Unveiling the diagnostic enigma of D-dimer testing in cancer patients: Current evidence and areas of application

BACKGROUND

Cancer is a well-known risk factor for venous thromboembolism (VTE). A combined strategy of D-dimer testing and clinical pre-test probability is usually used to exclude VTE. However, its effectiveness is diminished in cancer patients due to reduced specificity, ultimately leading to a decreased clinical utility. This review article seeks to provide a comprehensive summary of how to interpret D-dimer testing in cancer patients.

METHODS

In accordance with PRISMA standards, literature pertaining to the diagnostic and prognostic significance of D-dimer testing in cancer patients was carefully chosen from reputable sources such as PubMed and the Cochrane databases.

RESULTS

D-dimers have not only a diagnostic value in ruling out VTE but can also serve as an aid for rule-in if their values exceed 10-times the upper limit of normal. This threshold allows a diagnosis of VTE in cancer patients with a positive predictive value of more than 80%. Moreover, elevated D-dimers carry important prognostic information and are associated with VTE reoccurrence. A gradual increase in risk for all-cause death suggests that VTE is also an indicator of biologically more aggressive cancer types and advanced cancer stages. Considering the lack of standardization for D-dimer assays, it is essential for clinicians to carefully consider the variations in assay performance and the specific test characteristics of their institution.

CONCLUSIONS

Standardizing D-dimer assays and developing modified pretest probability models specifically for cancer patients, along with adjusted cut-off values for D-dimer testing, could significantly enhance the accuracy and effectiveness of VTE diagnosis in this population.

Homoarginine in the cardiovascular system: Pathophysiology and recent developments

Upcoming experimental and epidemiological data have identified the endogenous non-proteinogenic amino acid L-homoarginine (L-hArg) not only as a novel biomarker for cardiovascular disease but also as being directly involved in the pathogenesis of cardiac dysfunction. The association of low L-hArg levels with adverse cardiovascular events and mortality has proposed the idea of nutritional supplementation to rescue pathways inversely associated with cardiovascular health. Subsequent clinical and experimental studies contributed significantly to our knowledge of potential effects on the cardiorenal axis, acting either as a biomarker or a cardiovascular active agent. In this review article, we provide a comprehensive summary of the L-hArg metabolism, pathophysiological aspects, and current developments in the field of experimental and clinical evidence in favor of protective cardiovascular effects. Establishing a reliable biomarker to identify patients at high risk to die of cardiovascular disease represents one of the main goals for tackling this disease and providing individual therapeutic guidance.

Long-term outcomes following percutaneous microwave ablation for colorectal cancer liver metastases

PURPOSE

To evaluate the overall survival (OS), local progression-free survival (PFS) and prognostic factors of patients with colorectal cancer liver metastases (CRLM) undergoing microwave ablation (MWA).

METHOD

A total of 132 patients were retrospectively enrolled who had been treated between 2010 and 2018. For the evaluation of survival rates, all patients were divided according to their indications (curative n = 57 and debulking (patients with additional non-target extrahepatic metastases) n = 75). In total, 257 ablations were evaluated for prognostic factors: number of liver metastases, primary tumor origin (PTO), diameter and volume of metastases, duration and energy of ablation.

RESULTS

The OS was 32.1 months with 93.2% of patients free from recurrence at 28.3 months (median follow-up time). The one- year and three-year OS were 82.72% and 41.66%, respectively. The OS and recurrence-free survival of the curative group were statistically significantly higher than the debulking group (p < .001). Statistically significant prognostic factors for OS included the location of the primary tumor (p < .038) and the number of metastases (all p < .017). Metastasis diameter and volume and ablation duration and energy had no significant correlation with survival (p > .05).

CONCLUSIONS

Satisfactory OS and local tumor PFS can be achieved in patients with CRLM using MWA with the number of metastases and the location of the primary tumor influencing the outcome of patients. The metastasis's size and the duration and energy used for ablation were not of significant prognostic value.

Lung Opacity and Coronary Artery Calcium Score: A Combined Tool for Risk Stratification and Outcome Prediction in COVID-19 Patients

PURPOSE

To assess and correlate pulmonary involvement and outcome of SARS-CoV-2 pneumonia with the degree of coronary plaque burden based on the CAC-DRS classification (Coronary Artery Calcium Data and Reporting System).

METHODS

This retrospective study included 142 patients with confirmed SARS-CoV-2 pneumonia (58 ± 16 years; 57 women) who underwent non-contrast CT between January 2020 and August 2021 and were followed up for 129 ± 72 days. One experienced blinded radiologist analyzed CT series for the presence and extent of calcified plaque burden according to the visual and quantitative HU-based CAC-DRS Score. Pulmonary involvement was automatically evaluated with a dedicated software prototype by another two experienced radiologists and expressed as Opacity Score.

RESULTS

CAC-DRS Scores derived from visual and quantitative image evaluation correlated well with the Opacity Score (r=0.81, 95% CI 0.76-0.86, and r=0.83, 95% CI 0.77-0.89, respectively; p<0.0001) with higher correlation in severe than in mild stage SARS-CoV-2 pneumonia (p<0.0001). Combined, CAC-DRS and Opacity Scores revealed great potential to discriminate fatal outcomes from a mild course of disease (AUC 0.938, 95% CI 0.89-0.97), and the need for intensive care treatment (AUC 0.801, 95% CI 0.77-0.83). Visual and quantitative CAC-DRS Scores provided independent prognostic information on all-cause mortality (p=0.0016 and p<0.0001, respectively), both in univariate and multivariate analysis.

CONCLUSIONS

Coronary plaque burden is strongly correlated to pulmonary involvement, adverse outcome, and death due to respiratory failure in patients with SARS-CoV-2 pneumonia, offering great potential to identify individuals at high risk.

A prospective randomized trial comparing microwave and radiofrequency ablation for the treatment of liver metastases using a dual ablation system ─ The Mira study

Purpose

The aim of this study was to prospectively compare the therapy response and safety of microwave (MWA) and radiofrequency ablation (RFA) for the treatment of liver metastases using a dual ablation system.

Methods

Fifty patients with liver metastases (23 men, mean age: 62.8 ± 11.8 years) were randomly assigned to MWA or RFA for thermal ablation using a one generator dual ablation system. Magnetic resonance imaging (MRI) was acquired before treatment and 24 h post ablation. The morphologic responses to treatment regarding size, volume, necrotic areas, and diffusion characteristics were evaluated by MRI. Imaging follow-up was obtained for one year in three months intervals, whereas clinical follow-up was obtained for two years in all patients.

