Local Control of Squamous Cell Carcinoma of the Cervix Treated with CT-based Three-dimensional Image-Guided Brachytherapy with or without Central Shielding.

The purposes of this retrospective study were to analyze local control of squamous cell carcinoma of the cervix treated with computed tomography (CT)-based image-guided brachytherapy (IGBT), as well as the factors affecting local control. A total of 39 patients were analyzed. The prescribed dose to the pelvis was 45-50 Gy with or without central shielding (CS). IGBT was delivered in 1-5 fractions. The total dose for high-risk clinical target volume (HR-CTV) was calculated as the biologically equivalent dose in 2-Gy fractions. The median follow-up period was 29.3 months. The 2-year overall survival and local control rates were 97% and 91%, respectively. In univariate analysis, the dose covering 90% of the HR-CTV (D90) and tumor size were found to be significant factors for local control. The cutoff values of tumor size and D90 for local control were 4.3 cm (area under the curve [AUC] 0.75) and 67.7 Gy (AUC 0.84) in the CS group and 5.3 cm (AUC 0.75) and 73.7 Gy (AUC 0.78) in the group without CS, respectively. However, though the local control of CT-based IGBT was favorable, the results suggested that the dose required for tumor control may differ depending on the presence of CS.

Feasibility of 5-mm vs 2.5-mm width multileaf collimator in noncoplanar volumetric modulated arc stereotactic radiotherapy for multiple brain metastases.

The aim of this study was to examine the feasibility of noncoplanar volumetric modulated arc stereotactic radiotherapy (VMAT-SRT) using a 5-mm multileaf collimator (MLC) for multiple brain metastases. We identified 34 multiple-target cases (3 to 19 targets in each case) with a total of 257 of targets and constructed noncoplanar VMAT-SRT plans using 5-mm and 2.5-mm MLCs with 4-arc. The prescribed dose was 36 Gy/6 fr. Plans were evaluated using the Paddick conformity indices (PCI), Paddick gradient index (PGI), and normal brain dose (NBD, equal to the mean brain dose minus gross tumor volume). There were no significant differences in PCI (median [range]: 5 mm, 0.88 [0.78 to 0.94]; 2.5 mm, 0.89 [0.78 to 0.94]; p= 0.691), PGI (median [range]: 5 mm, 3.96 [2.21 to 6.63]; 2.5 mm, 3.96 [2.24 to 6.45]; p= 0.358), or NBD (median [range]: 5 mm, 7.5 Gy [2.5 to 12.4]; 2.5 mm, 7.5 Gy [2.5 to 12.5]; p= 0.675). The performance of the 5-mm MLC was not inferior to the 2.5-mm MLC in applications of noncoplanar VMAT-SRT for multiple brain metastases with regards to dose conformity, gradient, and NBD. This study provides the necessary background for generalizing noncoplanar VMAT-SRT approaches in treating multiple brain lesions.

An Adult Case of Nasal Chondromesenchymal Hamartoma: Imaging Characteristics Including Diffusion-Weighted Images.

Nasal chondromesenchymal hamartoma (NCMH), a rare, benign, nasal cavity tumor, typically occurs in children. Differential diagnosis is difficult because NCMH often presents with non-specific findings, including cystic components and invasion of the surrounding area on T2-weighted magnetic resonance images. Here, we present a rare adult case of NCMH, with no clear hyperintensity on diffusion-weighted images (DWI), and bone remodeling on the tumor margins on computed tomography. To the best of our knowledge, this is the first report of DWI on NCMH, and these findings, which suggest benign disease, may be useful in diagnosing NCMH.

Simultaneous Integrated Boost Volumetric Modulated Arc Therapy for Middle or Lower Esophageal Cancer Using Elective Nodal Irradiation: Comparison with 3D Conformal Radiotherapy.

We investigated the feasibility of simultaneous integrated boost (SIB) volumetric modulated arc therapy (VMAT) using elective nodal irradiation (ENI) for middle or lower esophageal cancer and compared it with three-dimensional conformal radiotherapy (3D-CRT). The study included 15 patients. The prescribed doses included a standard dose (50.4 Gy) and a high dose (60 Gy) for the planning target volume (PTV) of the involved lesions. The objective of the whole lung volume receiving ≥ 20 Gy (V20Gy) was < 30%, and the mean lung dose (MLD) was < 20 Gy. The volumes of the lung receiving 5 Gy (V5Gy) and the heart receiving 30-50 Gy (V30-50Gy) were kept as low as reasonably achievable. As a result, SIB-VMAT showed superior dose conformity for the PTV (p<0.001). Although the lung V5Gy was significantly increased (p<0.001), the V20Gy and MLD showed no significant increase. The heart V30-50Gy showed a > 20% reduction in the mean against 3D-CRTs. Our results demonstrate the feasibility of SIB-VMAT for the treatment of middle or lower esophageal cancer with ENI. Although attention should be paid to the low-dose area of the lungs, SIB-VMAT would be a promising treatment option with improved outcomes for esophageal cancer.

