In January 2022, a 58-year-old man was admitted to Sichuan Cancer Hospital with left-sided back pain that radiated to the chest. In 2014, he was diagnosed with gastric GIST and underwent a complete surgical excision followed by targeted therapy. In 2018, he developed sacral metastases and underwent a vertebrotomy. In 2019, he experienced rib metastasis and received treatment with radiotherapy, targeted therapy, and immunotherapy. But his chest wall pain persisted, scoring a 5 out of 10 on the numerical rating scale (NRS). The timeline of the clinical events was shown in. Magnetic resonance imaging (MRI) revealed a 5.6×3.2 cm mass in the rib, together with several solid nodules in the soft tissue (). Contrast-enhanced ultrasound (CEUS) showed a hypoechoic mass in the rib and several hypoechoic nodules in the chest wall, with heterogeneous enhancement in the arterial and venous phases (). Given the patient’s numerous metastases, palliative therapy was advised by the orthopedic and thoracic surgeons after consultation. Despite multiple treatment modalities, the patient continued to experience moderate pain. Consequently, microwave ablation (MWA) guided by ultrasound was advised. Postablation syndrome, characterized by fever, chills, and nausea, which is related to the size of the ablated tumor, can occur following ablation (). Furthermore, there was a positive correlation between tumor size and complications such as thermal damage (). Given the considerable size of the lesion and its proximity to the spleen, two separate sessions were adopted to reduce possible adverse effects. Preoperative assessments were carried out, and contraindications were ruled out. Informed consent was obtained. The diagnosis of GIST metastases was confirmed by preoperative pathological biopsies. The procedure was performed by an experienced interventional radiologist with the guidance of ultrasound (Philips EPIQ 7, Bothell, WA, USA). The ablation instrument (KY-2000; Kangyou Medical, Nanjing, China) and the microwave antenna (KY-2450B, Kangyou Medical, Nanjing, China) were used. CEUS was conducted before the ablation. 2 ml of sulfur hexafluoride lipid was administered intravenously and flushed with 5 ml of normal saline. Observe and record the volume of lesions and the vascular locations. After the safety of the puncture path was verified, the aseptic preparation was completed. 5 ml of 2% lidocaine was injected for the local anesthesia. By injecting physiological saline solution around the lesions through a 22-gauge catheter, thermal injury to normal tissues was prevented. Following the creation of a 2 mm incision in the skin at the percutaneous site, a microwave antenna was inserted into the rib lesion’s base. In January 2022, we performed the first ablation and ablated the central part of the rib lesion along with all the soft tissue lesions. The operator initiated the ablation and moved the antenna from the base to the shallow and the internal to the external, ensuring that the target lesion was covered by the vaporization area. Next, the operator ablated each lesion in the soft tissues separately. The output power was 40W, and the ablation lasted 24 minutes. After the ablation, CEUS was administered to assess the efficacy of the ablation. The absence of any enhancement in the ablation area suggests total necrosis. The pain in the left chest wall was alleviated following the first ablation, and the NRS score decreased to 2/10. In February 2022, MRI showed a comparable tumor size (). CEUS revealed both necrotic tissue and remaining enhanced tissue in the ablation sites (). In April 2022, a follow-up MRI scan conducted three months following the first ablation revealed that the rib lesion had decreased in size, now measuring 5.3×2.4 cm (). CEUS showed some degree of enhancement in the area (). The patient was in good physical condition and requested a second ablation. Therefore, we conducted further ablation to improve the local tumor control. The output power was 40W, and the ablation lasted 11 minutes. Complete ablation was confirmed by postoperative CEUS. His follow-up period lasted for 17 months, until September 2023. The MRI and CEUS revealed that the ablation area measured 4.7×1.6 cm, which was significantly smaller (). The pain in the chest wall was effectively managed, and the NRS score was 2/10 during the follow-up. No adverse effects were observed in relation to the ablation.