ACCIDENTS IN RADIATION ACCIDENTS IN RADIATION ONCOLOGY PRACTICEONCOLOGY PRACTICE

DR. ASHUTOSH MUKHERJIDR. ASHUTOSH MUKHERJI

ASST. PROFESSOR OF RADIOTHERAPY,ASST. PROFESSOR OF RADIOTHERAPY,

REGIONAL CANCER CENTRE, JIPMERREGIONAL CANCER CENTRE, JIPMER

RADIATIONRADIATION ONCOLOGYONCOLOGY

• Radiation therapy is that Radiation therapy is that branch of medicine that branch of medicine that deals deals with use of radiation in the with use of radiation in the treatment of malignant treatment of malignant diseasesdiseases..

• Goal of radiation therapy is to Goal of radiation therapy is to kill cancerous cells, while kill cancerous cells, while sparing normal tissue.sparing normal tissue.

• Radiation therapy can be Radiation therapy can be either curative, or palliative.either curative, or palliative.

• In contrast to diagnostic In contrast to diagnostic procedures, therapeutic doses procedures, therapeutic doses of radiation are high; for of radiation are high; for example: 5000 cGy in post example: 5000 cGy in post operative cases vs 10 cGy operative cases vs 10 cGy (CAT scan).(CAT scan).

RADIATION ONCOLOGY IN THE USRADIATION ONCOLOGY IN THE US

• In the US in 1995, 41% of the 1,252,050 newly diagnosed In the US in 1995, 41% of the 1,252,050 newly diagnosed cases of cancer were treated with radiation.cases of cancer were treated with radiation.

• These radiation treatments relieved suffering and extended These radiation treatments relieved suffering and extended the lives of the patients being treated.the lives of the patients being treated.

• Along with early diagnosis, radiation treatments contributed Along with early diagnosis, radiation treatments contributed to a 1.1% decrease in annual cancer death rates from 1993 to a 1.1% decrease in annual cancer death rates from 1993 through 2002.through 2002.

• In 1996 in the US there were 1,893 Linear Accelerators and In 1996 in the US there were 1,893 Linear Accelerators and 504 Co-60 machines. Present estimates put the number at 504 Co-60 machines. Present estimates put the number at 4492.4492.

RADIATION ONCOLOGY IN THE USRADIATION ONCOLOGY IN THE US

Radiotherapy Trends: 1975-1990

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500

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1970 1975 1980 1985 1990 1995

Year

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Accelerators

Cobalt

RADIATION ONCOLOGY IN INDIARADIATION ONCOLOGY IN INDIA

• In India, it is estimated that over 1 million cancer cases are detected every year and a majority of them require radiotherapy at one time or other during their course of the treatment.

• In India as per IAEA figures, there are 218 radiotherapy centres with 354 teletherapy units as of year 2004.

• About 131 of these centres have brachytherapy facilities, either manual, remote or both.

• Also there are about 140 nuclear medicine centres in the country, of which 25 centres have facilities for treatment of cancer of thyroid

Break-up of Radiation Therapy Facilities in India:(during the period 1980 – 2004)

•Radiotherapy Centres in India: 218•Radionuclide Therapy Units: 283•Linear Accelerators: 71•Remote Afterloading LDR/MDR Units: 37•Remote Afterloading HDR Units: 45•Manual Afterloading Intracavitary Kits: 76•Manual Afterloading Interstitial Kits: 27•Radiotherapy Simulators: 40•Treatment Planning Systems: 80•Nuclear Medicine Centres: 140•Nuclear Medicine Therapy Centres: 25

Year-wise distribution of growth of radiation therapy facilities in India

CASE HISTORIES OF RADIATION CASE HISTORIES OF RADIATION ACCIDENTSACCIDENTS

Case 1:Case 1: Use of an incorrect decay Use of an incorrect decay curve for curve for 6060Co (USA, 1974-76)Co (USA, 1974-76)

Initial calibration of a Initial calibration of a 6060Co beam was correct, but ..Co beam was correct, but ..