Recurrent arterial aneurysm rupture of the upper extremity in a patient with vascular-type Ehlers-Danlos syndrome.

Arterial aneurysm rupture is one of the most critical complications in patients with vascular-type Ehlers-Danlos syndrome (vEDS). Here, we report a case of recurrent aneurysm rupture successfully treated by endovascular embolization. A 38-year old woman who underwent brachial artery ligation for a ruptured aneurysm was diagnosed postoperatively with vEDS. Impending rupture of a collateral artery aneurysm was encountered 5 months after the initial open surgery. Endovascular embolization with a liquid embolic agent was successfully performed. Given that arterial rupture can occur repeatedly in patients with vEDS, careful life-long follow-up is necessary.

Risk factors for systemic air embolism as a complication of percutaneous CT-guided lung biopsy: multicenter case-control study.

PURPOSE: To determine risk factors for systemic air embolism by percutaneous computed tomography (CT)-guided lung biopsy. METHODS: This case-control study used data from 2216 percutaneous lung biopsy procedures performed over 11 years at 12 institutions in Japan. Systemic air embolism was identified by retrospective review of CT images obtained during and immediately after the procedures. To fulfill our objective, multiple variables were compared between cases and controls with univariate analyses by using Student's t test and Fisher's exact test for numerical and categorical values, respectively. Multivariate logistic regression analysis was then performed using selected variables. RESULTS: Ten cases of systemic air embolism and 2,206 controls were identified. Univariate analyses showed that the lesions in the lower lobe (P = 0.025) and occurrence of parenchymal hemorrhage (P = 0.019) were significant risk factors. Multivariate analysis showed that the use of a larger biopsy needle was a significant risk factor (P = 0.014). CONCLUSION: Parenchymal hemorrhage during the procedure, lesions in the lower lobe, and the use of larger biopsy needles may be risk factors for systemic air embolism by percutaneous CT-guided lung biopsy. Our findings may provide clues toward minimizing the risk of this complication.

Radiofrequency ablation of lung cancer at Okayama University Hospital: a review of 10 years of experience.

The application of radiofrequency ablation for the treatment of lung cancer by our group at Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences began in June 2001, and in the present report, we review our 10-year experience with this treatment modality at Okayama University Hospital. The local efficacy of radiofrequency ablation for the treatment of lung cancer depends on tumor size and the type of electrode used, but not on tumor type. An important factor for the prevention of local failure may be the acquisition of an adequate ablative margin. The combination of embolization and radiation therapy enhances the local efficacy. Local failure may be salvaged by repeating the radiofrequency ablation, particularly in small tumors. Survival rates after radiofrequency ablation are quite promising for patients with clinical stage I non-small cell lung cancer and pulmonary metastasis from colorectal cancer, hepatocellular carcinoma, and renal cell carcinoma. The complications caused by radiofrequency ablation can be treated conservatively in the majority of cases. However, attention should be paid to rare but serious complications. This review shows that radiofrequency ablation is a promising treatment for patients with lung cancer.

Radiofrequency ablation of small lung metastases by a single application of a 2-cm expandable electrode: determination of favorable responders.

PURPOSE: To determine which lung metastases are most likely to be treated effectively with a single radiofrequency (RF) application (defined as two separate applications of RF energy at a single electrode position) with a multitined expandable electrode with arrays 2 cm in diameter. MATERIALS AND METHODS: The authors retrospectively evaluated 88 lung metastases (mean long-axis diameter, 0.9 cm) in 36 patients (20 men and 16 women; mean age, 57 years) treated with a single RF application with a multitined expandable electrode with arrays 2 cm in diameter. Based on follow-up computed tomographic examinations, the technique effectiveness rates were estimated with Kaplan-Meier analysis. Multiple variables were analyzed with the log-rank test to determine risk factors for local progression. Then, the technique effectiveness rates were again estimated when considering only metastases without risk factors and compared with those of other tumors. RESULTS: The median follow-up period was 13.2 months (range, 6.0-24.7 months). Tumor size greater than 1.0 cm (P = .033) and contact with the bronchus with an inner diameter of at least 2 mm (P = .047) were the significant risk factors for local progression. The technique effectiveness rates for metastases 1.0 cm or smaller that were not in contact with the bronchus (n = 59) were 96% at 1 year and at 2 years; those rates were significantly (P = .010) higher than those in other tumors (n = 29). CONCLUSIONS: A single RF application with a multitined expandable electrode with arrays 2 cm in diameter is most likely to suffice in small (

Measurement of pleural temperature during radiofrequency ablation of lung tumors to investigate its relationship to occurrence of pneumothorax or pleural effusion.

