Hideo Gobara

Risk Factors for Local Progression After Percutaneous Radiofrequency Ablation of Lung Tumors Evaluation Based on a Preliminary Review of 342 Tumors

The purpose of the study was to retrospectively evaluate the risk factors for local progression after percutaneous radiofrequency (RF) ablation of lung tumors.

CT Fluoroscopy-Guided Biopsy of 1,000 Pulmonary Lesions Performed With 20-Gauge Coaxial Cutting Needles: Diagnostic Yield and Risk Factors for Diagnostic Failure

BACKGROUND Although conventional CT scan-guided needle biopsy is an established diagnostic method for pulmonary lesions, few large studies have been conducted on the diagnostic outcomes of CT fluoroscopy-guided lung biopsy. We have conducted a retrospective analysis to evaluate the diagnostic outcomes of 1,000 CT fluoroscopy-guided lung biopsies performed with 20-gauge coaxial cutting needles. METHODS We determined the diagnostic yield of CT fluoroscopy-guided lung biopsies performed with 20-gauge coaxial cutting needles for 1,000 lesions in 901 patients. Independent risk factors for diagnostic failure (ie, nondiagnostic, false-positive, and false-negative results) were determined with multivariate logistic regression analysis. RESULTS The biopsy results were nondiagnostic in 0.6% of the lesions (6 of 1,000 lesions). The sensitivity and specificity for the diagnosis of malignancy was 94.2% (741 of 787 lesions) and 99.1% (211 of 213 lesions), respectively; diagnostic accuracy was 95.2% (952 of 1,000 lesions). For lesions measuring <or= 1.0 cm, the diagnostic accuracy was 92.7% (140 of 151 lesions). The significant independent risk factors for diagnostic failure were as follows: the acquisition of two or fewer specimens (odds ratio [OR], 2.43; p = 0.007), lesions in the lower lobe (OR, 2.50; p = 0.003), malignant lesions (OR, 7.16; p = 0.007), and lesions measuring <or= 1.0 cm (OR, 3.85; p = 0.016) and >or= 3.1 cm (OR, 4.32; p = 0.007). CONCLUSIONS CT fluoroscopy-guided lung biopsy performed with 20-gauge coaxial cutting needles resulted in a high diagnostic yield, even in the case of small lesions. Factors such as the acquisition of two or fewer specimens, lesions in the lower lobe, malignant lesions, and lesions measuring <or= 1.0 cm or >or= 3.1 cm significantly increased the rate of diagnostic failure.

Incidence of and Risk Factors for Pneumothorax and Chest Tube Placement After CT Fluoroscopy–Guided Percutaneous Lung Biopsy: Retrospective Analysis of the Procedures Conducted Over a 9-Year Period

OBJECTIVE The objective of our study was to retrospectively evaluate the incidence of and the risk factors for pneumothorax and chest tube placement after CT fluoroscopy-guided lung biopsy. MATERIALS AND METHODS We analyzed 1,098 CT fluoroscopy-guided lung biopsies conducted with 20-gauge coaxial cutting needles for 1,155 lesions in 1,033 patients. Apart from evaluating the incidence of pneumothorax and chest tube placement, the independent risk factors for pneumothorax and chest tube placement for pneumothorax were determined using multivariate logistic regression analysis. RESULTS The overall incidence of pneumothorax was 42.3% (464/1,098). Chest tube placement was required for 11.9% (55/464) of pneumothoraces (5.0% [55/1,098] of the total number of procedures). The significant independent risk factors for pneumothorax were no prior pulmonary surgery (p = 0.001), lesions in the lower lobe (p < 0.001), greater lesion depth (p < 0.001), and a needle trajectory angle of < 45 degrees (p = 0.014); those for chest tube placement for pneumothorax were pulmonary emphysema (p < 0.001) and greater lesion depth (p < 0.001). CONCLUSION Pneumothorax frequently occurred and placement of a chest tube was occasionally required for pneumothorax after CT fluoroscopy-guided lung biopsy. To reduce the risk of pneumothorax necessitating chest tube placement, physicians should adopt the shortest needle path to the lesion.

