radiation protection in radiotherapy part 16 discharge of patients iaea training material on...
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Radiation Protection inRadiation Protection inRadiotherapyRadiotherapy
Part 16Part 16
Discharge of PatientsDischarge of Patients
IAEA Training Material on Radiation Protection in Radiotherapy
Part 16: Discharge of patients 2Radiation Protection in Radiotherapy
Discharge of patientsDischarge of patients
From a radiation safety perspective an issue...
If patients are discharged with radioactive sources remaining in the patient after a temporary implant - this is a severe accident
If a permanent radioactive implants are in place - others need to know about it
If the patient has been treated with unsealed radioactive isotopes (e.g. 131-I, 89-Sr) - NOT subject of this course but covered in the companion course on nuclear medicine
Part 16: Discharge of patients 3Radiation Protection in Radiotherapy
Advice from BSS appendix II.28. Advice from BSS appendix II.28. ““In order to restrict the exposure of any In order to restrict the exposure of any
members of the household of a patient who members of the household of a patient who has undergone a therapeutic procedure with has undergone a therapeutic procedure with sealed or unsealed radionuclides and sealed or unsealed radionuclides and members of the public, such a patient shall members of the public, such a patient shall not be discharged from hospital before the not be discharged from hospital before the activity of radioactive substances in the body activity of radioactive substances in the body falls below the level specifiedfalls below the level specified in Schedule III, in Schedule III, Table III-VI. Written instructions to the patient Table III-VI. Written instructions to the patient concerning contact with other persons and concerning contact with other persons and relevant precautions for radiation protection relevant precautions for radiation protection shall be provided as necessary”.shall be provided as necessary”.
Part 16: Discharge of patients 4Radiation Protection in Radiotherapy
ObjectivesObjectives
To appreciate the need for checks of patients To appreciate the need for checks of patients before discharge after radioactive implantsbefore discharge after radioactive implants
To understand the need to impose limit To understand the need to impose limit values for the discharge of patientvalues for the discharge of patient
To be familiar with the conditions for To be familiar with the conditions for discharge of patients with radioactive discharge of patients with radioactive implantsimplants
To be able to provide patients, clinicians and To be able to provide patients, clinicians and others with advice regarding the radiation others with advice regarding the radiation safety of the implant.safety of the implant.
Part 16: Discharge of patients 5Radiation Protection in Radiotherapy
ContentContent
1. Monitoring of patients after temporary 1. Monitoring of patients after temporary implantsimplants
2. Discharge rules for patients with 2. Discharge rules for patients with permanent implantspermanent implants
3. Information for persons in contact with 3. Information for persons in contact with patients who are discharged with patients who are discharged with permanent implantspermanent implants
Part 16: Discharge of patients 6Radiation Protection in Radiotherapy
1. Monitoring of patients after 1. Monitoring of patients after temporary implantstemporary implants If the implant is temporary, one MUST If the implant is temporary, one MUST
ensure that all sources are removed ensure that all sources are removed from the patient prior to dischargefrom the patient prior to discharge
This applies to all isotopes and all types This applies to all isotopes and all types of implants including HDR and LDR of implants including HDR and LDR remote afterloadingremote afterloading
All brachytherapy patients should be All brachytherapy patients should be monitored before dischargemonitored before discharge
Part 16: Discharge of patients 7Radiation Protection in Radiotherapy
Measurement objectiveMeasurement objective
Dose rate at 1m distance from the Dose rate at 1m distance from the patientpatient
1m
Part 16: Discharge of patients 8Radiation Protection in Radiotherapy
Potential for severe accidentsPotential for severe accidents
An example due to equipment design:An example due to equipment design: Sources were dislodged from the drive mechanism of Sources were dislodged from the drive mechanism of
an HDR remote afterloading machine and remained an HDR remote afterloading machine and remained in the patient; she died from radiationin the patient; she died from radiation
There were many contributing factors, such as:There were many contributing factors, such as: Equipment seemed not sufficiently testedEquipment seemed not sufficiently tested Conflicting signals of indicator for source positionConflicting signals of indicator for source position History of malfunction of a detectorHistory of malfunction of a detector
However, in any case the accident could have However, in any case the accident could have been prevented if appropriate patient monitoring been prevented if appropriate patient monitoring would have been in placewould have been in place
Part 16: Discharge of patients 9Radiation Protection in Radiotherapy
What needs to be established:What needs to be established:
Appropriate procedures in writingAppropriate procedures in writing An appropriately trained medical physicist An appropriately trained medical physicist
and/or RSO must be involved in the treatmentand/or RSO must be involved in the treatment A monitor at the door of brachytherapy A monitor at the door of brachytherapy
treatment rooms in the ward should be treatment rooms in the ward should be availableavailable