Results

Twenty-six patients received MWA and 24 patients received RFA (mean diameter: 1.6 cm, MWA: 1.7 cm, RFA: 1.5 cm). The mean volume 24 h after ablation was 37.0 cm³ (MWA: 50.5 cm³, RFA: 22.9 cm³, P < 0.01). The local recurrence rate was 0% (0/26) in the MWA-group and 8.3% (2/24) in the RFA-group (P = 0.09). The rate of newly developed malignant formations was 38.0% (19/50) for both groups (MWA: 38.4%, RFA: 37.5%, P = 0.07). The overall survival rate was 70.0% (35/50) after two years (MWA: 76.9%, RFA: 62.5%, P = 0.60). No major complications were reported.

Conclusion

In conclusion, MWA and RFA are both safe and effective methods for the treatment of liver metastases with MWA generating greater volumes of ablation. No significant differences were found for overall survival, rate of neoplasm, or major complications between both groups.

•

A dual ablation system allows for MWA and RFA treatment using the same hardware.

•

Both methods are safe and effective for the treatment of liver metastases.

•

MWA generates greater volumes of ablation and larger ablative margins compared to RFA.

MR angiography-planned prostatic artery embolization for benign prostatic hyperplasia: single-center retrospective study in 56 patients

PURPOSE

We aimed to evaluate the advantages of magnetic resonance angiography (MRA)-planned prostatic artery embolization (PAE) for benign prostatic hyperplasia (BPH).

METHODS

In this retrospective study, MRAs of 56 patients (mean age, 67.23±7.73 years; age range, 47-82 years) who underwent PAE between 2017 and 2018 were evaluated. For inclusion, full information about procedure time and radiation values must have been available. To identify prostatic artery (PA) origin, three-dimensional MRA reconstruction with maximum intensity projection was conducted in every patient. In total, 33 patients completed clinical and imaging follow-up and were included in clinical evaluation.

RESULTS

There were 131 PAs with a second PA in 19 pelvic sides. PA origin was correctly identified via MRA in 108 of 131 PAs (82.44%). In patients in which MRA allowed a PA analysis, a significant reduction of the fluoroscopy time (-27.0%, p = 0.028) and of the dose area product (-38.0%, p = 0.003) was detected versus those with no PA analysis prior to PAE. Intervention time was reduced by 13.2%, (p = 0.25). Mean fluoroscopy time was 30.1 min, mean dose area product 27,749 µGy•m2, and mean entrance dose 1553 mGy. Technical success was achieved in all 56 patients (100.0%); all patients were embolized on both pelvic sides. The evaluated data documented a significant reduction in IPSS (p < 0.001; mean 9.67 points).

CONCLUSION

MRA prior to PAE allowed the identification of PA in 82.44% of the cases. MRA-planned PAE is an effective treatment for patients with BPH.

Feasibility of diffusion-weighted magnetic resonance imaging in evaluation of early therapeutic response after CT-guided microwave ablation of inoperable lung neoplasms

Objective

To determine the early treatment response after microwave ablation (MWA) of inoperable lung neoplasms using the apparent diffusion coefficient (ADC) value calculated 24 h after the ablation.

Materials and methods

This retrospective study included 47 patients with 68 lung lesions, who underwent percutaneous MWA from January 2008 to December 2017. Evaluation of the lesions was done using MRI including DWI sequence with ADC value calculation pre-ablation and 24 h post-ablation. DWI-MR was performed with b values (50, 400, 800 mm²/s). The post-ablation follow-up was performed using chest CT and/or MRI within 24 h following the procedure; after 3, 6, 9, and 12 months; and every 6 months onwards to determine the local tumor response. The post-ablation ADC value changes were compared to the end response of the lesions.

Results

Forty-seven patients (mean age: 63.8 ± 14.2 years, 25 women) with 68 lesions having a mean tumor size of 1.5 ± 0.9 cm (range: 0.7–5 cm) were evaluated. Sixty-one lesions (89.7%) showed a complete treatment response, and the remaining 7 lesions (10.3%) showed a local progression (residual activity). There was a statistically significant difference regarding the ADC value measured 24 h after the ablation between the responding (1.7 ± 0.3 × 10⁻³ mm²/s) and non-responding groups (1.4 ± 0.3 × 10⁻³ mm²/s) with significantly higher values in the responding group (p = 0.001). A suggested ADC cut-off value of 1.42 could be used as a reference point for the post-ablation response prediction (sensitivity: 66.67%, specificity: 84.21%, PPV: 66.7%, and NPV: 84.2%). No significant difference was reported regarding the ADC value performed before the ablation as a factor for the prognosis of treatment response (p = 0.86).

Conclusion

ADC value assessment following ablation may allow the early prediction of treatment efficacy after MWA of inoperable lung neoplasms.

Key Points

• ADC value calculated 24 h post-treatment may allow the early prediction of MWA efficacy as a treatment of pulmonary tumors and can be used in the early immediate post-ablation imaging follow-up.

• The pre-treatment ADC value of lung neoplasms is not different between the responding and non-responding tumors.

Postoperative radiological assessment of the mastoid facial canal in cochlear implant patients in correlation with facial nerve stimulation

Objectives

To correlate the radiological assessment of the mastoid facial canal in postoperative cochlear implant (CI) cone-beam CT (CBCT) and other possible contributing clinical or implant-related factors with postoperative facial nerve stimulation (FNS) occurrence.

Methods

Two experienced radiologists evaluated retrospectively 215 postoperative post-CI CBCT examinations. The mastoid facial canal diameter, wall thickness, distance between the electrode cable and mastoid facial canal, and facial-chorda tympani angle were assessed. Additionally, the intracochlear position and the insertion angle and depth of electrodes were evaluated. Clinical data were analyzed for postoperative FNS within 1.5-year follow-up, CI type, onset, and causes for hearing loss such as otosclerosis, meningitis, and history of previous ear surgeries. Postoperative FNS was correlated with the measurements and clinical data using logistic regression.

Results

Within the study population (mean age: 56 ± 18 years), ten patients presented with FNS. The correlations between FNS and facial canal diameter (p = 0.09), wall thickness (p = 0.27), distance to CI cable (p = 0.44), and angle with chorda tympani (p = 0.75) were statistically non-significant. There were statistical significances for previous history of meningitis/encephalitis (p = 0.001), extracochlear-electrode-contacts (p = 0.002), scala-vestibuli position (p = 0.02), younger patients’ age (p = 0.03), lateral-wall-electrode type (p = 0.04), and early/childhood onset hearing loss (p = 0.04). Histories of meningitis/encephalitis and extracochlear-electrode-contacts were included in the first two steps of the multivariate logistic regression.

Conclusion

The mastoid-facial canal radiological assessment and the positional relationship with the CI electrode provide no predictor of postoperative FNS. Histories of meningitis/encephalitis and extracochlear-electrode-contacts are important risk factors.

Key Points

• Post-operative radiological assessment of the mastoid facial canal and the positional relationship with the CI electrode provide no predictor of post-cochlear implant facial nerve stimulation.

