We present a case of a 40-year-old female patient with midline carcinoma, who was admitted for chest pain and cough and diagnosed with concurrent mediastinal and pulmonary metastases. Single-agent chemotherapy proved ineffective and her clinical symptoms aggravated, accompanied by tracheal and superior vena cava compression. Following multidisciplinary consultation, CT-guided ¹²⁵Ⅰ seed implantation was initially performed. Local tumors regressed postoperatively while partial pulmonary metastatic lesions progressed, prompting seed reimplantation combined with bronchial arterial chemoembolization, followed by concurrent anlotinib targeted therapy and sintilimab immunotherapy. After six months of comprehensive treatment, the thoracic tumors resolved, lymph nodes shrank, radiological evaluation indicated partial response, and the patient's clinical symptoms were significantly relieved. This case demonstrates that the integrated regimen of interventional local therapy plus targeted and immunotherapy offers a viable therapeutic approach for inoperable midline carcinoma patients with refractory conventional chemotherapy, enabling rapid symptom relief and improved treatment efficacy.