Impact of methodical guidelines of gastric scintigraphy on patients’ radiation exposure

Summary

Introduction: Gastric emptying scintigraphy (GES) is a safe, noninvasive method for assessing the ability of the stomach to empty which has been used clinically for many years. It is considered as a “gold standard” to assess gastric emptying of both solids and liquids allowing assessment of early, mid and late emptying, each of which may be altered by pathology. The aim of the study was to analyse standard dia­gnostic approach and evaluate patients` radiation exposure, who underwent GES in Slovakia. Methods: A retrospective cohort study included 55 patients from 2 departments of nuclear medicine (department A, B). Patients’ radiation exposure was determined by dosimetry program IDAC-Dose2.1. The radiopharmaceutical <sup>99m</sup>Tc-DTPA, always with the same activity, was applied orally to patients at Department B. The applied activity of the radiopharmaceutical at GES was 185 MBq. The radiopharmaceutical <sup>99m</sup>Tc MAA, with various activity, was applied orally to patients at Department A. Results: According to ICRP60, the effective dose (ED) of every patient undergoing GES was 0.77 mSv and, according to ICRP103, the dose was 0.836 mSv at Department B. Patients at Department A were exposed to ionizing radiation with 5-times lower intensity, compared with patients at Department B. It was caused by radiopharmaceutical activity correction. The ED medians according to ICRP60, and according to ICRP103 were 0.167 mSv (range 0.105–0.208 mSv) and 0.181 mSv (range 0.113–0.226 mSv) at Department A, respectively. Discussion: Adequate correction of applied radiopharmaceutical activity is an essential part of GES guidelines and in accordance with ALARA principles. For the accuracy of GES examination, it is necessary to follow a standard 4-hour protocol and an approach which ensures full-featured utilization of the examination while decreasing patient`s radiation exposure. Conclusion: The results of our study show relatively low ED associated with GES, but also confirm that the GES methodology significantly affects the patient`s radiation exposure.

Conflict of Interest: The authors declare that the article/ manuscript complies with ethical standards, patient anonymity has been respected, and they state that they have no financial, advisory or other commercial interests in relation to the subject matter.

Publication Ethics: This article/ manuscript has not been published or is currently being submitted for another review. The authors agree to publish their name and e-mail in the published article/ manuscript.

Dedication: The article/ manuscript is not supported by a grant nor has it been created with the support of any company.

The Editorial Board declares that the manuscript met the ICMJE “uniform requirements” for bio­medical papers.

Keywords:

effective dose – gastric emptying – nuclear medicine – Radiation exposure – scintigraphy