Nephrotoxicity after PSMA-RLT using Lu-177-PSMA I&T

Ziel/Aim Lu-177-PSMA is increasingly used in mCRPC. Based on dosimetry results the kidneys are an organ at risk potentially limiting the number of cycles applied. We aimed to investigate the effect of Lu-177-PSMA on kidney function in patients who underwent at least 4 cycles with a minimum follow-up time of 12 months.

Methodik/Methods A total of 72 patients met the inclusion criteria for this retrospective analysis and underwent a total of 447 cycles Lu-177-PSMA I&T. Median follow-up time and median number of cycles were 17 months (range: 12-59 months) and 6 cycles (range: 4-20 cycles), respectively. Baseline CLR was estimated according to the Crockroft-Gault-formula. Annual decrease of CLR in percentage was determined by fitting a monoexponential function using all available post-therapy lab tests. Additional the impact of known risk factors for impaired renal function (diabetes, hypertension, age >65) was evaluated.

Ergebnisse/Results Baseline CLR (+/- SD) and median average annual decrease in CLR were 81.2+/-24.8 ml/min and 13.0+/-19.4 %, respectively. At one year after the first cycle Lu-177-PSMA I&T 17 of 72 patients (24 %) developed no CLR decline (defined as decline <5 %) while 36 patients (50 %) and 19 patients (26 %) showed a CLR decline between 5-25 % and >25 %, respectively. Median CLR decline at 12 months in patients who underwent less than 6 cycles was 9 % vs 14 % in patients with at least 6 cycles. CLR decline at 12 months was 5 %, 19 % and 28 % in patients with one, two or three risk factors for kidney disease and less than 6 cycles vs. 14 %, 9 % and 16 % in patients with one, two or three risk factors and more than 6 cycles, respectively.

Schlussfolgerungen/Conclusions Most patients do not develop relevant nephrotoxicity after Lu-177-PSMA I&T at 12 months after treatment initiation. However, a potential clinically relevant CLR decline of at least 25 % was observed in one quarter of patients. Both, the number of cycles as well as clinical risk factors correlated with the degree of renal impairment after Lu-177-PSMA I&T therapy.

Publication History

Article published online:
08 April 2021