• Radiological detection of extracochlear electrode contacts and the previous clinical history of meningitis/encephalitis are two important risk factors for postoperative facial nerve stimulation in cochlear implant patients.

• The presence of scala vestibuli electrode insertion as well as the lateral wall electrode type, the younger patient’s age, and early onset of SNHL can play important role in the prediction of post-cochlear implant facial nerve stimulation.

The value of different 18F-FDG PET/CT baseline parameters in risk stratification of stage I surgical NSCLC patients

OBJECTIVE

Administration of postoperative chemotherapy to patients with completely resected stage I NSCLC is still a matter of debate. The aim of the present study was to evaluate the value of different baseline ¹⁸F-FDG PET parameters in identifying surgical stage I NSCLC patients who are at high risk of recurrence, and thus are indicated for further postoperative treatment.

METHODS

This is a retrospective study, which included 49 patients (28 males, 21 females) with the median age of 69 years (range 28-84), who had pathologically proven stage I NSCLC. All patients underwent ¹⁸F-FDG PET/CT at baseline followed by complete surgical resection of the tumor (R0). Baseline SUV_max, MTV and TLG were measured. Patients' follow-up records were retrospectively reviewed, and DFS (disease-free survival) was assessed. For each parameter, the most accurate cut-off value for the prediction of recurrence was calculated using the ROC curve analysis and the Youden index. DFS was evaluated for patients above and below the calculated cut-off value using the Kaplan-Meier method and the difference in survival between the two groups was estimated using the log-rank test.

RESULTS

Median observation time of the patients after surgery was 28.7 months (range 3.5-58.8 months). 9 patients developed recurrence. The calculated cut-off values for SUV_max, MTV and TLG were 6, 6.6 and 33.6, respectively. Using these cut-offs, the observed sensitivity for SUV_max, MTV and TLG for prediction of recurrence was 100%, 89% and 89%, respectively, while the observed specificity was 43%, 73% and 65%, respectively. The difference in survival between patients below and above the cut-off value was statistically significant in all three studied parameters. The highest AUC was observed for MTV (AUC = 0.825, p = 0.003), followed by TLG (AUC = 0.789, p = 0.007), and lastly SUV_max (AUC = 0.719, p = 0.041). ROC curve analysis showed that volumetric parameters had better predictive performance than SUV_max as regards recurrence.

CONCLUSION

PET-derived parameters at baseline were predictive of recurrence in stage I surgical NSCLC patients. Moreover, the metabolic volume of the tumor was the most significant parameter for this purpose among the studied indices.

A comparison between 915 MHz and 2450 MHz microwave ablation systems for the treatment of small diameter lung metastases

PURPOSE

We aimed to retrospectively compare the local tumor control rates between low frequency (LF) and high frequency (HF) microwave ablation devices in the treatment of <3 cm lung metastases.

METHODS

A total of 36 patients (55 tumors) were treated with the LF system (915 MHz) and 30 patients (39 tumors) were treated with the HF system (2450 MHz) between January 2011 and March 2016. Computed tomography (CT) scans performed prior to and 24 hours after the ablation were used to measure the size of the ablation zone and to calculate the ablation margin. The subsequent CTs were used to detect local tumor progression. Possible predictive factors for local progression were analyzed. All patients had a minimum follow-up of 3 months with a median of 13.8 months for the LF group and 11.7 months for the HF group.

RESULTS

The ablation margin (P = 0.015), blood vessel proximity (P = 0.006), and colorectal origin (P = 0.029) were significantly associated with the local progression rate. The local progression rates were 36.3% for LF ablations and 12.8% for HF ablations. The 6, 12, and 18 months local progression-free survival rates were 79%, 65.2% and 53% for the LF group and 97.1%, 93.7%, and 58.4% for the HF group, with a significant difference between the survival curves (P = 0.048).

CONCLUSION

HF ablations resulted in larger ablation margins with fewer local progression compared with LF ablations.

The portal vein as a distinct immunological compartment - A comprehensive immune phenotyping study

Advanced liver diseases are associated with impaired intestinal barrier function, which results in bacterial influx via the portal vein to the liver, causing hepatic and systemic inflammation. Little is known about possible concomitant trafficking of immune cells from the intestines to the liver. We therefore performed a comprehensive immunophenotyping study of the portal venous versus peripheral blood compartment in patients with liver cirrhosis who received a transjugular intrahepatic portosystemic stent shunt (TIPS). Our analysis suggests that the portal vein constitutes a distinct immunological compartment resembling that of the intestines, at least in patients with advanced liver cirrhosis. In detail, significantly lower frequencies of naïve CD4⁺ T cells, monocytes, dendritic cells and Vδ2 T cells were observed in the portal vein, whereas frequencies of activated CD4⁺ and CD8⁺ T cells, as well as of mucosa-associated Vδ1 T cells were significantly higher in portal venous compared to peripheral blood. In conclusion, our data raises interesting questions, e.g. whether liver cirrhosis-associated chronic inflammation of the intestines and portal hypertension promote an influx of activated intestinal immune cells like γδ T cells into the liver.

Dynamic 4D-CT Angiography for Guiding Transarterial Chemoembolization: Impact on the Reduction of Contrast Material, Operator Radiation Exposure, Catheter Consumption, and Diagnostic Confidence

PURPOSE

 This study was carried out to investigate the impact of abdominal dynamic four-dimensional CT angiography (4D-CTA) for guiding transarterial chemoembolization (TACE) on the amount of contrast material used, operator radiation exposure, catheter consumption, and diagnostic confidence.

MATERIALS AND METHODS

 Written consent was waived for this IRB-approved retrospective study. 29 patients (20 men; mean age: 65.7 ± 11.5 years) with malignant liver lesions underwent 4D-CTA, prior to initial TACE. Time-resolved volume-rendering technique (VRT), maximum-intensity projection (MIP), and multiplanar reconstruction (MPR) series were reconstructed, enabling a direct selective catheterization of the tumor-supplying artery without prior conventional digital subtraction angiography (DSA). 29 patients (16 men; mean age: 69.4 ± 13.9) who underwent traditional TACE served as the control group. The amount of administered contrast media, operator radiation exposure, and catheter consumption during TACE were compared. Two radiologists assessed diagnostic confidence in the exclusion of portal vein thrombosis.

RESULTS

 4D-CTA TACE resulted in a significant reduction in the amount of contrast media used, compared to traditional TACE (-61.0 ml/ -66.3 % intra-arterial, -12.8 ml/ -13.8 % overall; P < 0.001). The dose-area product indicating operator radiation exposure during intervention was reduced by 50.5 % (P < 0.001), and 0.7 fewer catheters on average were used (P = 0.063), while 4D-CTA data was available to guide TACE. Diagnostic confidence in the exclusion of portal vein thrombosis was significantly enhanced by 4D-CTA, compared to traditional DSA images (scores, 3.9 and 2.4, respectively; P < 0.001).

