Usefulness of abdominal belt for restricting respiratory cardiac motion and improving image quality in myocardial perfusion PET.

BACKGROUND: The current study evaluated the usefulness of a belt technique for restricting respiratory motion of the heart and for improving image quality of 13N-ammonia myocardial PET/CT, and it assessed the tolerability of the belt technique in the clinical setting. METHODS: Myocardial 13N-ammonia PET/CT scanning was performed in 8 volunteers on Discovery PET/CT 690 with an optical respiratory motion tracking system. Emission scans were performed with and without an abdominal belt. The amplitude of left ventricular (LV) respiratory motion was measured on respiratory-gated PET images. The degree of erroneous decreases in regional myocardial uptake was visually assessed on ungated PET images using a 5-point scale (0 = normal, 1/2/3 = mild/moderate/severe decrease, 4 = defect). The tolerability of the belt technique was evaluated in 53 patients. RESULTS: All subjects tolerated the belt procedure. The amplitude of the LV respiratory motion decreased significantly with the belt (8.1 ± 7.1 vs 12.1 ± 6.1 mm, P = .0078). The belt significantly improved the image quality scores in the anterior (0.29 ± 0.81 vs 0.71 ± 1.04, P = .015) and inferior (0.33 ± 0.92 vs 1.04 ± 1.04, P < .0001) wall. No adverse events related to the belt technique were observed. CONCLUSIONS: The belt technique restricts LV respiratory motion and improves the image quality of myocardial PET/CT, and it is well tolerated by patients.

Frequency of and risk factors for complications after liver radiofrequency ablation under CT fluoroscopic guidance in 1500 sessions: single-center experience.

OBJECTIVE: The purpose of this article is to retrospectively evaluate the frequency of and risk factors for complications after liver radiofrequency ablation (RFA). MATERIALS AND METHODS: This was a retrospective study of 656 patients (with 1755 liver tumors) who underwent 1500 CT fluoroscopy-guided liver RFA sessions. Of those patients, 501 had primary liver tumor and 155 had liver metastases. Mortality and treatment-related complications were documented. Complications were evaluated according to the Common Terminology Criteria for Adverse Events (version 4.0). Major complications were defined as grade 3 or higher adverse events. Factors affecting frequent complications with a frequency of 1% or more were detected using multivariate analysis. RESULTS: Two deaths (0.1% [2/1500]) occurred. One patient died of liver failure subsequent to hemorrhage, and the other died of liver failure. The major complication rate was 2.8% (42/1500). The most frequent major complication was hemorrhage (1.1% [16/1500]). The absence of arterial embolization before RFA (p < 0.01), low hemoglobin level (p < 0.04), and elevated serum creatinine level (p < 0.04) were identified as significant risk factors for major hemorrhage. The minor complication rate was 17.1% (257/1500). Pneumothorax (7.7% [116/1500]) was the most frequent minor complication, followed by hemorrhage (7.0% [105/1500]). A transthoracic approach (p < 0.01) and subphrenic tumor location (p < 0.01) were significant risk factors for pneumothorax, and the use of a cluster needle (p < 0.02) and multiple tumors (p < 0.01) were significant risk factors for minor hemorrhage. CONCLUSION: CT fluoroscopy-guided RFA is a safe procedure with an acceptably low rate of major complications for liver tumor treatment. Factors identified in this study will help to stratify high-risk patients.

Computed tomography fluoroscopy-guided radiofrequency ablation following intra-arterial iodized-oil injection for hepatocellular carcinomas invisible on ultrasonographic images.

