Pulmonary sarcomatoid carcinoma (PSC), which is a type of non-small-cell lung carcinoma (NSCLC), is characterized by a high degree of malignancy, poor differentiation and a high incidence of pulmonary malignancy. In addition, PSC has a stronger invasive ability than other types of NSCLC and is not sensitive to radiation or chemotherapy. Furthermore, 90% of PSC cases exhibit vascular invasion; therefore, there is a risk of multiple metastases to the lung, bone, adrenal glands and brain, and consequently a poor prognosis, in the early stage. Targeted therapy and immunotherapy currently offer a new treatment direction; however, there have not been any significant advances in localized treatment in recent years. Thus, there is an urgent need for new localized treatment strategies. The present study describes the case of a 65-year-old man with recurrence of PSC after multi-line treatment with chemotherapy, radiotherapy, gamma knife and argon-helium knife treatment. In addition, the patient developed superior vena cava syndrome, and exhibited severe compression of the superior vena cava, chest discomfort, dyspnea and severe facial edema after chemotherapy, local gamma knife therapy (35 Gy, delivered through 14 2.5-Gy doses), argon-helium knife therapy and radiation therapy (28 Gy, delivered through seven 4-Gy doses). Partial remission was achieved after local implantation of iodine-125 (I125) seed under the guidance of a 3D-printed template, with progression-free survival observed up to 8 months afterwards. In conclusion, in patients with PSC who develop superior vena cava blockage after numerous treatment regimens, salvage I125 brachytherapy with a 3D-printed template may be suitable, and may improve local control and symptoms.