CONCLUSION

 Dynamic 4D-CTA enables TACE with a substantially reduced amount of contrast material, decreases operator radiation exposure, and increases diagnostic confidence in the exclusion of portal vein thrombosis.

KEY POINTS

  · 4D-CTA prior to TACE decreases the amount of utilized contrast material.. · The intra-arterial fraction of contrast media can be reduced by two-thirds.. · The risk of CIN may be decreased by means of 4D-CTA TACE.. · Operator radiation exposure is lower using 4D-CTA for guiding TACE.. · 4D-CTA portography allows for a higher diagnostic confidence than conventional DSA images..

CITATION FORMAT

· Albrecht MH, Vogl TJ, Wichmann JL et al. Dynamic 4D-CT Angiography for Guiding Transarterial Chemoembolization: Impact on the Reduction of Contrast Material, Operator Radiation Exposure, Catheter Consumption, and Diagnostic Confidence. Fortschr Röntgenstr 2018; 190: 513 - 520.

Microwave ablation of pancreatic tumors

OBJECTIVES

To evaluate the clinical performance of percutaneous microwave ablation (MWA) for treatment of locally-advanced-pancreatic-cancer (LAPC).

MATERIAL AND METHODS

Twenty-two MWA sessions (August 2015-March 2017) in 20 patients with primary pancreatic cancer (13 men, 7 women, mean-age: 59.9 ± 8.6 years, range: 46-73 years), who had given informed consent, were retrospectively evaluated. All procedures were performed percutaneously under CT-guidance using the same high-frequency (2.45-GHz) MWA device. Tumor location and diameter, ablation diameter and volume, roundness, duration, technical success and efficacy, output energy, complications, and local tumor progression defined as a tumor focus connected to the edge of a previously technically efficient ablation zone were collected.

RESULTS

Seventeen pancreatic malignant tumors (77.3%) were located in the pancreatic head and five (22.7%) in the pancreatic tail. Initial Mean Tumor Diameter was 30 ± 6 mm. Technical success and efficacy were idem (100%). No major complications occurred. Two patients (9.1%) showed minor complications of severe local pain related to MWA. Post-ablation diameter was on average 34.4 ± 5.8 mm. Mean ablation volume was 7.8 ± 3.8 cm³. The mean transverse roundness index was 0.74 ± 0.14. Mean ablation time was 2.6 ± 0.96 min. The mean applied energy per treatment was 9627 ± 3953 J. Local tumor progression was documented in one case (10%) of the 10/22 available three-month follow-up imaging studies.

CONCLUSION

High-frequency (2.45 GHz) microwave ablation (MWA) for treatment of unresectable and non-metastatic locally-advanced-pancreatic-cancer (LAPC) shows promising results regarding feasibility and safety of percutaneous approach after short-term follow-up and should be further evaluated.

Microwave Ablation (MWA): Basics, Technique and Results in Primary and Metastatic Liver Neoplasms - Review Article

Purpose The locoregional interventional oncological treatment approach is an accepted modality for liver neoplasms, especially for hepatocellular carcinoma (HCC) and oligonodular liver metastases. Materials and Methods The main aim of ablation therapies like microwave ablation (MWA) is to eradicate all malignant cells in a minimally invasive technique under imaging guidance while preserving the healthy tissue with a sufficient safety margin (at least 5 mm) surrounding the ablated lesion. Results Ablation therapy can be performed via a percutaneous, laparoscopic or intraoperative approach under ultrasound, MRI or CT guidance for adequate localization and monitoring of the ablation process. Conclusion Ablation is the method of choice for oligonodular HCCs ≤ 3 cm. The technical success rate varies from 88 % to 98 % and progression-free survival (PFS) at 3 years from 27 % to 91.7 %. The same criteria apply to the therapy of liver metastases. Key Points  · Careful selection of patients proves to be essential for optimum results of MWA. · Interventionists should be familiar with all aspects of complication and rapid assessment of imaging methods in order to evaluate induced damage by thermal ablation. · MWA seems to have some advantages over radiofrequency ablation, like shorter ablation time, less pain, less heat sink effect; however, scientific proof is needed. Citation Format · Vogl TJ, Nour-Eldin A, Hammerstingl RM et al. Microwave Ablation (MWA): Basics, Technique and Results in Primary and Metastatic Liver Neoplasms - Review Article. Fortschr Röntgenstr 2017; 189: 1055 - 1066.

Thermal Ablation of Lung Tumors: Focus on Microwave Ablation

Background Image-guided thermal ablation can be used for the treatment of medically inoperable primary and metastatic lung cancer. These techniques are based on the heating up or freezing (cryoablation) of a volume of tissue around a percutaneous applicator that induces necrosis of the tumor. Method The English-language literature concerning thermal ablation of the lung was reviewed. Radiofrequency ablation (RFA) is the most widely performed and investigated of these techniques. Microwave ablation (MWA) represents a relatively new alternative that shares the same indications and is conducted in a very similar fashion as RFA. It has been experimentally and clinically shown that MWA produces larger, more spherical ablation zones over shorter periods of time compared to RFA. Seven different MWA systems are available in Europe and the USA with significant differences in the size and shape of the produced ablation zones. Results The types of complications caused by MWA and their rates of occurrence are very similar to those caused by RFA. The local progression rates after MWA of lung malignancies vary between 0 % and 34 % and are similar to those in the RFA literature. Conclusion Despite technical improvements, the current generation of MWA systems has comparable clinical outcomes to those of RFA. Key Points  · MWA is a safe technique that should be considered one of the treatment options for medically inoperable lung tumors. · As thermal ablations of lung tumors are becoming more frequent, radiologists should be acquainted with the post-ablation imaging characteristics. · Although MWA has some theoretical advantages over RFA, the clinical outcomes are similar. Citation Format · Vogl TJ, Nour-Eldin NA, Albrecht MH et al. Thermal Ablation of Lung Tumors: Focus on Microwave Ablation. Fortschr Röntgenstr 2017; 189: 828 - 843.

Ablation therapy of non-colorectal cancer lung metastases: retrospective analysis of tumour response post-laser-induced interstitial thermotherapy (LITT), radiofrequency ablation (RFA) and microwave ablation (MWA)

PURPOSE

To retrospectively compare the local tumour response and survival rates in patients with non-colorectal cancer lung metastases post-ablation therapy using laser-induced thermotherapy (LITT), radiofrequency ablation (RFA) and microwave ablation (MWA).