BACKGROUND: We aimed to evaluate therapeutic outcomes of radiofrequency (RF) ablation following intra-arterial iodized-oil injection for hepatocellular carcinomas (HCCs) invisible on ultrasonographic (US) images. MATERIALS AND METHODS: Informed consent was waived for this retrospective study approved by our institutional review board. Sixty-seven consecutive patients with 150 HCCs (mean diameter 1.3 ± 0.6 cm; range 0.5-4.2 cm) received 90 RF sessions following intra-arterial iodized-oil injection. Each patient had at least one HCC invisible on US images. Computed tomography (CT) fluoroscopy-guided RF ablation was performed within 1 week after the injection of iodized oil from feeding arteries of each tumor. Technical success was defined as a planned electrode placement and completion of ablation protocol. Technical success, complications, changes in liver function, local tumor progression, and survival were evaluated. RESULTS: All HCCs became visible on CT fluoroscopy after iodized-oil injection, and RF ablation was technically successful in all sessions (technical success rate, 100%, 90/90). Major complications occurred in 6 RF sessions (6.7%, 6/90), including hemorrhage (2.2%, 2/90), portal thrombosis (2.2%, 2/90), and pneumothorax (2.2%, 2/90). No significant deterioration in Child-Pugh score was found. The mean follow-up period was 23.2 ± 18.0 months. The cumulative local tumor progression rates and overall survival rates were, respectively, 3.9 and 82.7% at 1 year, 5.3 and 45.3% at 3 years, and 5.3 and 26.4% at 5 years. CONCLUSION: CT fluoroscopy-guided RF ablation following intra-arterial iodized-oil injection is a feasible, safe, and useful therapeutic option for HCCs invisible on US images.

Factors influencing the outcome of image-guided percutaneous drainage of intra-abdominal abscess after gastrointestinal surgery.

PURPOSE: To improve the selection of patients for percutaneous abscess drainage (PAD) to treat postoperative intra-abdominal abscess after gastrointestinal surgery, we investigated the factors predictive of outcome. METHODS: Of 143 consecutive patients with symptomatic postoperative intra-abdominal abscess after a gastrointestinal tract resection, 104 who underwent image-guided PAD as the initial treatment were reviewed. We assessed the possible associations between successful PAD and patient-, abscess-, surgical-, and drainage-related variables, and investigated the success rates of PAD for patients with vs. those without the factors related to successful outcome. RESULTS: Based on monitoring for 1 year after PAD, the success rate of this procedure was 85.6% (89/104). Multivariate analysis revealed that the interval between surgery and the onset of abscess (p = 0.0234) and a single abscess (p = 0.0038) were independently associated with a successful outcome. Single late-onset abscess resolved completely within 10 weeks in 91.4% of these patients. CONCLUSIONS: Despite new strategies aimed at preventing surgical site infection, PAD remains an important factor in the postoperative management of gastrointestinal surgery in Japan. Initial recognition of the day of onset and the number of abscesses are important prognostic factors.

Computer-aided detection scheme for sentinel lymph nodes in lymphoscintigrams using symmetrical property around mapped injection point.

It is difficult to detect sentinel lymph nodes (SLNs) around an injection point of radiopharmaceuticals mapped in lymphoscintigrams. The purpose of this study was to develop a computer-aided detection (CAD) scheme for SLNs by a subtraction technique using the symmetrical property in the mapped injection point. Our database consisted of 78 lymphoscintigrams with 86 SLNs. In our CAD scheme, the mapped injection point of radiopharmaceuticals was first segmented from the lymphoscintigram using a gray-level thresholding technique. Lymphoscintigram was then divided into four regions by vertical and horizontal straight lines through the center of the segmented injection point. One of the four divided regions was defined as the target region. The correlation coefficients based on pixel values were calculated between the target region and each of the other three regions. The region with the highest correlation coefficient among three regions was selected as the similar region to the target region. The values of pixels on the target region were subtracted by the values of the corresponding pixels on the similar region. This procedure was repeated until every divided region had been used as target region. SLNs were segmented by applying a gray-level thresholding technique to the subtracted image. With our CAD scheme, sensitivity and the number of false positives were 95.3% (82/86) and 2.51 per image, respectively. Our CAD scheme achieved a high level of detection accuracy, and would have a great potential in assisting physicians to detect SLNs in lymphoscintigrams.

Quantification of myocardial blood flow using model based analysis of first-pass perfusion MRI: extraction fraction of Gd-DTPA varies with myocardial blood flow in human myocardium.

