Since ¹⁷⁷Lu-PSMA radioligand therapy, a highly effective internal molecular radiation treatment for advanced prostate cancer, is cleared partly through the kidneys, there has been concern that it might damage renal function over time. The recent study "Renal Function Stability in Patients Treated with ¹⁷⁷Lu-PSMA-617: A Longitudinal Analysis of eGFR and Creatinine Trends During and After Therapy" presented during SNMMI 2026 in Los Angeles, USA, looked at how kidney function changes over time in patients receiving the therapy.

Two common kidney measurements were monitored over time:

• Creatinine (a metabolic waste product in blood)
• eGFR (an estimate of how well the kidneys filter blood)

Think of your kidneys as a water filter.

• eGFR tells us how much water is flowing through the filter each minute, i.e. how well the kidneys are filtering.
• Creatinine is like dirt building up before the filter. If the filter slows down, more dirt accumulates in the water. A higher creatinine level can be a sign that the filter is not working as well; though as we'll see, it's not the whole picture.

Researchers found that for most patients, both eGFR and creatinine remained largely stable throughout treatment. Patients with pre-existing moderate kidney impairment showed a small increase in creatinine over time, suggesting that their kidneys may need closer monitoring. However, even in this group, the overall kidney safety profile remained favorable.

Why the values might diverge

In some cases, creatinine rose slightly while eGFR appeared unchanged. eGFR is not measured directly but estimated from the creatinine level and adjusted for age, sex, and other factors, so normally the two move together. In cancer patients with reduced muscle mass, however, less creatinine is produced, which can make blood creatinine appear lower than expected. Because eGFR is calculated from creatinine, this can sometimes make kidney function look better than it truly is – especially when muscle loss is significant.

Conclusion

For most patients, ¹⁷⁷Lu-PSMA did not appear to damage renal function in a meaningful way. Patients with pre-existing kidney problems should be monitored more closely during treatment.

Study design

“This was a retrospective analysis performed in 56 patients treated between 2022 and 2025. Renal function was assessed at baseline, throughout each ¹⁷⁷Lu-PSMA-617 treatment cycle, and 6–8 weeks post-therapy. Patients were categorized into normal, mild, or moderate renal impairment groups at baseline. …

There were a total of 33.9% of patients that received 2 cycles, 12.5% that received 3 cycles, 14.3% that received 4 cycles, 7.1% that received 5 cycles, and 32.1% that received 6 cycles of ¹⁷⁷Lu-PSMA-617. Among the 56 patients, 44.6% had normal renal function, 35.7% had mild impairment, and 19.6% had moderate impairment at baseline. The patient characteristics are as follows:

There were 4/20 (20%) of patients with mild impairment at baseline who progressed to grade 2 renal toxicity, and 1/11 (9.1%) of patients with moderate baseline impairment who progressed to grade 3. Across the cohort, eGFR remained stable, with no significant change per treatment cycle. Patients with normal or mild impairment showed no meaningful cycle-related change in eGFR, whereas patients with moderate impairment displayed a numerically greater decline, though not statistically significant.

Creatinine trends were similarly stable overall, however patients with moderate renal impairment exhibited a statistically significant rise in creatinine over treatment cycles.”^[1]

^[1] Klaassen, Z. SNMMI 2026: Renal function stability in patients treated with 177LU-PSMA-617: A longitudinal analysis of EGFR and creatinine trends during and after therapy, SNMMI 2026: Renal Function Stability in Patients Treated with ¹⁷⁷Lu-PSMA-617: A Longitudinal Analysis of eGFR and Creatinine Trends During and After Therapy. Accessed: 16 June 2026.