MATERIAL AND METHODS

Retrospective analysis of 175 computed tomography (CT)-guided ablation sessions performed on 109 patients (43 males and 66 females, mean age: 56.6 years). Seventeen patients with 22 lesions underwent LITT treatment (tumour size: 1.2-4.8 cm), 29 patients with 49 lesions underwent RFA (tumour size: 0.8-4.5 cm) and 63 patients with 104 lesions underwent MWA treatment (tumour size: 0.6-5 cm). CT scans were performed 24-h post-therapy and on follow-up at 3, 6, 12, 18 and 24 months.

RESULTS

The overall-survival rates at 1-, 2-, 3- and 4-year were 93.8, 56.3, 50.0 and 31.3% for patients treated with LITT; 81.5, 50.0, 45.5 and 24.2% for patients treated with RFA and 97.6, 79.9, 62.3 and 45.4% for patients treated with MWA, respectively. The mean survival time was 34.14 months for MWA, 34.79 months for RFA and 35.32 months for LITT. In paired comparison, a significant difference could be detected between MWA versus RFA (p = 0.032). The progression-free survival showed a median of 23.49 ± 0.62 months for MWA,19.88 ± 2.17 months for LITT and 16.66 ± 0.66 months for RFA (p = 0.048). The lowest recurrence rate was detected in lesions ablated with MWA (7.7%; 8 of 104 lesions) followed by RFA (20.4%; 10 of 49 lesions) and LITT (27.3%; 6 of 22 lesions) p value of 0.012. Pneumothorax was detected in 22.16% of MWA ablations, 22.73% of LITT ablations and 14.23% of RFA ablations.

CONCLUSION

LITT, RFA and MWA may provide an effective therapeutic option for non-colorectal cancer lung metastases with an advantage for MWA regarding local tumour control and progression-free survival rate.

Assessment of the cochlear nerve to facial nerve size ratio using MR multiplanar reconstruction of the internal auditory canal in patients presenting with acquired long-standing hearing loss

OBJECTIVE

To test using the facial nerve as a reference for assessment of the cochlear nerve size in patients with acquired long-standing sensorineural hearing loss (SNHL) using MRI multiplanar reconstruction.

METHODS

The study was retrospectively performed on 86 patients. Group 1 (study group, n = 53) with bilateral long-standing SNHL. Group 2 (control group, n = 33) without hearing loss. The nerve size was measured by drawing a region of interest around the cross-sectional circumference of the nerve in multiplanar reconstruction images.

RESULTS

No significant correlation was noted between the cochlear nerve and facial nerve size, and the patient's age, gender and weight (p > 0.05). In Group 1, the mean ratio of the cochlear to facial nerve size was 0.99 ± 0.30 (range: 0.52-1.86) and 1.12 ± 0.35 (range: 0.34-2.3) for the right and left sides, respectively. In Group 2, it was 1.18 ± 0.23 (range: 0.78-1.71) and 1.25 ± 0.25 (range: 0.85-1.94) for the right and left sides, respectively. The cochlear nerve size was statistically (p = 0.0004) smaller in Group 1 than in Group 2.

CONCLUSION

The cochlear nerve size and the cochlear to facial nerve size ratio are significantly smaller in patients with acquired long-standing SNHL. Advances in knowledge: The facial nerve can be used as a reference for assessment of the cochlear nerve in patients with acquired long-standing SNHL.

Computed tomography-guided biopsies in children: accuracy, efficiency and dose usage

Background

Computed-tomography-guided interventions are attractive for tissue sampling of paediatric tumor lesions; however, it comes with exposure to ionizing radiation. The aim of this study was to analyse the radiation dose, accuracy and speed of CT-guided interventions in paediatric patient cohort.

Methods

We retrospectively reviewed CT-guided interventions over a 10 -year period in 65 children. The intervention site consisted of bones in 38, chest (lung) in 15 and abdomen (liver, lymph nodes) in 12 cases. Radiation dose and duration of the procedures were analysed. The statistical analysis was performed using dedicated statistical software (BiAS 8.3.6 software, Epsilon Verlag, North Hasted).

Results

All interventions were performed successfully. Mean target access path to lesion within the patients was 6.0 cm (min 3.5 cm, max 11.2 cm). Time duration to complete intervention was 25:15 min (min 17:03 min, max 43:00 min). The dose-length product (DLP) of intervention scan was 29.5 mGy · cm (min 6 mGy · cm, max 85 mGy · cm) with the lowest dose for biopsies in the region of the chest (p = 0.04).

Conclusions

With justified indications, CT-guided paediatric interventions are safe, effective and can be performed both, with short intervention times and low radiation exposure.

Improved visual delineation of the intimal flap in Stanford type A and B dissections at 3rd generation dual-source high-pitch CT angiography

OBJECTIVE

Evaluation of the intimal flap visibility comparing 2nd and 3rd generation dual-source high-pitch CT.

METHODS

Twenty-five consecutive patients with aortic dissection underwent CT angiography on a second and third generation dual-source CT scanner using prospective ECG-gated high-pitch dual-source CT acquisition mode. Contrast material, saline flush and flow rate were kept equal for optimum comparability. The visibility of the intimal flap as well as the delineation of the different vascular structures was evaluated.

RESULTS

In 3rd generation dual-source high-pitch CT we could show a significant improvement of intimal flap visibility in aortic dissection. Especially, the far end of the dissection membrane could be better evaluated in 3rd generation high-pitch CT, reaching statistical significance (P < 0.01).

CONCLUSION

3rd Generation high-pitch CT angiography shows a better delineation of the aortic intimal flap in a small patient cohort, especially in the far ends of the dissection membrane. This might be due to higher tube power in this CT generation. However, to generalise these findings larger trials are needed.

Feasibility of assessing pulmonary blood volume using C-arm CT during transpulmonary chemoperfusion and chemoembolization in primary and secondary lung tumours

OBJECTIVE

Assessment of parenchymal blood volume (PBV) of primary and secondary pulmonary malignancies by using a C-arm CT, regarding its role in detecting early functional response to transpulmonary chemoembolization (TPCE) and clinical practicability.

METHODS

21 patients with a mean age of 56.77 years, who were assigned to TPCE during their palliative treatment, were included. PBV and the diameter of tumours were analyzed. PBV maps were calculated from three-dimensional CT-angiographic (3D-CTA) data sets. Imaging was performed on a flat detector, C-arm CT. Groups of response were classified according to the criteria of the response evaluation criteria in solid tumours. Statistically significant differences were determined and Pearson's regression analysis correlated PBV and diameter as parameters of response to treatment.