• A decay curve for A decay curve for 6060Co was drawn: by mistake, the slope Co was drawn: by mistake, the slope was steeper than the real decay and the curve was steeper than the real decay and the curve underestimated the dose rate underestimated the dose rate

• Treatment times based on it were longer than Treatment times based on it were longer than appropriate, thus leading to overdoses, which increased appropriate, thus leading to overdoses, which increased with time reaching up to 50% when the error was with time reaching up to 50% when the error was discovereddiscovered

• There were no beam measurements in 22 months and a There were no beam measurements in 22 months and a total of total of 426 patients were affected426 patients were affected

• Of these 183 patients who survived one year, 34% had Of these 183 patients who survived one year, 34% had severe complicationssevere complications

Case 2: Incomplete understanding & Case 2: Incomplete understanding & testing of a treatment planning system testing of a treatment planning system (TPS) (TPS) (UK, 1982-90)(UK, 1982-90)• In a hospital, most of the treatments were with a SSD of 100 In a hospital, most of the treatments were with a SSD of 100

cmcm

• For treatments treatments with SSD different from standard For treatments treatments with SSD different from standard (100 cm), corrections for distance were usually done by the (100 cm), corrections for distance were usually done by the technologiststechnologists

• When a TPS was acquired, technologists continued to apply When a TPS was acquired, technologists continued to apply manual distance correction, without realising that the TPS manual distance correction, without realising that the TPS algorithm already accounted for distancealgorithm already accounted for distance

• As a result, distance correction was applied twice, As a result, distance correction was applied twice, leading to leading to under-dosage (up to 30%)under-dosage (up to 30%)

• The procedure was not written, and therefore, it was not The procedure was not written, and therefore, it was not modified when new TPS was usedmodified when new TPS was used

• Problem remained undiscovered during eight years and Problem remained undiscovered during eight years and affected 1,045 patients and affected 1,045 patients and 492 patients developed local 492 patients developed local recurrence probably due to the underexposurerecurrence probably due to the underexposure!!!!!!

Case 3: Untested change of Case 3: Untested change of procedure for data entry into TPS procedure for data entry into TPS (Panama, 2000)(Panama, 2000)

• A TPS allowed entry of four shielding blocks for isodose A TPS allowed entry of four shielding blocks for isodose calculations, one block at a timecalculations, one block at a time

• Need for five shielding blocks led to deviation from standard Need for five shielding blocks led to deviation from standard procedure for block data entry: several blocks were entered procedure for block data entry: several blocks were entered in one stepin one step

• Instructions for users had some ambiguity with respect to Instructions for users had some ambiguity with respect to shielding block data entryshielding block data entry

• TPS computer calculated treatment time, which was double TPS computer calculated treatment time, which was double the normal one (leading to 100% overdose)the normal one (leading to 100% overdose)

• There was no written procedure for the use of TPS, and There was no written procedure for the use of TPS, and therefore, a change of procedure was neither written nor therefore, a change of procedure was neither written nor tested for validitytested for validity

• Computer output was not checked for treatment time with Computer output was not checked for treatment time with manual calculationsmanual calculations

• The The error affected 28 patientserror affected 28 patients and one year after the and one year after the eventevent, , andand at least five had died from the overexposureat least five had died from the overexposure !!!!

Case 3:Case 3:

Colonoscopy of a Colonoscopy of a patient treated with patient treated with overdoses of 100% overdoses of 100% with:with:

• Necrotic tissueNecrotic tissue

• TelangiectasiaTelangiectasia

Case 4: Accelerator software problems Case 4: Accelerator software problems (USA & Canada, 1985-87)(USA & Canada, 1985-87)

• Software from an older accelerator design was used for a Software from an older accelerator design was used for a new, substantially different, design new, substantially different, design

• Software flaws were later identified in the software used to Software flaws were later identified in the software used to enter treatment parameters, such as type of radiation and enter treatment parameters, such as type of radiation and energyenergy

• Six accidental exposuresSix accidental exposures occurred in different hospitals occurred in different hospitals and and three patients died from overexposure!!three patients died from overexposure!!

