Tomohisa Okuma

Ductus arteriosus aneurysm (DAA) in adulthood is a rare entity. We retrospectively reviewed our medical records from the past 10 years and identified 8 cases of adult DAA (6 males and 2 females aged between 69 and 89 years; mean, 76 years), using multiplanar reconstruction and three-dimensional reconstruction CT images. The aneurysm was suspected incidentally in all cases based on the results of chest radiographic screening or post-operative follow-up CT for lung or colon cancer. All eight patients were asymptomatic but had a history of or concurrent hypertension (n = 5, 62.5%), diabetes mellitus (n = 3, 37.5%), cerebrovascular disease (n = 3, 37.5%), ischemic heart disease (n = 1, 12.5%), and cardiac failure (n = 1). All patients had no history of trauma (n = 8, 100%). Six had a history of cigarette smoking. The aneurysm size ranged from 2.0 × 4.0 to 6.3 × 5.3 cm (mean, 3 × 5 cm). The surgical procedures used were four cases of total arch replacement and two cases of thoracic endovascular aortic repair. Two patients were not surgically treated. The median follow-up was 14.5 months (range, 2 months to 9 years). In the two patients who were not surgically treated, the aneurysm enlarged in one, and remained unchanged in the other. Of the six surgically managed cases, one was lost to follow-up, and another patient died of an unrelated cause. The remaining four cases had no enlargement of the aneurysm. No ruptures were reported in any of the cases. DAA should be considered when a saccular aneurysm is located in the minor curvature of the aortic arch and extending toward the left pulmonary trunk in adult patients. Differentiating adult DAA is important, because it is associated with a high risk of rupture due to the fragile nature of true aneurysms.

Radiofrequency ablation (RFA) is less effective for large tumors > 3 cm in diameter. Various studies of combination therapy using RFA and other treatments have been conducted to improve the results of RFA treatment of lung tumors, survival was extended in a tumor model when RFA was followed by concomitant use of systemic chemotherapy. Bevacizumab (BCM) is a one of molecular target drugs. Numerous clinical trials and reports have shown BCM’s effect when used in combination with cisplatin (CDDP) in lung tumor. Our objective is to evaluate the survival of concurrent, combined use of radiofrequency ablation and BCM, and platinum-doublet chemotherapy [CDDP/paclitaxel (PTX)] in a rabbit VX2 lung tumor. Survival times of the RFA alone, CDDP/PTX, CDDP/PTX/BCM, RFA/CDDP/PTX, and RFA/CDDP/PTX/BCM groups were significantly prolonged compared to that of the control group (P = 0.0055, P = 0.0055, P = 0.0004, P = 0.0002, P = 0.0019, respectively). Survival of the RFA/CDDP/PTX/BCM group was not significantly prolonged compared to the RFA alone (P = 0.53) and CDDP/PTX/BCM group (P = 0.68), while showing a significantly shorter survival time than that of the RFA/CDDP/PTX group (P = 0.017). The addition to BCM with combination RFA and systemic therapy with CDDP/PTX did not have a positive effect on survival.

Background: Collagen vascular disease-associated interstitial lung disease (CVD-ILD) must be differentiated from idiopathic pulmonary fibrosis (IPF) since prognosis and treatment strategies differ between these two conditions. However, differentiating between CVD-ILD and IPF is often difficult. Purpose: To examine the utility of expiratory high-resolution computed tomography (HRCT) for differentiating between CVD-ILD and IPF. Material and Methods: Seventy patients were examined with expiratory and inspiratory HRCT with CVD-ILD ( n = 36) or IPF ( n = 34). Associated diagnoses in patients with CVD-ILD were rheumatoid arthritis ( n = 22), Sjögren syndrome ( n = 3), scleroderma ( n = 2), polymyositis/dermatomyositis ( n = 1), and unspecified connective tissue disease ( n = 8). Parenchymal abnormalities on inspiratory HRCT and visual extent of air trapping on expiratory HRCT were evaluated, statistical differences in HRCT findings between the two conditions were determined, and air trapping CT scores were correlated with the results of pulmonary function testing. Results: Air trapping was found in 27 (75%) of 36 cases of CVD-ILD and four (12%) of 34 cases of IPF. Seventeen of the 27 cases for which air trapping was exhibited with CVD-ILD were diagnosed with rheumatoid arthritis. A significant difference in frequency of air trapping was seen between CVD-ILD and IPF ( P < 0.0001). Frequency of centrilobular nodules was significantly higher in CVD-ILD than in IPF ( P = 0.021). In contrast, frequencies of interlobular interstitial thickening and traction bronchiectasis were significantly higher in IPF than in CVD-ILD ( P = 0.005, P = 0.007, respectively). Correlations were seen between visual extent of air trapping and pulmonary function test results such as air trapping index ( P = 0.004, r = 0.34), closing volume/vital capacity ( P = 0.0002, r = –0.47), and closing capacity/total lung capacity ( P < 0.0001, r = –0.51). Conclusion: The presence of air trapping on expiratory HRCT suggests CVD-ILD rather than IPF.

