Therapy Medical Events in 2015

2015 Event 1
Summary This was an event involving superficial therapy. A patient was scheduled for consult with a positive biopsy report for three separate skin lesions. There were no specific recommendations from the referring dermatologist on which site to treat first. The radiation oncologist asked the patient which site was more problematic/painful and then delivered a treatment to the location with 500 cGy.

The following day, a hand written statement was found on the reverse side of one of the referring physician's notes indicating that the hand was treated with Electrodesiccation and Curettage (ED&C), a non-radiation based treatment. Therefore the medical event comprised of treatment to the wrong site.
Root Cause The root cause of this event was an incomplete compilation of patient history and information prior to radiation prescription because the reverse side of a particular physician's note was not photocopied.
Corrective Action Apart from increased diligence in locating the referring physician documents, use of an additional one page treatment request form was initiated. The referring physician will mark the location of the area to be treated on an anatomic diagram on the form as well as write a description of the site to be treated on the form.
Effect on Patient The patient received a single fraction of 500 cGy. The dose was confined to a 2 cm diameter circle on the skin and the depth was superficial as the treatment was given with low energy 50 kV x-rays. The unintended treatment area was monitored by the treating radiation oncologist and there was no sign of sequelae. In the opinion of the radiation oncologist, the unintended dose did not and will not adversely affect the patient.
2015 Event 2
Summary A patient undergoing external beam radiation therapy was incorrectly treated for a single dose fraction with the arc treatment designed for a different patient.
Root Cause The arc treatment plan for a different patient with the same treatment site diagnosis plan was loaded.
Corrective Action Time-out procedure was revised and is actively being reviewed.
Effect on Patient Dosimetric reconstruction shows clinically insignificant dose difference between prescribed versus delivered dose. No adverse effects are expected from this event.
2015 Event 3
Summary A patient being treated palliatively to the neck/chest region received an external beam radiation treatment to a site approximately 10 cm superior to the intended treatment site. The patient setup was initially verified using orthogonal portal images. While waiting for the prescribing radiation oncologist to verify the set-up images, the radiation therapist (RTT) entered the treatment room and shifted the treatment couch 10 cm superior to mark the reference position on the patient's mask as a more stable starting position. The RTT made a note on the side of the mask to indicate an inferior couch shift of 10 cm from the reference mark would be necessary. However, the RTT did not return the couch to the intended treatment position. After the radiation oncologist reviewed and approved the setup images, the RTT delivered a 4 Gy treatment fraction to a site 10 cm superior to the intended site.
Root Cause The facility evaluated the root causes of the event to include:
  • Rushed procedures due to patient's medical condition and discomfort
  • Stress associated with trying to hurry to reduce patient's discomfort
  • Moving the patient prior to acquiring couch coordinates at the treatment isocenter (and failure to move the patient back)
Corrective Action
  • Once patient images have been taken, do not make unnecessary shifts to the patient position prior to treatment (or acquiring couch coordinates)
  • Treatment couch location should be documented in the delivery system immediately upon approval of pre-treatment images
  • Re-educate staff regarding the display of isocenter on images in software
Effect on Patient Approximately half of the intended target volume was treated during fraction 1. The patient's treatment was for pain relief. The patient was scheduled for a total of five treatment fractions. Patient treatments were discontinued by the admitting physician due to the patient's worsening medical condition. The patient was to be discharged to hospice but died while still admitted to the hospital. Death was due to the deteriorating medical condition of the patient and not due to the apparent radiation therapy medical event.
2015 Event 4
Summary A patient undergoing radiation therapy to the left breast received an unintended dose of approximately 0.22 Gy to an area 7.5 cm inferior to the intended treatment site. Therapists observed by closed circuit video and audio intercom that the patient was unsure of treatment site and interrupted treatment upon its discovery.
Root Cause The event was caused due to human error in the alignment of the newly acquired Cone Beam CT (CBCT) to the original planning CT. Incorrect alignment of treatment and reference images caused incorrect couch parameters to be applied for treatment.
Corrective Action Departmental policy and procedures regarding treatment tolerances for couch correction values as determined from the pretreatment image guidance session have been formally reviewed with all radiation therapists.
Effect on Patient The patient received 0.22 mGy to the wrong site, which is not expected to have any medical implications.
2015 Event 5
Summary Patient received a fractional treatment of 300 cGy in the wrong location. The patient was being treated for four iso-centers, right hip, left hip, base of skull and c-spine with palliative intent. There were marks on the patient mask for both the c-spine iso-center and the base of skull iso-center. The RTTs used a mark on the mask which was intended for the c-spine set up for the base of skull treatment. Error was discovered after the last field for that iso-center (Lt lat, LPO and PA).
Root Cause The marks on the mask were inappropriately labeled. The set up notes were also incorrect. The patient was on a 2 week break in treatment and this event happened on the first day back.
Corrective Action The facility will now require imaging of each iso-center upon return from any treatment break of at least 5 business days and each iso-center will have to be clearly labeled with setup notes.
Effect on Patient Facility states that the patient should not experience any short or long term side effects/complications from this event.
2015 Event 6
Summary Patient received five fractions to a location that was 5 cm from that intended.

