A Comparison of Perceptual and Reported Errors in Radiation Therapy

The aims of this study are to investigate error perceptions in radiation therapy (RT), to analyze 13 years of reported errors by type and location, and to identify the similarities and differences between perceptual and reported errors.

Close-ended surveys were distributed to radiation therapists, RT students, medical physicists, and medical physicist residents at a large cancer centre. Two areas of relevance were: (1) to select the five most common categories of errors in radiation therapy and (2) to rank the many different stages where errors can be made in radiation therapy. The purpose of the survey was to investigate error perceptions based on type of error and location. The survey findings were compared to reported errors tabulated over 13 years (1998-2010) as collected by the Radiation Therapy Quality Assurance Committee on site. Frequency of survey responses and actual error occurrences were ranked and compared. Survey responses were analyzed by demographics based on gender, profession, and levels of experience. Statistical tests were also performed.

The total response rate for the survey was 45% (58 of 130 respondents). There is a consensus that documentation errors and treatment delivery errors occur most frequently. However, errors relating to bolus, geographic miss, and positioning device were outstanding in the perception of errors. Categories with high error frequencies for reported errors included field size, shielding, and monitor units calculation. There were no significant differences in survey responses based on demographics.

The incongruence in certain types of errors between those perceived and those reported is alarming. When there is lack of awareness, the errors can be even more prone to occur. Patient safety culture starts from the individual; hence, understanding staff perception is critical in managing a quality assurance program. As technological advancements decrease certain errors, they may also have the potential to introduce new types of errors. Therefore, the last line of defense in any system remains qualified and attentive staff members.