Encrypted login | home

Program Information

Results From 15 Years of Independent Peer Review of Beam Output at More Than 2000 Academic and Non-Academic Institutions


R Howell

R Howell1*, S Smith1 , J Palmer1 , (1) UT MD Anderson Cancer Center, Houston, TX,

Presentations

TU-FG-702-8 (Tuesday, August 1, 2017) 1:45 PM - 3:45 PM Room: 702


Purpose: Independent peer review is an important quality assurance tool for radiation therapy. While there are reports of results of such programs, they have largely focused on institutions that participate in clinical trials. The purpose of this study was to report independent peer review results from a broad spectrum of institutions, including both academic and non-academic centers.

Methods: We analyzed results from independent peer review of beam output for different types of radiation therapy beams, i.e. Photons (2 – 25 MV), electrons (2 – 20 MeV), and orthovoltage (1.9 mm AL – 3 mm Cu). Specifically, we calculated summary statistics for the ratio between dose measured by independent peer review and dose reported by the institution. The analysis included data from over 2000 institutions in the United States and more than 150 from other countries. All beams monitored over the past 15 years (2001 – 2016) were included in the analysis. In total data for 155,237 results from individual beam output checks were analyzed.

Results: Mean ratio between measured and stated doses for all beams, photon, electron, and orthovoltage beams were 0.999±0.018, 1.000±0.016, 0.999±0.019, and 0.995±0.033, respectively. While the mean values for each beam type were very close to one, > 5% of the beams monitored were more than more than ± 3% from a 1.000. Often discrepancies were found to indicative of incorrectly calibrated beams, misinterpreting the irradiation instructions, or errors in completing the irradiation form. In many instances communication with individual institutions led to identifying and correcting specific issues.

Conclusion: For a large sample of academic and non-academic institutions located throughout the world, the majority of beams monitored were found to be well within ± 3 of the stated dose. However, there were many instances where we identified serious calibration related issues that were subsequently corrected.


Contact Email: