Evaluation of Nephrotoxicity by Renal Scintigraphy During Radiotherapy <sup>177</sup>Lu-PSMA-617

Abstract

   Purpose: Evaluation of nephrotoxicity by renal scintigraphy in patients with metastatic castration-resistant prostate cancer receiving radionuclide therapy 177Lu-PSMA-617.   Material and methods: In this work the data obtained by renal scintigraphy using two radiopharmaceutical drugs 99mTc-MAG3 and 99mTc-DTPA were analyzed in 32 patients with metastatic castration-resistant prostate cancer receiving radionuclide therapy 177Lu-PSMA-617.   Results: In all patients included in this study, both before the start of radionuclide therapy and after receiving several fractions of therapy, there were no critically significant violations of renal function. By the last fraction of radionuclide therapy on the KDIGO scale, category C1, corresponding to normal renal function, was observed in 34 % of patients, which is 6 % more than before the start of therapy. At the same time, 6 % of patients began to have significantly reduced renal function (category C3b), which was not determined in any of the patients before the start of therapy with 177Lu-PSMA-617. In 13 % of patients there was a moderate decrease (category C3a) and in 47 % of patients there was a slight decrease (category C2) in renal function.   Conclusions: Despite the prevailing concerns about nephrotoxicity caused by 177Lu-PSMA-617 therapy, the glomerular filtration rate, calculated both by a formula based on creatinine levels in the blood and when using renal scintigraphy with 99mTc-DTPA, remained within the age norm in this study. At the same time, there was a tendency to increase the level of creatinine in the blood after the second fraction of radionuclide therapy, which may indicate initial functional changes in the kidneys. It was also noted that from fraction to fraction there is a gradual slowdown in the main time indicators of filtration and excretory kidney function (according to dynamic renal scintigraphy), such as Tmax and T1/2, which may also indicate functional changes in the kidneys against the background of therapy.