Introduction

Treatment with radioactive is the most commonly used method not only to treat cancer-related diseases but also used as palliative measures in managing cancer patients.

As in general, these radioactive materials will be prescribed to patients either via oral or intravenous injection. However, in some circumstances these radioactive materials will be directly placed within body cavities. Example of this is the use of ¹³¹I in treating hyperthyroidism related diseases or thyroid cancer, and the use of ⁸⁹Sr and ³²P as palliative management in the case of bone metastasis. The choice of selection of these radioactive materials in medicine therapy relies on its ability to emit beta particles, where tissue penetration is low, relative half-life and the biochemical reactions are appropriate. An ideal half-life would range from few hours to several days.The Beta particles emitted should have edequate energy to transfer to various tissues. If this radioactive material is able to emit characteristic gamma rays and X-rays simultaneously, the nuclear medicine imaging can easily be obtained. These emitted beta particles that has very low tissue penetration capabilities may indirectly has deposited its maximum energy collectively to the patient and destroy the identified cancer cells.However the degree of damages to healthy cell is still very low. The basis for an effective radioactive treatment is the activeness of a given radioactive material and its prolonged retention within cancer cells.

From ionizing radiation security point of view, these beta radiation is only limited within patient and the amount of radiation emanating from patients to public is kept to minimum.

Types of Radioactive Material Used in Treatment

There are various types of radioactive commonly used in treating patients in the field of nuclear medicine as listed in tables 1. In general, these radioactives will be given to patient as indicated.

Table 1: Radioactive used in treatment

Source : IAEA, 2009

1. Type of radioactive and its amount to be used
2. The treatment period and the date of treatment to be carried out
3. Advice on radiation safety during treatment
4. Additional advice on radiation safety after treatment.

Exposure of ionizing radiation from patients to publics can occur in the following ways:

1. Gamma rays emmiting out from patient’s body to air
2. Indoor pollution caused by waste products or gusts
3. Radioactive directly from patients

Advice from Radiation Safety Aspects While Undergoing Treatment

• Special Treatment ¹³¹I

  Patients undergoing treatment for more than 1100 MBq of ¹³¹I must be hospitalised in a special room for safety reason from ionizing radiation. However, if patient receives less than 1100 MBq of ¹³¹ I, they are not obliged to be hospitalised, but must comply with the advice on Safety Aspects of Radiation after treatment. Patients are kept hospitalised for 2-5 days depending on several factors, including availability of special room and patient’s general health.

  1. Use cloths that is provided
  2. flush of 2-3 times after use of toilet.
  3. use the toilet bowl if you feel like vomiting, and flush for 2-3 times
  4. If patient vomits on cloths, immediately clean the dirts in the toilet and isolate those dirty cloths
  5. Upon discharge, place the radiation contaminated clothes, bedsheets and pillowcases into the linen basket for easy isolation process.
  6. Patients are encouraged to change new attire every after bathing.

   

• For radioactive ⁸⁹Sr, ⁹⁰Y, ¹⁷⁷Lu, ¹⁵³Sm and ¹⁸⁸Re.

  Management of waste material from patient’s body must be compliance with radiation principles such as radiation safety;

  1. Flushing of toilets at least 2-3 times after use.
  2. Patients undergoing treatment are required to be hospitalised within 1 -2 days depending on their condition.

Advice on Safety Aspects of Radiation After treatment

In general, to minimize impact of radiation from patients, here are some recommendations and guidelines for of patients undergoing treatment with ¹³¹I gamma (additional of 3-5 days after completed treatment depends on the amount of radioactive taken by the patient).

1. Patients are advised to drive alone when returning home (if patient comes alone)
2. If invited, they shall seat at the back of the driver on left side (farthest distance)
3. Patients are advised to tell family members that only one person is allowed to pick up patients after treatment
4. If taking public transporte, it is suggested to take place or farthest distance from other passengers
5. Patient can take normal diet when at home.
6. It is recommended to drink plenty of water to remove the residual of 131I that is still in the body
7. Use separate bathroom if possible
8. Flush the toilet 2-3 times after use
9. Discouraged to have direct contact with infants, children and pregnant women
10. Appropriate communication distance is at least a meter away
11. Sleep separately
12. Avoid oneself from attending any parties/ crowds

Female patients are advised not to be pregnant within a given period depending on the type of radioactive material used.

References

1. https://rpop.iaea.org/RPOP/RPoP/Content/InformationFor/HealthProfessionals/3_NuclearMedicine/TherapeuticNuclearMedicine/Therapeutic_nuclear_medicine_-_specific_therapies.htm#NM_SpecTherFAQ10
2. http://hps.org/publicinformation/ate/faqs/nuclearmedicinetherapy.html
3. Luster, M. et al., 2007. Thyroid cancer in childhood: management strategy, including dosimetry and long-term results. Hormones (Athens, Greece), 6(4), pp.269–278.
4. Release Of Patients After Radionuclide Therapy (Safety Reports Series No. 63), IAEA, 2009