Radiofrequency Ablation in Patients with Interstitial Lung Disease and Lung Neoplasm: A Retrospective Multicenter Study.

PURPOSE: To retrospectively investigate the safety and effectiveness of percutaneous radiofrequency (RF) ablation by analyzing results in patients with lung neoplasm accompanied by interstitial lung disease (ILD) on computed tomography (CT) in a multicenter study. MATERIALS AND METHODS: Patients with lung neoplasm accompanied by ILD who underwent RF ablation between April 2002 and October 2017 at 7 institutions were investigated. Technical success rate and local tumor progression (LTP) of ablated tumors were evaluated. Adverse events including acute exacerbation of ILD were also evaluated. Univariate analyses were performed to identify factors associated with acute exacerbation. RESULTS: Forty-nine patients with 64 lung neoplasms (mean diameter, 23 mm; range, 4-58 mm) treated in 66 sessions were included. Usual interstitial pneumonia (UIP) pattern on CT was identified in 23 patients (47%). All patients underwent successful RF ablation. Acute exacerbations were seen in 5 sessions (8%, 7% with UIP pattern and 8% without) in 5 patients, all occurring on or after 8 days (median, 12 days; range, 8-30 days). Three of those 5 patients died of acute exacerbation. Treatment resulted in mortality after 5% of sessions, representing 6% of patients. Pleural effusion and fever (temperature ≥ 38°C) after RF ablation were identified by univariate analysis (P = .001 and P = .02, respectively) as significant risk factors for acute exacerbation. The cumulative LTP rate was 43% at 1 year. CONCLUSIONS: RF ablation appears feasible for patients with lung neoplasm complicated by ILD. Acute exacerbation occurred in 8% of patients with symptoms occurring more than 8 days after ablation and was associated with a 45% mortality rate.

Therapeutic Effects of CT-guided Radiofrequency Ablation with Concurrent Platinum-Doublet Chemotherapy in a Rabbit VX2 Lung Tumor Model.

Purpose To evaluate survival time with concurrent, combined use of radiofrequency ablation (RFA) and one of the commonly used platinum-doublet chemotherapies (cisplatin [CDDP]/paclitaxel [PTX], CDDP/vinorelbine [VNR], CDDP/adriamycin [ADR], or CDDP/pemetrexed [MTA] combinations) by using a rabbit VX2 lung tumor model. Materials and Methods The experiment was approved by the institutional animal care committee. VX2 cells were implanted into the lungs of 60 rabbits randomized into groups treated with supportive care (control group), RFA alone, chemotherapy alone (CDDP/PTX, CDDP/VNR, CDDP/ADR, or CDDP/MTA), or a combination of RFA and chemotherapy (RFA/CDDP/PTX, RFA/CDDP/VNR, RFA/CDDP/ADR, or RFA/CDDP/MTA). RFA was performed and followed by intravenous chemotherapy. Survival time was evaluated by using the Kaplan-Meier method. Results The median survival time of the control, RFA-alone, CDDP/PTX, CDDP/VNR, CDDP/ADR, CDDP/MTA, RFA/CDDP/PTX, RFA/CDDP/VNR, RFA/CDDP/ADR, and RFA/CDDP/MTA groups was 26.5, 40, 39, 26.5, 28, 26, 120, 16.5, 42, and 26.5 days, respectively. Survival of the RFA/CDDP/PTX group was significantly longer than that of the control (P = .0006), CDDP/PTX (P = .0117), and RFA-alone (P = .0495) groups. Survival was also significantly prolonged with combined RFA/CDDP/ADR treatment versus supportive care (P = .026), but not with RFA alone (P = .765) or CDDP/ADR (P = .167). Survival times in the RFA/CDDP/VNR and RFA/CDDP/MTA groups were significantly shorter than that in the RFA-alone group (P = .0282 and P = .0197, respectively). Conclusion The combination of RFA and systemic chemotherapy with CDDP/PTX may benefit survival. However, RFA with systemic CDDP may have a survival disadvantage when combined with VNR or MTA. © RSNA, 2016.

High-dose prednisolone after intravenous methylprednisolone improves prognosis of acute exacerbation in idiopathic interstitial pneumonias.

