Simple CT metric predicts treatment-induced kidney impairment in prostate cancer patients
New imaging data could help better inform providers on the potential side effects of a common treatment for prostate cancer.
Lutetium-177 (Lu-177) is a radioactive isotope used in targeted therapy for advanced prostate cancer. Though an effective treatment—research has shown that over half of patients treated with Lu-177 PSMA radioligand therapy show significant decreases in their PSA levels—it is not without side effects, some of which can be severe. Nephrotoxicity is associated with the treatment, but now experts believe they have identified an objective way of determining which patients are most susceptible to kidney damage.
They detailed their findings this week in an analysis published in the journal Radiology.
“Lutetium 177 prostate-specific membrane antigen (PSMA) radioligand therapy is a novel treatment option for metastatic castration-resistant prostate cancer. Evidence suggests nephrotoxicity is a delayed adverse effect in a considerable proportion of patients,” Lisa Steinhelfer, from the Institute for Diagnostic and Interventional Radiology at the Technical University of Munich, and colleagues noted.
For their work, the team focused on total kidney volume on CT imaging of individuals treated with Lu-177. They retrospectively analyzed who underwent at least four cycles of 177Lu-PSMA-I&T therapy between December 2015 and May 2022, measuring total kidney volume at three- and six-months post-treatment.
Using a 30% drop in estimated glomerular filtration rate (eGFR) as a threshold for defining clinically significant end-stage renal disease, the team compared baseline risk factors, total kidney volume and eGFR at 12 months to determine how each factor affected nephrotoxicity post-treatment.
On imaging, a 10% decrease of total kidney volume at 6-months predicted a minimum 30% decrease in eGFR at 12-months. The biomarker yielded 90% accuracy, making it more reliable than other parameters used to predict kidney function. Baseline risk factors, prior treatments and number of treatment cycles did not correlate with a decrease in eGFR after 12 months, the group noted.
The authors suggested that using total kidney volume as a biomarker has promise for improving treatment decisions in the future, noting that “its better performance than early relative eGFR change highlights its potential as a noninvasive marker when treatment decisions are pending.”
Learn more about the study here.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.