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Table 1 The top 20 FMs ranked by mean RPN and ‘S’ scores for each institution

From: A bi-institutional multi-disciplinary failure mode and effects analysis (FMEA) for a Co-60 based total body irradiation technique

Rank

FM#

Process description

Step description

Failure mode

Effects

O

S

D

RPN

A: K C I – F M E A (7 scorers: 3 MPs, 2 ROs, 2 RTs) ranked wrt mean RPN scores

 1

54

Treatment

Delivery

Patient moves after setup (with lung blocks)

Incorrect dose delivered

4.6 (2.1)

6.0 (0.6)

3.8 (1.9)

104.9 (72)

 2

16

Treatment

Setup

Setup error (significant wrt tx field)

Incorrect dose delivered

3.3 (2.3)

5.8 (1.8)

4.8 (3.3)

88.8 (92.4)

 3

8

Planning

Preparation of initial plan

Calculation error

Incorrect dose calculation

4.4 (3.1)

7.6 (2.0)

2.0 (0.6)

66.9 (54.9)

 4

80

QA

Machine QA

Couch is accidentally shifted after morning QA (shift insignificant wrt tx field)

Incorrect dose delivered

4.3 (2.6)

3.3 (0.8)

4.8 (1.5)

65.6 (47.9)

 5

49

Treatment

Delivery

Program wrong tx time

Incorrect dose delivered

3.0 (2.1)

7.0 (2.7)

3.0 (1.9)

63.0 (64.1)

 6

53

Treatment

Delivery

Patient moves after setup (significant move wrt tx field) (no lung blocks)

Incorrect dose delivered

3.6 (1.9)

4.2 (0.4)

4.0 (1.8)

60.5 (41.7)

 7

64

Treatment

Delivery

Used prone time for supine position or vice versa

Incorrect dose delivered

3.4 (2.1)

4.4 (0.5)

4.0 (3.3)

59.8 (61.4)

 8

52

Treatment

Delivery

Timer malfunction

Incorrect dose delivered

2.2 (1.2)

7.4 (2.3)

3.4 (1.4)

55.4 (40.7)

 9

18

Treatment

Setup

Missing lung blocks (one fraction)

Incorrect dose delivered

3.0 (1.7)

4.4 (0.8)

4.0 (3.2)

52.8 (52.0)

 10

5

Sim

Pt positioning

Incorrect documentation

Incorrect patient setup

3.6 (1.6)

3.0 (1.1)

4.8 (3.2)

51.8 (46.2)

 11

12

Planning

Ancillary

Incorrect lung block design/size

Lung overdose / target underdose

4.0 (3.0)

5.8 (2.8)

2.2 (1.0)

51.0 (50.5)

 12

63

Treatment

Delivery

Forget to flip to supine after prone field

Incorrect dose delivered

2.0 (1.1)

6.8 (1.7)

3.6 (3.4)

49.0 (54.7)

 13

3

Sim

Pt measurements

Incorrect mx

Incorrect dose calculation

3.8 (2.4)

4.0 (0.6)

3.2 (1.6)

48.6 (39.9)

 14

11

Planning

Preparation of initial plan

Corrupt spreadsheet

Incorrect dose calculation

3.0 (1.6)

8.0 (0.8)

2.0 (0.8)

48.0 (33.0)

 15

69

Treatment

Delivery

Image from wrong date is used for alignment verification

Lung blocks positioned incorrectly

2.8 (1.0)

4.2 (1.0)

4.0 (3.0)

47.0 (40.8)

 16

65

Treatment

Delivery

Patient has too many blankets covering them

Change in dose distribution

3.8 (2.7)

3.6 (1.0)

3.4 (2.2)

46.5 (47.1)

 17

4

Sim

Pt measurements

Incorrect documentation

Incorrect dose calculation

3.8 (2.7)

3.8 (1.5)

3.2 (1.7)

46.2 (45.0)

 18

81

QA

Machine QA

Couch is accidentally shifted after morning QA (shift significant wrt tx field)

Incorrect dose delivered

3.3 (1.5)

5.0 (1.6)

2.8 (1.5)

44.7 (34.5)

 19

68

Treatment

Delivery

Images saved under wrong patient

Inability to localize lung blocks, potentially incorrect dose delivered

3.0 (1.3)