BACKGROUND AND OBJECTIVE: Acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) (AE-IPF) is a poor prognostic disorder. AE is also reported to occur in other idiopathic interstitial pneumonias (IIPs). There are limited data available regarding the effectiveness of treatment for AE-IIPs. The objective of this study was to clarify the prognostic impact of the initial dose of prednisolone (PSL) for treating AE-IIPs. METHODS: Eighty-five patients with AE-IIPs, diagnosed according to the criteria of the Japanese Respiratory Society, were enrolled in this study (IPF/non-IPF: 63/22 patients) from 2004 to 2013. We performed multivariate Cox proportional hazard regression analysis to identify poor prognostic factors. HRCT patterns at the onset of AE-IIPs were classified as diffuse or non-diffuse. We evaluated the prognostic significance of the initial dose of PSL by adjusting for other prognostic factors. RESULTS: Median survival time (MST) after AE-IIPs diagnosis was 49 days. MST of AE-IPF and AE-non-IPF was 39 and 49 days, respectively. A diffuse HRCT pattern, lower serum IgG and higher serum surfactant protein-D at AE diagnosis, long-term oxygen therapy (LTOT) before AE and positive pressure ventilation (PPV) use for AE were significant poor prognostic factors for all patients, as were LTOT before AE and lower serum IgG for no-PPV patients. High-dose PSL ≥ 0.6 mg/kg was a significant prognostic factor for no-PPV patients after adjusting for other prognostic factors. CONCLUSION: We concluded that a dose of PSL ≥ 0.6 mg/kg after i.v. high-dose methylprednisolone therapy should be recommended for the treatment of AE-IIPs.

Combination radiofrequency ablation and local injection of the immunostimulant bacillus Calmette-Guérin induces antitumor immunity in the lung and at a distant VX2 tumor in a rabbit model.

PURPOSE: To evaluate whether the combination of radiofrequency (RF) ablation and local injection of the immunostimulant Mycobacterium bovis bacillus Calmette-Guérin (BCG) induces systemic antitumor immunity. MATERIALS AND METHODS: Japanese White rabbits with lung and auricle VX2 tumors were randomized into three groups: control (n = 8; no treatment), RF ablation only (n = 8; RF ablation to the lung tumor), and RF ablation with local BCG injection into the lung tumor (n = 8). Treatments were performed 1 week after tumor implantation. Survival was evaluated with Kaplan-Meier method and log-rank test. Weekly mean volume and specific growth rate (SGR) of auricle tumors were calculated, and comparisons were made by Mann-Whitney test. RESULTS: Median survival of control, RF-only, and RF/BCG groups were 23, 41.5, and 103.5 days, respectively. Survival was significantly prolonged in the RF-only and RF/BCG groups compared with the control group (P = .034 and P =.003, respectively), but no significant difference was found between the RF-only and RF/BCG groups (P = .279). Only in the RF/BCG group was mean auricle tumor volume decreased 5 weeks after implantation. No significant difference in SGR was found between the control and RF-only groups (P = .959), but SGR in the RF/BCG group was significantly lower than in the control group (P = .005). CONCLUSIONS: The combination of RF ablation and local injection of BCG resulted in distant tumor suppression compared with the control group, whereas RF ablation alone did not produce this effect. Therefore, the combination of RF ablation and local injection of BCG may induce systemic antitumor immunity.

Utility of expiratory thin-section CT for fibrotic interstitial pneumonia.

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.

Radiofrequency ablation and immunostimulant OK-432: combination therapy enhances systemic antitumor immunity for treatment of VX2 lung tumors in rabbits.

PURPOSE: To evaluate whether antitumor immunity is enhanced systemically by combining radiofrequency ablation (RFA) and local injection of an immunostimulant, OK-432. MATERIALS AND METHODS: Experiments were approved by the institutional animal care committee. Experimental Japanese rabbits inoculated with VX2 tumors in the lung and the auricle were randomized into four groups of eight: control (supportive care), RFA (RFA of lung tumor), OK-432 (direct injection of OK-432 into lung tumor), and combination therapy (lung RFA and direct OK-432 injection into lung tumor). All procedures were performed 1 week after implantation of VX2 tumors (week 1). In addition, a VX2 tumor rechallenge test was performed in the RFA and combination therapy groups. Survival time was evaluated by means of the Kaplan-Meier method and by using the log-rank test for intergroup comparison. Mean auricle tumor volumes were calculated every week. Specific growth rates (SGRs) were calculated and compared by using the Mann-Whitney test. RESULTS: The median survival times of the control, RFA, OK-432, and combination therapy groups were 23, 36.5, 46.5, and 105 days, respectively. Survival was significantly prolonged in the combination therapy group when compared with the other three groups (P <.05). The mean auricle tumor volume decreased only in the combination therapy group. The mean auricle tumor volumes of the combination therapy group from week 1 to week 7 were 205, 339, 264, 227, 143, 127, and 115 mm(3). SGR in the combination therapy group became significantly smaller than those in the other three groups (P < .05). In the rechallenge test, the volume of all reimplanted tumors decreased. CONCLUSION: Combining RFA with local injection of immunostimulant OK-432 may lead to indirectly activation of systemic antitumor immunity.

