Evaluation of a “Practically Significant Dose” 

Using NOCTS Data

Daniel Stancescu, Ph.D.

James W. Neton, Ph.D., CHP

February 25, 2014

This is a working document prepared by NIOSH or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, 

and White Paper documents are not final NIOSH or ABRWH (or their technical support 

and review contractors) positions unless specifically marked as such. This document 

represents preliminary positions taken on technical issues prepared by NIOSH or its 

contractor. 

NOTICE: This report has been reviewed to identify and redact any information that is 

protected by the Privacy Act 5 USC §552a and has been cleared for distribution.
1

Evaluation of a “Practically Significant Dose” Using NOCTS Data

Daniel Stancescu, Ph.D. 

James W. Neton, Ph.D., CHP

February 25, 2014

Introduction

During the SEC Work Group meeting on September 26, 2013, there was a discussion regarding the 

establishment of a practically significant dose (PSD) that could be used to guide the evaluation of 

coworker models. The concept was that this dose could be used to test the significance of observed 

differences between coworker distributions for various strata1. After some discussion, it was decided 

that an appropriate value for a PSD might be 100 mrem. If one were to adopt 100 mrem as a PSD, 

however, an evaluation of the impact on the outcome of a claim, i.e. the effect of probability of 

causation (PC), needed to be conducted.

Description of the Evaluation

Given the large number of variables involved in the PC calculation, it would be very difficult (if not 

impossible) to generate hypothetical test cases that adequately test the impact of employing a 100 

mrem significance threshold. NIOSH proposed, and the working group concurred, that the evaluation 

make use of the actual distribution of exposures and cancer scenarios contained in the approximately 

40,000 claims in the NIOSH/OCAS Claims Tracking System (NOCTS) database. The approach that was 

adopted for this evaluation is described below.

• Selection and characterization of the selected cases

Claims with 99th percentile PC values between 45.00% and 49.99% were identified in the NOCTS 

database. As of October 29, 2013, 175 cases that met this criterion were identified out of the 

approximately 40,000 cases in the NOCTS database. The 175 selected cases corresponded to 

either claims having only one primary cancer, or to claims having more than one primary 

cancer, but with at least one of the primary cancers having a PC value between 45.00% and 

49.99%. Only 25 out of the 33 available IREP cancer models are represented in the selected 175 

cases. Almost one third of selected cases are represented by the Lung cancer (30.9%). Other 

cancer models with a large representation of cases are Non-melanoma BCC (16.6%), followed 

by All Male Genitalia (7.4%), Colon (6.3%), Lymphoma and multiple myeloma (5.7%), and 

Malignant melanoma (5.1%); each of the remaining cancer models contain less than 5% of the 

cases. The distribution of the cancer models represented in the 175 cases is provided in Table 1 

 1 It was also discussed that this dose might have other applications, such as in the evaluation of exposures during residual 

contamination periods.
2

of Attachment 1. The gender distribution of the cases is very close to the percentages of the 

gender distribution in the NOCTS database (i.e., approximately 90 percent males). As depicted

in Figure 1 below, the median age at first exposure is 27 years and the median age at diagnosis 

is 68 years.

Figure 1: Distributions of the age of first exposure and the age of diagnosis.

All 175 cases were run on the IREP Enterprise Edition version at some point in the past, which 

means that the PC values on record, were generated based on 10,000 iterations and using a set 

of 30 different random seeds. 

• The scenarios evaluated

In order to compare the effect of adding a 100 mrem dose to each of these cases, it was 

decided that three separate scenarios were required. The three scenarios, and the rationale 

behind each of them, are discussed below.

1) Scenario 1, also denoted as ‘Original’, corresponded to rerunning each case on the current 

IREP v.5.7 version. This was necessary because there have been several updates to the IREP 

models during the years, which might change the PC values slightly. The set of 30 random 

seeds that was originally used for each case were reused for the majority of the 175 cases. 
3

For most of the 175 cases, the PC value obtained from Scenario 1 was the same as the 

original PC value recorded in the NOCTS database.

