Radiotherapy mistakes can be greatly reduced by a combination of existing security controls

A combination of several known security procedures can greatly reduce patient adverse consequences for errors in the use of radiation for the treatment of cancer, according to a new study by researchers at Johns Hopkins.

Radiation oncologists use more than a dozen quality assurance (QA) checks to radiotherapy to prevent mistakes, but so far, the Hopkins researchers say, nobody has systematically evaluated their effectiveness. Working with researchers at Washington University in St. Louis, collected the team with Hopkins data on about 4,000 "near-miss" events that have occurred during the 2008-2010 on the two institutions. They then narrowed the dataset on 290 events encountered errors that-if they are not caught in time-was could have allowed serious harm to patients. They determined for each QA control, the percentage of these potential patient-adverse effects of incidents that could have been avoided.

The Group's key finding was that a combination of about six common QA measures would have more than 90 percent of potential incidents.

"While clinicians in this field can be trusted with this quality assurance procedures, they may not have appreciated how effective they are in combination," said Eric Ford, Ph.d., D.A.B.R., Assistant professor of radiation oncology and molecular radiation sciences at Johns Hopkins, that of findings of the Group on August 3, on the joint American Association of physicists in Medicine (AAPM) and Canadian organization of Medical Physicists will present annual meeting, 31 July to 4 August 2011 held in Vancouver, Canada.

On a separate symposium during the meeting, also on 3 August, Ford and his colleagues related recommendations for the standardization of radiotherapy accident investigation procedures.

Ionizing radiation such as gamma radiation or proton beam radiation has long been a staple in the treatment of cancer, because it can efficiently cell-killing DNA breaks within tumors arise. The goal is to use it in a way that the dose delivered to a tumor, while keeping healthy tissue around the tumor as possible protected by sharp focus the radiation treatment area to maximize.

Unfortunately, the multi-step complexity of radiation therapy, and the numerous precision measurements using it entails, can sometimes cause errors, with patients getting too little radiation where it is needed, or too much where it is not.

One QA Inspector, a piece of hardware called an electronic Portal Imaging device (EPID), is built to much radio therapy-delivery engines, and can provide a real-time X-raylike image of the radiation comes from a patient. But Ford says less than one percent of radiotherapy clinics use EPID because the software and training needed to work usually absent.

However, Ford says, their investigation showed that another key to security turned out to be a modest checklist of relatively low-tech measures, "assuming that the is correctly used consistently, that it is often not," adds Ford. The checklist contains reviews of patient charts before treatment by doctors and radiation-physicists, which calculate the correct dose of radiation.

Using film-based radiation dose measurements as an alternative to EPID and a compulsory ' timeout ' by the radiation therapist before radiation is enabled to check that the written treatment plan and doses match what is on the radiation delivery engines also on the list of the most effective QA procedures were.

A common QA measure known as pre-treatment IMRT (intensity modulated radiation therapy), in which clinical staff do a "test run" of the radiotherapy device on the programmed strength with no patient present, ranked very low on the list because it would be almost none of the possible incidents studied. "This is important to know, because for IMRT treatment often consumes a lot of man-hours," says Ford.

Ford and his fellow Johns Hopkins Stephanie Terezakis, M.D., a pediatric radiation oncologist and a contribution to QA evaluation study, are also members of the Working Group of the AAPM on the prevention of errors. During the meeting of Vancouver, in a symposium on 3 August, the group will make recommendations for a national radiotherapy incident reporting system. The group develops a way of handling errors and near-misses reported and sent to a central group for evaluation and dissemination to clinics says Ford. "It could work in ways similar to how the air and train accidents at the National Transportation Safety Board are reported," he noted.

Other experts who have contributed to the QA check box control effectiveness study are Kendra Harris, M.D., a resident at Johns Hopkins; radiotherapy Annette Souranis, a therapist in the Department of Oncology, and Sasa Mutic, Ph.d., associate professor of radio therapy at Washington University School of Medicine in St. Louis, Missouri.

The study was financed by a grant from the pilot research of Elekta Inc.

Article reference:
Abstract title number/: WE-C-214-5--a quantification of the effectiveness of standard QA measures on preventing errors in radiation therapy and the promise of in Vivo dosimetry EPID-based Portal
Abstract Link: http://www.aapm.org/meetings/amos2/pdf/59-16302-92754-297.pdf
Johns Hopkins medical institutions