Integrating Histotripsy into Chemoimmunotherapy for Oligometastatic Recurrent Extrahepatic Cholangiocarcinoma: Case Report.

The management of advanced, recurrent extrahepatic cholangiocarcinoma has shifted toward prolonged systemic therapy including immune checkpoint inhibition. Incorporating local treatment for oligometastatic or oligoprogressive disease without interrupting systemic therapy remains challenging. Conventional liver-directed therapies frequently require a chemotherapy break. Histotripsy is a noninvasive, non-thermal, non-ionizing modality that permits continuation of systemic therapy. This case presents a 71-year-old woman with recurrent extrahepatic cholangiocarcinoma who developed multifocal hepatic metastases while receiving gemcitabine and durvalumab. She was deemed not a candidate for further radiation therapy or other locoregional therapies; thus, nine of ten hepatic lesions were treated with histotripsy in a single session. This case highlights the possibility of integrating histotripsy with chemoimmunotherapy by providing short-term local control of oligometastatic progression without the need to interrupt systemic treatment.Level of Evidence: Level 4, Case Report.