2) Scenario 2, also denoted as ‘Add 0 mrem’, corresponded to adding a constant dose of 0 

mrem in each of the IREP files for the 175 cases. The 0 mrem was entered as an acute dose

due to exposure from photons greater than 250 keV2. To ensure the effect of the cancer 

latency adjustment is minimized, the year of the additional exposure was selected 

differently for solid cancers versus leukemia cancers. For all solid cancers, and Chronic 

Lymphocytic Leukemia, the year corresponding to the additional 0 rem exposure was the 

first year of employment for each case. For all the leukemia cases, the year corresponding 

to the additional 0 rem exposure was 5 years before the diagnosis year, or the last year of 

employment (for those cases when the diagnosis year is more than five years after the last 

year of employment).

3) Scenario 3, also denoted as ‘Add 100 mrem’, corresponded to adding a constant dose of 

100 mrem to each of the IREP files for the 175 cases. Similar to Scenario 2, the 100 mrem 

dose was entered as an acute dose, due to exposure from photons greater than 250 keV. 

The employment year where this additional exposure was added is the same as that 

described for Scenario 2.

• Processing the case scenarios

All 175 cases were run on IREP Enterprise Edition v.5.7, for each of the three scenarios 

described above. For each case, the three dose scenarios were run at 10,000 iterations using 

the same set of 30 random seeds. The same set of 30 random seeds was used to minimize the 

statistical uncertainty associated with the Monte Carlo sampling. In this way, the effect of only 

the added dose could be quantified. However, as will be explained in more detail later, even 

though all three scenarios use the same set of 30 random seeds, the addition of a new 

exposure line in Scenarios 2 and 3 altered the sequence of random numbers as compared to

Scenario 1. Because of this, only Scenarios 2 and 3 use the exact same set of random numbers 

in the process of computing the PC values.

• Comparison of the results 

After running all the 175 cases on IREP Enterprise Edition v.5.7 for each of the three dose 

scenarios described above, the average of the 99th percentile PC values from the 30 runs 

 2 The Radiation Effectiveness Factor (REF) for photons >250 keV is considered to be a constant. Thus, the outcome of any 

change in PC would be directly related to the additional dose and not influenced by the uncertainty in REF that is associated

with lower energy photons.
4

(corresponding to the 30 different random seeds) was computed and recorded; these average 

PC values will be denoted from now on as Avg. PC values.

In order to determine the effect of adding the additional 100 mrem external dose to the 

existing dose for each case, the differences in the Avg. PC values were compared for each of the 

175 cases, among the three dose scenarios. The comparison of interest is the Avg. PC values 

between Scenarios 2 and 3. Since these two scenarios use the exact the same set of random 

numbers during the computation of the PC values, this allows for a direct comparison of the 

effect of the added dose.

Results of the evaluation

The summary statistics for the Avg. PC values from the three dose scenarios are shown in Table 1.

While the 175 cases were initially selected to have a PC value between 45.00% and 49.99%, in the 

process of rerunning the cases on the current IREP version v5.7, some of the cases had a small change

in the PC values, due to some of the updates that were implemented in the more recent IREP versions; 

as a result of this, two of the cases with lung cancer which had a small decrease in the PC values, had 

the Avg. PC values for Scenario 1 (Original) go slightly below the 45.00% threshold. The Avg. PC values 

obtained for each of the 175 cases, for each of three dose scenarios, are listed in Table 2 of 

Attachment 1. It is of interest to note that, after the addition of 100 mrem, not one of the 175 cases 

evaluated resulted in an Avg. PC value of greater than or equal to 50.00%. 

Table 1: Summary statistics for the Avg. PC values from the three dose scenarios.

Dose Scenario N Min Median Mean Max

Scenario 1 (Original) 175 44.93 47.43 47.38 49.87

Scenario 2 (Add 0 mrem) 175 44.73 47.39 47.38 49.90

Scenario 3 (Add 100 mrem) 175 44.92 47.44 47.45 49.92

The summary statistics for the Avg. PC values from the three dose scenarios, by cancer type are shown 

in Table 2. The leukemia cancers (excl. CLL) contain 2 cases with the ‘Acute Myeloid Leukemia’ cancer 

model, and 3 cases with ‘Leukemia (excl. CLL)’ cancer model.

Table 2: Summary statistics for the Avg. PC values from the three dose scenarios, by cancer type.

