Contrast-Enhanced CT Density Predicts Response to Sunitinib Therapy in Metastatic Renal Cell Carcinoma Patients

Area of Science:

• Oncology
• Radiology
• Medical Imaging

Background:

• Sunitinib is a first-line therapy for metastatic renal cell carcinoma (mRCC) with a ~30% objective response rate.
• Predicting patient response to sunitinib is essential due to therapeutic alternatives.
• There is a clinical need for noninvasive methods to predict sunitinib efficacy in mRCC.

Purpose of the Study:

• To evaluate the prognostic value of pretreatment portal venous phase contrast-enhanced computed tomography (CECT) mean tumor density.
• To assess the association between CECT tumor density and overall survival (OS), progression-free survival (PFS), and tumor growth in mRCC patients treated with sunitinib.
• To identify potential CECT density cut-off values for predicting patient outcomes.

Main Methods:

• Retrospective analysis of 63 sunitinib-treated mRCC patients.
• Measurement of pretreatment portal venous phase CECT mean tumor density.
• Statistical analysis including hazard ratios (HR) for OS and PFS, correlation with tumor growth, and receiver operating characteristic (ROC) analysis for cut-off values.

Main Results:

• Higher pretreatment CECT tumor density was significantly associated with longer PFS (HR=0.968, P=.002) and OS (HR=0.956, P=.001).
• CECT density showed an inverse correlation with tumor growth (P=.010).
• ROC analysis identified two CECT density cut-off values (63.67 HU and 68.67 HU) that defined subpopulations with significantly different PFS and OS (P<.001).

Conclusions:

• Pretreatment CECT mean tumor density is a promising noninvasive prognostic marker for sunitinib response in mRCC.
• CECT density can help identify patients likely to derive maximum therapeutic benefit from sunitinib.
• This imaging strategy aids in personalized treatment selection for mRCC patients.