Medical Errors in Radiation Therapy 2014 Amy L. Carlson Division of Emergency Preparedness and Community Support Bureau of Radiation Control Florida Department of Health
Reportable Medical Events State of Florida Radiation Therapy Use of Radioactive Materials The Joint Commission Fluoroscopy- Sentinel Event Prolonged fluoroscopy with cumulative dose >1500 rads to a single field or any delivery of radiotherapy to the wrong region or >25% above the planned dose.
Medical Events Facili&es delivering radia&on therapy are required to report medical events: Dose delivered by wrong mode of treatment, wrong treatment, or wrong treatment site; or Dose of radia&on that differs greater than a total of 30% of the prescribed dose in a week or 20% of the total prescribed dose.
Where to Report Facilities are required to report medical events within 24 hours of determination to: Radiation Machine Program 705 Wells Rd., Suite 300 Orange Park, FL 32073 904-278-5730
Reported Medical Events 2014 Six medical events were investigated: Five delivered to the wrong body part/field One delivered by wrong treatment
Event 1 Whole Brain / Wrong Treatment Prescribed treatment = 3750 cgy in 15 fractions of 250 cgy daily using IMRT; Delivered dose = 10 fractions of 375 cgy; Error discovered after seventh fraction; and Treatment reviewed and approved by dosimetrist, oncologist, physicist and therapists before delivery. Corrective Action: New policy regarding verification of physician prescription.
Event 2 Reportable Event Trigeminal Nerve / Wrong Treatment Site Original referral = Left side 60 Gy gamma radiation using Cyberknife; Prescribed/Delivered treatment = Right side 60Gy Cyberknife; and The oncologist and neurosurgeon developed and approved the treatment plan in error. Corrective Action: Laterality signed/verified by radiation oncologist and attending physician on all new trigeminal neuralgia patients.
Event 3 Left Posterior Arm / Wrong Treatment Site Prescribed treatment = 19.8 Gy in 11 fractions of 1.8 Gy each using EBR; Prescription did not clearly identify the anatomic location of the treatment site; Treatment site outline washed off; Therapist used old treatment setup photo; and Third fraction delivered to previously treated site. Corrective Action: Anatomic site names repeated in prescriptions only for re-treatment.
Event 4 Right Breast / Wrong Treatment Site Prescribed treatment = Total 6640 cgy: 5040 cgy in EBR with 1600 cgy boost HDR in 8 fractions of Iridium 192; Spot function button disengaged, displaying inaccurate values; Therapists, physicist, and oncologist attribute increased separation measurements to variation in patient thickness and positioning; and
Event 4 (continued) Physicist did not verify plate separations before continuing treatment. Corrective Action: Set up photos in two planes (CC & ML) taken with ruler to document plate separations then compared to display on unit.
Event 5 Posterior Fifth Rib/ Wrong Treatment Site Prescribed treatment = Total 3750 cgy in 15 fractions of 250 cgy daily using IGRT; Delivered dose = One fraction 250 cgy to one half the target volume and 4 cm. inferior to the intended site; Four therapists on five days used incorrect tattoos as reference point for treatment target; Oncologist approved IGRT imaging, which did not indicate tattoo positioning; Therapists failed to document or communicate to other therapists the large couch shifts used to adjust after IGRT imaging;
Event 5 (continued) Event 5 Ribs appeared aligned in IGRT images due to magnification, hiding adjacent peripheral anatomy; On treatments 7-10 different therapists set up to a tattoo from a previous treatment, after IGRT imaging, requiring a couch positioning shift 4 cm superiorly and 2 cm laterally to adjust; and On treatment 11 original therapist returns, also uses incorrect tattoo, IGRT images, and applies only a 2 cm lateral shift. Corrective Action: Therapist applying shifts greater than 1 cm require approval from physician, physicist or dosimetrist. (ASTRO guidelines). A triple-point tattoo is applied when new tattoo is within 15 cm of prior tattoo. The IGRT matching verified by second therapist, physician, physicist or dosimetrist. Set up notes are updated when parameters change.
Event 6 Left Lower Leg / Wrong Treatment Site Prescribed Treatment = 5500 cgy of EBR in 22 fractions of 250 cgy; Delivered = One fraction of 250 cgy to area 3 cm anterior to intended site on left leg; Patient had multiple lesions on same body part; Set up photos were taken at a distance and angle inadequately demonstrating landmark structures adjacent to treatment site; and The Vacloc immobilization device, transparent template, and set up sheet, all lacked adequate labeling to prevent incorrect positioning of patient. Corrective Action: Detailed labeling information on transparent template and set up sheet will identify at least three structures. Vacloc indexed and labeled for fixed location on table for simulation. Multiple set up photos at multiple angles and distances will document patient position.
Event Commonalities Failure to recognize deficiencies in policy and procedure; Inadequate transfer of information to all staff members; Staff relied on minimal methods of verification for treatment set up; and Staff counterintuitively resisted the need to verify treatment plans.
Summary Medical events occur following a breakdown of two or more control elements. Every facility is vulnerable to these events. Facilities who have clear, well-developed procedures and who train to those procedures minimize the risk. Event reporting is mandatory, and should ultimately aid a facility in the revision or development of good policy and procedures, following an investigation.
Contact Information Amy Carlson, Environmental Specialist X-Ray Machine Section Bureau of Radiation Control 705 Wells Road Orange Park, FL 32073 904-278-5730 Amy.Carlson@FLHealth.gov