Case 5: Reuse of outdated computer Case 5: Reuse of outdated computer file for file for 6060Co treatments (USA, 1987-88)Co treatments (USA, 1987-88)

• After source change, TPS computer files were updated…After source change, TPS computer files were updated…

• Except a computer file, which was no longer in use (this Except a computer file, which was no longer in use (this was intended for brain treatments with trimmer bars)was intended for brain treatments with trimmer bars)

• The computer file was not removed although no longer in The computer file was not removed although no longer in useuse

• A new radiation oncologist decided to treat with trimmer A new radiation oncologist decided to treat with trimmer bars and took the file corresponding to the prior bars and took the file corresponding to the prior 6060Co sourceCo source

• There was no double or manual check for dose calculationThere was no double or manual check for dose calculation

• 33 patients received 75% higher overexposure33 patients received 75% higher overexposure

Case 6: Incorrect accelerator repair & Case 6: Incorrect accelerator repair & communication problems (Spain, communication problems (Spain, 1990)1990)• Accelerator fault followed by an attempt to repair it by local Accelerator fault followed by an attempt to repair it by local

software firmsoftware firm

• Electron beam was restored but electron energy was misadjustedElectron beam was restored but electron energy was misadjusted

• Accelerator delivered 36 MeV electrons, regardless of energy Accelerator delivered 36 MeV electrons, regardless of energy selected selected

• Treatments resumed without notifying physicists for beam Treatments resumed without notifying physicists for beam checkschecks

• There was a discrepancy between energy displayed and energy There was a discrepancy between energy displayed and energy selected, and which was attributed to a faulty indicator, instead selected, and which was attributed to a faulty indicator, instead of investigating the reason for the discrepancyof investigating the reason for the discrepancy

• A total of A total of 27 patients were affected with massive 27 patients were affected with massive overdosesoverdoses and by distorted dose distribution due to wrong and by distorted dose distribution due to wrong electron energy of whom at least electron energy of whom at least 15 patients died15 patients died from the from the accidental overexposure and two more died with overexposure accidental overexposure and two more died with overexposure as major contributoras major contributor

Case 7: Malfunction of HDR Case 7: Malfunction of HDR brachytherapy equipment (USA, 1992)brachytherapy equipment (USA, 1992)

• HDR brachytherapy source detached from the driving HDR brachytherapy source detached from the driving mechanism while still inside the patientmechanism while still inside the patient

• While the console display indicated that the source was in While the console display indicated that the source was in retracted to the shielded position, an external radiation retracted to the shielded position, an external radiation monitor was indicating that there was radiation monitor was indicating that there was radiation

• Staff failed to investigate the discrepancy with available Staff failed to investigate the discrepancy with available portable monitor portable monitor

• The source remained in the patient for several days and the The source remained in the patient for several days and the patient died from overexposurepatient died from overexposure

Case 8: Beam miscalibration of Case 8: Beam miscalibration of 6060Co Co (Costa Rica, 1996)(Costa Rica, 1996)• Radioactive source of a teletherapy unit was exchangedRadioactive source of a teletherapy unit was exchanged

• During beam calibration, reading of the timer was confused, During beam calibration, reading of the timer was confused, leading to underestimation of the dose rateleading to underestimation of the dose rate

• Subsequent treatment times were calculated with the Subsequent treatment times were calculated with the wrong dose rate and were about 60% longer than required wrong dose rate and were about 60% longer than required

• 115 patients were affected115 patients were affected; two years after the event, at ; two years after the event, at least least 17 patients had died17 patients had died from the overexposure from the overexposure

Thus there was in this case……………………Thus there was in this case……………………

• Failure to perform independent calibrationFailure to perform independent calibration

• Failure to notice that treatment times were too long for a Failure to notice that treatment times were too long for a new source with higher activitynew source with higher activity

Child affected by overdoses to brain and spinal cord lost his ability to speak and walk

Further recent instances in the US (A study Further recent instances in the US (A study by the New York Times dated 24by the New York Times dated 24thth January January 2010)2010)

In a study of the number of radiation therapy accidents in the US In a study of the number of radiation therapy accidents in the US between 2000-2008, following instances were highlighted:between 2000-2008, following instances were highlighted:

October 2008 — Prostate Glands MisidentifiedOctober 2008 — Prostate Glands Misidentified: :

• Five prostate cancer patients were treated incorrectly after a Five prostate cancer patients were treated incorrectly after a faulty ultrasound machine misidentified their prostate glands. faulty ultrasound machine misidentified their prostate glands.