Cancer

Type

Dose Scenario N Min Median Mean Max

Solid 

cancers, 

and CLL

Scenario 1 (Original) 170 44.93 47.47 47.38 49.87

Scenario 2 (Add 0 mrem) 170 44.73 47.40 47.39 49.90

Scenario 3 (Add 100 mrem) 170 44.92 47.43 47.44 49.92

Leukemia 

cancers 

(excl. CLL)

Scenario 1 (Original) 5 45.32 47.43 47.37 49.08

Scenario 2 (Add 0 mrem) 5 45.16 47.37 47.31 49.09

Scenario 3 (Add 100 mrem) 5 45.40 47.67 47.59 49.43
5

Table 3 shows the distribution of positive/negative/zero changes in the Avg. PC values, when 

comparing two of the three dose scenarios, side by side. For the main comparison, between Scenario 2 

versus Scenario 3, 173 cases had an increase in the Avg. PC value, and 2 cases had no change in the 

Avg. PC values.

Table 3: Distribution of positive/negative/zero changes in the Avg. PC values

among the scenarios evaluated.

Change from Scenario 2 to Scenario 3 Frequency Percent

No change from Scenario 2 to Scenario 3 2 1.1

Positive change from Scenario 2 to Scenario 3 173 98.9

Total 175 100.00

Change from Scenario 1 to Scenario 3 Frequency Percent

Negative change from Scenario 1 to Scenario 3 64 36.6

No change from Scenario 1 to Scenario 3 4 2.3

Positive change from Scenario 1 to Scenario 3 107 61.1

Total 175 100.00

Change from Scenario 1 to Scenario 2 Frequency Percent

Negative change from Scenario 1 to Scenario 2 85 48.6

No change from Scenario 1 to Scenario 2 4 2.3

Positive change from Scenario 1 to Scenario 2 86 49.1

Total 175 100.00

The summary statistics for the differences in the Avg. PC from the three dose scenarios are shown in 

Table 4. The summary statistics for the differences in the Avg. PC from the three dose scenarios, by 

cancer type, are shown in Table 5.

Table 4: Summary statistics for the differences in Avg. PC values, between Scenario 3 vs. Scenario 1, 

and between Scenario 3 vs. Scenario 2.

Difference in Avg. PC values N Min 5th pctl. Median Mean 95th pctl. Max

Scenario 3 – Scenario 1 175 -0.43 -0.26 0.06 0.06 0.37 0.67

Scenario 3 – Scenario 2 175 0.00 0.01 0.02 0.06 0.25 0.34

Table 5: Summary statistics for the differences in Avg. PC values, by cancer type, 

between Scenario 3 vs. Scenario 1, and between Scenario 3 vs. Scenario 2.

Cancer Type

Difference in Avg. PC 

values

N Min Median Mean Max

Solid cancers, 

and CLL

Scenario 3 – Scenario 1 170 -0.43 0.05 0.06 0.67

Scenario 3 – Scenario 2 170 0.00 0.02 0.06 0.34

Leukemia cancers 

(excl. CLL)

Scenario 3 – Scenario 1 5 0.08 0.21 0.22 0.35

Scenario 3 – Scenario 2 5 0.18 0.30 0.28 0.34
6

A density plot for the differences in Avg. PC values, between Scenario 2 vs. Scenario 1, is shown in 

Figure 2. The differences in the Avg. PC values between Scenario 2 vs. Scenario 1 are normally 

distributed around 0, with a standard deviation of 0.18. Since the total dose in Scenarios 1 and 2 is 

exactly the same, and the uncertainty around each individual dose is exactly the same, the only factor 

that affect the differences in the Avg. PC values between these two scenarios, is the different sequence 

of random numbers that is used in generating the PC values. The reason for the different sequences of 

random numbers is due to the fact that Scenario 2 has one additional exposure than Scenario 1 (an 

additional exposure of 0 mrem is added to the IREP file in Scenario 2), which has the effect that an 

additional set of ERR (Excess Relative Risk) values is allocated by IREP for this additional exposure. This 

extra set of ERR values will use the next 10,000 random numbers in the sampling sequence, and this 

will have the effect of using a different set of random numbers for all the remaining computations. The 

final effect is that Scenario 2 is equivalent to running the same IREP file as in Scenario 1, but with a 

different set of 30 random seeds.

