Quantitative Single-Photon Emission Computed Tomography/Computed Tomography for Glomerular Filtration Rate...

Area of Science:

• Nuclear Medicine
• Radiopharmaceuticals
• Renal Physiology

Background:

• Accurate measurement of glomerular filtration rate (GFR) is crucial for assessing kidney function.
• Traditional GFR assessment methods may have limitations in terms of precision and individual kidney evaluation.
• Technetium-99m diethylenetriaminepentaacetic acid (Tc-99m DTPA) is a radiopharmaceutical commonly used in renal imaging.

Purpose of the Study:

• To propose and validate a quantitative Tc-99m DTPA SPECT/CT method for measuring GFR.
• To assess the reproducibility and accuracy of this novel SPECT/CT technique for GFR estimation.
• To establish a correlation between Tc-99m DTPA SPECT/CT derived % injected doses (%IDs) and Cr-51 EDTA GFR.

Main Methods:

• Quantitative SPECT/CT scans were performed 2-3 minutes post-Tc-99m DTPA injection to determine individual kidney %IDs.
• Reproducibility of %ID measurements was compared between SPECT/CT and planar scintigraphy.
• Cr-51 EDTA GFR served as the reference standard, with data analyzed in healthy volunteers, older volunteers, and renal tumor patients post-nephrectomy.

Main Results:

• Tc-99m DTPA SPECT/CT demonstrated high reproducibility for %ID measurements at 2-3 minutes post-injection (ICC: 0.9379, %CV: 6.5259%).
• A significant correlation was found between Cr-51 EDTA GFR and %ID (r=0.7906, p=0.0001), leading to a derived GFR equation.
• The derived equation revealed significant decreases in total and nephrectomized kidney GFR in renal tumor patients post-surgery.

Conclusions:

• Quantitative Tc-99m DTPA SPECT/CT provides reliable and clinically applicable %ID estimates.
• These %ID estimates accurately translate to individual kidney GFR measurements.
• The method shows promise for monitoring renal function, particularly in patients undergoing renal surgery.