Iodine concentration (IC) and Hounsfield units (HUs) are independent prognostic biomarkers for metastatic renal cell carcinoma (mRCC), according to a poster presented at the International Kidney Cancer Symposium (IKCS) 2021.
Researchers found that high combined IC and high combined HU were associated with better response and survival outcomes.
For this study (ClinicalTrials.gov Identifier: NCT03616951), researchers used spectral dual-layer detector CT (DL-CT) to quantify IC and HU in all target lesions (combined IC and combined HU). The data were adjusted for treatment and risk factors per International Metastatic RCC Database Consortium (IMDC) criteria.
Data from 115 patients with 313 target lesions were included. Most patients were men (75%), had clear-cell histology (87%), and had prior nephrectomy (79%). Patients had also received tyrosine kinase inhibitors (63%) and immune checkpoint inhibitors (37%).
Per IMDC criteria, 17% of patients had a favorable prognosis, 52% had an intermediate prognosis, and 31% had a poor prognosis.
At baseline, the median combined IC was 2.26 mg/mL (range, 0.04-9.46), and the median combined HU was 86 (range, 15-224).
In a multivariate analysis, high baseline combined IC was associated with better objective response rates (odds ratio [OR], 4.35; P =.001), progression-free survival (hazard ratio [HR], 0.51; P =.004), and overall survival (HR, 0.37; P <.001).
High baseline combined HU was associated with better objective response rates (OR, 2.52; P =.03) and overall survival (HR, 0.42; P =.001).
The C-index was 0.650 for IMDC risk factors. It increased to 0.687 when high combined HU was added and to 0.692 when high combined IC was added.
The researchers concluded that combined IC and HU are “independent prognostic imaging biomarkers in patients with mRCC and may add to the prognostic accuracy of IMDC.”
Disclosures: This research was supported by a grant from Ipsen. No other disclosures were reported.
Drljevic-Nielsen A, Mains JR, Andersen MB, et al. Spectral dual-layer detector CT: A new independent prognostic tool in metastatic renal cell carcinoma. Presented at IKCS 2021; November 5-6, 2021. Abstract N27.
This article originally appeared on Cancer Therapy Advisor