ABSTRACT
PURPOSE: Error reduction is an important concern in clinical medicine. Intensity-modulated radiotherapy (IMRT) is an important advancement in radiation oncology that increases the complexity of treatment, potentially increasing the error risk. We studied the frequency and severity of errors in a large multicenter practice to ascertain the impact of quality improvement interventions over time, IMRT, and type of practice. METHODS AND MATERIALS: We analyzed prospective data from three academic and 16 community practice sites with 24,775 courses of radiotherapy (9,210 IMRT courses and 15,565 non-IMRT) between January 2006 and December 2009. All IMRT treatment was performed using one centralized dose planning center for all sites. RESULTS: We prospectively identified various errors or potential errors in 0.14 % vs. 0.40 % of the IMRT vs. non-IMRT courses (13/9,210 vs. 62/15,565, p = 0.0004) and excluding potential errors: 0.03 % for IMRT vs. 0.21% for non-IMRT. We developed the Clinical Radiotherapy Error Severity Scale (CRESS) to classify error severity from 1 to 10, with 1 to 3 for potential or completely correctable errors, 4 to 5 for dose variations <5%, and 6 to 10 for dose variations >5%. Multivariate analyses of CRESS values, severity >4, and any error (including potential) correlated significantly reduced errors with IMRT (p = 0.0001-0.0024) but found no significant difference between the academic and community practice sites and no change in error frequency over time despite implementation of 39 system-wide policy changes by the centralized quality improvement committee. CONCLUSIONS: Despite the increase in complexity with IMRT compared with conventional radiotherapy, it can be delivered with reduced error frequency.