Figure 2: Density plot for the differences in Avg. PC values, between Scenario 2 vs. Scenario 1.
7

Boxplots with the differences in Avg. PC values, between Scenario 3 vs. Scenario 1, and between 

Scenario 3 vs. Scenario 2, are shown in Figures 3 and 4. These two boxplots show the first quartile, the 

median, and the third quartile of these distributions, while the whiskers of each boxplot extend to the

extreme values of the corresponding distributions; the diamond symbol in each boxplot represents the 

mean value of the distribution.

For our comparison of interest, between Scenario 3 vs. Scenario 2, the difference in the Avg. PC values 

between the two dose scenarios is between 0 and 0.34, with a median value of 0.02, and a mean value 

of 0.06. The middle 50% of the differences in the Avg. PC between Scenario 3 vs. Scenario 2, are 

between 0.02 and 0.08, and the middle 90% of the differences in the Avg. PC are contained between 

0.01 and 0.25. The largest increase of 0.34 in the Avg. PC values occur for three cases, with Leukemia 

(excl. CLL), Acute Myeloid Leukemia, and Non-melanoma BCC cancers; the next largest increases of 

0.31 and 0.30 also occur for the Non-melanoma BCC, and Acute Myeloid Leukemia cases. The two 

cases where there was no increase in the Avg. PC values have the same cancer model, Oral Cavity and 

Pharynx.

Figure 3: Boxplot for the differences in Avg. PC values, between Scenario 3 vs. Scenario 1.
8

Figure 4: Boxplot for the differences in Avg. PC values, between Scenario 3 vs. Scenario 2.

A histogram that shows the distribution in the difference of Avg. PC value between Scenarios 3 and 2 is 

provided in Figure 5. Unlike the values in Figure 2 which are normally distributed around zero 

(standard deviation = 0.18), the values in Figure 5 are log-normally distributed with a median value 

0.02. Because both Scenarios 2 and 3 were run using the same sequence of random numbers, the 

observed differences were solely due to the additional excess relative risk that was imparted due to 

the added dose. In fact, the majority of observed spread of the differences in PC is due to the 

differences in radiosensitivity associated with the various cancer models. 
9

Figure 5: Distribution of the change in Avg. PC values with the addition of 100 mrem.

Attachment 2 includes side-by-side boxplots for the 99th percentile PC values from the three dose 

scenarios, for each of the 175 cases. These boxplots show the distribution of the 99th percentile PC 

values, corresponding to the sets of 30 random seeds used for each case. Each of these boxplots shows

the first quartile, the median, and the third quartile of these distributions, while the whiskers from 

each boxplot extend to the 5th and 95th percentiles of the distributions. The Avg. PC values (which are 

also listed in Table 2 of Attachment 1) are displayed as small circles in these boxplots. The 175 cases 

are displayed in separate plots, which are grouped by the 25 IREP cancer models. 

These side-by-side boxplots show a pretty clear picture that the results from the three dose scenarios 

for each case have not only very close Avg. PC values, but the distributions of the PC values is very 

similar across the three dose scenarios and almost identical for Scenario 2 versus Scenario 3, for most 

of the cases.
10

Conclusion

An evaluation was designed to determine the effect of adding an additional 100 mrem external dose to 

the cases from NOCTS database, with PC values between 45.00% and 49.99%. Three different dose 

scenarios were used for each of the 175 cases selected for this experiment: Scenario 1 (also denoted as 

‘Original’), Scenario 2 (also denoted as ‘Add 0 mrem’), and Scenario 3 (also denoted as ‘Add 100 

mrem’). Comparing the results from Scenario 1 versus Scenario 3 doesn’t really show the true effect of 

adding the additional 100 mrem dose, since the two dose scenarios do not use the exact same 

sequence of random numbers in order to generate the Avg. PC values. In order to eliminate the 

random noise associated with choosing a different set of random numbers in the process of computing 

the PC values, our main focus was the comparison between Scenario 2 and Scenario 3, which allows for 

a direct comparison of the effect of adding the 100 mrem dose to the existing dose for each case. 

After running each case on the different dose scenarios, it was observed that for each of the 175 cases, 

the Avg. PC values from Scenario 3 is greater than or equal to the Avg. PC from Scenario 2, as was 

expected. However, the increase in the Avg. PC results from these two scenarios is small, with a range 

between the two dose scenarios from 0 to 0.34, with a median increase of 0.02, and a mean increase 

of 0.06. The largest increases occur for the leukemia cancer claims, which may be related to the 

relative radiosensitivity of blood forming organs over other tissue types. It was also observed that 90% 

of the increase in the Avg. PC values between Scenario 2 and Scenario 3 are contained between 0.01 

and 0.25. 
11

Attachment 1

Table 1: IREP cancer models for the 175 selected cases.

IREP Cancer Model Frequency Percent

Acute Myeloid Leukemia 2 1.1

All Male Genitalia 13 7.4

Bladder 4 2.3

Bone 2 1.1

Chronic Lymphocytic Leukemia 1 0.6

Colon 11 6.3

Connective tissue 1 0.6

Gallbladder 4 2.3

Leukemia (excl. CLL) 3 1.7

Liver 1 0.6

Lung 54 30.9

Lymphoma and multiple myeloma 10 5.7

Malignant melanoma 9 5.1

Nervous system 3 1.7

Non-melanoma BCC 29 16.6

Non-melanoma SCC 2 1.1

Oral Cavity and Pharynx 2 1.1

Other and ill-defined sites 2 1.1

Other respiratory 1 0.6

Ovary 1 0.6

Pancreas 2 1.1

Rectum 1 0.6

Stomach 8 4.6

Thyroid 3 1.7

Urinary organs (excl. bladder) 6 3.4

Total 175 100.0
Table 2: Avg. PC results from the scenarios evaluated for the 175 selected cases

Claim IREP Cancer Model Avg. PC 

(Original)

Avg. PC 

(Add 0 mrem)

Avg. PC 

(Add 100 mrem)

Claim IREP Cancer Model Avg. PC 

(Original)

Avg. PC 

(Add 0 mrem)

Avg. PC 

(Add 100 mrem)

1 Lung 44.93 45.16 45.17 32 Gallbladder 49.05 49.20 49.27

2 Lung 45.86 46.06 46.07 33 Non-melanoma BCC 45.21 45.22 45.37

3 Lung 46.52 46.57 46.61 34 Lung 45.94 45.97 45.99

4 Pancreas 47.11 47.08 47.10 35 Colon 46.66 46.59 46.64

5 Lung 47.71 47.76 47.77 36 Malignant melanoma 47.28 47.07 47.18

6 All Male Genitalia 48.28 48.31 48.33 37 Stomach 47.85 47.81 47.90

7 Malignant melanoma 45.08 44.73 44.92 38 Lung 48.42 48.45 48.46

8 Non-melanoma BCC 45.91 46.43 46.58 39 Leukemia (excl. CLL) 49.08 49.09 49.43

9 Malignant melanoma 46.52 46.50 46.63 40 Non-melanoma BCC 45.23 45.17 45.23

10 Lung 47.15 47.02 47.04 41 Oral Cavity and Pharynx 45.98 46.16 46.16

11 Non-melanoma BCC 47.74 47.59 47.72 42 Non-melanoma BCC 46.72 46.68 46.89

12 Lung 48.30 48.47 48.49 43 Thyroid 47.85 48.01 48.28

13 Non-melanoma BCC 48.88 48.79 48.91 44 Lymph. and mult. myel. 48.42 48.53 48.55

14 Non-melanoma BCC 45.13 45.32 45.41 45 Lung 49.08 48.97 49.07

15 Lung 45.90 45.76 45.80 46 Lung 45.24 45.34 45.47

16 Connective tissue 46.53 46.36 46.41 47 Non-melanoma BCC 46.81 46.72 46.78

17 Non-melanoma BCC 47.15 47.00 47.11 48 Malignant melanoma 47.33 47.03 47.11

18 Stomach 47.80 47.94 47.98 49 Lung 47.89 47.60 47.61

19 Lung 48.39 48.33 48.34 50 Lymphoma and multiple 

myeloma

48.42 48.84 48.86

20 All Male Genitalia 48.89 48.98 48.99 51 Lung 49.09 49.09 49.12

21 Lung 45.10 45.31 45.33 52 Non-melanoma BCC 45.31 45.37 45.71

22 Urinary organs (excl. 

bladder)

