[Influence of immunomodulators on urological imaging]

Area of Science:

• Oncology
• Radiology
• Immunotherapy

Background:

• Immune checkpoint inhibitors (ICI) represent significant therapeutic advances for metastatic renal cell carcinoma (RCC) and urothelial carcinoma (UC).
• Current approvals include first-line therapy for cisplatin-unfit patients (Atezolizumab, Pembrolizumab) and second-line therapy for metastatic UC (Atezolizumab, Nivolumab, Pembrolizumab).
• Nivolumab is approved for metastatic RCC as second-line therapy and in combination with Ipilimumab as first-line therapy.

Purpose of the Study:

• To define optimized radiological follow-up and therapy response assessment strategies for ICI therapies.
• To identify challenges in interpreting imaging acquired during ICI treatment due to differing mechanisms compared to chemotherapy or anti-angiogenic drugs.

Main Methods:

• A systematic literature search was conducted focusing on urothelial carcinoma and renal cell carcinoma.

Main Results:

• Immune-related Response Criteria (irRC) have been developed to better describe imaging changes associated with ICI therapy.
• Current response monitoring for immunotherapy still predominantly relies on Response Evaluation Criteria in Solid Tumors (RECIST).

Conclusions:

• Further studies with long-term follow-up are necessary to accurately identify and predict treatment response to ICI.
• Radiologists and urologists must be familiar with common immunotherapy-related imaging findings, such as pseudoprogression, for correct interpretation in clinical practice.