For the absolute quantification of myocardial blood flow (MBF), Patlak plot-derived K1 need to be converted to MBF by using the relation between the extraction fraction of gadolinium contrast agent and MBF. This study was conducted to determine the relation between extraction fraction of Gd-DTPA and MBF in human heart at rest and during stress. Thirty-four patients (19 men, mean age of 66.5 ± 11.0 years) with normal coronary arteries and no myocardial infarction were retrospectively evaluated. First-pass myocardial perfusion MRI during adenosine triphosphate stress and at rest was performed using a dual bolus approach to correct for saturation of the blood signal. Myocardial K1 was quantified by Patlak plot method. Mean MBF was determined from coronary sinus flow measured by phase contrast cine MRI and left ventricle mass measured by cine MRI. The extraction fraction of Gd-DTPA was calculated as the K1 divided by the mean MBF. The extraction fraction of Gd-DTPA was 0.46 ± 0.22 at rest and 0.32 ± 0.13 during stress (P < 0.001). The relationship between extraction fraction (E) and MBF in human myocardium can be approximated as E = 1 - exp(-(0.14 × MBF + 0.56)/MBF). The current results indicate that MBF can be accurately quantified by Patlak plot method of first-pass myocardial perfusion MRI by performing a correction of extraction fraction.

Percutaneous radiofrequency ablation for pulmonary metastases from hepatocellular carcinoma: results of a multicenter study in Japan.

PURPOSE: To retrospectively evaluate technical success, effectiveness, complications, patient survival, and prognostic factors with percutaneous radiofrequency (RF) ablation for pulmonary metastases resulting from hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Thirty-two patients from six institutions were included, with a total of 83 pulmonary metastases treated in 65 sessions. RF ablation was always performed percutaneously with computed tomography (CT) guidance. Primary endpoints were technical success and technique effectiveness. Technique effectiveness was evaluated based on sequential follow-up CT images. Secondary study endpoints were complications, patient survival, and determination of prognostic factors. Complications were classified as major or minor. Prognostic factors were determined by analyzing multiple variables with the log-rank test. RESULTS: Technical success rate was 100%. Primary technique effectiveness rates were 92% each at 1, 2, and 3 years. Major and minor complications occurred after 16 (25%) and 23 (35%) of the 65 sessions, respectively. The median follow-up period was 20.5 months. Overall survival rates were 87% at 1 year and 57% each at 2 and 3 years (median and mean survival times, 37.7 mo and 43.2 mo, respectively). Significantly better survival rates were obtained in cases of (i) no viable intrahepatic recurrence (P < .001), (ii) Child-Pugh class A disease (P < .001), (iii) absence of liver cirrhosis (P < .001), (iv) absence of hepatitis C virus infection (P = .006), and (v) α-fetoprotein level of 10 ng/mL or lower (P = .007) at the time of RF ablation. CONCLUSIONS: RF ablation appears effective, with an acceptable safety profile, in selected patients with pulmonary metastases resulting from HCC.

Radiofrequency ablation combined with chemoembolization: treatment of recurrent hepatocellular carcinomas after hepatectomy.

OBJECTIVE: The purpose of this study is to evaluate the treatment effect and prognostic factors of radiofrequency ablation (RFA) combined with chemoembolization for patients with recurrent hepatocellular carcinomas (HCCs) after hepatectomy. MATERIALS AND METHODS: Fifty-five consecutive patients who received combination therapy as a curative treatment of recurrent HCCs after hepatectomy were included in this retrospective study. The mean maximum tumor diameter was 2.2 cm (range, 1.0-4.8 cm). Under CT fluoroscopic guidance, RFA was performed 1-2 weeks after chemoembolization. Technique effectiveness rates, complications, local tumor progression rates, survival rates, and prognostic factors were evaluated. RESULTS: Tumor enhancement disappeared on contrast-enhanced CT images in all patients after 72 RFA sessions (technique effectiveness rate, 100%). Pneumothorax requiring chest drainage was the only major complication that developed in one RFA session (1%). Four of 55 patients (7%) showed local tumor progression. New tumors emerged in the untreated liver in 27 patients (49%) during the mean follow-up of 35 months (range, 1-82 months). The 5-year overall and recurrence-free survival rates after combination therapy were 74% (95% CI, 54-87%) and 28% (95% CI, 14-45%), respectively. The presence of a single tumor at initial hepatectomy and a low α-fetoprotein level (≤ 100 ng/mL) at recurrence were significantly favorable independent factors affecting overall and recurrence-free survival. CONCLUSION: For treatment of recurrent HCCs after hepatectomy, RFA combined with chemoembolization is a useful therapeutic option. This study identified prognostic factors that will help to stratify patients with recurrent HCCs after hepatectomy.

