Outcomes of Routine Intensity Modulated Radiation Therapy Quality Assurance in a Large Head and Neck Cancer Center

Abstract

Purpose: The primary endpoint was to ascertain whether the percentage of major changes implemented from our routine intensity modulated radiation therapy (IMRT) quality assurance (QA) process was more than 10%. The secondary endpoints were to document the percentage of minor changes, ascertain the time taken to perform the IMRT QA process, evaluate potential predictors for major changes, and ascertain the perceived value of the program by the compliance of radiation oncologists (ROs) treating head and neck cancer (HNC).

Methods and materials: This was a retrospective analysis of a prospective database for all radically treated HNC patients. Recommended changes were predefined with criteria as either "major changes" or "minor changes."

Results: Of 595 patients treated radically between May 21, 2012, and May 21, 2014, 548 patients were entered, giving a compliance of 92.1%. The vast majority were treated with IMRT (470/548, 89%), 49.3% treated definitively and 50.7% treated adjuvantly; overall, 63% had stage IV disease. Eighty-one patients (14.8%) had 1 or more major changes recommended and implemented, and 21 patients (3.8%) had major changes recommended but not implemented because of a lack of consensus. Of minor recommendations, in 115 patients (21%) they were implemented and in 13 patients (2.4%) they were not implemented. No changes were recommended in the remaining 324 patients (59.1%). The only factor correlating with the likelihood of a major change was treatment with IMRT (P=.001). In the vast majority of cases (85%), the time taken for IMRT QA was less than 20 minutes.

Conclusions: Our routine HNC IMRT QA program resulted in the implementation of a significant number of major changes. The high compliance with the program is indicative of the belief in its clinical value. This study can inform discussion on optimal RT QA processes in routine clinical practice.