4.2 (1.7)

3.4 (3.3)

42.8 (48.9)

 20

6

Planning

Preparation of initial plan

Miscommunication of Rx

Incorrect dose or fractionation

1.6 (0.5)

7.0 (2.3)

3.6 (3.4)

40.3 (42.0)

Rank

FM#

Process description

Step Description

Failure mode

Effects

O

S

D

RPN

B: K C I—F M E A (7 scorers: 3 MPs, 2 ROs, 2 RTs) ranked wrt mean ‘S’ scores

 1

42

Treatment

Setup

Flattening filter falls on patient

Patient injury

1.8 (1.6)

8.4 (2)

1.2 (0.4)

18.1 (17.7)

 2

47

Treatment

Delivery

Wrong patient

Incorrect dose delivered

1.4 (0.5)

8.2 (2.1)

1.2 (0.4)

13.8 (7.6)

 3

11

Planning

Preparation of initial plan

Corrupt spreadsheet

Incorrect dose calculation

3.0 (1.6)

8.0 (0.8)

2.0 (0.8)

48.0 (33.0)

 4

79

QA

Machine QA

Source stuck and emergency shutter not operational

Patient overdose

1.0 (0.0)

8.0 (2.8)

3.7 (3.8)

29.3 (31.9)

 5

8

Planning

Preparation of initial plan

Calculation error

Incorrect dose calculation

4.4 (3.1)

7.6 (2.0)

2.0 (0.6)

66.9 (54.9)

 6

19

Treatment

Setup

Missing lung blocks (all fractions)

Incorrect dose delivered

1.4 (0.8)

7.6 (2.6)

3.2 (3.5)

34.0 (43.5)

 7

39

Treatment

Setup

Flattening filter not inserted

Incorrect dose delivered

1.4 (0.5)

7.6 (2.2)

1.6 (0.8)

17.0 (11.5)

 8

56

Treatment

Delivery

Source stuck

Incorrect dose delivered/staff exposure

1.6 (0.5)

7.6 (2.3)

1.2 (0.4)

14.6 (8.0)

 9

52

Treatment

Delivery

Timer malfunction

Incorrect dose delivered

2.2 (1.2)

7.4 (2.3)

3.4 (1.4)

55.4 (40.7)

 10

45

Treatment

Setup

Motor run away causing head to contact patient

Patient injury

1.4 (0.5)

7.4 (2.2)

1.2 (0.4)

12.4 (7.0)

 11

28

Treatment

Setup

Couch not at treatment height for multiple fx (large change > 5 cm)

Incorrect dose delivered

2.0 (1.5)

7.2 (2.3)

1.4 (0.5)

20.2 (18.3)

 12

49

Treatment

Delivery

Program wrong tx time

Incorrect dose delivered

3.0 (2.1)

7.0 (2.7)

3 (1.9)

63.0 (64.1)

 13

6

Planning

Preparation of initial plan

Miscommunication of Rx

Incorrect dose or fractionation

1.6 (0.5)

7.0 (2.3)

3.6 (3.4)

40.3 (42.0)

 14

13

Planning

Ancillary

Incorrect compensator

Incorrect dose delivered

2 (1)

7.0 (2.0)

2.5 (1.5)

35.0 (29.1)

 15

37

Treatment

Setup

Head not at correct treatment height for multiple fx (large change > 5 cm)

Incorrect dose delivered

1.4 (0.5)

7.0 (2.0)

3.0 (3.5)

29.4 (37.0)

 16

63

Treatment

Delivery

Forget to flip to supine after prone field

Incorrect dose delivered

2.0 (1.1)

6.8 (1.7)

3.6 (3.4)

49.0 (54.7)

 17

32

Treatment

Setup

Treatment head in wrong rotational position, not locked

Incorrect dose delivered

1.6 (0.8)

6.8 (1.6)

1.4 (0.5)

15.2 (10.0)

 18

43

Treatment

Setup

Wrong flattening filter inserted

Incorrect dose delivered

1.0 (0.0)

6.3 (2.6)

4.3 (4.0)

27.4 (27.9)

 19

73

QA

Machine QA

Incorrect calibration

Incorrect dose delivered

2.3 (1.2)

6.3 (2.6)

1.3 (0.5)

19.7 (15.0)

