Since local thermal ablation of lung cancer was first reported in 2000, the number of patients treated each year has increased dramatically [1], and the number of cases of lung tumors treated with thermal ablation has exceeded 150 000 cases per year in 2010. Microwave ablation, as one of the commonly used methods for thermal ablation of lung tumors, has received increasing clinical attention, but the efficacy and safety of microwave ablation combined with chemotherapy for advanced non-small cell lung cancer still need further confirmation. The aim of this study was to evaluate the efficacy and complications of microwave ablation combined with chemotherapy in the treatment of advanced non-small cell lung cancer. Data and methods 1.1 Clinical data Eighty-five patients with advanced peripheral non-small cell lung cancer (NSCLC) admitted to our department from June 2008 to June 2012 were collected, including 49 males and 36 females, aged 45-74 years (mean 67.2 years). All patients were diagnosed by CT-guided puncture or bronchoscopic biopsy pathology, including 42 cases of adenocarcinoma, 29 cases of squamous carcinoma, 7 cases of adenosquamous carcinoma, 4 types of large cell carcinoma, 2 cases of undifferentiated carcinoma, and 1 case of carcinoid tumor. Preoperative TNM staging was performed in 64 cases of stage III and 21 cases of stage IV. A total of 89 intrapulmonary nodular lesions were detected by CT, with lesion diameters ranging from 1.2 to 6.4 cm (mean 3.9 cm). The 85 patients were randomly divided into two groups: 45 patients in the microwave ablation combined with chemotherapy group (combined group: 34 patients in stage III and 11 patients in stage IV, totaling 47 intrapulmonary nodular lesions) and 40 patients in the chemotherapy group (30 patients in stage III and 10 patients in stage IV, totaling 42 intrapulmonary nodular lesions). Patients in both groups did not receive any chemotherapy before enrollment, had expected survival >3 months, had no bleeding and coagulation dysfunction, no cardiopulmonary insufficiency, and no significant malignancy. 1.2 Treatment 1.2.1 Combined group: all patients in this group were positioned using a GE-lightspeed 16 or GE-lightspeed 64V spiral CT machine. [zhang2] Microwave ablation therapy instrument: MTC-3C type (produced by Nanjing Qinghai Microwave Electronics Research Institute, registration standard: YZB/Guo 1408-2003. its microwave emission frequency is 2450±50 MHz, output power: 0~100 W). The effective length of the [zhang3] microwave antenna is 100-180 mm, the outer diameter is 14-20 G, the tip is long conical, and a water circulation cooling system is used to reduce the antenna surface temperature. Local anesthesia and over-the-top analgesia were used [2]. Morphine 10 mg and diazepam 10 mg were administered intramuscularly 30 min before surgery; flurbiprofen ester 50 mg was administered intravenously 15 min before surgery for over-the-top analgesia, and another 50 mg was administered intravenously 8 h after surgery. 2% lidocaine and 0.75% bupivacaine were used for local layer-by-layer anesthesia to the tumor site. Procedure: Preoperative treatment plan: ① Determine the location, size, morphology and relationship of the lesion to the adjacent organs; ② Position the puncture site on the body surface; ③ Optimal access: the puncture channel from the puncture site to the lesion, this distance is called “target skin distance”. The access point should meet the shortest distance from the puncture point to the lesion and the target skin distance >2 cm, the lesion and the adjacent organs are clearly identifiable, the largest cross section of the lesion can be punctured, no bone obstruction, no large blood vessels and trachea or other important tissues; ④ select the appropriate microwave antenna and the number of antennas (single ablation antenna for tumor ≤3.5 cm, 2 ablation antennas for tumor 3.5-5.0 cm; 3 ablation antennas for tumor >5.0 cm) 3 ablation antennas [3]), with preset ablation power and ablation time. After satisfactory anesthesia, the skin is broken at the puncture site with a surgical blade, and the ablation microwave antenna is punctured layer by layer according to the preoperative planned optimal entry path, and the depth of puncture is the preoperative planned “target skin distance”. If it reaches the intended location, ablation treatment can be performed. The cold circulation pipeline and circulation pump are connected, and the cable is connected to the microwave antenna and microwave ablation machine. After the ablation is completed, the needle tract is ablated, then the power is turned off and the microwave antenna is removed, and the local sterilization is wrapped. Immediately after ablation, CT scan was performed to observe whether there was pneumothorax or bleeding. If the patient has normal blood pressure, heart rate and oxygen saturation, no hemoptysis, shortness of breath, chest tightness, dyspnea and other symptoms, he can return to the ward. Patients were given cisplatin combined with docetaxel or gemcitabine regimen chemotherapy 1 week after microwave ablation, cisplatin: 40 mg, dl~3; docetaxel: 75 mg/m2, dl or gemcitabine 1000 mg/m2 dl, d8. 21-28 days was one cycle, and a total of 4-6 cycles of chemotherapy were given. 1.2.2 Chemotherapy group: chemotherapy with cisplatin combined with docetaxel or gemcitabine regimen alone, with the same dosing time, dose and dosing cycle as the combination group. 1.2.3 During treatment and follow-up treatment: bisphosphonate drugs and radiotherapy for local bone metastases were given to those who developed bone metastases during treatment; for intracranial metastases, whole-cranial radiotherapy and local intracranial metastases with conformal complementary radiotherapy were given; for thoracic or pericardial effusion, routine drainage by implantation tube and intracavitary injection of IL-2 or mushroom polysaccharide (without chemotherapeutic drugs) were given; for metastases in liver, kidney or adrenal gland, no local treatment. After the completion of 4-6 cycles of chemotherapy in both groups, patients with enlarged lymph nodes in the hilum or mediastinum (41 patients in the combination group and 37 patients in the chemotherapy group) were treated with conventional radiotherapy 5500-6000 cGy. 1.3 Efficacy evaluation criteria According to the reference RECIST solid tumor efficacy assessment criteria [4]: complete remission (CR), partial remission (PR), stable (SD) and progressive (PD). Toxic reactions were evaluated according to WHO anticancer drug toxicity reactions classified as 0 to IV degree. Follow-up: Follow-up was conducted every 3 months after the end of treatment, and the cause of death was registered for deceased patients, and the 1-, 2- and 3-year survival rates were calculated. 1.4 Statistical methods The SSP software package was used for numerical processing. Treatment efficiency was compared using the χ2 test. The Kaplan-Meier method was used to calculate survival, and the log-rank test was used for survival rate comparison, and P < 0.05 was considered a statistically significant difference. Results 2.1 Efficacy The number of cases in which the efficacy could be evaluated after the end of treatment in the combination group and chemotherapy group was 41 and 37 cases, respectively. The effective rates of the combined group and chemotherapy group were 29.3% and 27.0%, respectively, with χ2=0.6522, P>0.05. The disease control rates of the combined group and chemotherapy group were 78.1% and 56.7%, respectively, with χ2=2.9608, P<0.05. 2.2 Survival rate The follow-up results of the survival rate of the combined group and chemotherapy group: 3 out of 40 patients in the chemotherapy group (1 case in 1 year, 2 cases in 3 years) and 3 cases in 45 cases in the combination group (1 case in 1 year, 1 case in 2 years, 1 case in 3 years) were lost to follow-up, and the loss was calculated as death. The follow-up period ranged from 6 months to 40 months.