A survey on table tolerances and couch overrides in radiotherapy.

Bonnie Chinsky,Rakesh Patel,Murat Surucu,John C Roeske,Joshua Panfil

doi:10.1120/jacmp.v17i6.6261

Abstract

The purpose of this study was to survey current departmental policies on treatment couch overrides and the values of table tolerances used clinically. A 25‐question electronic survey on couch overrides and tolerances was sent to full members of the American Association of Physicists in Medicine (AAPM). The first part of the survey asked participants if table overrides were allowed at their institution, who was allowed to perform these overrides, and if imaging was required with overrides. The second part of the survey asked individuals to provide table tolerance data for the following treatment sites: brain/head and neck (H&N), lung, breast, abdomen/pelvis and prostate. Each site was further divided into IMRT/VMAT and 3D conformal techniques. Spaces for free‐text were provided, allowing respondents to enter any table tolerance data they were unable to specify under the treatment sites listed. A total of 361 individuals responded, of which approximately half participated in the couch tolerances portion of the survey. Overall, 86% of respondents’ institutions allow couch tolerance overrides at treatment. Therapists were the most common staff members permitted to perform overrides, followed by physicists, dosimetrists, and physicians, respectively. Of the institutions allowing overrides, 34% reported overriding daily. More than half of the centers document the override and/or require a setup image to radiographically verify the treatment site. With respect to table tolerances, SRS/SBRT table tolerances were the tightest, while clinical setup table tolerances were the largest. There were minimal statistically significant differences between IMRT/VMAT and 3D conformal table tolerances. Our results demonstrated that table overrides are relatively common in radiotherapy despite being a potential safety concern. Institutions should review their override policy and table tolerance values in light of the practices of other institutions. Careful attention to these matters is crucial in ensuring the safe and accurate delivery of radiotherapy.PACS number(s): 87.55.N‐, 87.55.Qr, 87.55.T‐

Highlights

406 Chinsky et al.: Radiotherapy table tolerances and couch overrides survey rounds.[2,3,4,5,6] Larger hospital systems have provided an infrastructure for sharing and disseminating critical information related to patient safety, “near misses,” and treatment errors.[3,4] Guidelines have been provided nationally and internationally by ASTRO, Association of Physicists in Medicine (AAPM), and other organizations, through “Safety is no Accident,” as well as the IAEA.[7,8,9] More recently, a radiation oncology dedicated Patient Safety Organization (PSO) has been established for the reporting of errors on a national level to reduce the risk of future occurrences.[10]
We present the results of the first North American survey conducted on couch overrides and table tolerances
This survey was motivated by an increased frequency of couch parameter overrides that were observed in our clinic

Summary

Introduction

406 Chinsky et al.: Radiotherapy table tolerances and couch overrides survey rounds.[2,3,4,5,6] Larger hospital systems have provided an infrastructure for sharing and disseminating critical information related to patient safety, “near misses,” and treatment errors.[3,4] Guidelines have been provided nationally and internationally by ASTRO, AAPM, and other organizations, through “Safety is no Accident,” as well as the IAEA.[7,8,9] More recently, a radiation oncology dedicated Patient Safety Organization (PSO) has been established for the reporting of errors on a national level to reduce the risk of future occurrences.[10]Treatment errors can be broadly classified as failures of software, equipment, or work practices. Concerning work practices, a 10-year study of voluntary error reporting by Kalapurkal et al[4] showed that approximately 51% of the errors recorded were related to patient setup and/or delivery. Most radiotherapy departments have a number of safeguards to ensure that the correct site is treated. These include indexing the immobilization device to the treatment table, as well as the acquisition and verification of couch parameters within the record-and-verify system. One can potentially limit the daily variability of the couch, and the daily position of the patient, provided he/she is positioned consistently at the same location on the treatment couch

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Results

Discussion

Conclusion