Most MWA procedures were well tolerated

Most MWA procedures were well tolerated. an EGFR\TKI (such as gefitinib, erlotinib, afatinib); (iii) focal disease progression in a single lesion while on continuous treatment with an EGFR\TKI; and (iv) willing to provide written knowledgeable consent. The internal review board approved this retrospective study. Treatment methods All patients enrolled were orally administered 150 mg erlotinib and 250 mg of gefitinib or 40 mg of afatinib daily. Patients underwent routine chest and abdominal computed tomography (CT) scans or positron emission tomography scans every one to two months to assess the local response according to Response Evaluation Criteria in Solid Tumors (RECIST).13 Additional procedures including CT, magnetic resonance imaging, and bone scintigraphy were applied to evaluate metastatic sites. Patients continued oral EGFR\TKI during MWA intervals until disease progression, death, or the appearance of intolerable toxicity. If their oncologist and interventional radiologist deemed it safe, patients underwent a biopsy at the site of their progressive disease before MWA to elucidate mechanisms of acquired drug resistance. Microwave ablation For MWA, we used a commercially available system (ECO\2450B MWA, ECO Microwave Institute, Nanjing, China) and a 14\gauge cooled\shaft antenna (FORSEA, Vision Microwave Electronic Institute, Nanjing, China). The output power was generally set at 50C70 W. If the tumor could not be covered by one ablation session according to the size, location, and geometry, multiple sequential ablations were performed to achieve complete necrosis. Following treatment, CT scanning was again performed to evaluate the immediate necrotic conditions after ablation and to examine whether there were any complications, such as bleeding or pneumothorax. Response evaluation Main technical success was defined as a complete lack of enhancement in the ablation zone on initial follow\up contrast CT. A thin ( 5 mm), symmetric rim of peripheral enhancement at the ablation zone was considered to indicate benign peritumoral enhancement. Irregular nodular enhancement ( 15 HU) at the ablation site was considered to show recurrent or residual disease. The response to EGFR\TKIs was assessed according to RECIST version 1.1. Statistical analysis Progression\free survival was determined according to KaplanCMeier method. First PFS (PFS1) was measured from the time of initiation of targeted therapy to first progression of disease. Second PFS (PFS2) was measured from the date of focal progression until further progression of disease (defined by RECIST) or death from any cause. Overall survival (OS) was calculated from the date of initiation of the EGFR\TKI to the date of death. OS was censored at 17-Hydroxyprogesterone the date of the last visit for patients whose deaths could not be confirmed. SPSS version 16.0 (SPSS Inc., Chicago, IL, USA) was utilized for statistical analysis. Results Patient 17-Hydroxyprogesterone characteristics Initially, 205 lung malignancy patients treated with MWA at our institutions between RASGRP2 May 2012 and December 2017 were recognized, but only 15 patients satisfied the inclusion criteria. Patient characteristics are shown in Table ?Table11. Table 1 Clinical characteristics of patients with mutation type19 del960.021 L858R533.318 G719X16.7Best response to TKICR213.3PR853.4SD533.3Line of EGFR\TKIFirst\collection960Second/third\collection640Site of RECIST PDLung1066.7Liver416.6Adrenal16.7 Open in a separate window CR, complete response; ECOG PS, Eastern Cooperative Oncology Group overall performance status; NSCLC, non\small cell lung malignancy; PD, progressive disease; PR, partial response; SD, stable disease; TKI, tyrosine kinase inhibitor. The median age of the included patients was 53 years (range 29C81); eight (53%) patients were female; 11 were by no means smokers; and 33% (5/15) experienced received at least one chemotherapy regimen before commencing EGFR\TKI 17-Hydroxyprogesterone treatment. All patients experienced an Eastern Cooperative Oncology Group (ECOG) overall performance status (PS) of 0C2 before MWA was performed. Fourteen patients experienced adenocarcinomas, and one individual experienced squamous cell carcinoma. All patients harbored mutation T790M, two (20%) developed MET amplification, and one developed small cell histologic transformation. The other biopsy did not reveal any new mutations. Response to therapy, survival, and toxicity At the first response assessment, two patients (13%) had achieved a complete response (CR) to treatment, eight (53%) a PR,.