Feasibility of percutaneous radiofrequency ablation for intrathoracic malignancies: a large single-center experience.

Radiofrequency ablation (RFA) has become an accepted alternative for treating intrathoracic malignancies; however, the incidence and characteristics of peri‐ and postprocedural complications are not well described. The purpose of the study was to assess the safety and technical feasibility of percutaneous RFA in unresectable intrathoracic malignancies.

Percutaneous radiofrequency ablation of clinical stage I non―small cell lung cancer

OBJECTIVE This study aimed at retrospectively evaluating the outcomes of radiofrequency ablation of clinical stage I non-small cell lung cancer. METHODS This study was carried out on 50 nonsurgical candidates (29 men and 21 women; mean age, 74.7 years) with clinical stage I (IA, n = 38; IB, n = 12) histologically proven non-small cell lung cancer. A total of 52 tumors were treated with 52 ablation sessions. Radiofrequency ablation was performed percutaneously under computed tomography fluoroscopic guidance. The outcomes of radiofrequency ablation were evaluated, including toxicity, local efficacy, and patient survival. Toxicity was evaluated using the National Cancer Institute Common Terminology Criteria for Adverse Events Version 4.0. Local efficacy was evaluated by using computed tomography scan with a contrast medium. The overall, cancer-specific, and disease-free survivals were estimated with Kaplan-Meier analysis. RESULTS Grade 2 and 3 adverse events occurred after 6 (12%) and 3 (6%) of the 52 sessions, respectively. The median follow-up period was 37 months. Local progression was observed in 16 (31%) of the 52 tumors. The median survival time was 67 months. The overall, cancer-specific, and disease-free survivals were 94%, 100%, and 82% at 1 year, 86%, 93%, and 64% at 2 years, and 74%, 80%, and 53% at 3 years, respectively. CONCLUSIONS Radiofrequency ablation of clinical stage I non-small cell lung cancer was minimally invasive and provided promising patient survival, although the local efficacy needs to be improved.

Does tumor type affect local control by radiofrequency ablation in the lungs

OBJECTIVE : To retrospectively evaluate the effect of tumor type on local control by radiofrequency ablation in the lungs. MATERIALS AND METHODS : This study included 252 lung tumors (mean size, 13.5mm) in 105 patients (73 men and 32 women; mean age, 66.6 years) who underwent radiofrequency ablation with a multitined expandable electrode. Those tumors comprised five tumor types: primary lung cancer (n=35) and pulmonary metastases from colorectal cancer (n=117), lung cancer (n=23), renal cell carcinoma (n=49), and hepatocellular carcinoma (n=28). Local control was evaluated with contrast-enhanced computed tomography. The overall local control rates were estimated as well as those for each tumor type using the Kaplan-Meier analysis. Local control rates for a given tumor type were compared with those for the four other types. Then, multivariate multilevel analysis was performed using the variables of tumor type, tumor size, contact with a vessel or bronchus, and procedure period. RESULTS : The overall local control rates were 97%, 86%, 81%, and 76% at 6, 12, 18, and 24 months, respectively. Local control rates varied among the tumor types, and metastatic colorectal cancer showed significantly (P=.023) higher local control rates than those of the four other types. However, multivariate analysis indicated that the relative risk of local progression for a given tumor type was comparable to the risks for the four other types. CONCLUSION : Tumor type per se did not significantly influence local control.