RESULTS

During 4.91 sessions, median diameter increased 18.18% (p > 0.05) and PBV reduced 39.62% (p > 0.05). Functional and imaging response per tumour was statistical significantly different (p ≤ 0.05). Correlation coefficient was r = 0.058. 2/41 tumours showed partial response; 31/41 tumours showed stable disease; and 8/41 tumours showed progressive disease. The highest pre-treatment PBV values were measured in decreasing tumours (206.93 ml l(-1)), and the lowest values were measured in increasing tumours (60.17 ml l(-1); p > 0.05). The lowest values were also measured in lung cancer (53.02 ml l(-1)) that was significantly different to uterine leiomyosarcoma (103.31 ml l(-1)) and renal cell cancer (113.14 ml l(-1); p ≤ 0.05).

CONCLUSION

Assessment of PBV maps by using 3D-CTA image data is feasible in the clinical routine. PBV shows a stronger response to TPCE treatment than measurement in diameter and should be considered as a response parameter for early detection.

ADVANCES IN KNOWLEDGE

Assessment of PBV using C-arm CT during TPCE is a feasible technique. Assessment of PBV might be useful in assessing response to treatment.

ECG-gated Versus Non-ECG-gated High-pitch Dual-source CT for Whole Body CT Angiography (CTA)

RATIONALE AND OBJECTIVES

To investigate motion artifacts, image quality, and practical differences in electrocardiographic (ECG)-gated versus non-ECG-gated high-pitch dual-source computed tomography angiography (CTA) of the whole aorta.

MATERIALS AND METHODS

Two groups, each including 40 patients, underwent either ECG-gated or non-ECG-gated high-pitch dual-source CTA of the whole aorta. The aortic annulus, aortic valve, coronary ostia, and the presence of motion artifacts of the thoracic aorta as well as vascular contrast down to the femoral arteries were independently assessed by two readers. Additional objective parameters including image noise and signal-to-noise ratio were analyzed.

RESULTS

Subjective and objective scoring revealed no presence of motional artifacts regardless of whether the ECG-gated or the non-ECG-gated protocol was used (P > 0.1). Image acquisition parameters (examination length, examination duration, radiation dose) were comparable between the two groups without significant differences. The aortic annulus, aortic valve, and coronary ostia were reliably evaluable in all patients. Vascular contrast was rated excellent in both groups.

CONCLUSIONS

High-pitch dual-source CTA of the whole aorta is a robust and dose-efficient examination strategy for the evaluation of aortic pathologies whether or not ECG gating is used.

CT chest and gantry rotation time: does the rotation time influence image quality?

BACKGROUND

Computed tomography (CT) gantry rotation time is one factor influencing image quality. Until now, there has been no report investigating the influence of gantry rotation time on chest CT image quality.

PURPOSE

To investigate the influence of faster gantry rotation time on image quality and subjective and objective image parameters in chest CT imaging.

MATERIAL AND METHODS

Chest CT scans from 160 patients were examined in this study. All scans were performed using a single-source mode (collimation, 128 × 0.6 mm; pitch, 1.2) on a dual-source CT scanner. Only gantry rotation time was modified, while other CT parameters were kept stable for each scan (120 kV/110 reference mAs). Patients were divided into four groups based on rotation time: group 1, 1 s/ rotation (rot); group 2, 0.5 s/rot; group 3, 0.33 s/rot; group 4, 0.28 s/rot. Two blinded radiologists subjectively compared CT image quality, noise, and artifacts, as well as radiation exposure, from all groups. For objective comparison, all image datasets were analyzed by a radiologist with 5 years of experience concerning objective measurements as well as signal-to-noise ratio (SNR).

RESULTS

We found that faster gantry rotation times (0.28 s/rot and 0.33 s/rot) resulted in more streak artifacts, image noise, and decreased image quality. However, there was no significant difference in radiation exposure between faster and slower rotation times (P > 0.7).

CONCLUSION

Faster CT gantry rotation reduces scan time and motion artifacts. However, accelerating rotation time increases image noise and streak artifacts. Therefore, a slower CT gantry rotation speed is still recommended for higher image quality in some cases.

Neoadjuvant TACE before laser induced thermotherapy (LITT) in the treatment of non-colorectal non-breast cancer liver metastases: feasibility and survival rates

PURPOSE

To evaluate safety, feasibility and overall survival rates for transarterial chemoembolization (TACE) alone or combined with MR-guided laser-induced-thermotherapy (LITT) in liver metastases of non-colorectal and non-breast cancer origin.

METHODS AND MATERIALS

Included were patients with unresectable non-colorectal non-breast cancer liver metastases with progression under systemic chemotherapy. Excluded were patients with Karnofsky score ≤ 70, respiratory, renal and cardiovascular failure, and general TACE contraindications. TACE using Mitomycin alone, Mitomycin-Gemcitabine or Mitomycin-Gemcitabine-Cisplatin was performed to all patients. After TACE 146 metastases were ablated with MR-guided LITT. To be eligible for LITT metastases should be < 5 cm in size and ≤ 5 in number. Tumor response was evaluated using MRI according to RECIST. Survival was evaluated using Kaplan-Meier analysis.

RESULTS

A total of 110 patients (mean age 59.2 years) with 371 metastases received TACE (mean 5.4 sessions/patient, n=110) with 76 (69%) receiving LITT (mean 1.6 session/patient) afterwards. TACE resulted in a mean decrease of mean maximum diameter of 52% ± 26.6 and volume change of -68.5% ± 22.9 in the 25 patients (23%) with partial response. Stable disease (n=59, 54%). Progressive disease (n=26, 23%). The RECIST outcome after LITT showed complete response (n=13, 17%), partial response (n=1, 1%), stable situation (n=41, 54%) and progressive disease (n=21, 28%). The mean time to progression (TTP) was 8.6 months. Median survival of all patients was 21.1 months.

CONCLUSION

TACE with different protocols alone and in combination with LITT is a feasible palliative treatment option resulting in a median survival of 21.1 months for unresectable liver metastases of non-colorectal and non-breast cancer origin.

Risk factor analysis of pulmonary hemorrhage complicating CT-guided lung biopsy in coaxial and non-coaxial core biopsy techniques in 650 patients

PURPOSE

To evaluate the risk factors involved in the development of pulmonary hemorrhage complicating CT-guided biopsy of pulmonary lesions in coaxial and non-coaxial techniques.

MATERIALS AND METHODS

Retrospective study included CT-guided percutaneous lung biopsies in 650 consecutive patients (407 males, 243 females; mean age 54.6 years, SD: 5.2) from November 2008 to June 2013. Patients were classified according to lung biopsy technique in coaxial group (318 lesions) and non-coaxial group (332 lesions). Exclusion criteria for biopsy were: lesions <5mm in diameter, uncorrectable coagulopathy, positive-pressure ventilation, severe respiratory compromise, pulmonary arterial hypertension or refusal of the procedure. Risk factors for pulmonary hemorrhage complicating lung biopsy were classified into: (a) patient's related risk factors, (b) lesion's related risk factors and (d) technical risk factors. Radiological assessments were performed by two radiologists in consensus. Mann-Whitney U test and Fisher's exact tests for statistical analysis. p values <0.05 were considered statistically significant.

