.809 0.817 0.825 0.833 0.842 0.848 0.849
12.0 0.784 0.791 0.797 0.803 0.810 0.817 0.823 0.826
13.0 0.754 0.762 0.769 0.777 0.785 0.793 0.800 0.803
14.0 0.735 0.742 0.749 0.755 0.762 0.770 0.776 0.780
15.0 0.694 0.707 0.714 0.724 0.734 0.745 0.754 0.758
16.0 0.692 0.699 0.705 0.712 0.718 0.726 0.733 0.738
17.0 0.661 0.670 0.678 0.687 0.695 0.704 0.713 0.717
18.0 0.650 0.656 0.663 0.669 0.674 0.683 0.690 0.695
19.0 0.624 0.631 0.639 0.646 0.654 0.663 0.671 0.676
20.0 0.602 0.609 0.617 0.624 0.632 0.641 0.649 0.655
21.0 0.591 0.597 0.603 0.610 0.616 0.623 0.630 0.635
22.0 0.569 0.576 0.582 0.589 0.596 0.604 0.611 0.617
23.0 0.555 0.561 0.567 0.573 0.579 0.586 0.593 0.599
24.0 0.539 0.544 0.550 0.555 0.561 0.567 0.573 0.579
25.0 0.520 0.526 0.532 0.538 0.544 0.551 0.558 0.564
26.0 0.507 0.513 0.518 0.523 0.528 0.534 0.540 0.547
27.0 0.482 0.489 0.496 0.502 0.509 0.517 0.524 0.531
28.0 0.472 0.479 0.485 0.491 0.497 0.504 0.511 0.517
29.0 0.459 0.465 0.470 0.476 0.481 0.488 0.494 0.500
30.0 0.440 0.446 0.453 0.459 0.465 0.472 0.479 0.486
31.0 0.427 0.433 0.439 0.445 0.451 0.458 0.465 0.472
32.0 0.414 0.420 0.426 0.432 0.438 0.444 0.451 0.457
33.0 0.401 0.407 0.413 0.419 0.424 0.431 0.437 0.444
34.0 0.389 0.395 0.400 0.406 0.411 0.418 0.424 0.430
35.0 0.377 0.383 0.388 0.393 0.399 0.405 0.411 0.417
36.0 0.366 0.371 0.376 0.381 0.387 0.392 0.398 0.404
37.0 0.355 0.360 0.365 0.370 0.375 0.380 0.386 0.390
38.0 0.344 0.349 0.353 0.358 0.363 0.369 0.374 0.380
39.0 0.333 0.338 0.343 0.347 0.352 0.357 0.363 0.368
40.0 0.323 0.327 0.332 0.336 0.341 0.346 0.352 0.357

Table 7. continue.