Optimal scan parameters for CT fluoroscopy in lung interventional radiologic procedures: relationship between radiation dose and image quality.

PURPOSE: To evaluate the relationship between radiation doses and lung computed tomographic (CT) fluoroscopic scan parameters and to determine optimal scan parameters for performance of lung interventional radiologic (IR) procedures. MATERIALS AND METHODS: The institutional review board approved this prospective study, which included 32 patients with a single lung tumor; written informed consent was obtained. CT fluoroscopic images were obtained with three tube voltages (80,120,135 kV) and three tube currents (10, 20, 30 mA) in each patient. The signal-to-noise ratios (SNRs) and the contrast-to-noise ratios (CNRs) were measured quantitatively. To evaluate the feasibility of performing lung IR procedures, four readers visually scored the image quality. Acceptable CT fluoroscopic images were determined by using agreement of at least three of the four readers. The weighted CT dose index for each CT scan parameter was measured. A piecewise linear regression equation was obtained from the relationship between radiation doses and visual image scores. RESULTS: Both the SNR and the CNR improved as the radiation dose increased, leading to improvement in the image quality. Acceptable image quality was achieved in 94% (30 of 32) of patients when the radiation dose was 1.18 mGy/sec (120 kV, 10 mA) and in all patients when it was greater than 1.48 mGy/sec (135 kV, 10 mA). The piecewise linear curve showed rapid improvement in image quality until the radiation dose increased to 1.48 mGy/sec (135 kV, 10 mA). When the radiation dose was increased greater than 1.48 mGy/sec, improvement in the image quality became more gradual. CONCLUSION: Results of this study can be used to guide the determination of optimal scan parameters in lung CT fluoroscopy.

Radiofrequency ablation for the treatment of bone metastases from hepatocellular carcinoma.

OBJECTIVE: The objective of our study was to retrospectively evaluate the clinical utility of bone radiofrequency ablation in patients with bone metastases from hepatocellular carcinoma (HCC). MATERIALS AND METHODS: At three institutions, 40 consecutive HCC patients with 54 bone metastases received radiofrequency ablation. The mean maximum diameter of the bone metastases was 4.8 +/- 2.3 (SD) cm (range, 1.0-12.0 cm). The feasibility and safety of the procedure and the pain relief achieved from the procedure were reviewed. Technical success was defined as correct placement of the radiofrequency electrode into the tumor target and completion of the planned ablation protocol. Survival and prognostic factors were evaluated. RESULTS: Technical success was 100%. No major complication occurred aside from transient nerve injury in one patient (2.5%, 1/40). Pain relief was achieved in all patients with painful bone metastases except one (96.6%, 28/29). The respective 1-, 2-, and 3-year survival rates were 34.2% (95% CI, 19.2-49.1), 19.9% (95% CI, 7.0-32.8), and 10.0% (95% CI, 0-20.2), with a median survival time of 7.1 months. Complete ablation of bone metastases, a single bone lesion, negative alpha-fetoprotein levels, and the absence of viable intrahepatic lesions were significant factors for a better prognosis. The median survival time was, respectively, 12.5 months in 16 patients with negative alpha-fetoprotein levels, 16.8 months in 12 patients with complete tumor ablation, 16.8 months in 16 patients with a single bone metastasis, and 21.9 months in 17 patients with no viable intrahepatic HCCs. CONCLUSION: Bone radiofrequency ablation is a safe, useful, and feasible therapeutic option for relieving pain in patients with HCC bone metastases. Prognostic factors reported herein can facilitate stratification of patients with HCC bone metastases.

