The Current State of Nuclear Nephrology in Modern Medicine.

Glomerular filtration rate (GFR) is the most reliable parameter of renal function. Regarding the complexity of the gold standard inulin clearance, different estimating equations have been developed with CKD-EPI creatinine equation recommended as the most reliable one. In some clinical situations where creatinine based equations might not be valid, alternative methods are needed. Nuclear medicine methods for measuring GFR with 51Cr EDTA and 99mTc DTPA have been widely used for decades. There are different methodologies for the measurement of kidney function with radiopharmaceuticals: urinary clearance, plasma clearance, multiple plasma sampling, slope intercept, single sample plasma equation, slope only, and the gamma camera-based method. Greater precision of measuring GFR is needed in certain clinical situations. The most common are diagnosis and follow up of chronic kidney disease and definition of the beginning of replacement therapy. The assessment of renal function is also important for potential kidney donors. In recent years, with the introduction of new chemotherapeutic drugs and targeted therapy, oncologic patients treated with nephrotoxic drugs have become more commonly referred for measuring GFR. The monitoring of renal function is important during treatment in order to detect the transformation from reversible acute kidney injury to irreversible chronic kidney disease as well as in the cases of renal insufficiency reduce the dosage and prevent accumulation of the drug and avoid dosage related toxic effects. Assessment of kidney function using measured mGFR will be an important milestone in the creation of more accurate and expanding personalized medicine principle in current onconephrology practice.

Comparative analysis of different nuclear medicine techniques in evaluation of renal function.

INTRODUCTION: Nuclear medicine (NM) methods play an important role in the evaluation of renal function in a wide range of clinical indications. The aim of our study was to evaluate the correlation between measured GFR (mGFR) obtained by the three-plasma sample slope-intercept NM method (TPSM) - reference method vs. estimated GFR (eGFR) using Fleming's single plasma sample method (SPSM) at 120 min, 180 min, and 240 min and correlation of reference method with eGFR with camera-based Gates' protocol. MATERIAL AND METHODS: A total of 82 subjects (33 male/49 female) with a mean age of 54.87 ± 15.65 years were included and mGFR value was obtained by the three-plasma sample slope-intercept NM method and eGFR was obtained with Fleming's single sample method. eGFR was also quantified with the camera-based Gates' protocol after i.v. application of [99mTc]Tc-DTPA. RESULTS: Our study revealed a very strong positive significant correlation between all three SPSMs with the TPSM as the reference method. Between the Gates' method and the TPSM in the group of patients with mGFR ≥ 61-84 mL/min/1.73 m2 and mGFR ≥ 84 mL/min/1.73 m2, a moderate positive statistically significant correlation was obtained. CONCLUSIONS: The SPSM method shows a very strong correlation with the reference and low bias in all three groups of patients and can be routinely used for GFR estimation.

Preoperative detection of sentinel lymph node in patients with endometrial cancer - comparison of planar lymphoscintigraphy, spect and SPECT/CT.

BACKGROUND: Sentinel lymph node (SLN) mapping allows minimal invasive assessment of lymph node status in patients with early-stage endometrial cancer (EC). Intraoperative detection of SLNs is based on the results obtained from preoperative nuclear medical images. The purpose of this study was to compare the data obtained from planar lymphoscintigraphy (PL), single-photon emission computed tomography (SPECT), and SPECT with computed tomography (SPECT/CT) for preoperative SLN detection in patients with EC. MATERIAL AND METHODS: A total of 44 images in 22 patients with early-stage EC (22 PL, 9 SPECT and 13 SPECT/CT) were analyzed. The scans were performed in the period 2018-2020 at the Institute of Pathophysiology and Nuclear Medicine in Skopje. Thirteen patients underwent PL and SPECT/CT and nine patients underwent PL and SPECT after cervical injection of 4 mCi 99mTc-SENTI-SCINT on the day of surgery. Descriptive statistics, Wilcoxon Matched Pairs Test, and Spearman rank R coefficient were used for data analyses. RESULTS: Twenty-two patients with mean age of 61.1 ± 7.5 and body mass index (BMI) 34.62 ± 6.4 kg/m2 were included in the study. In four patients (18.2%) SLN was not detected on PL. Detection rate on SPECT and SPECT/CT was 100%. The average number of detected SLN was 1.4 ± 1.05, 2.2 ± 1.1 и 2.15 ± 1.1 on PL, SPECT and SPECT/CT respectively. We found a statistically significant difference in the number of detected SLNs on PL vs SPECT/CT (p = 0.0077). The most common SLN location on SPECT/CT was the right internal iliac followed by the left common iliac region. CONCLUSIONS: The results of the presented study indicate a higher diagnostic value of SPECT/CT in terms of SLN detection and exact anatomic localization as compared to planar lymphoscintigraphy (PL).