Depth[cm] Field size[cm]
9 10 11 12 13 14 15 16 17
0.0 0.298 0.310 0.322 0.343 0.343 0.353 0.363 0.373 0.384
1.0 0.775 0.784 0.791 0.799 0.805 0.811 0.817 0.822 0.828
2.0 0.953 0.955 0.960 0.964 0.968 0.971 0.974 0.976 0.977
3.0 1.003 1.002 1.002 1.002 1.002 1.002 1.002 1.002 1.001
4.0 1.003 0.998 0.995 0.995 0.995 0.997 0.998 0.998 0.996
5.0 0.985 0.982 0.981 0.982 0.983 0.983 0.984 0.983 0.981
6.0 0.965 0.964 0.964 0.964 0.964 0.963 0.962 0.961 0.960
7.0 0.939 0.940 0.941 0.944 0.947 0.947 0.946 0.945 0.944
8.0 0.921 0.919 0.918 0.920 0.921 0.923 0.924 0.925 0.925
9.0 0.898 0.896 0.895 0.898 0.902 0.903 0.904 0.905 0.905
10.0 0.873 0.874 0.874 0.875 0.877 0.880 0.883 0.886 0.887
11.0 0.851 0.852 0.854 0.857 0.861 0.863 0.864 0.864 0.864
12.0 0.829 0.831 0.833 0.835 0.837 0.840 0.842 0.844 0.846
13.0 0.806 0.808 0.810 0.814 0.818 0.822 0.824 0.826 0.827
14.0 0.783 0.785 0.787 0.791 0.796 0.800 0.803 0.806 0.808
15.0 0.761 0.765 0.769 0.772 0.773 0.776 0.780 0.783 0.787
16.0 0.743 0.747 0.750 0.753 0.757 0.760 0.763 0.766 0.768
17.0 0.721 0.724 0.727 0.730 0.736 0.741 0.744 0.747 0.749
18.0 0.700 0.704 0.706 0.709 0.715 0.721 0.725 0.729 0.732
19.0 0.681 0.685 0.688 0.690 0.696 0.702 0.706 0.708 0.710
20.0 0.660 0.665 0.668 0.672 0.678 0.684 0.668 0.690 0.691
21.0 0.639 0.644 0.650 0.656 0.661 0.666 0.670 0.673 0.676
22.0 0.623 0.628 0.632 0.635 0.640 0.646 0.651 0.655 0.659
23.0 0.604 0.610 0.615 0.619 0.625 0.631 0.636 0.640 0.643
24.0 0.585 0.592 0.597 0.601 0.606 0.610 0.614 0.618 0.623
25.0 0.571 0.577 0.581 0.584 0.589 0.594 0.599 0.603 0.606
26.0 0.554 0.562 0.566 0.570 0.574 0.578 0.583 0.587 0.591
27.0 0.538 0.545 0.549 0.553 0.557 0.563 0.568 0.572 0.575
28.0 0.522 0.528 0.533 0.539 0.545 0.549 0.553 0.557 0.560
29.0 0.505 0.511 0.516 0.522 0.528 0.533 0.538 0.542 0.546
30.0 0.491 0.496 0.501 0.507 0.512 0.518 0.523 0.528 0.531
31.0 0.576 0.481 0.486 0.492 0.497 0.503 0.508 0.513 0.516
32.0 0.462 0.467 0.472 0.478 0.483 0.488 0.494 0.499 0.502
33.0 0.448 0.453 0.458 0.463 0.469 0.474 0.479 0.485 0.488
34.0 0.435 0.439 0.444 0.450 0.455 0.460 0.466 0.471 0.474
35.0 0.422 0.426 0.431 0.436 0.441 0.447 0.452 0.457 0.461
36.0 0.409 0.413 0.418 0.423 0.428 0.433 0.439 0.444 0.447
37.0 0.396 0.401 0.405 0.410 0.415 0.421 0.426 0.431 0.435
38.0 0.384 0.388 0.393 0.398 0.403 0.408 0.413 0.418 0.422
39.0 0.372 0.377 0.381 0.386 0.391 0.396 0.401 0.406 0.410
40.0 0.361 0.365 0.369 0.374 0.379 0.384 0.389 0.394 0.398

Table-8shows the correct measurement of output at the maximum dose depth distance(Dmax) and reference depth(Zref) for different beam of electron. Table-9 is the measurement of output factor for different field size and electron beam.

Table 8. Measured output of electron beam for several energy.

Output
Energy Dmax Zref
6 1.00 1.00
9 1.015 1.01
12 0.996 0.996
15 1.00 0.989
18 0.98 0.955
22 0.939 0.893

Table 9. Output factor.

Output Factor
Energy Applicator 6×6 10×10 15×15 20×20 25×25
6 10×10 0963 1 1 1.019 1.006
9 0.98 1 0.997 0.986 0.965
12 0.982 1 0.994 0.979 0.952
15 0.967 1 0.989 0.973 0.944
18 20×20 1.035 1.036 1.018 1 0.97
22   1.047 1.035 1.017 1 0.969

Table 10. Depth vs Dose(dose curve).

Table Depth Vs PDD
Energy Ds Dmax 95% 90% 50% Rp Applicator
6 81% 13.0 17.0 18.5 23.6 30.0 10×10
9 84% 21.0 25.5 27.5 35.5 43.6
12 88% 27.0 36.0 38.5 50.3 61.0
15 93% 32.0 43.0 47.0 61.7 75.0
18 95% 24.5 49.0 55.4 74.3 90.0 20×20
22 95% 24.3 50.5 59.0 84.2 103.5

Figure 4. Measured percent depth dose for electron beam.