The purpose of this study was to investigate the relationship between pleural temperature and pneumothorax or pleural effusion after radiofrequency (RF) ablation of lung tumors. The pleural temperature was measured immediately outside the lung surface nearest to the tumor with a fiber-type thermocouple during 25 ablation procedures for 34 tumors in 22 patients. The procedures were divided into two groups depending on the highest pleural temperature: P-group I and P-group II, with highest pleural temperatures of <40 degrees C and >/=40 degrees C, respectively. The incidence of pneumothorax or pleural effusion was compared between the groups. Multiple variables were compared between the groups to determine the factors that affect the pleural temperature. The overall incidence of pneumothorax and pleural effusion was 56% (14/25) and 20% (5/25), respectively. Temperature data in five ablation procedures were excluded from the analyses because these were affected by the pneumothorax. P-group I and P-group II comprised 10 procedures and 10 procedures, respectively. The incidence of pleural effusion was significantly higher in P-group II (4/10) than in P-group I (0/10) (p = 0.043). However, the incidence of pneumothorax did not differ significantly (p = 0.50) between P-group I (4/10) and P-group II (5/10). Factors significantly affecting the pleural temperature were distance between the electrode and the pleura (p < 0.001) and length of the lung parenchyma between the electrode and the pleura (p < 0.001). We conclude that higher pleural temperature appeared to be associated with the occurrence of pleural effusion and not with that of pneumothorax.

Percutaneous radiofrequency ablation for clinical stage I non-small cell lung cancer: results in 20 nonsurgical candidates.

OBJECTIVE: Our objective was to evaluate the outcomes of radiofrequency ablation for nonsurgical candidates with clinical stage I non-small cell lung cancer. METHODS: This study was carried out on 20 nonsurgical candidates (11 men and 9 women; mean age, 75.6 years) with clinical stage I (IA, n = 14; IB, n = 6) non-small cell lung cancer. All patients were deemed nonsurgical candidates because of poor pulmonary function (n = 7), poor cardiac function (n = 3), poor performance status (n = 4), or refusal to undergo surgery (n = 6). The mean long-axis tumor diameter was 2.4 cm. Twenty patients underwent 23 percutaneous ablation sessions, including 3 repeat sessions for the treatment of local progression. The outcomes of radiofrequency ablation were retrospectively evaluated. RESULTS: Procedural complications included pneumothorax (n = 13 [57%]) and pleural effusion (n = 4 [17%]). One case of pneumothorax required chest tube placement. The median follow-up period was 21.8 months. Local progression was observed in 7 (35%) patients a median of 9.0 months after the first session. The local control rates were 72% at 1 year, 63% at 2 years, and 63% at 3 years. The mean survival time was 42 months. The overall survivals and cancer-specific survivals were 90% and 100% at 1 year, 84% and 93% at 2 years, and 74% and 83% at 3 years, respectively. CONCLUSIONS: Treating clinical stage I non-small cell lung cancer with one or more radiofrequency ablation sessions provided promising outcomes in terms of survival, although the rate of local progression was relatively high. A prospective study with a larger population and longer follow-up is warranted.

Percutaneous radiofrequency ablation for pulmonary metastases from colorectal cancer: midterm results in 27 patients.

PURPOSE: To retrospectively evaluate the midterm outcomes (eg, safety, local efficacy, and survival) after radiofrequency (RF) ablation for pulmonary metastases from colorectal cancer. MATERIALS AND METHODS: Twenty-seven patients (19 men and eight women; mean age, 61.6 years) with 49 pulmonary metastases (mean long axis diameter, 1.5 cm) from colorectal cancer underwent 41 percutaneous computed tomography (CT)-guided RF ablation sessions. Follow-up examinations were performed with CT by using contrast medium administration in all patients; positron emission tomography was performed in five patients. The safety of the procedure, local tumor control, and patient survival were evaluated. Multiple variables were analyzed to determine prognostic factors. RESULTS: Pneumothorax occurred after 20 of the 41 sessions (49%), three of which necessitated chest tube placement. A small pleural effusion was found after six of the 41 sessions (15%). No major hemorrhagic event was observed. None of the patients died due to the procedure. The median follow-up period was 20.1 months (range, 11.2-47.7 months). The primary and secondary technique effectiveness rates were 72% and 85%, respectively, at 1 year, 56% and 62% at 2 years, and 56% and 62% at 3 years. The overall survival rates after RF ablation were 96% at 1 year, 54% at 2 years, and 48% at 3 years. The presence of extrapulmonary metastasis was determined to be a prognostic factor (P = .001). CONCLUSIONS: The midterm outcomes of percutaneous RF ablation for colorectal pulmonary metastases appear promising. The presence of extrapulmonary metastasis had an adverse effect on survival after RF ablation.

