Whole-Body PET/CT Studies with Lowered 18F-FDG Doses: The Influence of Body Mass Index in Dose Reduction

Abstract

BMI-calculated doses, which are often lower than strictly weight-based doses, can be administered while maintaining acquisition times. This dose reduction is not only consistent with the as-low-as-reasonably-achievable principle but can be performed without diminishing diagnostic accuracy and should lead to lower dose to staff and potential economic savings.

Optimisation of BMI-based Images for Overweight and Obese Patients – Implications on Image Quality, Quantitative Accuracy and Radiation Dose in Whole Body 18F-FDG PET/CT Imaging.

“…Similar trends and magnitude in radiation dose reduction were reported in previous studies [18][19][20]28]. to improve image quality either by varying the administered dose [16,[18][19][20]28] or adjusting time per bed position [13,16,17] and/or using the OSEM-TOF-PSF or other reconstruction methods as provided by the manufacturer [21][22][23]. Our approach aimed to improve both image quality and quantitative accuracy of 18 F-FDG PET whole body images; acquired using the BMI-based injected activity approach to keep radiation dose low for these categories of patients.…”

“…The optimised BMI-based images lower radiation dose by approximately 59% in overweight and 51% in obese patients compare to BW-based injected activity, as was also reported in previous studies [16,[18][19][20]28]. The reduction in radiation dose helps in keeping with the ALARA principle (i.e.…”

“…The reduction in radiation dose helps in keeping with the ALARA principle (i.e. radiation doses are kept as low as reasonably achievable) and results in lower radiation doses to staff as it was also reported in reference [19].…”

“…The results showed (BMI to BW) that image quality was better in 59% of the cases with a 95% reduction in radiation dose. In a study published by Sánchez-Jurado et al [19], the administered 18 F-FDG dose can be greatly reduced using the BMI-based approach compared to the BW-based approach without diminishing image quality in two groups of patients (180 BW and 180 BMI-based scans). This study shows a higher image quality in the BMI group at approximately double the rate in the BW group.…”

A JAFROC study of nodule detection performance in CT images of a thorax acquired during PET/CT

“…5 Patient dose associated with PET/CT can be very high, and a high proportion of the dose is due to the diagnostic quality (DQ) CT examination. Recent technological improvements, notably time of flight (TOF), 6,7 have been implemented to enable the superior spatial resolution of modern PET/CT systems, and along with a strategy of calculating weight based injected activity [8][9][10] it has resulted in reduced radiation dose, with a preference to increase emission time rather than injected activity for obese patients. 6 Early reports of radiation dose in PET/CT, combining 18 F-FDG with DQ CT could produce effective dose in the range of 24-46 mSv.…”