Diagnostic reference levels for
            18
            F‐
            FDG
            whole body
            PET
            /
            CT
            procedures: Results from a survey of 12 centres in Australia and New Zealand

Background In the assessment of diseases causing skeletal lesions such as multiple myeloma (MM), whole-body low-dose computed tomography (WBLDCT) is a sensitive diagnostic imaging modality, which has the potential to replace the conventional radiographic survey. Purpose To optimize radiation protection and examine radiation exposure, and effective and organ doses of WBLDCT using different modern dual-source CT (DSCT) devices, and to establish local diagnostic reference levels (DRL). Material and Methods In this retrospective study, 281 WBLDCT scans of 232 patients performed between January 2017 and April 2020 either on a second- (A) or third-generation (B) DSCT device could be included. Radiation exposure indices and organ and effective doses were calculated using a commercially available automated dose-tracking software based on Monte-Carlo simulation techniques. Results The radiation exposure indices and effective doses were distributed as follows (median, interquartile range): (A) second-generation DSCT: volume-weighted CT dose index (CTDIvol) 1.78 mGy (1.47–2.17 mGy); dose length product (DLP) 282.8 mGy·cm (224.6–319.4 mGy·cm), effective dose (ED) 1.87 mSv (1.61–2.17 mSv) and (B) third-generation DSCT: CTDIvol 0.56 mGy (0.47–0.67 mGy), DLP 92.0 mGy·cm (73.7–107.6 mGy·cm), ED 0.61 mSv (0.52–0.69 mSv). Radiation exposure indices and effective and organ doses were significantly lower with third-generation DSCT ( P < 0.001). Local DRLs could be set for CTDIvol at 0.75 mGy and DLP at 120 mGy·cm. Conclusion Third-generation DSCT requires significantly lower radiation dose for WBLDCT than second-generation DSCT and has an effective dose below reported doses for radiographic skeletal surveys. To ensure radiation protection, DRLs regarding WBLDCT are required, where our locally determined values may help as benchmarks.

Download Full-text

The 2020 national diagnostic reference levels for nuclear medicine in Japan

Annals of Nuclear Medicine ◽

10.1007/s12149-020-01512-4 ◽

2020 ◽

Vol 34 (11) ◽

pp. 799-806

Author(s):

Koichiro Abe ◽

Makoto Hosono ◽

Takayuki Igarashi ◽

Takashi Iimori ◽

Masanobu Ishiguro ◽

...

Keyword(s):

Computed Tomography ◽

Nuclear Medicine ◽

Radiation Dose ◽

Single Photon ◽

Photon Emission ◽

Emission Computed Tomography ◽

Diagnostic Reference Levels ◽

Reference Levels ◽

Positron Emission ◽

Pet Ct

Abstract The diagnostic reference levels (DRLs) are one of several effective tools for optimizing nuclear medicine examinations and reducing patient exposure. With the advances in imaging technology and alterations of examination protocols, the DRLs must be reviewed periodically. The first DRLs in Japan were established in 2015, and since 5 years have passed, it is time to review and revise the DRLs. We conducted a survey to investigate the administered activities of radiopharmaceuticals and the radiation doses of computed tomography (CT) in hybrid CT accompanied by single photon emission computed tomography (SPECT)/CT and positron emission tomography (PET)/CT. We distributed a Web-based survey to 915 nuclear medicine facilities throughout Japan and survey responses were provided by 256 nuclear medicine facilities (response rate 28%). We asked for the facility's median actual administered activity and median radiation dose of hybrid CT when SPECT/CT or PET/CT was performed for patients with standard habitus in the standard protocol of the facility for each nuclear medicine examination. We determined the new DRLs based on the 75th percentile referring to the 2015 DRLs, drug package inserts, and updated guidelines. The 2020 DRLs are almost the same as the 2015 DRLs, but for the relatively long-lived radionuclides, the DRLs are set low due to the changes in the Japanese delivery system. There are no items set higher than the previous values. Although the DRLs determined this time are roughly equivalent to the DRLs used in the US, overall they tend to be higher than the European DRLs. The DRLs of the radiation dose of CT in hybrid CT vary widely depending on each imaging site and the purpose of the examination.