To evaluate survival and distant tumor growth after radiofrequency ablation (RFA) and local OK-432 injection at a single tumor site in a rabbit model with intra- and extrahepatic VX2 tumors and to examine the effect of this combination therapy, which we termed immuno-radiofrequency ablation (immunoRFA), on systemic antitumor immunity in a rechallenge test. Our institutional animal care committee approved all experiments. VX2 tumors were implanted to three sites: two in the liver and one in the left ear. Rabbits were randomized into four groups of seven to receive control, RFA alone, OK-432 alone, and immunoRFA treatments at a single liver tumor at 1 week after implantation. Untreated liver and ear tumor volumes were measured after the treatment. As the rechallenge test, tumors were reimplanted into the right ear of rabbits, which survived the 35 weeks and were followed up without additional treatment. Statistical significance was examined by log-rank test for survival and Student’s t test for tumor volume. Survival was significantly prolonged in the immunoRFA group compared to the other three groups (P < 0.05). Untreated liver and ear tumor sizes became significantly smaller after immunoRFA compared to controls (P < 0.05). In the rechallenge test, the reimplanted tumors regressed without further therapy compared to the ear tumors of the control group (P < 0.05). ImmunoRFA led to improved survival and suppression of distant untreated tumor growth. Decreases in size of the distant untreated tumors and reimplanted tumors suggested that systemic antitumor immunity was enhanced by immunoRFA.

We report a case of serious complications following computed tomography (CT)-guided radiofrequency ablation (RFA) performed for the treatment of lung cancer with interstitial pneumonia. The patient developed delayed-onset pyopneumothorax, which required 6 months of antibiotic treatment, drainage, and video-assisted thoracoscopic debridement. Although CT-guided RFA is a promising, effective procedure for difficult-to-treat lung cancer, the present case suggests a risk of complications for patients complicated with interstitial pneumonia and warrants caution.

The aim of this study was to examine the actual temperature during lung radiofrequency ablation (RFA) and pathological changes due to thermal damage in the pleural tissue of the chest wall in a rabbit model. The study was conducted on 14 Japanese white rabbits with normal lungs. Under computed tomography guidance, the electrode with a 2-cm expandable tip was inserted into the lower lung lobe and positioned so the tip of the needle touched the thoracic wall upon expansion. A thermometer was inserted 5 mm lateral to the point of electrode insertion. RFA was applied at 30 W (n = 7) or 15 W (n = 7) until maximum impedance (i.e., roll-off) or for 4 min at the longest. Local tissue temperature was recorded. The chest wall was dissected out immediately after RFA for histological examination. The mean (± SD) maximum tissue temperature at 30 W (86.7° ± 10.0°C) was not significantly different from that at 15 W (82.1° ± 6.2°C). The mean ablation time to increase tissue temperature to 50°, 60°, and 70°C was faster at 30 W (13, 27, and 49 s, respectively) than at 15 W (13, 56, and 115 s, respectively) (P < 0.05). Histological examination showed pleural sloughing at the point of needle insertion and ring-shaped thermal injury in the chest wall. With rabbit lung RFA near the chest wall, ablation immediately below the pleura resulted in a rise of local tissue temperature to >80°C and thermal injury.

The purpose of this study was to retrospectively determine the local control rate and contributing factors to local progression after computed tomography (CT)-guided radiofrequency ablation (RFA) for unresectable lung tumor. This study included 138 lung tumors in 72 patients (56 men and 16 women; age 70.0 ± 11.6 years (range 31–94); mean tumor size 2.1 ± 1.2 cm [range 0.2–9]) who underwent lung RFA between June 2000 and May 2009. Mean follow-up periods for patients and tumors were 14 and 12 months, respectively. The local progression-free rate and survival rate were calculated to determine the contributing factors to local progression. During follow-up, 44 of 138 (32%) lung tumors showed local progression. The 1-, 2-, 3-, and 5-year overall local control rates were 61, 57, 57, and 38%, respectively. The risk factors for local progression were age (≥70 years), tumor size (≥2 cm), sex (male), and no achievement of roll-off during RFA (P < 0.05). Multivariate analysis identified tumor size ≥2 cm as the only independent factor for local progression (P = 0.003). For tumors P = 0.011). The present study showed that 32% of lung tumors developed local progression after CT-guided RFA. The significant risk factor for local progression after RFA for lung tumors was tumor size ≥2 cm.

The aim of this study was to evaluate prospectively the early treatment response after CT-guided radiofrequency ablation (RFA) of unresectable lung tumours by MRI including diffusion-weighted imaging (DWI). The study protocol was approved by the ethics committee of our hospital and signed consent was obtained from each patient. We studied 17 patients with 20 lung lesions (13 men and 4 women; mean age, 69±9.8 years; mean tumour size, 20.8±9.0 mm) who underwent RFA using a LeVeen electrode between November 2006 and January 2008. MRI was performed on a 1.5T unit before and 3 days after ablation. We compared changes in the apparent diffusion coefficient (ADC) on DWI and response evaluation based on subsequent follow-up CT. 14 of the 20 treatment sessions showed no local progression on follow-up CT, whereas 6 treatment sessions showed local progression (range, 3–17 months; mean, 6 months). For the no-progression group, the ADC pre- and post-RFA were 1.15±0.31 × 10⁻³ mm² s⁻¹ and 1.49±0.24 × 10⁻³ mm² s⁻¹, respectively, while the respective ADC values for those that showed local progression were 1.05±0.27 × 10⁻³ mm² s⁻¹ and 1.24±0.20 × 10⁻³ mm² s⁻¹. The ADC of the ablated lesion was significantly higher than before the procedure (pp<0.05). Our prospective pilot study showed that the ADC without local progression was significantly higher than with local progression after RFA, suggesting that the ADC can predict the response to RFA for lung tumours.