Seishi Nakatsuka

Percutaneous cryoablation of lung tumors: Feasibility and safety

PURPOSE To evaluate the safety and feasibility of cryoablation for lung tumors as well as the incidence of, and risk factors for, complications. MATERIALS AND METHODS This study included 193 cryoablation sessions for 396 lung tumors in 117 consecutive patients. Univariate and multivariate analyses were performed to assess risk factors for common complications. Changes in laboratory values were analyzed the day after cryoablation. RESULTS Pneumothorax, pleural effusion, and hemoptysis occurred after 119 (61.7%), 136 (70.5%), and 71 (36.8%) sessions, respectively. Phrenic nerve palsy, frostbite, and empyema occurred after one session each (0.52%). Proximal tumor implantation was observed in one of 471 punctures (0.20%). Of 119 sessions with pneumothorax, 21 (17.6%) required chest tube insertion and two (1.7%) required pleurodesis. Delayed and recurrent pneumothorax occurred in 15 of 193 sessions each (7.8%). A greater number of cryoprobes was a significant (P = .001) predictor of pneumothorax. Male sex (P = .047) and no history of ipsilateral surgery (P = .012) were predictors for the need for chest tube insertion, and no history of ipsilateral surgery (P = .021) was a predictor for delayed/recurrent pneumothorax. Greater number of cryoprobes (P = .001) and no history of ipsilateral surgery (P = .004) were predictors for pleural effusion. Greater number of cryoprobes (P < .001) and younger age (P = .034) were predictors for hemoptysis. Mean changes in white blood cell count, platelet count, hemoglobin level, and C-reactive protein level were 2,418/μL ± 2,260 (P < .001), -2.0 × 10(4)/μL ± 3.2 (P < .001), -0.77 mg/dL ± 0.89 (P < .001), and 3.0 mg/dL ± 2.9 (P < .001), respectively. CONCLUSIONS Percutaneous cryoablation could be performed minimally invasively with acceptable rates of complications.

Percutaneous cryoablation for the treatment of medically inoperable stage I non-small cell lung cancer.

Background To evaluate the midterm results of percutaneous cryoablation for medically inoperable stage I non-small cell lung cancer. Methodology/Principal Findings Between January 2004 and June 2010, 160 patients underwent computer tomography guided percutaneous cryoablation for lung tumors at our institution. Of these patients, histologically proven stage I lung cancer patients with more than one year of follow-up, were retrospectively reviewed. All of these patients were considered to be medically inoperable with Charlson comorbidity index of 3 or greater. Follow-up was based primarily on computed tomography. There were 22 patients with 34 tumors who underwent 25 sessions of cryoablation treatment. Complications were pneumothoraces in 7 treatments (28%, chest tube required in one treatment), and pleural effusions in 8 treatments (31%). The observation period ranged from 12–68 months, average 29±19 months, median 23 months. Local tumor progression was observed in one tumor (3%). Mean local tumor progression-free interval was 69±2 months. One patient died of lung cancer progression at 68 months. Two patients died of acute exacerbations of idiopathic pulmonary fibrosis which were not considered to be directly associated with cryoablation, at 12 and 18 months, respectively. The overall 2- and 3-year survivals were 88% and 88%, respectively. Mean overall survival was 62±4 months. Median overall survival was 68 months. The disease-free 2- and 3-year survivals were 78% and 67%, respectively. Mean disease-free survival was 46±6 months. Pulmonary function tests were done in 16 patients (18 treatments) before and after cryoablation. Percentage of predicted vital capacity, and percentage of predicted forced expiratory volume in 1 second, did not differ significantly before and after cryoablation (93±23 versus 90±21, and 70±11 versus 70±12, respectively). Conclusions/Significance Although further accumulation of data is necessary regarding efficacy, cryoablation may be a feasible option in medically inoperable stage I lung cancer patients.

Accuracy of preoperative prediction of microinvasion of portal vein in hepatocellular carcinoma using superparamagnetic iron oxide-enhanced magnetic resonance imaging and computed tomography during hepatic angiography

BackgroundOur aim was to diagnose microinvasion of the portal vein in hepatocellular carcinoma from preoperative radiological findings and to construct a scoring system.MethodsForty-seven patients (38 men and 9 women; median age, 66.8 years) who underwent hepatic resections for hepatocellular carcinoma were selected retrospectively. Microscopically, 22 had portal vein invasion (PVI) and 25 had no PVI. All patients were examined preoperatively with superparamagnetic iron oxide-enhanced magnetic resonance imaging and computed tomography during hepatic angiography (CTHA). Perilesional enhancement on T1-weighted imaging, tumorous arterioportal (AP) shunt, and corona enhancement (contrast enhancement of the adjacent liver appearing in the late phase of CTHA) were assessed. Relative risk for PVI in terms of clinical and tumor characteristics was also assessed. The relative contribution to PVI was determined by the coefficient of a stepwise logistic regression. Each variable was given a score relative to the coefficient.ResultsOn univariate analysis, distortion of corona, tumorous AP shunt, and tumor size indicated a higher prevalence of PVI. The PVI predictive score was calculated as: total score = (maximum size in cm) + (T1 ring; + = 1, − = 0) + (tumorous AP shunt; + = 3, − = 0) + (distortion of corona; + = 10, − = 0). The PVI (+) group score was four times that of the PVI (−) group (16 vs 4). At a cutoff score of 10, the sensitivity, specificity, and accuracy were 82%, 84%, and 86%.ConclusionsDistortion of corona, tumorous AP shunt, and tumor size are good predictors of the risk of PVI. This scoring system is simple and worth using clinically.