Clinical and magnetic resonance imaging feature differences between solitary and multiple type Langerhans cell histiocytosis involving the craniofacial bone.

PURPOSE: To investigate the clinical and contrast-enhanced magnetic resonance imaging (MRI) features of craniofacial bone Langerhans cell histiocytosis (LCH) and discuss the differences between a solitary lesion group (SLG) and multiple lesions group (MLG). METHOD: This study included 22 consecutive patients with pathologically proven LCH who underwent contrast-enhanced MRI. The clinical data and MRI features were retrospectively assessed. RESULTS: The mean patient age was 5 years, and 15 patients were male. The frontal bone was the most frequently affected bone. Ten and 12 patients were classified into the SLG and the MLG, respectively. The following MRI features were observed in >50% cases: T1WI hyperintensity in 15 (68%) cases, T2WI hyperintensity in 16 (73%) cases, bulging sign in 18 (82%) cases, concentric or eccentric soft tissue mass formation in 13 (59%) cases, soft tissue edema in 16 (73%) cases, any grade of bone marrow edema in 16 (73%) cases, surrounding bone enhancement in 17 (77%) cases, and surrounding soft tissue enhancement in 16 (73%) cases. Patient age was significantly higher in the SLG than that in the MLG (P = 0.0014). Perilesional bone marrow edema and enhancement were significantly more prominent in the SLG than in the MLG (P = 0.032, P = 0.040). CONCLUSIONS: Contrast-enhanced MRI showed additional significant findings of mainly the surrounding details. Older age, extensive bone marrow edema, and enhancement may indicate solitary-type LCH rather than multiple-type LCH. These differences may help distinguish between solitary- and multiple-type LCH, which have different treatment strategies.

A case of Schistosoma japonicum retroperitoneal pseudotumor diagnosed by cone-beam CT-guided coaxial biopsy system.

We report a rare case of retroperitoneal pseudotumor caused by Schistosoma japonicum that was diagnosed by computed tomography (CT) guided percutaneous biopsy in a 15-year-old Filipino male. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a mass lesion, including a mesenteric artery, in the right retroperitoneal space. His mother had a history of S. japonicum infection but his initial stool examination was negative. As schistosomiasis was suspected, cone-beam CT-guided biopsy was performed to enable transcatheter therapeutic arterial embolization to be performed immediately in the event of hemorrhage. Histopathological examination revealed schistosomal eggs. Cone-beam CT-guided technique with a coaxial biopsy system is a safe and accurate diagnostic procedure for S. japonicum retroperitoneal pseudotumor.

Long-term follow-up high-resolution CT findings in non-specific interstitial pneumonia.

BACKGROUND: The aims of this study were to retrospectively assess the change in findings on follow-up CT scans of patients with non-specific interstitial pneumonia (NSIP; median, 72 months; range, 3-216 months) and to clarify the correlation between the baseline CT findings and mortality. METHODS: The study included 50 patients with a histologic diagnosis of NSIP. Two observers evaluated the high-resolution CT (HRCT) findings independently and classified each case into one of the following three categories: (1) compatible with NSIP, (2) compatible with UIP or (3) suggestive of alternative diagnosis. The correlation between the HRCT findings and mortality was evaluated using the Kaplan-Meier method and the log-rank test, as well as Cox proportional hazards regression models. RESULTS: Ground-glass opacity and consolidation decreased, whereas coarseness of fibrosis and traction bronchiectasis increased on the follow-up HRCT scans, however, in 78% of cases the overall extent of parenchymal abnormalities had no change or decreased. Patients with HRCT diagnosed compatible with NSIP had a longer survival than those with HRCT findings more compatible UIP or an alternative diagnosis. On multivariate analysis, the coarseness of fibrosis alone was associated with prognosis (HR: 1.480; 95% CIs 1.100 to 1.990). CONCLUSIONS: The HRCT patterns seen in patients with a histopathologic diagnosis of NSIP progress in a variable manner. Overall disease extent may decrease over time in some, while fibrosis may progress in others. The initial HRCT diagnosis may impact survival in this group of patients.