A portable radiation monitor available for A portable radiation monitor available for check of the patient prior to dischargecheck of the patient prior to discharge
Part 16: Discharge of patients 10Radiation Protection in Radiotherapy
Appropriate monitoringAppropriate monitoring
Requires trained Requires trained personalpersonal
Knowledge of the Knowledge of the sources usedsources used
Knowledge of the Knowledge of the implant typeimplant type
Radioactivesource
Part 16: Discharge of patients 11Radiation Protection in Radiotherapy
Brachytherapy with sealed sourcesBrachytherapy with sealed sources
Area monitor helps to Area monitor helps to monitor presence of monitor presence of radioactive sourcesradioactive sources
Typically there is no Typically there is no hazard from hazard from contamination of linen contamination of linen (however, for seed (however, for seed implants watch for lost implants watch for lost seeds) seeds)
Part 16: Discharge of patients 12Radiation Protection in Radiotherapy
2. Permanent radioactive implants2. Permanent radioactive implants
Short half life: 198-Au seedsShort half life: 198-Au seeds Most common: 125-I seed for Most common: 125-I seed for
prostate implantsprostate implants Increasingly popular: 103-Pd Increasingly popular: 103-Pd
(palladium) seeds for prostate (palladium) seeds for prostate implantsimplants
(Not considered here: radioactive (Not considered here: radioactive stents for prevention of restenosis in stents for prevention of restenosis in blood vessels (typically 32-P))blood vessels (typically 32-P))
Mentor
Part 16: Discharge of patients 13Radiation Protection in Radiotherapy
Characteristics of the isotopesCharacteristics of the isotopes
198-Au 125-I 103-Pd
T1/2 (d) 2.7 60 17
Mean/max gamma energy (keV)
420/680 28/35 20/480
Typical form seed seed seed
HVL (cm of water) 4 0.02 1.6
Part 16: Discharge of patients 14Radiation Protection in Radiotherapy
Risks:Risks: Dislocation of sourcesDislocation of sources Irradiation of other persons in contact Irradiation of other persons in contact
with the patientwith the patient Irradiation of persons in case of a Irradiation of persons in case of a
medical emergency involving the patientmedical emergency involving the patient Irradiation of persons after the patient’s Irradiation of persons after the patient’s
deathdeath
Part 16: Discharge of patients 16Radiation Protection in Radiotherapy
IAEA BSS (1996) App. II.28IAEA BSS (1996) App. II.28 BSS Schedule III, Table III-VI: Guidance level BSS Schedule III, Table III-VI: Guidance level
only given for 131-I: Maximum activity for only given for 131-I: Maximum activity for discharge 1100MBqdischarge 1100MBq
Other isotopes not mentionedOther isotopes not mentioned Legal limit values are stillLegal limit values are still
applicableapplicable
Part 16: Discharge of patients 17Radiation Protection in Radiotherapy
Legal limit valuesLegal limit values
May vary from state to stateMay vary from state to state May not be available for the isotope of May not be available for the isotope of
interest…interest… However, limit values should be However, limit values should be
established by each facility using established by each facility using professional judgement if no regulatory professional judgement if no regulatory guidance is availableguidance is available
Part 16: Discharge of patients 18Radiation Protection in Radiotherapy
Maximum activities of radionuclides at which patients may be dischargedfrom hospitals (adapted from NHMRC 1984). Please note that these limitvalues are guidelines only - they may need to be modified to suit localconditions and the life style of individual patients.
Isotope Typical application Maximum activity atdischarge (MBq)
32-P Systemic injection 120090-Y Local injection 1200125-I Seed permanent implant No limit131-I Systemic injection 600198-Au Seed permanent implant 200089-Sr Systemic injection 300
Example for limit values in AustraliaExample for limit values in Australia
Part 16: Discharge of patients 19Radiation Protection in Radiotherapy
Discharge rulesDischarge rules
In addition to the limit values for activity In addition to the limit values for activity within the patient other discharge rules within the patient other discharge rules may be established. Examples are:may be established. Examples are: Maximum dose rate at different distances Maximum dose rate at different distances
of the patientof the patient Likelihood of dislocation of sourcesLikelihood of dislocation of sources Consideration of the performance and Consideration of the performance and
mental status of the patientmental status of the patient
Part 16: Discharge of patients 20Radiation Protection in Radiotherapy
A set of typical discharge rules:A set of typical discharge rules: A patient shall not be discharged if it seems likely that a sealed
source (125-I, 198-Au) may become dislocated and lost. Patients treated with Co-60, Cs-137 or Ir-192 shall not be
discharged from hospital until the sources have been removed. A patient shall not be discharged if leakage from an unsealed
source is likely. It is assumed that patients who are discharged with incorporated
radioactive substances do not use public transport for more thanone hour to avoid long exposures of others.
Special precautions and advice must be given to female patientswho breast feed their babies. In particular radioactive iodine maybe excreted in breast milk and breast feeding mothers should onlybe treated with radioactive material in emergency situations.
Part 16: Discharge of patients 21Radiation Protection in Radiotherapy
3. Advice to patients:3. Advice to patients: IAEA BSS (1996) App. II.28:IAEA BSS (1996) App. II.28: ““Written instructions to the patient concerning Written instructions to the patient concerning
contact with other persons and relevant contact with other persons and relevant precautions for radiation protection shall be precautions for radiation protection shall be provided as necessary.”provided as necessary.”