Subphrenic versus nonsubphrenic hepatocellular carcinoma: combined therapy with chemoembolization and radiofrequency ablation.

OBJECTIVE: This retrospective study was conducted to evaluate the clinical utility of the combination of chemoembolization and real-time CT fluoroscopically guided radiofrequency ablation in the treatment of patients with subphrenic hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Patients who had a single HCC with a maximum diameter of 5 cm or less were included in the study. None of the patients was a candidate for surgery, and all underwent combination therapy as initial treatment. The patients were divided into two groups based on tumor location. In all, the 93 men and 38 women (mean age, 67.9 +/- 9.4 years; range, 43-83 years) had 46 subphrenic HCCs and 85 nonsubphrenic HCCs. No differences were found in the pretreatment baseline characteristics of the two patient groups. Safety profiles, local tumor progression rates, and prognoses were compared. RESULTS: Tumor enhancement disappeared after 58 radiofrequency sessions (1.3 sessions/tumor) in patients with subphrenic HCC and after 104 radiofrequency sessions (1.2 sessions/tumor) in patients with nonsubphrenic HCC. The 5-year local tumor progression rates (subphrenic, 3% [95% CI, 0.2-12%]; nonsubphrenic, 9% [95% CI, 3-20%]; p = 0.31) and survival rates (subphrenic, 63% [95% CI, 36-81%]; nonsubphrenic, 69% [95% CI, 53-81%]; p = 0.55) were similar for the two patient groups. Although the incidence of self-limited pneumothorax was significantly higher among the patients with subphrenic HCC (13.8% vs 3.85%; p < 0.03), other complication rates were similar for the two patient groups. CONCLUSION: Combination therapy with chemoembolization and real-time CT-guided radiofrequency ablation is safe and useful even when HCC is in the subphrenic region.

Regional myocardial perfusion reserve determined using myocardial perfusion magnetic resonance imaging showed a direct correlation with coronary flow velocity reserve by Doppler flow wire.

AIMS: Quantitative analysis of rest-stress myocardial perfusion magnetic resonance imaging (MRI) can provide assessments of regional myocardial perfusion reserve (MPR). The purpose of this study was to compare regional MPR determined by myocardial perfusion MRI with coronary flow reserve (CFR) by intracoronary Doppler flow wire. METHODS AND RESULTS: Twenty patients with suspected coronary artery disease (CAD) were studied. Average peak velocity was measured by Doppler flow wire in the resting state and during adenosine triphosphate (ATP) stress in 36 coronary arteries. CFR measurements for each patient were performed in the culprit and one non-culprit non-stenotic artery. First-pass, contrast-enhanced myocardial perfusion MR images were obtained in the resting state and during ATP stress within the week before the Doppler wire procedure. Regional myocardial blood flow (MBF) was quantified in 16 myocardial segments by analysing arterial input and myocardial output using a Patlak plot method. MPR was calculated as stress MBF divided by rest MBF. CFR measured by Doppler flow wire was compared with MPR in the myocardial segments corresponding to vessel territories. The average MPR measured by perfusion MRI was 1.77 +/- 0.62 for the culprit arteries and 3.45 +/- 0.78 for the non-culprit arteries, respectively (P < 0.001). The averaged CFR by Doppler flow wire was 1.72 +/- 0.44 in the culprit arteries and 3.14 +/- 0.74 in the non-culprit arteries, respectively (P < 0.001). For both culprit and non-culprit vessel groups, significant direct correlations were observed between MR assessments of MPR and Doppler assessments of CFR (culprit artery: R = 0.87, Non-culprit artery: R = 0.86) On Bland-Altman analysis, the mean differences between MPR determined by myocardial perfusion MRI and CFR measured by Doppler wire were 0.05 in culprit arteries (95% limit of agreement; -0.65 to 0.56) and 0.36 in non-culprit arteries (95% limit of agreement; -1.24 to 0.44). The sensitivity and specificity of MR measurement of MPR for predicting physiologically significant reduction of Doppler CFR (<2) was 88% (95% CI 61.7-98.5) and 90% (95% CI 68.3-98.8), respectively. CONCLUSION: The current results using Doppler flow wire as a reference method demonstrated that quantitative analysis of stress-rest myocardial perfusion MRI can provide a non-invasive assessment of reduced MPR in patients with CAD.