Incidentally identified ductus arteriosus aneurysm in eight adults: a case series.

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.

Quantitative evaluation of COVID-19 pneumonia severity by CT pneumonia analysis algorithm using deep learning technology and blood test results.

PURPOSE: To evaluate whether early chest computed tomography (CT) lesions quantified by an artificial intelligence (AI)-based commercial software and blood test values at the initial presentation can differentiate the severity of COVID-19 pneumonia. MATERIALS AND METHODS: This retrospective study included 100 SARS-CoV-2-positive patients with mild (n = 23), moderate (n = 37) or severe (n = 40) pneumonia classified according to the Japanese guidelines. Univariate Kruskal-Wallis and multivariate ordinal logistic analyses were used to examine whether CT parameters (opacity score, volume of opacity, % opacity, volume of high opacity, % high opacity and mean HU total on CT) as well as blood test parameters [procalcitonin, estimated glomerular filtration rate (eGFR), C-reactive protein, % lymphocyte, ferritin, aspartate aminotransferase, lactate dehydrogenase, alanine aminotransferase, creatine kinase, hemoglobin A1c, prothrombin time, activated partial prothrombin time (APTT), white blood cell count and creatinine] differed by disease severity. RESULTS: All CT parameters and all blood test parameters except procalcitonin and APPT were significantly different among mild, moderate and severe groups. By multivariate analysis, mean HU total and eGFR were two independent factors associated with severity (p < 0.0001). Cutoff values for mean HU total and eGFR were, respectively, - 801 HU and 77 ml/min/1.73 m2 between mild and moderate pneumonia and - 704 HU and 53 ml/min/1.73 m2 between moderate and severe pneumonia. CONCLUSION: The mean HU total of the whole lung, determined by the AI algorithm, and eGFR reflect the severity of COVID-19 pneumonia.

Survival Benefit of Radiofrequency Ablation with Intratumoral Cisplatin Administration in a Rabbit VX2 Lung Tumor Model.

PURPOSE: This study evaluated the survival benefit of a combination therapy with radiofrequency ablation (RFA) and intratumoral cisplatin (ITC) administration for lung tumors by using a rabbit VX2 tumor model. MATERIALS AND METHODS: Experiments were approved by the institutional animal care committee. VX2 tumor suspension was injected into the lungs of Japanese white rabbits under CT guidance to create a lung tumor model. Thirty-two rabbits bearing a transplanted VX2 lung tumor were randomly assigned to four groups of eight: control (untreated); RFA alone; ITC alone; and RFA with ITC. All treatments were performed one week after tumor transplantation. Kaplan-Meier survival curves were compared by the log-rank test. RESULTS: The median survival time was 24.5 days (range 17-33 days) in the control group, 40 days (30-80 days) in the RFA alone group, 31.0 days (24-80 days) in the ITC alone group, and not reached (53-80 days) in the RFA with ITC group. The median survival was significantly longer with the RFA/ITC combination compared to the control group (P < 0.001), RFA alone (P = 0.034), and ITC alone (P = 0.004). The survival time after RFA alone was also significantly longer than that of the control group (P < 0.001). There was no significant difference in tumor size or the rate of pneumothorax between each group. CONCLUSION: RFA prolonged the survival of rabbits with lung VX2 tumors when combined with ITC.

Seroradiologic prognostic evaluation of acute exacerbation in patients with idiopathic interstitial pneumonia: a retrospective observational study.

