Radiation exposure in the environment of patients after application of radiopharmaceuticals
| Autor: | W. Eschner, Carsten Kobe, Harald Schicha, Jochen Hammes, F. Boldt, F. Sudbrock |
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| Rok vydání: | 2009 |
| Předmět: | |
| Zdroj: | Nuklearmedizin. 48:17-25 |
| ISSN: | 2567-6407 0029-5566 |
| DOI: | 10.3413/nukmed-0193 |
| Popis: | Summary Aim: After therapeutical application of radionuclides the patient has to be regarded as a radioactive source. The radiation exposure differs from diagnostic nuclear medicine due to the amount of radioactivity and due to β-radiation. Measurements of photon dose rates were carried out and estimates of β-radiation outside the patient using Monte-Carlo methods. Calculations of maximum β-ranges in tissue were also performed. Detailed knowledge of the radiation exposure close to the patient is of major importance with respect to radiation protection of the staff. Method: Photon dose rates for 32 patients were determined after treatment with [131I]NaI and [131I]meta-iodobenzylguanidin, [32P]Na2HPO4, [90Y]Zevalin and [153Sm]EDTMP. Readings were taken immediately after application at eight distances. Results: For therapies with 131I photon dose rates amount to 2 mSv·h-1·GBq-1 close to the patient. Taking the typical activities of 3.7 GBq for thyroid carcinoma and up to 11 GBq for mIBG therapies into account this leads to a considerable radiation exposure of approximately 7.5 mSv/h and 20 mSv/h, respectively. At a distance of 2 m the dose rates fall to 1/100 compared to the vicinity. For 153Sm the maximum of 100 μSv·h-1·GBq-1 is significantly lower compared to therapies using radioiodine. After application of 32P or 90Y all photon dose rates are lower (>10 μSv·h-1·GBq-1) but in both cases high energy β-particles associated with high maximum ranges exceeding 1 cm in tissue have to be considered. Conclusion: The remarkable difference of the dose rates in the vicinity of the radioactive patient compared to readings at 2 m distance underlines the major importance of the distance for radiation protection. After application of nuclides emitting high energy β-particles their contribution outside the patient should be considered. For typical procedures in the patient's vicinty the radiation exposure of the personnel remains below the annual limit of 20 mSv. |
| Databáze: | OpenAIRE |
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