Quantitative analysis of first-pass contrast-enhanced myocardial perfusion MRI using a Patlak plot method and blood saturation correction.

The objectives of this study were to develop a method for quantifying myocardial K(1) and blood flow (MBF) with minimal operator interaction by using a Patlak plot method and to compare the MBF obtained by perfusion MRI with that from coronary sinus blood flow in the resting state. A method that can correct for the nonlinearity of the blood time-signal intensity curve on perfusion MR images was developed. Myocardial perfusion MR images were acquired with a saturation-recovery balanced turbo field-echo sequence in 10 patients. Coronary sinus blood flow was determined by phase-contrast cine MRI, and the average MBF was calculated as coronary sinus blood flow divided by left ventricular (LV) mass obtained by cine MRI. Patlak plot analysis was performed using the saturation-corrected blood time-signal intensity curve as an input function and the regional myocardial time-signal intensity curve as an output function. The mean MBF obtained by perfusion MRI was 86 +/- 25 ml/min/100 g, showing good agreement with MBF calculated from coronary sinus blood flow (89 +/- 30 ml/min/100 g, r = 0.74). The mean coefficient of variation for measuring regional MBF in 16 LV myocardial segments was 0.11. The current method using Patlak plot permits quantification of MBF with operator interaction limited to tracing the LV wall contours, registration, and time delays.

Percutaneous radiofrequency ablation for unresectable pulmonary metastases from renal cell carcinoma.

OBJECTIVE: To evaluate the clinical utility of lung radiofrequency ablation (RFA) in patients with unresectable pulmonary metastasis from renal cell carcinoma (RCC). PATIENTS AND METHODS: We retrospectively examined 39 patients with unresectable metastases from RCC who were treated with lung RFA. Patients with six or fewer lung metastases measuring < or =6 cm that were confined in the lung, had all lung tumours ablated (curative ablation). Patients with extrapulmonary lesions, seven or more lung tumours, or large tumours of >6 cm, had mass reduction (palliative ablation). The primary endpoints was the overall survival, secondary endpoints were safety, local tumour progression rate, and recurrence-free survival in the curative ablation group. RESULTS: There were significant differences in the overall survival rates between the curative and palliative groups at 1 year (100% vs 90%), 3 years (100% vs 52%) and 5 years (100% vs 52%) (P < 0.05). The maximum lung tumour diameter was also a significant prognostic factor. There was local tumour progression in 13 patients (33%) during the mean follow-up of 25 months. The recurrence-free survival rates were 92% at 1 year, 23% at 3 years and 23% at 5 years in the curative ablation group. Pneumothorax requiring chest tube placement (six of 89, 7%) and pneumonia (one of 89, 1%) were major complications. CONCLUSION: Lung RFA is a safe and effective treatment for prolonging survival in patients with unresectable RCC lung metastases.

Radiofrequency ablation combined with chemoembolization for the treatment of hepatocellular carcinomas larger than 5 cm.

PURPOSE: To evaluate survival, recurrence-free survival, technical success, technique effectiveness, and safety of radiofrequency (RF) ablation combined with chemoembolization in patients with hepatocellular carcinomas (HCCs) larger than 5 cm. MATERIALS AND METHODS: Patients with Child-Pugh class A or B cirrhosis and three or fewer HCCs with a maximum tumor diameter of 5.1-10 cm were included. Twenty patients with 32 HCCs were included. There were 16 men and four women with mean age of 69 years +/- 7.4 (range, 46-79 years).The maximum mean tumor diameter was 6.2 cm (range, 5.1-9.5 cm). RF ablation was performed under computed tomographic (CT) fluoroscopic guidance 1-2 weeks after chemoembolization. The primary endpoint of this study was survival. RESULTS: RF electrodes were placed in the planned sites, and RF ablation was completed with a planned protocol (technical success rate, 100%). Tumor enhancement was eradicated in all patients after 32 RF sessions. The primary and secondary technique effectiveness rates were 40% and 100%, respectively. There were two major complications in the 32 RF sessions (6%)--hepatic abscess and diaphragm perforation. Local tumor progression developed in five of the 20 patients (25%) during the mean follow-up of 30 months. The overall and recurrence-free survival rates were, respectively, 100% and 74% at 1 year, 62% and 28% at 3 years, and 41% and 14% at 5 years. The serum bilirubin level of 1.0 mg/dL (17.1 micromol/L) or less was a significantly better prognostic factor in the univariate analysis. CONCLUSIONS: This combination therapy may enhance survival in patients with HCCs larger than 5 cm.