45.90 45.79 45.87 53 Colon 46.09 45.92 45.94

23 Non-melanoma BCC 46.53 46.52 46.69 54 Stomach 46.81 47.14 47.18

24 Bladder 47.18 47.32 47.34 55 Non-melanoma BCC 47.41 47.12 47.28

25 Lung 48.41 48.37 48.39 56 Non-melanoma BCC 47.94 48.11 48.17

26 Oral Cavity and Pharynx 48.69 48.94 48.94 57 Malignant melanoma 48.46 48.42 48.54

27 Non-melanoma BCC 45.17 45.08 45.13 58 Bladder 49.13 49.00 49.03

28 Malignant melanoma 45.91 45.82 45.93 59 Leukemia (excl. CLL) 45.32 45.16 45.40

29 Other and ill-defined sites 46.61 46.63 46.65 60 All Male Genitalia 46.11 45.93 45.95

30 Ovary 47.23 47.56 47.60 61 All Male Genitalia 46.82 46.90 46.91

31 Non-melanoma BCC 47.85 47.45 47.58 62 Colon 47.41 47.53 47.57
Table 2: Avg. PC results from the scenarios evaluated for the 175 selected cases (continued)

13

Claim IREP Cancer Model Avg. PC 

(Original)

Avg. PC 

(Add 0 mrem)

Avg. PC 

(Add 100 mrem)

Claim IREP Cancer Model Avg. PC 

(Original)

Avg. PC 

(Add 0 mrem)

Avg. PC 

(Add 100 mrem)

63 Acute Myeloid Leukemia 47.93 47.80 48.14 92 Non-melanoma BCC 45.43 45.35 45.54

64 Urinary organs (excl. 

bladder)

