Patients Receiving Radioimmunotherapy Must Practice Radiation Safety Precautions

SAN DIEGO—Lead aprons, radiation badges, and patient laundry are not the normal concerns of nurses. But as new radioimmunotherapy agents are evaluated and introduced into practice, nurses will need to familiarize themselves with radiation safety precautions, said Patricia A. Kramer, RN, MSN, a San Francisco-based oncology nurse educator and consultant. Patient education and instruction throughout the whole process is key.

Speaking at a Cure for Lymphoma Foundation Symposium at the Oncology Nursing Society’s 26th Annual Congress, Ms. Kramer reviewed issues involved in the administration of I-131 tositumomab (Bexxar^™), a radiolabeled monoclonal antibody under review by the FDA for the treatment of non-Hodgkin’s lymphoma. Tositumomab emits beta and gamma radiation. Gamma radiation has a half-life of 8 days.

Administering tositumomab requires strict radiation safety procedures and may require overnight hospitalization because the patient is radioactive.

"The radiation safety procedures we need to familiarize ourselves with when using this agent have to do with utilizing the principles of time, distance, and shielding," Ms. Kramer said. Decreasing one’s time spent with a patient receiving tositumomab will decrease one’s radiation exposure. Increasing distance from a patient will also decrease radiation exposure, she said.

Radiation precautions, as outlined below, should be observed for 1 week, she said. Patients need to maintain a distance of approximately 6 feet from other people whenever possible.

All staff need to wear monitoring badges to monitor their radiation exposure and lead aprons when coming into contact with radioimmunotherapy patients. The aprons will absorb up to 99% of radiation, she said, but pregnant nurses cannot work with these patients. Special rooms must also be designated within the institution for administration of radiolabeled antibodies.

A recent change in the standards set by the Nuclear Regulatory Commission makes it possible in some cases for patients to receive radioimmunotherapy as outpatients. The new discharge criteria are dose-based, determined by patient-specific calculations or the use of a default table.

Making Discharge Decisions

The distance required between the patient and others for 1 week after radioimmunotherapy rules out a patient driving a long distance after treatment with someone in a car or flying in a plane. The fact that a patient might have a 4- to 6-hour car ride home with someone else might be a reason for the hospital radiation safety officer to keep the patient in the hospital. The hospital radiation safety officer or radiation team has ultimate responsibility for making these discharge decisions, she said.

Patient precautions include separate bedrooms and sole use of a bathroom if possible. Men should sit when they urinate. When finished, they should close the lid and flush twice.

Patients also need to use separate towels, washcloths and toiletries. They should wash their hands frequently, shower daily, keep themselves well hydrated, keep dishes and utensils separate, and wash the dishes separately.

Clothing and linen should be put in a bag and kept separate for a week, then laundered separately. Patients should not have any sexual contact and should minimize time in public places.

Those receiving radioimmunotherapy with tositumomab require treatment with potassium iodine to protect their thyroid from uptake of iodine. Potassium iodine treatment starts before the patient gets the first tracer dose for dosimetry and continues for 14 days after the therapeutic dose. "This is a very big patient education issue for compliance," Ms. Kramer noted.

Ibritumomab tiuxetan (Zevalin^™) is another radiolabeled monoclonal antibody under FDA review. It contains ytrrium 90, a beta emitter. Beta travels only a small distance in the body. Its half-life is 2.7 days, and radiation precautions are less strict than with tositumomab. There are no limitations on activities or interactions with others, but for 1 week, precautions must be observed when handling the body secretions (sweat, saliva, blood, urine, and stool) of a patient who has had an infusion of ibritumomab.

As with tositumomab, patients receiving ibritumomab should wash well with soap and water, and wash items that come into contact with body fluids immediately. Patients should use separate utensils and wash them separately. Male patients should sit when urinating and flush twice with a closed lid.

The dose-limiting toxicity of radioimmunotherapy is myelosuppression. For 3 months after administration, patients will need to be carefully monitored with weekly blood counts and appropriate support.

The most frequent nonhematologic toxicities include transient fever and chills during administration and a range of usually mild symptoms. Serious adverse events are rare, Ms. Kramer said.

"The nursing implications of managing patients receiving these kinds of new therapies are tremendous," she said. "Their ability to comprehend and comply depends on the collaborative efforts of many, and, as always, nurses play an integral role."