• One patient was irradiated incorrectly on 32 of 38 treatments; One patient was irradiated incorrectly on 32 of 38 treatments; another on 19 of 45 treatmentsanother on 19 of 45 treatments. After the ultrasound was . After the ultrasound was repaired, quality checks were performed by the vendor, and not repaired, quality checks were performed by the vendor, and not the consulting physics group that was servicing the facility. The the consulting physics group that was servicing the facility. The therapist warned the oncologist that the treatment position therapist warned the oncologist that the treatment position appeared incorrect, but nothing was done about it.appeared incorrect, but nothing was done about it.

June 2008 — Therapist Mistakes Treatment on Alternate DaysJune 2008 — Therapist Mistakes Treatment on Alternate Days: :

• A 63-year-old woman was to undergo two different A 63-year-old woman was to undergo two different treatments on alternate days — one to the upper lung and treatments on alternate days — one to the upper lung and the other to the mediastinum — an area in the chest. the other to the mediastinum — an area in the chest.

• But because of a therapist’s error, But because of a therapist’s error, her upper lung received her upper lung received one-tenth the prescribed dose and her mediastinum got 10 one-tenth the prescribed dose and her mediastinum got 10 times the prescribed dose. times the prescribed dose. The patient died of cancer later The patient died of cancer later in the yearin the year. .

• The hospital now requires two radiation therapists to attend The hospital now requires two radiation therapists to attend whenever a complex treatment plan is being delivered. The whenever a complex treatment plan is being delivered. The therapists must also use a checklist to verify the patient’s therapists must also use a checklist to verify the patient’s identity, the type of treatment, the dose and the site to be identity, the type of treatment, the dose and the site to be treated.treated.

December 2007 — Radioactive Seeds Implanted in Wrong December 2007 — Radioactive Seeds Implanted in Wrong LocationLocation: :

• A patient’s prostate cancer was underdosed by 50 percent A patient’s prostate cancer was underdosed by 50 percent — increasing the odds that cancer would recur — because a — increasing the odds that cancer would recur — because a doctor implanted radioactive seeds in the wrong location. doctor implanted radioactive seeds in the wrong location. Consequently, the rectum and urethra received more Consequently, the rectum and urethra received more radiation than intended. radiation than intended.

• Also the radiation oncologist then failed to promptly Also the radiation oncologist then failed to promptly interpret a post-implant CT scan, which would have interpret a post-implant CT scan, which would have revealed the error sooner.revealed the error sooner.

March 2007 — Radioactive Seeds Measured IncorrectlyMarch 2007 — Radioactive Seeds Measured Incorrectly: :

• A 31-year-old woman with vaginal cancer was overdosed A 31-year-old woman with vaginal cancer was overdosed because of confusion over the method of measuring the because of confusion over the method of measuring the strength of radioactive seeds. strength of radioactive seeds.

• The operator failed to enter the correct information into the The operator failed to enter the correct information into the treatment planning software, causing an overdose to her treatment planning software, causing an overdose to her rectum and vagina. rectum and vagina.

• The patient faced an The patient faced an increased risk of radiation cystitis, increased risk of radiation cystitis, rectal proctitisrectal proctitis, and the formation of a fistula between the , and the formation of a fistula between the rectum and the vagina. Neither the physicist nor the rectum and the vagina. Neither the physicist nor the radiation oncologist had prepared a treatment plan using radiation oncologist had prepared a treatment plan using iridium-192 — an isotope — in six years.iridium-192 — an isotope — in six years.