Download Full-text

Determining and updating PET/CT and SPECT/CT diagnostic reference levels: A systematic review

Radiation Protection Dosimetry ◽

10.1093/rpd/ncy113 ◽

2018 ◽

Vol 182 (4) ◽

pp. 532-545 ◽

Cited By ~ 7

Author(s):

Essam M Alkhybari ◽

Mark F McEntee ◽

Patrick C Brennan ◽

Kathy P Willowson ◽

Peter Hogg ◽

...

Keyword(s):

Systematic Review ◽

Diagnostic Reference Levels ◽

Reference Levels ◽

Pet Ct

Download Full-text

Optimization of Whole-Body CT Examinations of Polytrauma Patients in Comparison with the Current Diagnostic Reference Levels

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren ◽

10.1055/a-0881-3113 ◽

2019 ◽

Vol 191 (11) ◽

pp. 1015-1025

Author(s):

Stefan B. Schäfer ◽

Claudia Rudolph ◽

Martin Kolodziej ◽

Frank Mauermann ◽

Fritz Christian Roller ◽

...

Keyword(s):

Image Quality ◽

Visual Assessment ◽

Whole Body ◽

Dose Optimization ◽

Diagnostic Reference Levels ◽

Reference Levels ◽

Whole Body Ct ◽

Before And After ◽

The Mean ◽

Body Ct

Purpose Evaluation of the dose values of a polytrauma whole-body CT examination used in clinical practice with regard to the 2016 updated diagnostic reference levels and reduction of the mean exposure levels using simple optimization steps. Materials and Methods In each case, 100 exposure values before and after dose optimization were compared with the old and new diagnostic reference levels. The grayscale values and the signal-to-noise ratio (SNR) were determined for the lung, the aortic arch and the liver. A visual assessment of the image quality was performed by two radiologists on the basis of a Likert scale (0 – non-diagnostic, 1 – poor visualization, 2 – moderate visualization, 3 – good visualization, 4 – excellent visualization) for CT examinations both before and after optimization. Results The acquired exposure values after dose optimization were below the old and new diagnostic reference levels (1319.98 ± 463.16 mGy · cm) while the mean value of the exposure values before optimization (1774.96 ± 608.78 mGy · cm) exceeded the current diagnostic reference levels. The measured grayscale values (HU) were (before versus after optimization): lung – 833 HU vs. – 827 HU (p = 0.43), aortic arch 341 HU vs. 343 HU (p = 0.70) and liver 68 HU vs. 67 HU (p = 0.35). After dose optimization the SNR in the lung was minimally higher, while it was minimally lower in the two other regions than before the optimization. Visual assessment of the image quality showed almost identical values with 3.85 evaluation points before and 3.82 evaluation points after dose optimization (p = 0.57). Conclusion Due to the updating of the diagnostic reference levels, an analysis of the own exposure values is necessary in order to be able to detect high values promptly and to initiate appropriate measures for dose reduction. Appropriate adaptation of the examination parameters with consideration of the necessary image quality allows a significant reduction of the radiation exposure in most cases, also on CT devices of older generations. Key Points: Citation Format

Download Full-text

PET/CT

Nuklearmedizin ◽

10.1055/s-0038-1625216 ◽

2005 ◽

Vol 44 (S 01) ◽

pp. S51-S57 ◽

Cited By ~ 12

Author(s):

T. Beyer ◽

G. Brix

Keyword(s):

Diagnostic Accuracy ◽

Radiation Exposure ◽

Dose Reduction ◽

Pet Imaging ◽

Clinical Studies ◽

Review Article ◽

Whole Body ◽

High Radiation ◽

Radiation Burden ◽

Pet Ct

Summary:Clinical studies demonstrate a gain in diagnostic accuracy by employing combined PET/CT instead of separate CT and PET imaging. However, whole-body PET/CT examinations result in a comparatively high radiation burden to patients and thus require a proper justification and optimization to avoid repeated exposure or over-exposure of patients. This review article summarizes relevant data concerning radiation exposure of patients resulting from the different components of a combined PET/CT examination and presents different imaging strategies that can help to balance the diagnostic needs and the radiation protection requirements. In addition various dose reduction measures are discussed, some of which can be adopted from CT practice, while others mandate modifications to the existing hardand software of PET/CT systems.

Download Full-text