Radiation exposure of patients and personnel from a PET/CT procedure with 18F-FDG

Abstract

The positron emission tomography (PET)/computed tomography (CT) camera is a combination of a PET camera and a CT. The image from the PET camera is based on the detection of radiation that is emitted from a radioactive tracer, which has been given to the patient as an intravenous injection. The radiation that is emitted from the radioactive tracer is more energetic than any other radiation used in medical diagnostic procedures and this requires special radiation protection routines. The CT image is based on the detection of radiation produced from an X-ray tube and transmitted through the patient. The radiation exposure of the personnel during the CT procedure is generally very low. Regarding radiation exposure of the patient, it is important to notice whether a CT scan has been performed prior to the PET/CT in order to avoid any unnecessary irradiation. The total effective dose to the patient from a PET/CT procedure is approximately 10 mSv. The major part comes from internal irradiation due to radiopharmaceuticals within the patients (e.g. (18)F-FDG: approximately 6-7 mSv), and a minor part is due to the CT scan (low-dose CT scan: approximately 2-4 mSv). If a full diagnostic CT investigation is performed, the effective dose may be considerably higher. If the patient is pregnant, a PET/CT procedure should be avoided or postponed, unless it is vital for the patient. An interruption in breastfeeding is not necessary after a PET/CT procedure of the nursing mother. Close contact between the patient and a small child should however be avoided for a couple of hours after the administration of the radiopharmaceutical. The radiation dose to the personnel arises mainly due to handling of the radiopharmaceuticals (syringe withdrawal, injection, waste handling, etc.) and from close contact to the patient. This radiation dose can be limited by using the inverse-square law, i.e. by using the fact that the absorbed dose decreases substantially with increasing distance between the radiation source and the personnel.

Positron emission tomography imaging approaches for external beam radiation therapies: current status and future developments

“…The average dose burden for whole-body PET/CT using 18 F-FDG for adults is reported as 10-32 mSv, although this is dependent on many variables including the radioactivity of the injected radioisotope, the CT protocol used, and hardware/software optimisations [6][7][8]. Four-dimensional (4D) scans (i.e.…”

Impacto en el ámbito comunitario de una instalación de tomografía por emisión de positrones-tomografía computada (PET/CT)

“…Debido al constante incremento del uso de técnicas de imagen, la dosis recibida por los pacientes que debe ser tenida en cuenta como elemento de juicio en la justificación de los estudios, ha sido objeto de extensiva consideración en la literatura, particularmente en forma de recomendaciones internacionales 3,4 . Los trabajadores profesionalmente expuestos están en el mismo caso 3,4,6 , pero aún no había sido abordado un enfoque desde el punto de vista del impacto comunitario .…”

“…Los trabajadores profesionalmente expuestos están en el mismo caso 3,4,6 , pero aún no había sido abordado un enfoque desde el punto de vista del impacto comunitario .…”

“…A diferencia de otras actividades sanitarias, la medicina nuclear, particularmente la tomografía por emisión de positrones, es creadora de una serie de posibles riesgos externos bien conocidos asociados al uso de isótopos radiactivos 3,4 . Consideraremos que otro tipo de efectos, como los derivados de residuos sanitarios o posible contaminación biológica, son pequeños y están controlados dentro de la unidad.…”

Mapping Radiation Injury and Recovery in Bone Marrow Using 18F-FLT PET/CT and USPIO MRI in a Rat Model

“…Although medical imaging is at the forefront of early diagnosis of disease and patient triaging, imaging is not yet an integrated tool in emergency preparedness plans in response to a nuclear disaster (3). In this article, we address this issue by making use of 39-deoxy-39- 18 F-fluorothymidine ( 18 F-FLT) PET/CT and ultra-small superparamagnetic iron oxide (USPIO) MRI in a rat model of whole-and partial-body radiation exposure to measure BM proliferation and vascular damage as surrogates for mapping the amount of body exposed and the anatomic region irradiated. BM occupies interstices within the bones distributed throughout the entire skeleton and is one of the most proliferative and radiosensitive organs in the body, with a highly vascularized network of thin-walled, fenestrated sinusoidal endothelial cells (4).…”