Part 16: Discharge of patients 22Radiation Protection in Radiotherapy
Advice to patients:Advice to patients: Must be in writingMust be in writing Easy to understandEasy to understand May require translation in other May require translation in other
languageslanguages Should be discussed with the patientShould be discussed with the patient Should contain contact details for Should contain contact details for
clinical and radiation protection staffclinical and radiation protection staff
Part 16: Discharge of patients 23Radiation Protection in Radiotherapy
Advice on the implantAdvice on the implant
May be also provided to relatives and May be also provided to relatives and carerscarers
May be also provided to referring May be also provided to referring clinicianclinician
Information should be carried by the Information should be carried by the patient at all timespatient at all times
Part 16: Discharge of patients 24Radiation Protection in Radiotherapy
Advice to patientsAdvice to patients Describe the implant purposeDescribe the implant purpose Advice on precautions:Advice on precautions:
e.g.e.g. after 125-I seed implant in the prostate after 125-I seed implant in the prostate urinate through a strainer for a couple of urinate through a strainer for a couple of days to catch all dislocated sourcesdays to catch all dislocated sources
Any restrictions for contact: Any restrictions for contact: e.g.e.g. go not stay in the vicinity of pregnant go not stay in the vicinity of pregnant
women for an extended period of time women for an extended period of time (best specify the time)(best specify the time)
Part 16: Discharge of patients 25Radiation Protection in Radiotherapy
Advice to others who may be in Advice to others who may be in contact with the patientcontact with the patient RelativesRelatives FriendsFriends CarersCarers Referring cliniciansReferring clinicians
Part 16: Discharge of patients 26Radiation Protection in Radiotherapy
Also consider:Also consider:
What happens if the patient requires What happens if the patient requires emergency treatment?emergency treatment? Surgery?Surgery?
What happens if the patient dies? What happens if the patient dies? Autopsies?Autopsies? Cremation?Cremation?
Part 16: Discharge of patients 27Radiation Protection in Radiotherapy
Also consider:Also consider:
What happens if the patient requires What happens if the patient requires emergency treatment?emergency treatment? Surgery?Surgery?
What happens if the patient dies? What happens if the patient dies? Autopsies?Autopsies? Cremation?Cremation?
In practice this depends onmany factors - it is best to
involve the responsible medical physicist or RSO in
the procedure for advice
Part 16: Discharge of patients 28Radiation Protection in Radiotherapy
Emergency surgery, autopsies, Emergency surgery, autopsies, cremationcremation Must involve a radiation expertMust involve a radiation expert Therefore it is essential thatTherefore it is essential that
the patient can be identified as having a the patient can be identified as having a radioactive implantradioactive implant
it is possible for others to contact someone it is possible for others to contact someone who knows the radiation details of the who knows the radiation details of the implantimplant
Part 16: Discharge of patients 29Radiation Protection in Radiotherapy
Identification of patient who have Identification of patient who have a permanent implanta permanent implant Patient and relatives must know about itPatient and relatives must know about it Patient should carry relevant Patient should carry relevant
information (implant type, isotope, information (implant type, isotope, activity, date of implant, contact details) activity, date of implant, contact details) with him/her at all times:with him/her at all times: wristbandwristband card in walletcard in wallet
Part 16: Discharge of patients 30Radiation Protection in Radiotherapy
SummarySummary It is essential to monitor patients prior to It is essential to monitor patients prior to
discharge after they had received a discharge after they had received a temporary brachytherapy implanttemporary brachytherapy implant
There are recommended limit values for the There are recommended limit values for the implanted activity above which patients implanted activity above which patients should not be discharged from hospital. should not be discharged from hospital.
Written discharge rules should be established Written discharge rules should be established for patients with permanent implants which for patients with permanent implants which include limit values for activities in the patientinclude limit values for activities in the patient
Written advice must be provided to patients Written advice must be provided to patients with permanent implantswith permanent implants
Part 16: Discharge of patients 31Radiation Protection in Radiotherapy
Where to Get More InformationWhere to Get More Information
Parts 6 and 11Parts 6 and 11 References: NRCP 37References: NRCP 37
Any questions?Any questions?
Question:Question:
What information would you look for in an What information would you look for in an information sheet handed out to a patient information sheet handed out to a patient after a radioactive implant using 198-Au after a radioactive implant using 198-Au
seeds of a half life of 2.7 days?seeds of a half life of 2.7 days?
Part 16: Discharge of patients 34Radiation Protection in Radiotherapy
Information requiredInformation required Description of the implant including isotope, half life Description of the implant including isotope, half life
and estimated activityand estimated activity Treating clinician and/or other persons who could Treating clinician and/or other persons who could
provide more details on the implantprovide more details on the implant Contact in case of emergencyContact in case of emergency Advice on appropriate precautions: Advice on appropriate precautions: e.g.e.g. Do avoid Do avoid
contact with pregnant women and children for … dayscontact with pregnant women and children for … days Advice on appropriate actions if a source becomes Advice on appropriate actions if a source becomes
dislodgeddislodged A note to make sure other clinicians or health A note to make sure other clinicians or health
professionals are informed about the nature of the professionals are informed about the nature of the implant if they are in contact with the patient within the implant if they are in contact with the patient within the next … daysnext … days