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Quantitative measurement of 219Rn radioactivity in exhaled breath from patients with bone metastasis of castration-resistant prostate cancer treated with 223RaCl2.
- Source :
- EJNMMI Physics; 7/26/2019, Vol. 6 Issue 1, pN.PAG-N.PAG, 1p
- Publication Year :
- 2019
-
Abstract
- Background: The α-emitting radionuclide radium-223 (<superscript>223</superscript>Ra) is widely used for the treatment of bone metastasis in patients with castration-resistant prostate cancer. However, <superscript>223</superscript>Ra decays into radon-219 (<superscript>219</superscript>Rn) which is a noble-gas isotope, and <superscript>219</superscript>Rn may escape from patients treated with <superscript>223</superscript>Ra via their respiration. In this study, we quantified the amount of <superscript>219</superscript>Rn contained in the breath of patients treated with <superscript>223</superscript>Ra to estimate its effect on the internal exposure dose of caregivers. Methods: A total of 12 breath samples were collected using a breath collection bag from a total of six patients treated with <superscript>223</superscript>RaCl<subscript>2</subscript>. Approximately 300 mL of exhaled breath was collected in a breath bag at 1 min and at 5 min after the start of <superscript>223</superscript>RaCl<subscript>2</subscript> administration. The contents of each bag were measured using an HPGe detector, and the amount of <superscript>219</superscript>Rn was quantified based on the detection of the γ peak of <superscript>211</superscript>Bi, which is a descendant nuclide of <superscript>219</superscript>Rn, persisting in the breath bag. The effective dose to caregivers arising from the inhalation of <superscript>219</superscript>Rn was estimated by referring to the scenario for the calculation of release criteria established for <superscript>131</superscript>I therapy in Japan. Results: A small peak for the 351-keV γ ray of <superscript>211</superscript>Bi originating from the exhalation of <superscript>219</superscript>Rn was observed. Using the observed γ peak of <superscript>211</superscript>Bi, the average amounts of <superscript>219</superscript>Rn per unit breath volume at 1 min and 5 min after the start of <superscript>223</superscript>RaCl<subscript>2</subscript> administration were calculated as 90 ± 56 Bq/mL and 28 ± 9 Bq/mL, respectively. The effective dose of <superscript>219</superscript>Rn to caregivers was estimated to be 3.5 μSv per injection. Conclusions: The amount of <superscript>219</superscript>Rn in the exhaled breath of patients treated with <superscript>223</superscript>RaCl<subscript>2</subscript> was quantitatively calculated using breath collection bags. The internal radiation exposure of caregivers from <superscript>219</superscript>Rn in the exhaled breath of patients treated with <superscript>223</superscript>RaCl<subscript>2</subscript> is relatively small. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 21977364
- Volume :
- 6
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- EJNMMI Physics
- Publication Type :
- Academic Journal
- Accession number :
- 137721446
- Full Text :
- https://doi.org/10.1186/s40658-019-0249-8