Measurement of Iodine-131 Contamination in a Nuclear Medicine Department

Nuclear medicine is the medical specialty using radioactive isotopes for research, diagnosis & treatment of sick tissues & organs. Due to the exposure of patients & health personnel to unsealed radioisotopes, resorting to nuclear medicine is not without risk. And yet, every year, thousands of patients suffering from tumors, cancers, & bone pains resulting from cancer, are treated with iodine-131, whose dose is variable depending on the type of intervention to perform & the body part to examine. As it is a fission product, the risk of accidental release & contamination of the surrounding environment, is extremely feared. To stick to the ALARA principle (As Low as Reasonably Achievable), the Health Physics Department of the CaenNormandie University Hospital Center (CHU) thus decided to provide oneself with Bertin Technologies’ alpha & beta contamination meter SaphyRAD C.

Testimony

In this case study, an iodine 131 capsule was taken by a patient to treat his cancer of thyroid.

As a therapeutic agent, the radioactive iodine is indeed detected by the thyroid cells, in which it masses & radiates, thus
destroying them.

Following iodine 131 intake, the patient regurgitated the drug, thus causing instant fluid contamination on the floor’ surface. In order to decontaminate the soiled area, the alpha & beta contamination meter SaphyRAD C was used to search for the slightest trace of contamination on the floor.

Thanks to the device’s ease of use & ergonomic design, the operator was able to control a large surface by taking a direct measure & hence to decontaminate the area with the appropriate cleaning agents.

Material

To control the radioactive contamination of a soiled surface, a SaphyRAD C device equipped with a A/B100 probe was used by the Radiation Protection Department of the CaenNormandie University Hospital Center.

Being medium-sized, the A/B100 probe has 2 measurement channels – 1 for α, 1 for β – allowing for an effective alpha/beta discrimination. To take a direct measure, the 131I radionuclide was selected beforehand: this sensitivity being stored in the device’s memory, a reliable measurement was therefore conducted from the probe’s first passages.

A/B100 probe

Characteristics of the A/B100 probe

  • Surface of detection: 100 cm²

Sensitivity

  • α: 0.14 c/s/Bq (241Am)
  • β: 0.23 c/s/Bq (36Cl)

Measurement range

  • α: from 0.01 to 100 Bq/cm²
  • β: from 0.1 to 1,000 Bq/cm²

There are two visual indicators on the probe: one to trigger the alarm, the other to signal the correct distance for a fast & efficient control.

A/B100 probe

Customer

Health Physics Department Mr. Yannick Tancray CHU

Conclusion

Designed by Bertin Technologies, the alpha & beta contamination meter SaphyRAD C was able to efficiently fulfil the needs of direct measurement expressed by the Radiation Protection Department of the Caen-Normandie University Hospital Center, France. Thanks to the large surface A/B100 probe, the risk of accidental release & contamination of the surrounding environment was avoided, with the utmost respect for the ALARA principle. The reactivity, reliability & ergonomic design of the device allow the operators to react quickly to instant radioactive contamination.


Measurement of Iodine-131 Contamination in a Nuclear Medecine Department

saphyrad