Comparison of Accuracy in Calculation of Absorbed Dose to the Kidneys Following Radioligand Therapy with Lu-DKFZ-PSMA-617 by Two Different Background Correction Methods.

BACKGROUND

To improve the accuracy of activity image quality, scatter correction is a critical method. The aim of this study is to compare the accuracy in calculation of absorbed dose to patients following radioligand therapy (RLT) with Lu-DKFZ-PSMA-617 by two different methods of background correction in the conjugate view method.

MATERIALS AND METHODS

This study involved 10 patients. The individualized patient dosimetry calculations were based on whole-body planar scintigraphy images acquired in 10 patients with a mean age of 71.4 ± 6.07 years (range 63-85 years) at approximately 0-2 h, 4-6 h, 18-24 h, and 36-48 h after administration of the mean 6253 ± 826.4 MBq (range 5500-7400 MBq) of Lu-DKFZ-PSMA-617. Organ activities were calculated using the conjugate view method by Buijs and conventional background correction. Eventually, the absorbed dose of radiation was calculated using Medical Internal Radiation Dose formalism.

RESULTS

The dose per unit of injected activity (mGy/MBq) ± standard deviation for kidney using Buijs and conventional methods was 1.05 ± 0.11 and 0.63 ± 0.14, respectively.

CONCLUSION

The Buijs background correction method was more accurate than the conventional method.