RESULTS

Incidence of pulmonary hemorrhage was 19.6% (65/332) in non-coaxial group and 22.3% (71/318) in coaxial group. The difference in incidence between both groups was statistically insignificant (p=0.27). Hemoptysis developed in 5.4% (18/332) and in 6.3% (20/318) in the non-coaxial and coaxial groups respectively. Traversing pulmonary vessels in the needle biopsy track was a significant risk factor of the development pulmonary hemorrhage (incidence: 55.4% (36/65, p=0.0003) in the non-coaxial group and 57.7% (41/71, p=0.0013) in coaxial group). Other significant risk factors included: lesions of less than 2 cm (p value of 0.01 and 0.02 in non-coaxial and coaxial groups respectively), basal and middle zonal lesions in comparison to upper zonal lung lesions (p=0.002 and 0.03 in non-coaxial and coaxial groups respectively), increased lesion's depth from the pleural surface (p=0.021 and 0.018 in non-coaxial and coaxial groups respectively), increased distance of traversed lung in the needle track of more than 2.5 cm (p=0.001 in both groups). Insignificant risk factors were patient's age, gender or emphysema in both groups (p value >0.1 in both groups). Concomitant incidence of pneumothorax was 32.3% (21/65) in non-coaxial group and 36.6% (26/71) in coaxial group. Pulmonary hemorrhage in the majority of cases was treated conservatively.

CONCLUSION

Pulmonary hemorrhage complicating CT-guided core biopsy of pulmonary lesions, showed insignificant difference between coaxial and non-coaxial techniques. Significant risk factors of pulmonary hemorrhage included small and basal lesions, increased lesion's depth from pleural surface, increased length of aerated lung parenchyma crossed by biopsy needle and passing through vessels within the lung during puncture.

Whole-body MR angiography: first experiences with the new TimCT technology with single contrast injection

PURPOSE

To assess image quality, presence of artifacts, arterial stenosis, and interobserver agreement of Tim-CT in assessment of the arterial system using contrast-enhanced whole-body-MRA (CE-Wb-MRA) with a single contrast-medium injection in patients with arteriosclerosis.

MATERIALS AND METHODS

The retrospective study included 18 patients (mean age, 68 years). A total of 468 arteries were evaluated. CE-Wb-MRA was performed using Tim-CT technology on a 1.5 Tesla (T) MRI after injecting a single dose of Vasovist. Evaluations were independently performed by two radiologists. The arterial system was divided into seven anatomic locations. Each radiologist assessed the image quality, degree of artifacts, and arterial stenosis in different locations.

RESULTS

All Wb-MRA examinations were technically successful. Image quality: 28.42% arteries were excellent, 29.17% were good, 22.54% were satisfactory, 9.40% were poor, and 5.13% of insufficient quality. Occurrence of artifacts: 37.25% were free of artifacts, 49.44% minimal artifacts not affecting diagnosis, and 13.31% strong artifacts not permitting a diagnosis. A total of 60.00% arteries showed no stenosis, 8.76% were ≤50% stenotic, 5.17% were 51-75% stenotic, 4.38% were 76-99%, and 8.54% total occlusion. The interobserver agreement was good for supra-aortic, pelvic, and upper and lower leg regions.

CONCLUSION

CE-Wb-MRA using the TimCT technology and with a single contrast injection is a feasible tool for whole-body MRA.

Nonselective transarterial chemoperfusion: a palliative treatment for malignant pleural mesothelioma

PURPOSE

To evaluate tumor response by means of volumetric assessment, survival, and changes in patient symptoms after the treatment of unresectable and/or recurrent pleural mesothelioma by using regional nonselective transarterial chemoperfusion as a palliative treatment option.

MATERIALS AND METHODS

This retrospective study was approved by the hospital ethical committee, and all patients signed an informed consent prior to treatment. Thirty-nine patients (mean age, 64.0 years; 10 women and 29 men) with unresectable pleural mesothelioma were treated with repetitive transarterial chemoperfusion between March 2007 and March 2010, with a mean of 2.9 sessions per patient at 4-week intervals. Transarterial chemoperfusion was performed by using mitomycin C, cisplatin, and gemcitabine. Computed tomography findings and patient symptoms were evaluated. Tumor response was evaluated by using Response Evaluation Criteria in Solid Tumors guidelines, and survival was assessed with the Kaplan-Meier method. The change in volume for the partial-response group was tested by using the Wilcoxon signed-rank test.

RESULTS

In 36% of treated tumors (14 of 39), partial response was achieved, and tumor volume decreased from a mean value ± standard deviation of 839.6 mL ± 590.3 (range, 3.9-1972.2 mL) to 137 mL ± 399.8 (range, 0.88-1131.4; P = .00012). In 49% of tumors (19 of 39), stable disease was noted. In 15% of tumors (six of 39), progressive disease was seen. Mean specific growth rate of the tumor was 0.00158% per day. The mean survival time was 14.2 months (range, 2.1-33.1 months) from the start of treatment. For patients with tumors that responded to treatment, mean survival time was 15 months (range, 4.5-33.1 months). Mean time to disease progression was 2.6 months for all tumors, 1.5 months for stable disease, and 1.3 months for progressive disease.

CONCLUSION

Transarterial chemoperfusion may have the potential to yield positive results and response in the treatment of recurrent and/or unresectable pleural mesothelioma. © RSNA, 2012.

Repetitive transarterial chemoembolization (TACE) of liver metastases from gastric cancer: local control and survival results

OBJECTIVE

To evaluate the local tumor control and survival data after transarterial chemoembolization with different drug combinations in the palliative treatment of patients with liver metastases of gastric cancer.

MATERIALS AND METHODS

The study was retrospectively performed. 56 patients (mean age, 52.4) with unresectable liver metastases of gastric cancer who did not respond to systemic chemotherapy were repeatedly treated with TACE in 4-week intervals. In total, 310 chemoembolization procedures were performed (mean, 5.5 sessions per patient). The local chemotherapy protocol consisted of mitomycin alone (30.4%), mitomycin and gemcitabine (33.9%), or mitomycin, gemcitabine and cisplatin (35.7%). Embolization was performed with lipiodol and starch microspheres. Local tumor response was evaluated by MRI according to RECIST. Survival data from first chemoembolization were calculated according to the Kaplan-Meier method.

RESULTS

The local tumor control was: complete response in 1.8% (n=1), partial response in 1.8% (n=1), stable disease in 51.8% (n=29) and progressive disease in 44.6% (n=25) of patients. The 1-, 2-, and 3-year survival rate from the start of chemoembolization were 58%, 38%, and 23% respectively. The median and mean survival times were 13 and 27.1 months. A Statistically significant difference between patients treated with different chemotherapy protocols was noted (ρ=0.045) with the best survival time in the mitomycin, gemcitabine and cisplatin group.