March 2006 — Wrong Patient Receives TreatmentMarch 2006 — Wrong Patient Receives Treatment: :

• Patient A had just completed treatment for a brain tumor Patient A had just completed treatment for a brain tumor received additional radiation intended for Patient B, who received additional radiation intended for Patient B, who had breast cancer. Patient A did not realize that treatment had breast cancer. Patient A did not realize that treatment had been completed when a therapist closed the patient’s had been completed when a therapist closed the patient’s electronic chart and pulled up the chart for Patient B. A electronic chart and pulled up the chart for Patient B. A second therapist arrived, saw the breast cancer treatment second therapist arrived, saw the breast cancer treatment had not been administered, and mistakenly administered it had not been administered, and mistakenly administered it to the first patient.to the first patient.

December 2005 — Therapist Overrides a Computer December 2005 — Therapist Overrides a Computer MalfunctionMalfunction: :

• A patient undergoing I.M.R.T. for prostate cancer was A patient undergoing I.M.R.T. for prostate cancer was irradiated incorrectly after a therapist overrode a computer irradiated incorrectly after a therapist overrode a computer malfunction. malfunction.

• After the guidance system froze, the therapist manually After the guidance system froze, the therapist manually entered co-ordinates but left out a negative sign, shifting entered co-ordinates but left out a negative sign, shifting the aim in the wrong direction. the aim in the wrong direction.

• Hospital policy required that a second therapist review the Hospital policy required that a second therapist review the data before treatment, but that was not done!!data before treatment, but that was not done!!

A Breast Cancer Patient who received massive A Breast Cancer Patient who received massive overdose to the chest wall resulting in sloughing off overdose to the chest wall resulting in sloughing off of the skin!!of the skin!!

New Delhi radiation accident, 1967New Delhi radiation accident, 1967

• Date:Date: May 1967 May 1967

• Location:Location: Safdarjang Hospital, New Delhi, India Safdarjang Hospital, New Delhi, India

• Type of event:Type of event: accidental exposure to source accidental exposure to source

• Description:Description: While replacing a Co-60 source in a While replacing a Co-60 source in a teletherapy unit, an employee received a localized radiation teletherapy unit, an employee received a localized radiation exposure of about 800 rads to the hand while pushing the exposure of about 800 rads to the hand while pushing the source into place. The employee noticed an immediate source into place. The employee noticed an immediate burning sensation but no other symptoms until 12 days burning sensation but no other symptoms until 12 days later, when burning pain and itching developed. A blistering later, when burning pain and itching developed. A blistering burn developed while the employee was hospitalized.burn developed while the employee was hospitalized.

• Consequences:Consequences: 1 injury. 1 injury.

India x-ray accident, 1974India x-ray accident, 1974

• Date:Date: 9 August 1974 9 August 1974

• Location:Location: India India

• Type of event:Type of event: x-ray accident x-ray accident

• Description:Description: A worker using an x-ray crystallography unit A worker using an x-ray crystallography unit was exposed to the x-ray beam. After returning from a was exposed to the x-ray beam. After returning from a lunch break, he operated the unit for 15 minutes before lunch break, he operated the unit for 15 minutes before realizing that one shutter was open, exposing his right realizing that one shutter was open, exposing his right forearm to the beam. A wound developed on the arm after forearm to the beam. A wound developed on the arm after 14 days which healed after 3 months, leaving a white scar. 14 days which healed after 3 months, leaving a white scar. Dose was on the order of 8,000-12,000 rads to the skin or Dose was on the order of 8,000-12,000 rads to the skin or more.more.

• Consequences:Consequences: 1 injury. 1 injury.