BACKGROUND: We previously reported that high-resolution computed tomography (HRCT) patterns and certain serum marker levels can predict survival in patients with acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) and in those with idiopathic interstitial pneumonias (IIPs). The utility of serum marker changes before and during AE has not been previously evaluated. This study aimed to clarify whether changes in serum marker levels could improve the prognostic significance of HRCT patterns in patients with AE-IIPs. METHODS: Seventy-seven patients (60 males, 17 females) with AE-IIP diagnosed between 2004 and 2016 and whose serum Krebs von den Lungen (KL)-6 and surfactant protein (SP)-D levels were measured before and at the onset of AE were enrolled in this study. The HRCT pattern of each patient was classified as diffuse, multifocal, or peripheral. We examined the prognostic significance of the HRCT pattern, increased serum marker levels, and a combination of these parameters using Cox proportional hazard regression analysis. RESULTS: Fifty-three patients had IPF and 24 had non-IPF IIP. A serum KL-6 level that was increased compared with the level in the stable state (ΔKL-6/ST-KL-6: ≤0.211) was a significantly poor prognostic factor in patients with a multifocal pattern. Multivariate Cox analysis identified long-term oxygen therapy, a partial oxygen tension/fraction of inspired oxygen ratio ≤200 Torr, and an elevated SP-D level during a stable state to be significantly poor prognostic factors in all patients. A diffuse HRCT pattern was not a significant prognostic factor in an AE-IIP in multivariate analysis after adjustment; however, a multifocal pattern accompanying a ΔKL-6/ST-KL-6 ≤0.211 or a diffuse pattern was a significantly poor prognostic factor than a peripheral pattern or a multifocal pattern with ΔKL-6/ST-KL-6 >0.211. CONCLUSIONS: Combining the HRCT pattern and the ΔKL-6/ST-KL-6 value can improve our ability to predict the survival of AE-IIP patients.

Computed tomography-guided re-radiofrequency ablation for unresectable lung tumor with local progression previously treated with the same procedure.

PURPOSE: The aim of this study was to evaluate the technical success, complications, and effectiveness of re-radiofrequency (re-RF) ablation for recurrent lung tumors previously treated with RF ablation. MATERIALS AND METHODS: Reenlargement at the site of ablation seen on follow-up computed tomography (CT) is defined as local progression. CT-guided re-RF ablation was performed during 11 treatment sessions (mean tumor size 2.6 cm diameter) in 10 patients. The treated lesions consisted of five recurrences of primary lung cancer and six metastatic lung tumors from the esophagus (n = 2), bladder (n = 2), kidney (n = 1), and colon (n = 1). RESULTS: At 3 of the 11 treatment sessions there were no relapses; at 8 of the 11 sessions local progression was seen at a median of 7 months (range 3-17 months). The local progression rate was significantly higher for tumors > 2.5 cm (P < 0.05). Minor complications included pneumothorax not requiring drainage (n = 3), subcutaneous emphysema (n = 1), and self-limited hemoptysis (n = 2). CONCLUSION: Re-RF ablation for lung tumors was feasible without any major complications. Although our study comprised only a few cases with a short follow-up period, patients with re-RF ablation were at higher risk of local progression.

Combination therapy involving radiofrequency ablation and targeted chemotherapy with bevacizumab plus paclitaxel and cisplatin in a rabbit VX2 lung tumor model.

OBJECTIVE: 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. RESULTS: 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.

Factors contributing to cavitation after CT-guided percutaneous radiofrequency ablation for lung tumors.

PURPOSE: Cavitation has been described in lung neoplasms after radiofrequency ablation (RFA). In this retrospective study, the frequency and timing of cavitation after RFA of unresectable lung tumors was analyzed to determine the factors that contribute to cavitation and to assess the clinical course of patients who develop cavitation. MATERIALS AND METHODS: The authors retrospectively studied 100 lung RFA lesions in 48 patients (37 men, 11 women, age 69.7 years +/- 10.7, mean +/- SD) who underwent lung RFA between June 2000 and March 2006. RFA was performed using a LeVeen electrode inserted under guidance by computed tomography (CT). Follow-up consisted of CT performed at 1 week, 1 month, and every 2 to 3 months thereafter to determine the frequency of, time of radiographic appearance of, and factors contributing to cavity formation and the clinical course after cavitation. RESULTS: Cavitation was detected by CT at 1.5 months +/- 0.8 after RFA (14 sessions). No symptoms were noted in 12 sessions, but high fever developed after 1 month in two sessions. The frequency of cavitation was significantly higher in patients with lung cancer as the primary lesion (10/14), those who underwent RFA for lesions located within 1 cm of the chest wall (11/14), and those with pulmonary emphysema (7/14) (P < .05). Age, sex, maximum power output,total ablation time, minimum impedance, and tumor diameter were not significant contributors to cavity formation. CONCLUSIONS: In our study, cavitation occurred at a frequency of 14% at 1.5 months +/- 0.8 after RFA ablation, but the majority of patients were asymptomatic. Cavitation seems to occur more frequently in patients with a lesion near the chest wall, lung cancer as the primary lesion, and in those with pulmonary emphysema at baseline before the lung RFA.