Preliminary retrospective investigation of FDG-PET/CT timing in follow-up of ablated lung tumor

ObjectiveThe aim of this study was to clarify the most appropriate follow-up initiation time point for positron emission tomography (PET)/computed tomography (CT) following radio frequency ablation (RFA) of lung tumors, and the cutoff values of maximum standard uptake value (SUVmax) to evaluate local tumor progression.MethodsWe enrolled 15 patients (8 men, median age 62 years) with 60 tumors, who were treated with RFA of lung tumors and underwent fluorodeoxyglucose (FDG)-PET/CT following RFA. Local tumor progression was assessed by periodic chest CT images prior to and following intravenous administration of a contrast medium. The SUVmax of three periods, namely, 0–3 months, 3–6 months, and 6–9 months after RFA, was evaluated. The appropriate time point for follow-up initiation and the cutoff value of SUVmax were determined using receiver-operating characteristic (ROC) analysis.ResultsThe median follow-up period was 357 days. Of 60 tumors, 10 showed local progression. The area under the ROC curve (Az) for the 6–9 months (P = 0.044) was the largest and almost equal to that of the 3–6 months (P = 0.024). Az for the 0–3 months was the smallest and statistically insignificant (P = 0.705). The cutoff value of 1.5 of SUVmax at 3–9 months after RFA showed 77.8% sensitivity and 85.7–90.5% specificity.ConclusionsThe appropriate follow-up initiation time point is at least 3 months following RFA. Thus, SUVmax is a useful and reliable predictive indicator.

Detection of EGFR gene mutations using the wash fluid of CT-guided biopsy needle in NSCLC patients.

Introduction: In this study, we examined whether epidermal growth factor receptor (EGFR) mutations were detectable using a polymerase chain reaction-based assay and wash fluid of computed tomography (CT)-guided lung biopsy needles. Methods: DNA was extracted from wash fluid of CT-guided biopsy needles of 53 lung tumors (as diagnosed according to the results of the CT-guided biopsies). EGFR mutations, specifically exon19 deletions and exon21 L858R mutations, were examined using a mutant-enriched polymerase chain reaction assay. We also examined the presence of EGFR mutations in 26 surgically resected tumor specimens and compared the results with those obtained for the corresponding wash fluid samples. Results: The amount of DNA obtained for the wash fluid of the CT-guided biopsy needles ranged from 35 to 2360 ng. There were no significant differences in the amount of extracted DNA according to the tumor characteristics, including tumor size and the percentage of ground glass opacity. Thirty-four of the 53 lung tumor samples were histologically diagnosed as non-small cell lung cancer (NSCLC). Exon19 deletions and exon21 L858R mutations in EGFR were detected in 4 (12%) and 13 (38%) of 34 NSCLC cases, respectively. No EGFR mutations were found in the non-NSCLC cases. The EGFR mutation status in the wash fluid samples was consistent with those obtained for all 26 corresponding surgical specimens. Conclusion: Our results indicate that EGFR mutations can be detected using wash fluid of CT-guided biopsy needles. In this manner, the DNA genotype can be determined even in extremely small clinical specimens using highly sensitive assays.

Two Cases of Needle-Tract Seeding after Percutaneous Radiofrequency Ablation for Lung Cancer

The authors describe two cases of needle-tract seeding after percutaneous radiofrequency (RF) ablation for lung cancer. Needle biopsy was performed immediately before RF ablation in one case. In both cases, RF ablation was performed with a single internally cooled electrode, which was removed without cauterizing the electrode tract. The seeding nodule appeared 4 or 7 months after RF ablation and was then completely treated with a repeat RF ablation.

Brachial Nerve Injury Caused by Percutaneous Radiofrequency Ablation of Apical Lung Cancer: A Report of Four Cases

The present report describes four cases of brachial nerve injury caused by percutaneous radiofrequency (RF) ablation of lung cancer. All the tumors were located in the lung apex. The patients developed symptoms indicative of a low brachial plexus injury during RF ablation or as long as 7 days afterward. These symptoms partially receded over time. The indications of RF ablation in patients with apical lung cancer should be carefully determined because of the risk of brachial nerve injury associated with the procedure.