Long-term results of radiofrequency ablation in colorectal lung metastases: single center experience.

This study was undertaken to evaluate long-term results of radiofrequency (RF) ablation in patients with colorectal lung metastases and to stratify patients benefitting from lung RF ablation. Lung RF ablation was performed in 78 patients with 198 colorectal lung metastases. Safety, local tumor progression, and survival were evaluated retrospectively. The mean follow-up period after the 140 lung RF ablation sessions was 24.6+/-7.6 months. Pneumothorax and pleural effusion requiring chest tube placement occurred respectively in 18 (12.9%, 18/140) and 2 (1.4%, 2/140) sessions. The respective 1-, 3- and 5-year local tumor progression rates were 10.1% (95% CI, 2.9-17.3%), 20.6% (95% CI, 8.9-22.2%) and 20.6% (95% CI, 8.9-22.2%). The 1-, 3- and 5-year survival rates were 83.9% (95% CI, 75.2-92.7%), 56.1% (95% CI, 41.7-70.5%) and 34.9% (95% CI, 18.0-51.9%), with median survival time of 38.0 months. Univariate analysis revealed maximum tumor diameter of 3 cm or less, single-lung metastasis, lack of extrapulmonary metastasis and normal carcinoembryonic antigen (CEA) level as better prognostic factors. The latter two were significant independent prognostic factors. The 1-, 3- and 5-year survival rates were 97.7% (95% CI, 93.3-100%), 82.5% (95% CI, 68.2-96.8%) and 57.0% (95% CI, 34.7-79.2%) in 54 patients with no extrapulmonary metastases and 96.9% (95% CI, 90.8-100%), 86.1% (95% CI, 71.1-100%) and 62.5% (95% CI, 36.3-88.6%) in 33 patients with negative CEA levels. Lung RF ablation is a safe and useful therapeutic option. These identified prognostic factors will help to stratify patients who benefit from lung RF ablation.

Adrenal metastasis from hepatocellular carcinoma: radiofrequency ablation combined with adrenal arterial chemoembolization in six patients.

OBJECTIVE: The purpose of this study was to evaluate the clinical utility of adrenal radiofrequency ablation combined with adrenal arterial chemoembolization in the treatment of patients with adrenal metastasis of hepatocellular carcinoma. MATERIALS AND METHODS: This retrospective study was conducted at two institutions. Adrenal radiofrequency ablation and chemoembolization were performed on the same day. Safety, local tumor progression, and survival were evaluated. RESULTS: Six patients with eight adrenal metastatic lesions were treated. The mean maximum diameter of the lesions was 5.2 +/- 1.8 cm (range, 3.5-8.0 cm). During initial combination therapy, an adrenal metastatic lesion was isolated in one patient. The other five patients had four associated intrahepatic lesions and three extraadrenal distant metastatic lesions. On contrast-enhanced CT scans, tumor enhancement of all eight adrenal tumors ceased after combination therapy. No major complications were related to combination therapy. During the mean follow-up period of 37.7 +/- 27.6 months (range, 4.0-70.9 months), two of eight adrenal tumors (25%) had undergone local tumor progression. The median survival time was 24.9 months. Three patients treated for both intrahepatic and extrahepatic lesions survived longer than 4 years. CONCLUSION: The combination therapy described is a safe multidisciplinary therapeutic option that can lengthen survival among patients with adrenal metastasis from hepatocellular carcinoma.