Figure: 4illustrated that as the energy of the electron beam increased the maximum dose occurred at higher depth. From above we observed that many corrections were included to get more accuracy on the monitor unit calculation. From case_1(cervix), the required monitor unit was 56 but according to TPS(treatment planning system) calculation it was 53 which was lesser than required, suppose we may assume the machine calculation is greater or less than 3 from the our calculation which means that per 100cGy the access or less monitor unit is 6, To delivered 5000cGy, it will be 300cGy so that the patient get more or less 300cGy from required which take a violent effect and the normal tissue around the tumor may be get permanently damaged if it is excess, it may not possible to damage the tumor cell if it is lesser than accurate. The result will more accurate if the ionization chamber perfect work due to use old ionization chamber.

4. Conclusion

Computer calculations are commonly verified using an independent manual procedure. It is difficult to calculate treatment delivery monitor units for this variant of IMRT using manual method, since manual calculations are not feasible, it is important both to understand and to verify the calculation of treatment monitor units by the planning system algorithm. A formal analysis was made of the dose calculation model and the monitor unit calculation embedded in the algorithm. Experimental verification of the dose delivered by plans computed with methodology demonstrated an agreement of better than 4% between the dose model and measurement. So it must be required to take corrected form for the calculation of monitor unit to survive the cancerous patient.

Appendix

Notation and Definition.

D=The absorbed does at the point of interest from the individual field under calculation.

OP=Output or The dose rate or does per monitor unit at the point of interest.

d=Depth of the point of calculation.

deff=Water-equivalent depth of the point of calculation.

d0=The normalization depth for photon and electron dosimetry. For photon, do= 10cm is recommended, but not required. For each photon beam, do is independent of field size and shall be greater than or equal to the maximum dm.

For electrons, dois taken to be the depth of maximum dose along the central axis for the same field incident on a water phantom at the same SSD. It is field-size de-pendent.

Dm=The depth of maximum dose on the central axis.

OAR(d,x)= Off-axis ratio (sec. 1.A.1.f). The ratio of the open field dose rate at an off-axis point to that for the same field (e.g, 10*10 cm2) shifted such that the point of calculation lies on the central axis. The Primary Off-Axis Ratio, POAR, is preferred to be used for OAR(d,x).

PDD(d,r,SSD)=Percent depth dose. The ratio, expressed as a percentage, of the dose rate at depth to the dose rate at dm in a water phantom for a given field size and SSD.

PDD(d,r,SSD)= Normalized percent depth dose (sec.1.A.1.b). The ratio, expressed as a percentage, of the dose rate at depth to the dose rate at the normalization depth in a water phantom for a given field for a given field size and SSD.

SAD= Source-axis distance. Distance between the x-ray physical source position and the isocenter. For most linear accelerators, this value is nominally 100cm.

SPD= Source-point distance. The distance from the x-ray physical source to the plane(perpendicular to the central axis) that contains the point of calculation.

SSD=source-surface distance. The distance along the central axis from the physical source to the patient/phantom surface.

SSDo=Standard source-surface distance. The distance along the central axis from the physical source to the patient/phantom surface under normalization conditions.

SSDeff=Effective source surface distance. The distance along the central axis from the effective source to the patient /phantom surface, determined by beat fit of output versus the inverse of the distance squared.

TPR(d, rd)=Tissue phantom ratio(sec. 1.A.1.c). the ratio of the dose rate at a given depth in phantom to the dose rate at the normalization depth for a given field size.

TF=Try factor. The ratio of the central-axis dose rate for a given field with and without a blocking tray. TF is assumed independent of depth and field size in this report. This factor may be used to account for the attenuation through additional materials(e.g, special patient support devices) as needed.

WF(d,rd,x)=wedge factor (sec.1.A.1.i). the ratio of the dose rate at the point of calculation for a wedged field to that for the same field without a wedge modifier. The wedge may be a physical filter or not(i.e, dynamic or virtual). Depending on the type and angle of the WF may depend on the wedge angle, field size, depth, and off-axis distance.

Rmax=The maximum range(cm) is define as the depth at which maximum electron absorbed.

Rp=It is the practical range define as the depth at which the tangent plotted through the steepest section of the electron depth dose curve intersects with the extrapolation line of the background.


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