Nonfatal systemic air embolism complicating percutaneous CT-guided transthoracic needle biopsy: four cases from a single institution.

BACKGROUND: Systemic air embolism is recognized as a potentially fatal but extremely rare complication following percutaneous transthoracic needle biopsy. However, its incidence might be underestimated by missing systemic air in patients without cardiac or cerebral symptoms. METHODS: This study was based on four cases (one man and three women; age range, 54 to 75 years) of systemic air embolism complicating CT scan-guided transthoracic needle biopsy, which were encountered among 1,010 procedures performed at our institution from April 1999 to December 2006. The target lesion was a lung tumor in three patients, and a mediastinal tumor in one patient. The procedure was performed percutaneously under CT scan-fluoroscopic guidance by using a coaxial biopsy needle system. RESULTS: In all four patients, a specimen was successfully obtained from the lesions. During or immediately after the procedure, all patients experienced paroxysms of coughing. In three patients without cardiac or cerebral symptoms, the presence of systemic air was confirmed on postprocedural CT scan images; it was resolved without causing morbidity after the immediate therapy. The presence of systemic air was missed in one initially asymptomatic patient, resulting in a subsequent neurologic deficit. CONCLUSIONS: Systemic air embolism following CT scan-guided transthoracic needle biopsy was encountered more frequently than would be expected. The considerable attention we gave to this complication enabled us to recognize it in patients without cardiac or cerebral symptoms. No sequelae were observed in the three patients in whom systemic air embolism was detected, and the therapy was initiated immediately, whereas missing systemic air led to cerebral embolism in one patient in our four cases.

Radiofrequency ablation followed by radiation therapy for large primary lung tumors.

We report the clinical experience of radiofrequency ablation followed by radiation therapy for large primary lung tumors. Two patients with large primary lung tumors were treated with combined radiofrequency ablation and radiation therapy, and good local control was observed. Combined radiofrequency ablation and radiation therapy that involves minimally invasive techniques appears to be promising for the treatment of large lung tumors.

Percutaneous radiofrequency ablation of lung tumors close to the heart or aorta: evaluation of safety and effectiveness.

PURPOSE: The authors retrospectively evaluated the safety and effectiveness of percutaneous radiofrequency ablation of lung tumors close to the heart or aorta. MATERIALS AND METHODS: Forty-two tumors (mean diameter, 25 mm +/- 16; range, 5-73 mm) located less than 10 mm from the heart or aorta were treated with radiofrequency ablation in 47 sessions. Lung tumors were classified into two groups according to their distance from the heart or aorta: group A (n = 27) comprised tumors at a distance of 1-9 mm; group B (n = 15) comprised contiguous tumors (distance, 0 mm). The safety and technique effectiveness of the procedure, defined as no evidence of local tumor progression, were evaluated. RESULTS: Radiofrequency ablation was feasible for all the 42 tumors. Procedural complications included asymptomatic pleural effusion (n = 5), small pneumothorax (n = 11), pneumothorax that necessitated chest tube placement (n = 4), and lung abscess (n = 1). No complications related to the specific tumor location, such as the accidental insertion of the electrode into the heart or aorta, pericardial effusion, arrhythmia, or cardiac infarction, occurred. The overall primary technique effectiveness rate was 75.8%, 45.9%, and 45.9% at 6, 12, and 24 months, respectively. This rate in group A (94.7%, 69.3%, and 69.3% at 6, 12, and 24 months, respectively) was significantly (P < .001) higher than that in group B (42.9% and 8.6% at 6 and 12 months, respectively). CONCLUSIONS: Radiofrequency ablation of lung tumors close to the heart or aorta was safely performed. The local control of tumors contiguous to the heart or aorta was considerably lower compared with the tumors that were close but not contiguous to these structures.

Transhepatic approach for percutaneous computed-tomography-guided radiofrequency ablation of renal cell carcinoma.

