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RADIOTHERAPY ACCIDENT IN COSTA RICA - CAUSE AND PREVENTION OF RADIATION ACCIDENTS IN HOSPITALS . Module XIX. Cause and prevention of radiation accidents in hospitals. Radiation accidents with severe and even fatal consequences do occur in medical facilities
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RADIOTHERAPY ACCIDENT IN COSTA RICA - CAUSE AND PREVENTION OF RADIATION ACCIDENTS IN HOSPITALS Module XIX
Cause and prevention of radiation accidents in hospitals • Radiation accidents with severe and even fatal consequences do occur in medical facilities • Human error is most common cause of radiation accidents
Main initiating event • 22 Aug 1996, at San Juan de Dios Hospital in San Jose, Costa Rica, a calibration error was made for new 60-Co source • Consequently, the delivered dose to cancer patients was overestimated by about 60 % • By 27 Sept 96 115 patients treated
Severity of effects in surviving 73 patients • 4 patients had catastrophic effects • 16 marked effects and high risk for future • 26 not severe at that time • 22 no effect of significance at that time • 2 underexposed patients (radiotherapy was discontinued) • 3 could not be seen
Findings of IAEA team in July 1997 • 42 patients died by July 1997 (10 months after exposure) • 7 deaths primarily due to overexposure • 22 deaths not related to the overexposure • 13 insufficient data
Findings of IAEA mission in Oct 1998 • 61 patients died by Oct 1998 (25 months after exposure) • 13 deaths primarily due to overexposure • 4 possibly related to overexposure • 35 death not related to overexposure • 9 insufficient data
Effects on the skin • severe erythema in the sacral region
Brain necrosis and paralysis • lethargy, ataxy • dementia • leuko-enceophalopathy • cerebral necrosis • deafness • paralysis (myelopathy) • spinal cord changes
Cause and prevention of radiation accidents in hospitals • Significant overdoses or underdoses (errors exceeding 10% of prescribed dose) result in unacceptable severe consequences • Doses administered in fewer than normal sessions but with higher doses per treatment result in excessive number of early and late complications
Distribution of expected radiation effects from standard radiotherapy protocols and clinical examinations of the surviving patients, %
Prevention of radiation accidents in hospitals • Regulations should cover training and competence required to deal with potentially hazardous radiotherapy sources • Specific training of staff should be provided before they work in a radiotherapy unit
Prevention of radiation accidents in hospitals • Calibration of radiotherapy devices should be done by appropriately trained persons and independently checked • When there is a high incidence and severity of acute side effects during radiotherapy treatment, further treatment should be stopped and the source calibration immediately checked
Prevention of radiation accidents in hospitals • In radiotherapy accidents, the tumour dose may not be the parameter of primary interest • Often the biologically equivalent 2 Gy per fraction dose to radiosensitive organs, e.g. intestine, spinal cord and heart, more important
Prevention of radiation accidents in hospitals • Early and reliable information and clear communication crucial to good management of radiation accidents • Radiotherapy records should be uniform, clear, consistent and complete • Use defence-in-depth methodology to test and ensure that quality assurance programme has sufficient safety layers to make accidents very unlikely
Lessons learned Recommendations • Define responsibilities, develop procedures and supervise compliance • Implement, monitor and enforce existing regulations as soon as possible
Lessons learned Recommendations • Establish and foster safety culture and provide education and training • Implement additional educational programmes for radiotherapy staff
Lessons learnedRecommendations • Implement quality assurance and record keeping programme • Include • verification of physical arrangements and clinical aids (patients’ charts) used in treatment • verification of appropriate calibration and conditions of operation of dosimetry equipment
Lessons learned Recommendations • regular and independent quality audit reviews of programme • participation in intercomparison exercises such as IAEA-WHO postal dose check service • procedures to take action if deviation found