Clinical Radiation Safety.pdf

8/20/2019 Clinical Radiation Safety.pdf

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CLINICAL RADIATION SAFETY



PATIENT HANDLING AND

PROTECTION STANDARDS



1. A patient has just undergone an oralradiotherapy and will be staying in thehospital for 2 days. How can the hospitalsafely transfer the patient to his/her room?

What should be the precautions of thehospital to prevent contamination?



HOW TO SAFELY TRANSPORT THEPATIENT ?

• Transport the patient by the most direct route.

• The patient shall not be left in public waiting areasor corridors. If necessary the transporter shall

remain in the area to keep other people at least 6feet from the patient.

•

When transporting the patient, do not shareelevators with other staff or patients.



PRECAUTIONS TO PREVENTCONTAMINATION

•

The patient is restricted to his/her room where the walls haveproper shielding.

• The patient must use disposable eating utensils. Theseutensils should be placead in the special waste container afteruse.

•

The patient should flush the toilet two or three times aftereach use. This will insure that all radioactive urine is washedfrom the toilet bowl.

•

Both male and female patients must sit down on the toilet to

prevent urine splatter.• Adult family visitors are encouraged but avoid physical contact

with visitors.

• The floor should be covered with plastic.



2. A patient was implanted with 192Ir and will be staying in the hospital for one nightafter the operation. What are theprotection standards that the nurses and

hospital staff should observe?



PROTECTION STANDARDS TO BEOBSERVED

•

The nurses should not stay at the patient’s room after doingnecessary care to to the patient.

•

There should be a specific “stay times” posted at the patient’sdoor.

•

Housekeeping can only enter the room when escorted by anurse.

• The laundry should be placed in a linen bag and be saveduntil surveyed and released by the radiation oncologist.

• Visitors should be above 18 years old and should not bepregnant.

•

Visitors should be 6 feet away from the patient and should notstay for more than 2 hours.

• A radiation survey must be performed before the patient is

discharged.



OPTIMIZATION OF RADIATION

THERAPY



3. Head-and –Neck Cancer was the case of one

patient in the hospital, treatment planningcame with the Neurosurgeons, RadiationOncologist, and medical Physicist. What istheir objective in creating a treatment plan?



GOAL IN DESIGNING A TREATMENTPLAN

The objective is simply to deliver a prescribeddose to targets while sparing, to the greatestextent possible, critical structures.



4. A study had eight cases of head and neck cancer.Two beam arrangements were placed in the treatmentplanning system, the B/L and the A-P fields. TheDVH’s for the cord does were recorded and compared

in both plans with a standard fraction size of 200cGy/fraction. The results showed that in the A-Parrangement 168.06cGy was the mean dose to thespinal cord whereas only 133.75cGy only in the B/L

arrangement. What are the possible effects for suchdoses? What can you conclude given the results?



• Delivering a high dose to the spinal cord is the samething as cutting it down

• The A-P field arrangement delivered a higher dose

compared to the B/L hence, there is a need to sparethe cord at an earlier dose limit.



RADIATION THERAPY

• External-Beam Radiation Therapy

• Intensity-modulated radiation therapy (IMRT)

• Image-guided radiation therapy

•

Tomotherapy• Stereotactic radiosurgery

• Stereotactic body radiation therapy

• Proton therapy

•

Other charged particle beams

• Internal Radiation Therapy (Brachytherapy)

•

Systemic Radiation Therapy



5.

A patient comes in and complains of a sore throat

that has been on for 4 weeks, and is experiencingpain when swallowing. After evaluating the patient’smedical history, physical examination and tests havebeen run, the doctor diagnoses the patient as having

Oropharyngeal cancer. Radiation Oncologists,Medical Physicists, Medical Dosimetrists convenefor the patient’s treatment planning. What areconsiderations in such planning and what doesoptimization have to do with the treatmentplanning?



WHEN A RADIOTHERAPY TREATMENTIS CREATED

• Physician provides prescription dose

•

Treatment planner chooses incident beam directions

•

Determines radiation fields

• Calculates final dose distribution

•

Physician reviews/approves the plan

Treatment plans can be of different strengths of weaknesses and it is thephysician’s goal to choose the best possible treatment that will provide theneeded dose to the tissue/organ whilst sparing other healthy tissues and

organs around it’s vicinity.



MEDICAL EQUIPMENTMAINTENANCE



6. A radiation technician is about to commence

a linearity test for their dose calibrator using a 50mCi Tc-99m source (half life is 6 hours). Thetechnician started at 8am, and recorded thereadings in regular intervals. The recorded

activity was plotted against time, but the graphlooked scattered and not linear at all. Whatpossible reasons could explain this?



WHAT COULD’VE HAPPENED?

• Loss of battery voltage on the chamber

• Pressure leak from the chamber

• Temperature changes in the chamber due to

environmental conditions (change in heat or air-conditioning systems)

• Operator / human error



7. A radiation technician forgot to set-up the

collimators for their clinic’s gamma camera. Hefailed to notice this and continued to use thegamma camera on a patient for diagnosticpurposes. What would happen?



WHAT WOULD HAPPEN?

The Images will be blurry.



TREATMENT VENUE

SPECIFICATIONS & STRATEGIES



8. A female patient was treated for thyroidcarcinoma. After a few hours ofradioiodine administration, it was foundthat she was 3 weeks pregnant. What can

happen? What should be done?



The dose will endanger the development of thefetus. To reduce the risks, advise the patient to

drink lots of water and urinate frequently.



9. After performing the daily warm-up routines

for their linear accelerator, a radiation therapistprepares the treatment for a breast cancerpatient. What should be done if the patient has ahistory of twitching and restlessness?



A mold should be prepared for the patient sothat she will stay still during treatment.



REFERENCES

•

https://rpop.iaea.org/RPOP/RPoP/Content/SpecialGroups/1_PregnantWomen/PregnancyNuclearMedicine.htm

•

https://www.mskcc.org/cancer-care/patient-education/radiation-therapy-breast-chest-wall

•

http://www.nuclearfields.com/collimators-nuclear-medicince.htm

•

http://www.biodex.com/sites/default/files/documents/tips/tip-dose-calibrator-linearity-testing-14194.pdf

•

http://web.stanford.edu/dept/EHS/prod/researchlab/radlaser/Hospital_Guidance_document.pdf

•

http://www.ucalgary.ca/rop/node/174

•

http://gray.mgh.harvard.edu/attachments/article/166/166_lecture0_intro.pdf



CLINICAL RADIATION SAFETY

ALCANTARA. JIMENEZ. MUNGCAL

Clinical Radiation Safety.pdf

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