CT-guided percutaneous radiofrequency ablation of spleen: a preliminary study.

OBJECTIVE: The objective of our study was to evaluate the technical feasibility, safety, and changes of platelet counts of CT-guided percutaneous radiofrequency ablation of normal spleen in a porcine model. CONCLUSION: It is feasible and safe to perform CT-guided percutaneous radiofrequency ablation of the spleen in a pig. Although further study is still required in clinical applications, this method can be a minimally invasive and effective therapeutic technique in patients with hypersplenism.

Comparison of dynamic FDG-microPET study in a rabbit turpentine-induced inflammatory model and in a rabbit VX2 tumor model.

PURPOSE: We investigated the optimum time for the differentiation tumor from inflammation using dynamic FDG-microPET scans obtained by a MicroPET P4 scanner in animal models. MATERIALS AND METHODS: Forty-six rabbits with 92 inflammatory lesions that were induced 2, 5, 7, 14, 30 and 60 days after 0.2 ml (Group 1) or 1.0 ml (Group 2) of turpentine oil injection were used as inflammatory models. Five rabbits with 10 VX2 tumors were used as the tumor model. Helical CT scans were performed before the PET studies. In the PET study, after 4 hours fasting, and following transmission scans and dynamic emission data acquisitions were performed until 2 hours after intravenous FDG injection. Images were reconstructed every 10 minutes using a filtered-back projection method. PET images were analyzed visually referring to CT images. For quantitative analysis, the inflammation-to-muscle (I/M) ratio and tumor-to-muscle (T/M) ratio were calculated after regions of interest were set in tumors and muscles referring to CT images and the time-I/M ratio and time-T/M ratio curves (TRCs) were prepared to show the change over time in these ratios. The histological appearance of both inflammatory lesions and tumor lesions were examined and compared with the CT and FDG-microPET images. RESULTS: In visual and quantitative analysis, All the I/M ratios and the T/M ratios increased over time except that Day 60 of Group 1 showed an almost flat curve. The TRC of the T/M ratio showed a linear increasing curve over time, while that of the I/M ratios showed a parabolic increasing over time at the most. FDG uptake in the inflammatory lesions reflected the histological findings. For differentiating tumors from inflammatory lesions with the early image acquired at 40 min for dual-time imaging, the delayed image must be acquired 30 min after the early image, while imaging at 90 min or later after intravenous FDG injection was necessary in single-time-point imaging. CONCLUSION: Our results suggest the possibility of shortening the overall testing time in clinical practice by adopting dual-time-point imaging rather than single-time-point imaging.

A Semiquantitative Computed Tomographic Grading System for Evaluating Therapeutic Response in Pulmonary Alveolar Proteinosis.

RATIONALE: A useful semiquantitative method of using computed tomographic (CT) images to evaluate therapeutic response in pulmonary alveolar proteinosis (PAP) has not been established, although the extent score or grading score of ground-glass opacities has been used. OBJECTIVES: The purpose of this study was to establish a semiquantitative method for evaluating therapeutic response in PAP. METHODS: CT scans were obtained within 1 month before and after therapy from 32 patients with PAP who participated in a multicenter phase II trial of granulocyte-macrophage colony-stimulating factor inhalation therapy. The scans were evaluated by two chest radiologists independently. Increased parenchymal opacity was evaluated on the basis of its intensity and extent (CT grade), and the severity scores were compared with CT scores based on the extent alone (CT extent), as well as on the basis of physiological and serological results. RESULTS: CT grade score and CT extent score had significant correlation with diffusing capacity of the lung for carbon monoxide percent predicted (%DlCO), PaO2, VC percent predicted (%VC), Krebs von den Lungen (KL)-6, and surfactant protein D. The change in CT grade score between pre- and post-treatment examinations (ΔCT grade) correlated better with difference of PaO2 between pre- and post-treatment examinations (ΔPaO2) than ΔCT extent (difference of CT extent score between pre- and post-treatment examinations). In univariate analysis, ΔCT grade, ΔCT extent, ΔKL-6, Δ%DlCO, Δ%VC, and change in surfactant protein D correlated significantly with ΔPaO2. In multivariate analysis, ΔCT grade and ΔKL-6 correlated more closely with ΔPaO2. CONCLUSIONS: Although a number of CT variables were collected, the currently proposed grading system that correlates well with PaO2 should be viewed as a retrospective scoring system that needs future validation with another PAP cohort.