Mayapuri orphaned source, 2010Mayapuri orphaned source, 2010• A cobalt-60 source at a scrap metal shop in Mayapuri area of A cobalt-60 source at a scrap metal shop in Mayapuri area of

Delhi caused radiation injuries to several individuals. Delhi caused radiation injuries to several individuals. • The University of Delhi disposed off a Gammacell 220 The University of Delhi disposed off a Gammacell 220

research irradiator unused since 1985 which was auctioned research irradiator unused since 1985 which was auctioned on 26 February 2010 to a scrap metal dealer. By late March on 26 February 2010 to a scrap metal dealer. By late March the shop owner developed diarrhea followed by skin legions; the shop owner developed diarrhea followed by skin legions; and on 4 April was hospitalized with radiation sickness. and on 4 April was hospitalized with radiation sickness. Authorities found the source on 5 April. By 14 April a Authorities found the source on 5 April. By 14 April a total of 7 total of 7 people had been hospitalized with radiation injuriespeople had been hospitalized with radiation injuries. One . One person died on 26 April from multiple organ failure. Six person died on 26 April from multiple organ failure. Six individuals, including the owner of the scrap dealer shop, individuals, including the owner of the scrap dealer shop, remained hospitalized on 28 April at three hospitals; two remained hospitalized on 28 April at three hospitals; two individuals were in critical condition.individuals were in critical condition.

• Authorities recovered 8 sources at the original shop, two at a Authorities recovered 8 sources at the original shop, two at a nearby shop, and one from the dealer's wallet. India's Atomic nearby shop, and one from the dealer's wallet. India's Atomic Energy Regulatory Board announced on 28 April having traced Energy Regulatory Board announced on 28 April having traced the origin of the source to the University of Delhi. On 5 May the origin of the source to the University of Delhi. On 5 May the AERB stated that all material from the Gammacell unit the AERB stated that all material from the Gammacell unit was accounted for. Further cleanup of the scrap metal site in was accounted for. Further cleanup of the scrap metal site in Mayapuri was conducted 15-16 May.Mayapuri was conducted 15-16 May.

• Consequences:Consequences: 1 fatality, 7 injuries 1 fatality, 7 injuries

CLINICAL CONSEQUENCESCLINICAL CONSEQUENCES

Side effects and complications in Side effects and complications in radiotherapyradiotherapy

• Side effects are usually minor and transientSide effects are usually minor and transient– e.g : xerostomia and localised subcutaneous fibrosise.g : xerostomia and localised subcutaneous fibrosis– Relatively high frequency acceptable to achieve cureRelatively high frequency acceptable to achieve cure

• Complications are more severe and long lastingComplications are more severe and long lasting– e.g : radiation myelitise.g : radiation myelitis– Expected only at very low frequencyExpected only at very low frequency

Impact of accidental Impact of accidental underexposureunderexposure

• Accidental underdosage may jeopardise tumour control Accidental underdosage may jeopardise tumour control probabilityprobability

• They are difficult to discover, may only be detected after They are difficult to discover, may only be detected after relatively long time and, therefore, may involve a large relatively long time and, therefore, may involve a large number of patientsnumber of patients

Impact of overdoses on early (or acute) Impact of overdoses on early (or acute) complicationscomplications

• Usually observed in tissues with rapid cell turnover (skin, Usually observed in tissues with rapid cell turnover (skin, mucosa, bone marrow)mucosa, bone marrow)

• Overexposure may increase the frequency and severity (up Overexposure may increase the frequency and severity (up to necrosis)to necrosis)

Early (acute) complicationsEarly (acute) complications

• Determinant factors for acute complications are: Determinant factors for acute complications are: – 1) total delivered dose 1) total delivered dose – 2) total duration (protraction) 2) total duration (protraction) – 3) size and location of irradiated volume3) size and location of irradiated volume

• Little correlation of early complications with fraction size Little correlation of early complications with fraction size and dose rate (except if the latter is very high)and dose rate (except if the latter is very high)

Late complicationsLate complications• Mainly observed in tissues Mainly observed in tissues

with slowly proliferating cells with slowly proliferating cells (arteriolar narrowing which (arteriolar narrowing which occurs with a time delay)occurs with a time delay)

• Can also become manifest in Can also become manifest in rapidly proliferating cells (in rapidly proliferating cells (in addition to and after acute addition to and after acute effects) effects)

• Manifest more than six Manifest more than six months after irradiation and months after irradiation and even much latereven much later

• Usually irreversible and often Usually irreversible and often slowly progressiveslowly progressive

