Therapy Medical Events in 2017

2017 Event 1
Summary A patient received a single fraction of treatment to the wrong site.  The site treated was 9 cm superior to the correct treatment site due to a failure of the therapists to recognize a planned shift from the original simulation isocenter.  The patient received 180 cGy out of a total prescribed course dose of 4500 cGy to the 10th thoracic vertebra and surrounding areas. 
Root Cause The therapist failed to recognize a planned shift from the original simulation isocenter.
Corrective Action

1)  Therapist now verbalizing daily with their partnering therapist the shifts needed to setup the patient correctly.

2)  Emphasized correctly identifying couch match coordinates with the shift instructions.

3)  Now double checking table index parameters with the shift instructions.
Effect on Patient The physician elected to add one additional fraction to make up for the wrong site fraction delivery.  Parts of the lower lungs, liver, and small intestine received the 180 cGy.  It was determined that the patient would not be harmed from the radiation amount administered incorrectly.  Full disclosure was made to the patient by the Hospital Administration and the Department Manager.
2017 Event 2
Summary A patient with lung cancer and secondary metastases received the first of 3 of 12 fractions of 400 cGy/fraction to a site approximately 2 cm x 1.5 cm superior and lateral to the intended treatment site.
Root Cause A covering radiation oncologist was overseeing the care of this patient in the absence of the prescribing physician.  The covering physician approved daily image matching that showed to be 2cm x 1.5 cm superior and lateral to the treatment target.  Error discovered upon return of prescribing physician.
Corrective Action Physician providing oversight will verify complete accuracy of approved image matching with the planned digitally reconstructed radiograph with respect to the prescribed treatment volumes.
Effect on Patient

It was determined that the PTV received 4440 cGy of the intended 5015 cGy mean dose.  Thereby, showing only an 11.5% difference.  Due to this and adjacent small bowel dose concerns, the physician elected not to prescribe additional fractions to this site.

It was determined that the patient would not be harmed from the radiation amount administered incorrectly and full disclosure to the patient was made of the incident.
2017 Event 3

A therapy patient received the second of five electron treatment fractions to the wrong treatment site. During set-up for the second treatment, the two treating therapists had a disagreement as to whether the treatment set-up was correct.  The 2nd therapist asked the 3rd therapist, who had treated the patient for the first fraction, to verify the set-up. The 3rd therapist assessed the set-up and confirmed that the location seemed correct.  It was later determined that a geometric miss of the treatment site occurred because of an incorrect shift made at the time of patient set-up.

Root Cause

At the time of simulation, no pictures were taken of the patient set-up, so there was not an adequate level of documentation to verify the setup of the treatment field.  Also, the 2nd therapist did not witness the shifts made by the 1st therapist during patient setup.

Corrective Action Corrective action includes requiring photos of the treatment area during simulation and during first treatment, and all treating therapists must witness and verify patient setups in the future.  Also, disagreements in patient setup will require review of setup photos and notes.
Effect on Patient The prescribing physician informed the patient of the geometric miss, and that he did not anticipate there would be any biological consequence or injury associated with the geometric miss.
2017 Event 4

A patient undergoing radiation therapy to the left breast received an unintended breast cavity boost dose of 500 cGy instead of 200 cGy as prescribed by the physician.

Root Cause

The event was due to human error. Treatment calculations were done for a 5 Gy x 2 treatment plan instead of the 2 Gy x 5 prescribed treatment plan.

Corrective Action Corrective action has been taken in the form of dosimetry timeouts and physics timeouts along with pretreatment "New Start Chart Review" for each new patient.
Effect on Patient The facility performed a BED (biological effective dose) calculation and determined that no acute or long-term adverse effects are to be expected.
2017 Event 5

A non-prescribed region (pelvis) was given almost 1200 cGy over four days, and the prescribed region (upper abdomen) was given 1800 cGy over 6 days. The prescription was for 3000 cGy to the upper abdomen over 10 days.

Root Cause

Dose to unintended treatment site due to improper differentiation between leveling marks and isocenter marks, and a record and verify alarm that indicated the couch was set to the wrong length was ignored. Also, a therapy time out was not conducted.

Corrective Action A new setup instruction has been created for upper abdomen, staff has been retrained on leveling and isocenter marks, and port films must be taken any time a record and verify alarm is received. A therapist's time out policy between the two treating therapists has been implemented as well.
Effect on Patient The dose to the non-prescribed region is not expected to have adverse effects, but the dose to the prescribed region may not have been adequate to achieve clinical goals. Patient has been informed and has declined extra treatments to complete the original prescription.

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