Three-dimensional stereotactic ROI template for measuring regional cerebral blood flow in 99mTc-ECD SPECT: comparison with the manual tracing method.

PURPOSE: The three-dimensional stereotactic region of interest template (3DSRT) is computer software, which enables the automatic measurement of regional cerebral blood flow (rCBF). This study was undertaken to compare the rCBF values obtained using the 3DSRT method and the conventional manual tracing method. MATERIALS AND METHODS: Twelve patients with normal brains who underwent technetium-99m L,L-ethyl cysteinate dimer single-photon emission computed tomography studies were enrolled in this study. The brains were divided into 12 segments in each hemisphere, and rCBF was measured in each segment. The regions of interest were automatically placed in the segments in the 3DSRT method and were manually traced by five nuclear medicine technicians in the manual tracing method. The rCBF values obtained were compared between the two methods. Interoperator reliability was evaluated in the manual tracing method. RESULTS: The rCBF values were significantly higher in the manual tracing method than in the 3DSRT method in all segments except for the angular segment. A good correlation was seen between the two methods in the rCBF values in 10 (83.3%) of the 12 brain segments (range of coefficient of determinations: 0.73-0.94). A poor correlation, however, was seen in the pericallosal (0.50) and hippocampal (0.53) segments. Interoperator reliability was lower in these two segments than in the other segments in the manual tracing method. CONCLUSION: Although the rCBF values obtained using the manual tracing method and the 3DSRT method show good correlation in most segments, care is required when comparing the results for the pericallosal and hippocampal segments.

Stent placement for portal venous stenosis following major abdominal surgery.

BACKGROUND/AIMS: This study was retrospectively undertaken to evaluate clinical utility of portal venous stent placement in the treatment of portal venous stenosis after major abdominal surgery combined with portal reconstruction. METHODOLOGY: Portal venous stent placement was done in 4 consecutive patients with anastomotic portal venous stenosis following major abdominal surgery combined with portal reconstruction. Liver dysfunction developed in all patients and consciousness loss in one patient, 1-55 days (mean, 19 days) after surgical intervention. Portal venous blood flow was not recognized by Doppler ultrasonographic studies in all patients. Expandable metallic stents were placed in the portal vein by percutaneous transhepatic approach in 2 patients and by transiliac approach in the other 2 patients. RESULTS: Stents were successfully placed across the anastomotic stenosis in all patients. Portal venous blood flow restored immediately after stent placement and liver dysfunction and consciousness loss resolved. Portal venous blood flow was maintained during the follow-up period ranging from 99 days to 765 days (mean, 438 days) in all patients. CONCLUSIONS: Portal venous stent placement is a useful therapeutic option for the treatment of anastomotic stenosis of portal vein following major abdominal surgery combined with portal reconstruction.

Value of the apparent diffusion coefficient for quantification of low-grade hepatic encephalopathy.

BACKGROUND AND AIMS: Minimal hepatic encephalopathy (HE) is associated with poorer quality of life and increased work disability. Recently, low-grade cerebral edema has been implicated in chronic liver disease. METHODS: We measured the apparent diffusion coefficient (ADC) of water in various regions of the brains of patients with cirrhosis, and elucidated the significance of the evaluation of ADC in quantifying low-grade HE and predicting overt HE and survival. Forty patients with cirrhosis and 24 controls underwent diffusion-weighted imaging, and patients were followed up every month. RESULTS: The mean ADC values were increased in cirrhotic patients with minimal HE versus no HE or controls. Minimal HE patients separated from no HE patients with a sensitivity of 70 approximately 90% and a specificity of 85 approximately 90%. ADC values correlated with individual neuropsychological tests. ADC values of white matter, such as the frontal (log-rank test 4.35, P < 0.05) and parietal (log-rank test 5.98, P < 0.05) white matter, was predictive of further bouts of overt HE. CONCLUSIONS: ADC is a reliable tool for quantification of low-grade HE, and could predict the development of overt HE.