AUTHOR=Zhang Lan , Ai Conghui , Yu Shuhui , Li Kangming , Jiang Meiping , Zhao Chunfang , Li Zheng , Wu Xingrao TITLE=Successful sequential chemo-immunotherapy and reduced-volume brachytherapy for bulky residual cervical tumor after external beam radiotherapy: two case reports JOURNAL=Frontiers in Immunology VOLUME=Volume 16 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2025.1687247 DOI=10.3389/fimmu.2025.1687247 ISSN=1664-3224 ABSTRACT=BackgroundBulky residual tumor after external beam radiotherapy (EBRT) presents a major technical challenge for brachytherapy (BT) and is a significant prognostic risk factor in locally advanced cervical cancer (LACC). The use of chemotherapy combined with an immune checkpoint inhibitor to reduce tumor volume (TV) during the interval between EBRT completion and BT initiation has been rarely explored.Case descriptionWe present two cases of stage IIIC1r cervical squamous cell carcinoma with residual tumors larger than 5 cm following EBRT. Patient characteristics, examination findings, laboratory and imaging data, treatment responses, and adverse events were recorded. After sequential treatment with albumin-bound paclitaxel plus cisplatin combined with zimberelimab, both patients achieved marked tumor volume reduction and subsequently underwent reduced-volume BT. Neither patient experienced recurrence at 36-month and 25-month follow-ups, respectively.ConclusionSequential chemo-immunotherapy followed by reduced-volume BT may represent an alternative treatment option for patients with bulky residual disease after EBRT. Further clinical studies are warranted to validate the effectiveness of this combined regimen.