• Eg:- Picture showing case of Eg:- Picture showing case of eextensive fibrosis of the left xtensive fibrosis of the left groin with limitation of hip groin with limitation of hip motion as a result of motion as a result of accidental overexposureaccidental overexposure

Impact of overexposure on late Impact of overexposure on late complications complications

• Determinant factors: Determinant factors: – 1) total delivered dose1) total delivered dose– 2) fraction size and dose rate2) fraction size and dose rate

• In the case of accidental exposure, increased fraction size In the case of accidental exposure, increased fraction size may amplify the effects (as occurred in some accidents)may amplify the effects (as occurred in some accidents)

• In serial organs (spinal cord, intestine, large arteries), a In serial organs (spinal cord, intestine, large arteries), a lesion of small volume irradiated above threshold may lesion of small volume irradiated above threshold may cause major incapacity, for example paralysiscause major incapacity, for example paralysis

• In organs arranged in parallel (e.g. lung and liver), severity In organs arranged in parallel (e.g. lung and liver), severity is related to the tissue volume irradiated above threshold is related to the tissue volume irradiated above threshold

Clinical detection of accidental Clinical detection of accidental medical exposuremedical exposure

• Careful clinical follow-up may lead to detect accidental Careful clinical follow-up may lead to detect accidental overdose through early enhanced reactionsoverdose through early enhanced reactions

• Experienced radiation oncologists can detect overdoses of Experienced radiation oncologists can detect overdoses of 10 % during regular weekly consultations10 % during regular weekly consultations

• Some overdoses may cause late severe effects without Some overdoses may cause late severe effects without

abnormal early effects abnormal early effects

• In the case of unusual reactions in a single patient, other In the case of unusual reactions in a single patient, other patients treated in the same period may need to be patients treated in the same period may need to be recalledrecalled

Recommendations for Recommendations for PreventionPrevention

List of Recommendations for List of Recommendations for preventionprevention

• Overall preventive measure: a Quality Assurance Overall preventive measure: a Quality Assurance Programme, involvingProgramme, involving– OrganisationOrganisation– Education and trainingEducation and training– Acceptance testing and commissioning Acceptance testing and commissioning – Follow-up of equipment faultsFollow-up of equipment faults– CommunicationCommunication– Patient identification and patient chartsPatient identification and patient charts– Specific recommendations for teletherapySpecific recommendations for teletherapy– Specific recommendations for brachytherapySpecific recommendations for brachytherapy

Quality Assurance Programme for Quality Assurance Programme for Radiation Therapy (QART)Radiation Therapy (QART)

• Quality assurance programmes have evolved from Quality assurance programmes have evolved from equipment verifications to include the entire process, from equipment verifications to include the entire process, from the prescription to delivery and post treatment follow-up the prescription to delivery and post treatment follow-up

• Major accidental exposures occurred in the absence of Major accidental exposures occurred in the absence of written procedures and checks (QART); either because a written procedures and checks (QART); either because a QART did not exist or it was not fully implemented (checks QART did not exist or it was not fully implemented (checks omitted)omitted)

OrganizationOrganization

• Comprehensive QAComprehensive QA

Is crucial in prevention and involve clinical, physical and Is crucial in prevention and involve clinical, physical and safety components.safety components.

• QA implementation requiresQA implementation requires– complex multi-professional team workcomplex multi-professional team work– clear allocation of functions and responsibilitiesclear allocation of functions and responsibilities– functions and responsibilities understoodfunctions and responsibilities understood– number of qualified staff, commensurate to workloadnumber of qualified staff, commensurate to workload

Education and trainingEducation and training

• The most important component of QA is qualified The most important component of QA is qualified personnel, including radiation oncologists, medical personnel, including radiation oncologists, medical physicists, technologists and maintenance engineers physicists, technologists and maintenance engineers