The patient underwent treatment (course 1) and then returned for additional treatment (course 2). The second treatment plan was generated using tattoos from course 1. Upon review of the treatment area a 5 cm shift was needed for course 2. The shift was caught on the first day while taking setup images for verification. However, the setup note was changed while the plan was still loaded on the treatment unit and was not properly saved.

Five fractions were made before the error in the shift was noted. Prior to fraction 6, imaging was taken and that is when the incorrect alignment was noted. At that time treatment was paused to revise the plan to account for the change in shift.
Root Cause Incorrect shift was caught on the first treatment day when taking images for setup verification. However, since the setup note was changed in treatment planning while the plan was still loaded on the treatment unit, it was reverted back by the treatment console (and, unknown to the team, the corrected set up note was not saved).
Corrective Action Corrective action included verification by physics for a second check if the dosimetrist or therapist find that a change in treatment planning is needed. All staff were notified of the issue and that if more than one person is working on a treatment plan, one or more plans will not save properly and that message will pop up with that warning.
Effect on Patient The plan was modified to account for the needed shift. The final dose to the treatment area is within 10% of the original plan. The incorrect shift resulted in a dose that was 45% lower than the original prescribed dose. This was compensated for in the modified plan. No adverse effects were noted or are expected.
2015 Event 7
Summary Patient received 3 fractional treatments that differed from the prescribed dose by 50%.

Original treatment was prescribed as 15 fractions at 300 cGy for a total of 4500 cGy. The first 3 fractions were delivered at 450 cGy instead of 300 cGy. The treatment was halted and modified. Final treatment was a total of 4050 cGy delivered over 9 fractions of 300 cGy plus the first three at 450.
Root Cause When generating the initial treatment plan the fraction number was inadvertently entered as 10 instead of 15 fractions.
Corrective Action Corrective action included re-education on the verification policy for treatment plans and the institution of a treatment planning checklist.
Effect on Patient No adverse effects were noted or are expected. The patient was notified of the event.
2015 Event 8
Summary This was an event involving superficial x-ray radiation therapy. A radiation therapy oncologist defined the treatment field as a 2 cm diameter circle on the patient's left superior parietal scalp. The total prescribed dose was 40 Gy to be delivered in 8 fractions twice weekly using 50 kVp x-rays. The first treatment was delivered correctly. When the patient returned for the second treatment the radiation therapy technician incorrectly identified the treatment area and the patient was treated to a 2 cm diameter region on his left parietal scalp. The patient continued treatment in this fashion for four more fractions. The patient received a total of 25 Gy to the incorrect area before the error was discovered.
Root Cause The event was caused by human error by the technician incorrectly identifying the treatment area.
Corrective Action The radiation therapy technician was instructed to take additional photographs of treatment areas including close up photos to better define the treatment area. A copy of the biopsy photo will be referenced prior to every treatment. Finally, the therapist will utilize clear film as an overlay template to define the daily treatment area marking any obvious and stable landmarks. Superimposing this template over the patient will provide a clear and objective method for treatment field localization.
Effect on Patient The patient exhibited a slight erythema to the area that was treated to 25 Gy. There oncologist feels that there should be no lasting effect on the patient. The patient, patient's spouse, referring physician and the facility RSO were all notified.
2015 Event 9
Summary A patient was to be treated for ten fractions to the right femur. At CT simulation, the patient's skin was tattooed to mark the simulation isocenter location. In the patient's treatment plan, a treatment isocenter 5cm inferior to the tattooed point was used. This 5cm discrepancy in position from the planned isocenter to the tattooed point was not noticed, so the setup notes indicated that there was to be no shift from the tattooed point. The patient was treated for the first three fractions with this 5cm geometric miss from the planned isocenter. On the fourth treatment day the 5cm shift was identified. The appropriate shift was made, and the patient was treated at the planned isocenter.
Root Cause The set up notes failed to properly document the required shifts from the BB markers used during simulation.
Corrective Action Setup images will be taken so that either a superior or inferior border of the field is visible to assess its location relative to patient anatomy. At simulation, shifts made from the BB markers to the tattoo point will be recorded so that they may be verified later in the planning system.
Effect on Patient This is not expected to cause a significant clinical effect to the patient.

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