Table 2 FMEA of the stage of delivery to liver lesions. Failures with RPN ≥ 80 or S ≥ 9 are listed

IX. Patient’s instruction on how to request the intervention of the technician in case of need (voice call via intercom and/or lifting a hand)

1

Absent or insufficient patient’s information on the request for help in case of need

Negligence, difficult communication with the patient, inattention, haste (intensive scheduling)

Lack of assistance in case of need, discomfort to the patient

10

1

3

30

XVI. Verifying the right vision of the patient from the control room with swiveling cameras

2

Failure to verify the vision of the patient from the cameras, suboptimal patient’s vision

Negligence, inattention, haste (intensive scheduling), superficiality, cameras not working, presence of objects in the treatment room that limit the vision of the patient

Lack of monitoring (i) possible collisions between the treatment manipulator and the patient; (ii) the patient’s welfare; (iii) possible collisions between the treatment manipulator and any object present in the treatment room. Lack of action in anomalous situations; treatment not in accordance with the planned one; postponement of the treatment session

10

1

3

30

XVIII. Checking the correctness of patient and treatment plan data, check that the Synchrony field displays “Yes”

3

Failure to verify the patient and treatment data correctness, failure to verify that the Synchrony field is active

Negligence, inattention, haste (intensive scheduling), interruption of the activity, patient clinical record not present at the time of treatment

Wrong dose delivery (in case of wrong prescription of dose or number of fractions in the planning stage), elongation of the work time, unnecessary live X-ray images acquisition, postponement of the treatment session

10

2

8

160

XXX. Selection of the appropriate size of the safety zone (small/medium/large), based on the patient’s size

4

Not appropriate selection of the size of the safety zone

Negligence, superficiality, inattention, haste (intensive scheduling), wrong estimate of the actual size of the patient

Risk of collision between the treatment manipulator and the patient (if PDP alerts are ignored), elongation of the treatment time (for PDP alerts)

10

2

2

40

XXXVIII. At the end of each session, compilation of the specific section in the worklist by the technician who delivered the treatment

5

Missed/wrong/partial/not clear compilation of the worklist at the end of each session

Negligence, inexperience, inattention, haste (intensive scheduling), interruption of the activity, patient clinical records not present at the end of the treatment, shift of technicians during the treatment (high workload)

Incorrect delivery of treatment plans (wrong plan, wrong day,…) if multiple lesions (plans) are present, incomplete patient clinical records, slowdown of the workflow.

8

2

5

80