Renal disease

An Australian local diagnostic reference level for paediatric whole-body 18F-FDG PET/CT

OBJECTIVE:

The aim of this study is to report a local diagnostic reference level (DRL) for paediatric whole-body (WB) fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) CT examinations.

METHODS:

The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) national DRL (NDRL) age category (0-4 years and 5-14 years), the International Commission on Radiological Protection age category (ICRP age) (<1, >1-5, >5-10, and >10-15 years), and European guideline weight category ( EG weight) (<5, 5-<15, 15-<30, 30-<50, and 50-<80 kg) were used to determine a local DRL for WB ¹⁸F FDG PET/CT studies. Two-structured questionnaires were designed to collect dose data, patient demographics, equipment details, and acquisition protocols for WB ¹⁸F-FDG PET/CT procedures. The local DRL was based on the median ¹⁸F-FDG administered activity (MBq), dose-length product (DLP), and the CT dose index volume (CTDI_vol), values. The effective dose (E) was also calculated and reported.

RESULTS:

The local DRLs for ¹⁸F-FDG administered activity, CTDI_vol and DLP values based on ARPANSA age and ICRP age were increased from lower to higher age categories. For the EG weight category, the local DRL for ¹⁸F-FDG administered activity, CTDI_vol and DLP values were increased from the low EG weight category to the high EG weight category. The mean administered activity in our study based on ICRP age category >1-5, >5-10, and >10-15 years is 79.97, 119.40, and 176.04 MBq, which is lower than the mean administered activity reported in the North American Consensus guideline published in 2010 (99, 166, and 286 MBq) and European Association of Nuclear Medicine and Dosage Card (version 1.5.2008) (120, 189, and 302 MBq). However, the mean administered activity in our study based on ICRP age category <1 year was 55 MBq compared to the EANM Dosage card (version 1.5.2008) (70 MBq) and the NACG 2010 (51 MBq). Our study shows that the finding for ICRP age category <1 year was similar to the NACG 2010 value.

CONCLUSION:

The determined local DRL values for the radiation doses associated with WB ¹⁸F FDG PET/CT examinations are differed considerably between the ARPANSA and ICRP age category and EG weight category. Although, the determined ¹⁸F-FDG value for ICRP < 1 year is in good agreement with available publish data, it is preferable to optimise the ¹⁸F-FDG administered activity while preserving the diagnostic image quality.

ADVANCES IN KNOWLEDGE:

The local DRL value determined from WB ¹⁸F-FDG PET/CT examinations may help to establish the ARPANSA NDRL for WB FDG ¹⁸F-PET/CT examinations.

Evaluation of Nephroprotective Efficacy of Hypoxic Preconditioning in Patients Undergoing Coronary Artery Bypass Surgery

BACKGROUND

Nonpulsatile blood flow plays an important role in the pathogenesis of renal dysfunction in patients with extracorporeal circulation. In our opinion, hypoxic preconditioning (HP) can be used to protect kidneys from postsurgical dysfunction. The aim of this study was to evaluate nephroprotective efficacy of HP in myocardial revascularization with extracorporeal circulation.

METHODS

The randomized, controlled trial was performed in 63 patients undergoing coronary artery bypass grafting (CABG). Thirty-three patients were subjected to HP during CABG; 30 patients were included in the comparison group. All patients underwent dynamic renal scintigraphy with (99m)Тc-diethylenetriaminepentaacetic acid and were subjected to measuring the concentration of lipocalin in blood serum before and after CABG.

RESULTS

After CABG, the mean values of the total glomerular filtration rate (GFR) and GFR for each kidney significantly decreased only in patients of the comparison group. Significant increases in the concentration of serum neutrophil gelatinase-associated lipocalin occurred 5 h after surgery both in the group with HP (70.65 ± 46.71 to 127.58 ± 98.46 ng/ml) and in the comparison group (65.01 ± 38.64 to 171.65 ± 89.91 ng/ml). At the same time, the mean difference values between pre- and postoperative lipocalin levels were 56.94 ± 51.75 ng/ml in the study group and 106.64 ± 51.27 ng/ml in the comparison group; these differences were highly statistically significant (р = 0.004).

CONCLUSION

The results of our study showed that (i) HP exerts nephroprotection in patients undergoing on-pump CABG, and (ii) determination of the lipocalin-2 level can be used for early diagnosis of acute kidney injury in cardiac surgery patients.