T-Cell Clonal Expansion in Peripheral Blood Following Interventional Radiology Procedures for Metastatic Liver Cancer

Interventional radiology (IR) procedures may induce anti-tumor immune responses, with subsequent clonal expansion of specific T-cells recognizing tumor antigens. This exploratory study aims to investigate the clonal expansion of T-cells in the peripheral blood after interventional radiology procedures for metastatic liver cancer.

This prospective study included 16 patients with metastatic liver cancer undergoing IR procedures (13 embolizations and 3 ablations). Biopsy samples were collected prior to the procedure, and peripheral blood samples were obtained both pre- and post-procedure. Bulk T-cell receptor (TCR) sequencing was conducted to assess T-cell clonality dynamics and to evaluate the impact of procedures on the T-cell repertoire.

The overall clonality of the T-cell repertoire in the peripheral blood did not demonstrate significant variations following IR procedures (p = 0.27-0.77). A subset of patients exhibited limited T-cell clonal expansion in peripheral blood one month after IR procedures, with more than 10 T-cell clonotypes expanding in 43% of patients. Most clonal expansions decreased in frequency by three months; however, 3 patients displayed persistently expanding T-cell clonotypes in peripheral blood ≥ 3 months following IR procedures.

IR procedures do not alter the overall clonality of the T-cell repertoire but may promote the expansion of a limited number of clonotypes. This study demonstrates that it is feasible to detect and longitudinally track expanding T-cell clonotypes following IR liver-directed therapy. Further studies are needed to determine whether these expanding clonotypes contribute to systemic anti-tumor immunity.