 20

70

Treatment

Delivery

Treatment paused but not restarted

Incorrect dose delivered

1.8 (0.7)

6.2 (1.7)

3.6 (3.3)

40.2 (41.6)

Rank

FM#

Process description

Step Description

Failure mode

Effects

O

S

D

RPN

C: D F B W—F M E A (6 scorers: 2 MPs, 2 ROs, 2 RTs) ranked wrt mean RPN scores

1

11

Planning

Preparation of initial plan

Corrupt spreadsheet

Incorrect dose calculation

1.8 (0.7)

7.0 (1.2)

5.8 (2.3)

74.9 (42.3)

2

51

Treatment

Delivery

Neglect to subtract in-vivo delivery time from remaining tx time

Incorrect dose delivered

2.5 (0.9)

6.5 (1.7)

4.0 (1.9)

65.0 (41.3)

3

16

Treatment

Setup

Setup error (significant wrt tx field)

Incorrect dose delivered

2.5 (1.6)

6.5 (2.1)

3.8 (2.6)

62.3 (61.6)

4

49

Treatment

Delivery

Program wrong tx time

Incorrect dose delivered

2.5 (0.8)

7.0 (1.8)

3.5 (1.7)

61.3 (38.7)

5

14

Planning

Ancillary

Incorrect compensator placement

Incorrect dose delivered

2.3 (0.4)

6.3 (1.3)

4.0 (1.9)

56.3 (30.8)

6

8

Planning

Preparation of initial plan

Calculation error

Incorrect dose calculation

2.0 (0.6)

7.2 (0.9)

3.8 (2)

54.9 (33.9)

7

9

Planning

Preparation of initial plan

Incorrect treatment date

Incorrect dose calculation

2.2 (0.7)

6.3 (1.4)

4.0 (2.3)

54.9 (38.1)

8

6

Planning

Preparation of initial plan

Miscommunication of Rx

Incorrect dose or fractionation

2.2 (0.4)

7.2 (1.1)

3.5 (1.9)

54.3 (31.9)

9

10

Planning

Preparation of initial plan

Incorrect documentation in EMR

Incorrect plan/dose delivered

2.2 (0.4)

6.2 (2.5)

4.0 (2.5)

53.4 (41.2)

10

52

Treatment

Delivery

Timer malfunction

Incorrect dose delivered

1.7 (0.5)

7.7 (1.6)

3.8 (2.0)

49.0 (30.3)

11

2

Logistics

Plan approval

Plan changed after checks but before approval on tx day

Incorrect plan delivered

2.5 (0.8)

5.3 (2.9)

3.7 (2.1)

48.9 (41.1)

12

40

Treatment

Setup

Flattening filter partially inserted

Incorrect dose delivered

1.8 (0.4)

6.7 (1.8)

3.8 (1.6)

46.9 (24.9)

13

41

Treatment

Setup

Flattening filter inserted but not latched

Incorrect dose delivered

1.8 (0.4)

5.7 (1.9)

4.5 (2.1)

46.8 (28.1)

14

13

Planning

Ancillary

Incorrect compensator

Incorrect dose delivered

2.0 (0.0)

6.5 (1.1)

3.5 (2.1)

45.5 (27.9)

15

7

Planning

Preparation of initial plan

Incorrect documentation

Incorrect dose calculation

2.0 (0.0)

7.2 (0.9)

3.2 (1.9)

45.4 (27.3)

16

1

Logistics

Treatment calendar

Miscommunication of dates

Plan not ready on tx date, plan calculated for wrong tx date

3.2 (1.0)

4.0 (2.4)

3.5 (1.4)

44.8 (35.4)

17

43

Treatment

Setup

Wrong flattening filter inserted

Incorrect dose delivered

1.5 (0.5)

6.8 (1.7)

4.2 (2.2)

42.7 (28.6)

18

22

Treatment

Setup

Wrong compensator

Incorrect dose delivered

2.0 (0.7)

6.0 (1.6)

3.5 (2.1)

42 (30.9)

19

53

Treatment

Delivery

Patient moves after setup (significant move wrt tx field) (no lung blocks)

Incorrect dose delivered

2.8 (0.9)

5.5 (2.0)

2.7 (0.9)

41.6 (24.8)