Superparamagnetic iron oxide-enhanced MR imaging for focal hepatic lesions: a comparison with CT during arterioportography plus CT during hepatic arteriography.

BackgroundWe aimed to evaluate the efficacy of a breath-hold superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging protocol for the detection of focal hepatic lesions, in comparison with a non-breath-hold SPIO-enhanced imaging protocol and computed tomography during arterioportography (CTAP) plus CT during hepatic arteriography (CTHA).MethodsFindings of SPIO-enhanced MR imaging and CTAP/CTHA for 24 hepatic metastases in 17 patients and 29 HCCs in 21 patients were analyzed. All patients underwent breath-hold SPIO-enhanced MR imaging (1.5 tesla), breath-hold plus non-breath-hold SPIO-enhanced MR imaging, and CTAP plus CTHA prior to partial hepatectomy or laparoscopic ablation therapy. Histopathology for lesion characterization and intraoperative ultrasound for lesion detection were available for all patient. Breath-hold SPIO-enhanced MR imaging consisted of T2-weighted single-short fast spin echo (FSE), T2-weighted (T2W) FSE, T2*-weighted gradient echo (GRE), and T1-weighted GRE. For the non-breath-hold imaging protocol, respiratory-triggered, fat-suppressed T2W-FSE was added to the breath-hold MR imaging protocol. Double phase CTAP plus CTHA was performed on an angio-CT system. To compare the three imaging protocols, three radiologists performed blind film reading, and all data, on a hepatic segment-to-segment basis, were entered for alternative free-response receiver-operating characteristic (AFROC) analysis.ResultsROC analysis showed that there was no significant difference in the area under the AFROC curve (A1) value for metastases and HCCs among the three protocols; the breath-hold SPIO-enhanced MR imaging protocol, non-breath-hold MR imaging protocol, and CTAP plus CTHA. The breath-hold SPIO-enhanced MR imaging protocol showed a sensitivity, specificity, and accuracy equivalent to the non-breath-hold MR imaging protocol and CTAP plus CTHA.ConclusionsAs a preoperative test, SPIO-enhanced MR imaging could have the potential to replace CTAP plus CTHA in a certain clinical setting.

Intraarterial digital subtraction angiography with carbon dioxide: superior detectability of arteriovenous shunting.

Intraarterial digital subtraction angiography (IADSA) with carbon dioxide (CO2) was performed on 41 patients with liver or renal diseases. CO2 produced no hypersensitivity reactions, and the pain or feeling of warmth was relatively mild compared with iodinated contrast media. Although the image quality of the arterial or capillary phase was inferior to that with iodinated contrast media, the detectability of arteriovenous shunting was excellent. IADSA with CO2 may become an effective method for detecting arteriovenous shunting which cannot be demonstrated with conventional angiography or DSA with iodinated contrast medium.

Percutaneous Cryoablation of Pulmonary Metastases from Colorectal Cancer

Objective To evaluate the safety and efficacy of cryoablation for metastatic lung tumors from colorectal cancer. Methods The procedures were performed on 24 patients (36–82 years of age, with a median age of 62; 17 male patients, 7 female patients) for 55 metastatic tumors in the lung, during 30 sessions. The procedural safety, local progression free interval, and overall survival were assessed by follow-up computed tomographic scanning performed every 3–4 months. Results The major complications were pneumothorax, 19 sessions (63%), pleural effusion, 21 sessions (70%), transient and self-limiting hemoptysis, 13 sessions (43%) and tract seeding, 1 session (3%). The 1- and 3-year local progression free intervals were 90.8% and 59%, respectively. The 3-years local progression free intervals of tumors ≤15 mm in diameter was 79.8% and that of tumors >15 mm was 28.6% (p = 0.001; log-rank test). The 1- and 3-year overall survival rates were 91% and 59.6%, respectively. Conclusion The results indicated that percutaneous cryoablation is a feasible treatment option. The local progression free interval was satisfactory at least for tumors that were ≤15 mm in diameter.