48.50 48.76 48.78 93 Nervous system 46.23 46.03 46.04

65 Lung 49.14 49.12 49.13 94 Lung 46.98 46.96 46.98

66 Lung 44.97 44.98 44.99 95 Stomach 47.51 47.34 47.39

67 All Male Genitalia 46.05 46.09 46.16 96 Lung 48.09 48.04 48.06

68 Colon 46.83 46.85 46.89 97 Non-melanoma BCC 48.66 48.43 48.74

69 Acute Myeloid Leukemia 47.43 47.37 47.67 98 Bladder 49.19 49.15 49.17

70 Lung 47.93 48.14 48.18 99 Bone 45.44 45.29 45.30

71 Chronic Lymphocytic 

Leukemia

48.52 48.43 48.45 100 Lung 46.24 46.33 46.35

72 Non-melanoma BCC 49.18 49.64 49.73 101 Thyroid 46.99 47.15 47.36

73 Lymphoma and multiple 

myeloma

45.33 45.07 45.08 102 Colon 47.53 47.55 47.58

74 Lung 46.13 46.12 46.13 103 Lymph. and mult. myel. 48.12 48.42 48.44

75 Lymphoma and multiple 

myeloma

46.92 46.99 47.02 104 Liver 48.66 48.81 48.90

76 All Male Genitalia 47.43 47.34 47.35 105 Other and ill-defined

sites

49.36 49.35 49.37

77 Nervous system 47.99 47.89 47.90 106 Lymphoma and multiple 

myeloma

45.47 45.67 45.69

78 Lung 48.53 48.40 48.42 107 All Male Genitalia 46.31 46.46 46.49

79 Stomach 49.18 49.07 49.26 108 Malignant melanoma 47.00 46.65 46.77

80 Lymphoma and multiple 

myeloma

45.33 45.64 45.65 109 Lung 47.53 47.87 47.88

81 Colon 46.19 46.02 46.07 110 Lung 48.14 48.11 48.13

82 Lung 48.02 48.07 48.09 111 Lung 48.72 48.72 48.73

83 Lung 48.58 48.70 48.72 112 Non-melanoma BCC 49.38 49.46 49.61

84 Lung 49.22 49.26 49.27 113 Colon 45.49 45.57 45.60

85 Thyroid 45.33 45.41 45.64 114 Stomach 46.24 46.09 46.15

86 Lung 46.23 46.16 46.19 115 Colon 47.02 46.99 47.01

87 All Male Genitalia 46.98 46.72 46.74 116 Other respiratory 47.53 47.53 47.54

88 Lung 47.51 47.72 47.73 117 Colon 48.15 48.24 48.26

89 Malignant melanoma 48.08 48.15 48.28 118 All Male Genitalia 48.73 48.90 48.91

90 Bone 48.61 48.40 48.42 119 Urinary org. (excl. blad.) 49.44 49.62 49.64

91 Lung 49.23 49.19 49.20 120 Lung 45.50 45.19 45.20
Table 2: Avg. PC results from the scenarios evaluated for the 175 selected cases (continued)

14

Claim IREP Cancer Model Avg. PC 

(Original)

Avg. PC 

(Add 0 mrem)

Avg. PC 

(Add 100 mrem)

Claim IREP Cancer Model Avg. PC 

(Original)

Avg. PC 

(Add 0 mrem)

Avg. PC 

(Add 100 mrem)

121 Malignant melanoma 46.33 46.42 46.50 150 Urinary organs (excl. 

bladder)

49.84 49.74 49.75

122 All Male Genitalia 47.04 46.74 46.76 151 Lung 45.24 45.68 45.73

123 All Male Genitalia 47.54 47.77 47.79 152 Colon 46.49 46.41 46.44

124 Lymphoma and multiple 

myeloma

48.15 47.71 47.72 153 Leukemia (excl. CLL) 47.10 47.13 47.31

125 Non-melanoma BCC 48.77 48.80 49.05 154 Non-melanoma BCC 47.72 47.95 48.04

126 Lung 49.57 49.82 49.84 155 Lung 48.27 48.27 48.31

127 Non-melanoma BCC 45.56 45.67 45.73 156 Lung 48.87 48.72 48.73

128 All Male Genitalia 46.44 46.37 46.39 157 Urinary organs (excl. 

bladder)

49.87 49.88 49.90

129 Bladder 47.06 47.22 47.24 158 Gallbladder 45.86 45.90 45.97

130 Lung 47.55 47.49 47.50 159 Non-melanoma BCC 46.49 46.48 46.59

131 Lung 48.38 48.53 48.55 160 Lung 47.11 46.86 46.89

132 Lung 48.81 48.75 48.76 161 Lung 47.71 47.31 47.32

133 Lung 45.41 45.13 45.15 162 Urinary organs (excl. 

bladder)

48.27 47.99 48.01

134 Lymphoma and multiple 

myeloma

46.46 46.45 46.46 163 Non-melanoma BCC 48.87 48.92 49.19

135 Colon 47.06 46.92 46.95 164 Lung 49.36 49.54 49.55

136 Lung 47.57 47.39 47.41 165 Non-melanoma BCC 48.88 48.92 49.02

137 Non-melanoma BCC 48.24 48.35 48.42 166 Rectum 47.83 48.00 48.01

138 Nervous system 48.92 48.71 48.74 167 Gallbladder 48.42 48.11 48.18

139 Lung 45.67 45.71 45.72 168 Stomach 47.30 47.40 47.44

140 Non-melanoma BCC 46.46 46.20 46.32 169 Pancreas 46.06 46.27 46.29

141 Lung 47.21 47.02 47.06 170 Lung 49.61 49.77 49.78

142 Lung 47.63 47.89 47.90 171 Stomach 48.74 48.60 48.64

143 Lung 48.24 48.36 48.38 172 Non-melanoma SCC 46.88 46.60 46.61

144 Gallbladder 45.70 45.67 45.76 173 Lymphoma and multiple 

myeloma

47.23 47.36 47.39

145 Non-melanoma BCC 46.48 46.52 46.82 174 All Male Genitalia 49.05 49.04 49.06

146 Non-melanoma SCC 47.14 47.24 47.25 175 Non-melanoma BCC 49.81 49.90 49.92

147 Lung 47.69 47.50 47.51

148 Lung 48.25 48.39 48.40

149 Lung 48.87 48.90 48.94
Attachment 2

This attachment provides side-by-side box plots for the 99th percentile PC values from the three dose 

scenarios for each of the 175 cases. The cases are grouped by IREP cancer model.
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49
50
51
52
53
54
55
56
57
58