• Comprehensive education together with specific training on Comprehensive education together with specific training on – procedures and responsibilities procedures and responsibilities – everyone’s role in the QART programmeeveryone’s role in the QART programme– lessons from typical accidents with a description of lessons from typical accidents with a description of

methods for preventionmethods for prevention– additional training when new equipment and techniques additional training when new equipment and techniques

are being introducedare being introduced

Acceptance testing & Acceptance testing & commissioningcommissioning

• Errors in these phases may affect many patientsErrors in these phases may affect many patients

• Acceptance testing:Acceptance testing:– Should include test of safety interlocks, verification of Should include test of safety interlocks, verification of

equipment specifications, as well as understanding and equipment specifications, as well as understanding and testing TPS testing TPS

• Commissioning: Commissioning: – Should includes measuring and entering all basic data Should includes measuring and entering all basic data

for future treatments into computerfor future treatments into computer

• Systematic acceptance and commissioning, including a Systematic acceptance and commissioning, including a cross check and independent verification, form a major part cross check and independent verification, form a major part of accident preventionof accident prevention

Follow-up on equipment faultsFollow-up on equipment faults

• Experience has shown that some equipment Experience has shown that some equipment faults are difficult to isolate and to correctfaults are difficult to isolate and to correct

• If an equipment fault or malfunction has not been If an equipment fault or malfunction has not been fully understood and corrected, there is a need fully understood and corrected, there is a need for for – communication and follow-up with communication and follow-up with

manufacturermanufacturer– dissemination of information and experience to dissemination of information and experience to

other maintenance engineersother maintenance engineers

Communication and repairsCommunication and repairs

• Need for a written communication policy, Need for a written communication policy, including: including: – Reporting of unusual equipment behaviour Reporting of unusual equipment behaviour – Notification to the physicist and clearance by Notification to the physicist and clearance by

before resuming treatments (because of before resuming treatments (because of possible need for control checks after repairs)possible need for control checks after repairs)

– Reporting of unusual patient reactionsReporting of unusual patient reactions

Patient identification and patient Patient identification and patient chartchart

• Effective patient identification procedures and Effective patient identification procedures and treatment charts (consideration of photographs treatment charts (consideration of photographs for identification …)for identification …)

• Double check of chart data at the beginning of Double check of chart data at the beginning of treatment, before changes in the course of treatment, before changes in the course of treatment (for example, a new field) and once a treatment (for example, a new field) and once a week at leastweek at least

Specific items for external beam Specific items for external beam therapytherapy

• CalibrationCalibration– Provisions for initial beam calibration and follow-Provisions for initial beam calibration and follow-

up calibrationsup calibrations– Independent verification of the calibrationIndependent verification of the calibration– Following an accepted protocolFollowing an accepted protocol– Participation in dose quality auditsParticipation in dose quality audits

• Treatment planning Treatment planning – Include TPS in the programme of acceptance Include TPS in the programme of acceptance

testing commissioning and quality assurancetesting commissioning and quality assurance– Cross-checks and manual verificationCross-checks and manual verification

• Adequate in-vivo dosimetry would prevent most Adequate in-vivo dosimetry would prevent most accidental exposuresaccidental exposures

Specific items for brachytherapySpecific items for brachytherapy

• Provisions for checking source activity and source Provisions for checking source activity and source identification before useidentification before use

• Dose calculation and treatment planningDose calculation and treatment planning

– Provisions for dose calculation and cross-Provisions for dose calculation and cross-checkschecks

• Source positioning and source removalSource positioning and source removal– Provisions to verify source positionProvisions to verify source position– Provisions to ensure that sources do not Provisions to ensure that sources do not

remain in the patient (including monitoring remain in the patient (including monitoring patients and clothes)patients and clothes)

Summary………Summary………

• Radiotherapy has unique features from the point Radiotherapy has unique features from the point of view of the potential for accidental exposureof view of the potential for accidental exposure

• Consequences of accidental exposure can be very Consequences of accidental exposure can be very severe and affect many patientssevere and affect many patients

• Careful clinical follow up may detect overdoses Careful clinical follow up may detect overdoses from about 10%from about 10%

• A quality assurance programme is the key A quality assurance programme is the key element in prevention of accidental exposureelement in prevention of accidental exposure