We performed percutaneously radiofrequency (RF) ablation of 5 renal cell carcinomas (mean diameter 26 +/- 15 mm) with computed-tomography (CT) fluoroscopic guidance using the transhepatic route. The RF electrode was successfully advanced into all tumors. RF ablation caused one minor complication (small asymptomatic perirenal hematoma); no major complications occurred. The follow-up contrast-enhanced CT images showed no local tumor progression of any tumors in a median period of 10 months (range 3-14 months). In conclusion, it seems that this transhepatic approach is safe and can be an alternative method for electrode insertion during RF ablation of selected renal tumors.

Intractable pneumothorax due to bronchopleural fistula after radiofrequency ablation of lung tumors.

We describe two cases of intractable pneumothorax that were attributed to a bronchopleural fistula (BPF) after radiofrequency ablation of lung tumors. In both cases, radiofrequency ablation induced necrosis of the lung tissue between the pleural space and the bronchus. The bronchopleural fistula formed after sloughing of the necrotic tissue. Management of the bronchopleural fistula was quite challenging, requiring frequent treatments, including pleurodesis, endobronchial management, and/or surgical repair. In one of the patients, air leakage persisted despite these efforts, and the patient died of acute pneumonia 52 days after the procedure. Although it is rare, with an incidence of 0.6% (2/334) at our institution, intractable pneumothorax due to bronchopleural fistula should be recognized as a risk associated with radiofrequency ablation of lung tumors.

Radiofrequency ablation of normal lungs after pulmonary artery embolization with use of degradable starch microspheres: results in a porcine model.

PURPOSE: The present study was performed to evaluate the effect of pulmonary artery embolization on radiofrequency (RF) ablation of normal porcine lungs. MATERIALS AND METHODS: RF ablation zones (n=34) were created in the normal lungs of five domestic pigs (five zones in each of the first two pigs and eight zones in each of the remaining three pigs) with an expandable multitined electrode with use of bilateral thoracotomy. RF ablation was performed without pulmonary artery embolization (group 1, n=8), immediately after embolization (group 2, n=11), 15 minutes after embolization (group 3, n=7), and 30 minutes after embolization (group 4, n=8) with degradable starch microspheres. Among them, 12 ablation zones were excluded from this study because they were considerably limited by the presence of the pleura or large bronchi. The remaining 22 zones were included (n=7, n=5, n=4, and n=6 in groups 1, 2, 3, and 4, respectively). Coagulation necrosis volumes in the ablation zones were measured and compared among the groups. RESULTS: Coagulation necrosis volumes were 0.9+/-0.5 cm3, 2.1+/-0.4 cm3, 2.1+/-1.0 cm3, and 1.9+/-0.6 cm3 in groups 1, 2, 3, and 4, respectively. Groups 2-4 showed significantly larger coagulation volumes than group 1 (P=.012, P=.023, and P=.010 in groups 2, 3, and 4, respectively). CONCLUSION: Pulmonary artery embolization contributed to larger volumes of coagulation necrosis after RF ablation of normal lungs.

Pneumothorax, pleural effusion, and chest tube placement after radiofrequency ablation of lung tumors: incidence and risk factors.

PURPOSE: To retrospectively evaluate the incidence of and risk factors for pneumothorax, pleural effusion, and chest tube placement for pneumothorax after radiofrequency (RF) ablation of lung tumors. MATERIALS AND METHODS: Institutional review board approval was obtained, with waiver of informed consent. This retrospective study comprised 224 ablation sessions for 392 tumors in 142 patients (92 men, 50 women; mean age, 64.0 years). Multiple variables were analyzed by using the Student t test or the Mann-Whitney U test for numerical values and by using the chi(2) test or the Fisher exact test for categorical values in order to assess risk factors for pneumothorax, pleural effusion, and chest tube placement for pneumothorax. RESULTS: The incidence of pneumothorax, pleural effusion, and chest tube placement for pneumothorax was 52% (117 of 224 sessions), 19% (42 of 224 sessions), and 21% (24 of 117 sessions), respectively. For pneumothorax, risk factors included male sex (P = .030), no history of pulmonary surgery (P < .001), a greater number of tumors ablated (P < .001), involvement of the middle or lower lobe (P = .008), and increased length of the aerated lung traversed by the electrode (P = .014). For pleural effusion, risk factors included the use of a cluster electrode (P = .008), decreased distance to the nearest pleura (P = .040), and decreased length of the aerated lung traversed by the electrode (P = .019). For chest tube placement for pneumothorax, risk factors included no history of pulmonary surgery (P = .002), the use of a cluster electrode (P < .001), and involvement of the upper lobe (P < .001). CONCLUSION: Pneumothorax and pleural effusion can occur after RF ablation in patients with lung tumors, and chest tube placement for pneumothorax is sometimes required.