Factors affecting local progression after percutaneous cryoablation of lung tumors

PURPOSE To evaluate factors predicting local tumor progression after percutaneous cryoablation of lung tumors (PCLT). MATERIALS AND METHODS Seventy-one consecutive patients with 210 tumors (11 primary and 199 metastatic pulmonary neoplasms; mean maximum diameter, 12.8 mm) were treated with 102 sessions of PCLT. Rates of local tumor progression and technique effectiveness were estimated by Kaplan-Meier method. Multiple variables were evaluated with the log-rank test, followed by uni- and multivariate multilevel analyses to identify independent risk factors, and hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated. All statistical tests were two-sided. RESULTS Median follow-up period was 454 days (range, 79-2,467 d). Local tumor progression occurred in 50 tumors (23.8%). One-, 2-, and 3-year local progression-free rates were 80.4%, 69.0%, and 67.7%, respectively, and technique effectiveness rates were 91.4%, 83.0%, and 83.0%, respectively. Existence of a thick vessel (diameter≥3 mm) no more than 3 mm from the edge of the tumor was assessed as an independent factor (HR, 3.84; 95% CI, 1.59-9.30; P = .003) associated with local progression by multivariate analysis. CONCLUSIONS Presence of a vessel at least 3 mm in diameter close to the tumor represents an independent risk factor for local progression after PCLT.

Diagnostic performance of percutaneous core needle lung biopsy under multi-CT fluoroscopic guidance for ground-glass opacity pulmonary lesions

OBJECTIVE The diagnostic performance of percutaneous core needle lung biopsy under multi-CT fluoroscopic guidance for ground-glass opacity (GGO) pulmonary lesions was evaluated. MATERIALS AND METHODS Out of 90 patients who underwent CT fluoroscopy-guided core needle biopsy of GGO lesions at our institution, the biopsy results and the final diagnoses were retrospectively compared in 67 patients with available data (one lesion per patient). Diagnostic performance was also compared according to the lesion size (≤ 10 mm (n=8) versus 11-20mm (n=42) versus >20mm (n=17)), the percentage of GGO component (50-90% (n=31) versus >90% (n=36)), and the length of needle path (≤ 7 cm (n=45) versus > 7 cm (n=22)). Finally, all 90 cases were reviewed for complications. RESULTS The overall sensitivity, specificity, and accuracy were 97%, 100%, and 97%, respectively. The diagnostic sensitivity and accuracy tended to be lower in smaller lesions (≤ 10 mm; 86 and 88%, 11-20mm; 97 and 98%, >20mm; 100 and 100%, respectively, p>0.05), and in lesions with lower percentage of GGO component (50-90%; 93 and 94%, >90%; 100 and 100%, respectively, p=0.21), but statistical significances were not reached. The sensitivity and accuracy were not significantly affected by the length of needle path (≤ 7 cm; 98 and 98%, > 7 cm; 95 and 96%, respectively, p=1.00). Fourteen patients (16%) developed pneumothoraces, and 13 patients (14%) experienced mild hemoptysis, all of which resolved conservatively. CONCLUSION The diagnostic performance was satisfactory, and it was considered that the procedure was appropriate for GGO lesions regardless of lesion size, the percentage of GGO component, or the length of needle path. The procedure was also feasible without any major complications.

On freeze-thaw sequence of vital organ of assuming the cryoablation for malignant lung tumors by using cryoprobe as heat source

Regarding cryoablation for the malignant lung tumors, multiple trials of the freeze-thaw process have been made, and we considered it necessary to view and analyze the freeze-thaw process as a freeze-thaw sequence. We caused the sequence in a porcine lung in vivo by using an acicular, cylindrical stainless-steel probe as the heat source for the freeze-thaw sequence and cooling to -150 °C with super high-pressure argon gas by causing the Joule-Thomson effect phenomenon at the tip of the probe. In this experiment, we examined the sequence by measuring the temperature and using the isothermal curve and the freezing function. As a result, it was demonstrated that the freezing characteristics considerably differed in the first sequence and the second sequence from those of non-aerated organs such as liver and kidney. In our experiments on porcine lung, thermal properties were considered to change as the bleeding caused by the first thawing infiltrated in the lung parenchyma, and it was confirmed that the frozen area in the second cycle was dramatically enlarged as compared with the first cycle (when a similar sequence is continuously repeated, we say it as cycle). This paper provides these details.

Cryoablation of Early-Stage Primary Lung Cancer

Worldwide, lung cancer is the most commonly diagnosed cancer, and lobectomy is the gold-standard treatment for early-stage non-small cell lung cancer (NSCLC). However, many patients are poor surgical candidates for various reasons. Recently, image-guided ablation is being used for lung tumors. Cryoablation has been applied for the treatment of cancer in various nonaerated organs; recently it has been adapted to the treatment of lung tumors. Since an ice ball can be detected by computed tomography (CT), cryoablation of lung tumors is performed under CT guidance. Its first clinical application was reported in 2005, and it has been reported to be feasible in a few studies. Minor complications occurred at a high frequency (up to 70.5%), but major complications were rare (up to 1%). The most common complication is pneumothorax, and most cases need no further intervention. Local efficacy depends on tumor size and presence of a thick vessel close to the tumor. Midterm survival after cryoablation is 77%–88% at 3 years in patients with early-stage NSCLC. Although surgery is the gold-standard treatment for such patients, the initial results of cryoablation are promising. In this paper, the current status of cryoablation for primary lung tumors is reviewed.