20

17

Treatment

Setup

Wrong lung blocks

Incorrect dose delivered

2.2 (0.4)

5.0 (2.0)

3.8 (2.3)

41.5 (30.5)

Rank

FM#

Process description

Step Description

Failure mode

Effects

O

S

D

RPN

D: D F B W—F M E A (6 scorers: 2 MPs, 2 ROs, 2 RTs) ranked wrt mean ‘S’ scores

 1

47

Treatment

Delivery

Wrong patient

Incorrect dose delivered

1.2 (0.4)

8.7 (0.9)

2.7 (1.4)

27.0 (16.6)

 2

56

Treatment

Delivery

Source stuck

Incorrect dose delivered / staff exposure

1.2 (0.4)

8.7 (1.1)

1.3 (0.5)

13.5 (6.6)

 3

79

QA

Machine QA

Source stuck and emergency shutter not operational

Patient overdose

1.2 (0.4)

8.3 (2.2)

2.2 (1.5)

21.1 (16.7)

 4

42

Treatment

Setup

Flattening filter falls on patient

Patient injury

1.5 (0.5)

8.2 (0.9)

2.3 (2.1)

28.6 (28.0)

 5

45

Treatment

Setup

Motor run away causing head to contact patient

Patient injury

1.2 (0.4)

8.0 (2.0)

1.5 (0.8)

14.0 (9.1)

 6

52

Treatment

Delivery

Timer malfunction

Incorrect dose delivered

1.7 (0.5)

7.7 (1.6)

3.8 (2.0)

49.0 (30.3)

 7

25

Treatment

Setup

Compensator falls on patient

Patient injury

1.5 (0.5)

7.5 (1.5)

2.8 (3.0)

30.9 (36.2)

 8

8

Planning

Preparation of initial plan

Calculation error

Incorrect dose calculation

2.0 (0.6)

7.2 (0.9)

3.8 (2.0)

54.9 (33.9)

 9

6

Planning

Preparation of initial plan

Miscommunication of Rx

Incorrect dose or fractionation

2.2 (0.4)

7.2 (1.1)

3.5 (1.9)

54.3 (31.9)

 10

7

Planning

Preparation of initial plan

Incorrect documentation

Incorrect dose calculation

2.0 (0.0)

7.2 (0.9)

3.2 (1.9)

45.4 (27.3)

 11

28

Treatment

Setup

Couch not at treatment height for multiple fx (large change > 5 cm)

Incorrect dose delivered

1.8 (1.1)

7.2 (2)

2.8 (2.1)

37.2 (36.8)

 12

11

Planning

Preparation of initial plan

Corrupt spreadsheet

Incorrect dose calculation

1.8 (0.7)

7.0 (1.2)

5.8 (2.3)

74.9 (42.3)

 13

49

Treatment

Delivery

Program wrong tx time

Incorrect dose delivered

2.5 (0.8)

7.0 (1.8)

3.5 (1.7)

61.3 (38.7)

 14

21

Treatment

Setup

Lung blocks/tray fall on patient

Patient injury

1.2 (0.4)

7.0 (1.5)

2.0 (2.2)

16.3 (19.3)

 15

19

Treatment

Setup

Missing lung blocks (all fractions)

Incorrect dose delivered

1.2 (0.4)

7.0 (1.8)

1.5 (0.8)

12.3 (8.0)

 16

43

Treatment

Setup

Wrong flattening filter inserted

Incorrect dose delivered

1.5 (0.5)

6.8 (1.7)

4.2 (2.2)

42.7 (28.6)

 17

39

Treatment

Setup

Flattening filter not inserted

Incorrect dose delivered

1.8 (0.4)

6.8 (2.0)

3.0 (1.4)

37.6 (22.3)

 18

63

Treatment

Delivery

Forget to flip to supine after prone field

Incorrect dose delivered

1.7 (0.5)

6.8 (0.7)

2.2 (1.3)

24.7 (17.0)

 19

40

Treatment

Setup

Flattening filter partially inserted

Incorrect dose delivered

1.8 (0.4)

6.7 (1.8)

3.8 (1.6)

46.9 (24.9)

 20

74

QA

Machine QA

Incorrect beam data

Incorrect dose delivered

2.0 (0.6)

6.7 (1.8)

2.7 (1.1)

35.6 (20.4)