CONCLUSION

Transarterial chemoembolization is a minimally invasive therapy option for palliative treatment of liver metastases in patients with gastric cancer.

Pediatric primary and metastatic neuroblastoma: MRI findings: pictorial review

Magnetic resonance imaging (MRI) has become one of the most valuable modalities for initial and follow-up imaging of suspected or known neuroblastoma (NBL) owing to its excellent inherent contrast, lack of ionizing radiation and multiplanar imaging capability. Importantly, NBL has a variable appearance on different imaging modalities, and this is particularly pertinent to MRI. MRI is a cornerstone for management of NBL, providing essential information at initial presentation regarding diagnosis, staging, resectability and relation to vital structures. It can also define the extent of residual disease after surgical resection or assess the efficacy of treatment. Follow-up MRI is frequently performed to ensure sustained complete remission or to monitor known residual disease. This pictorial review article aims to provide the reader with a concise, yet comprehensive, collection of MR images of primary and metastatic NBL lesions with relevant correlation with other imaging modalities.

Retrospective study on the use of different protocols for repeated transarterial chemoembolization in the treatment of patients with hepatocellular carcinoma

PURPOSE

To evaluate local tumor control and survival rate after repeated transarterial chemoembolization using two different protocols in hepatocellular carcinoma (HCC) patients.

MATERIALS AND METHODS

A total of 190 patients (mean, 68 years) with HCC were repeatedly treated with transarterial chemoembolization in 4-week intervals. The chemotherapy protocol consisted of mitomycin C alone (n = 111) and mitomycin C with gemcitabine (n = 79). Embolization was performed with lipiodol and microspheres. Tumor response was evaluated by magnetic resonance imaging using Response Evaluation Criteria In Solid Tumors (RECIST) criteria. Survival rates were calculated using Kaplan-Meier method.

RESULTS

In the mitomycin C-only group, we observed partial response in 38.8% (43/111), stable disease in 27% (30/111), and progressive disease in 34.2% (38/111). In the mitomycin C/gemcitabine group (n = 79), partial response was observed in 43% (34/79), stable disease in 16.5% (13/79) and progressive disease in 40.5% (32/79). The overall 1- and 2-year survival rates were 56% and 28%, respectively. The overall median survival time from the start of transarterial chemoembolization treatment was 15 months. The median survival of patients treated with mitomycin C was 16.5 months and it was 12 months for patients treated with a combination of mitomycin C and gemcitabine. No statistically significant difference between the two groups was observed (P = .7).

CONCLUSION

Chemoembolization is an effective minimally invasive therapy option for palliative treatment of HCC patients. Mitomycin C only proves to be effective, the addition of gemcitabine was not advantageous.

MR-based thermometry of laser induced thermotherapy: temperature accuracy and temporal resolution in vitro at 0.2 and 1.5 T magnetic field strengths

PURPOSE

To evaluate MR-thermometry using fast MR sequences for laser induced interstitial thermotherapy (LITT) at 0.2 and 1.5 T systems.

METHODS & MATERIALS

In-vitro experiments were performed using Agarose gel mixture and lobes of porcine liver. MR-thermometry was performed by means of longitudinal relaxation time (T1) and proton resonance frequency shift (PRF) methods under acquisition of amplitude and phase shift images. Four different sequences were used for T1 thermometry: A gradient-echo (GRE), a True Fast Imaging with Steady Precession (TRUFI), a Saturation Recovery Turbo-FLASH (SRTF), and an Inversion Recovery Turbo-FLASH (IRTF) sequence (FLASH-Fast Low Angle Shot). PRF was measured with four sequences: Two fast-spoiled GRE sequences (one as WIP sequence), a Turbo-FLASH (TFL) sequence (WIP sequence), and a multiecho-TrueFISP sequence. Temperature was controlled and verified using a fiber-optic Luxtron device. The temperature was correlated with the MR measurement.

RESULTS

All sequences showed a good linear correlation R(2) = 0.97-0.99 between the measured temperature and the MR-thermometry measurements. The only exception was the TRUFI sequence in the Agarose phantom that showed a non-linear calibration curve R(2) = 0.39-0.67. At 1.5 T, the Agarose experiments revealed similar temperature accuracies of 4-6°C for all sequences excluding TRUFI. During experiments with the liver, the PRF sequences showed better performance than the T1, with accuracies of 5-12°C, contrary to the T1 sequences at 14-18°C. The accuracy of the Siemens PRF-FLASH sequence was 5.1°C. At 0.2 T, the Agarose experiments provided the highest accuracy of 3.3°C for PRF measurement. At the liver experiments the T1 sequences SRTF and FLASH revealed the best accuracies at 6.4 and 7.0°C.

CONCLUSION

The accuracy and speed of MR temperature measurements are sufficient for controlling the temperature-based tumor destruction. For 0.2 T systems SRTF and FLASH sequences are recommended. For 1.5 T systems SRTF and FLASH are the most accurate.

Initial experience with repetitive transarterial chemoembolization (TACE) as a third line treatment of ovarian cancer metastasis to the liver: indications, outcomes and role in patient's management

OBJECTIVE

To evaluate local tumor control and survival data after transarterial chemoembolization (TACE) with different drug combinations in the palliative third-line treatment of patients with ovarian cancer liver metastases.

METHODS

Sixty-five patients (mean age: 51.5 year) with unresectable hematogenous hepatic metastases of ovarian cancer who did not respond to systemic chemotherapy were repeatedly treated with TACE in 4-week intervals. The local chemotherapy protocol consisted of Mitomycin (group 1) (n=14; 21.5%), Mitomycin with Gemcitabine (group 2) (n=26; 40%), or Mitomycin with Gemcitabine and Cisplatin (group 3) (n=25; 38.5%). Embolization was performed with Lipiodol and starch microspheres. Local tumor response was evaluated by MRI according to RECIST criteria. Survival data were calculated according to the Kaplan-Meier method.

RESULTS

The local tumor control was: partial response (PR) in 16.9% (n=11), stable disease (SD) in 58.5% (n=38) and progressive disease (PD) in 24.6% (n=16) of patients. In group 1, we observed SD in 78.6% (11/14), and PD in 21.4% (3/14) of patients. In group 2, PR in 7.7% (2/26), SD in 57.7% (15/26), and PD in 34.6% (9/26) of patients. In group 3, PR in 36% (9/25), SD in 48% (12/25), and PD in 16% (4/25) of patients. Survival rate from the start of TACE was 58% after 1-year, 19% after 2-years, and 13% after 3-years. The median and mean survival times were 14 and 18.5 months without statistically significant difference for the 3 groups of patients (p=0.502).

CONCLUSION

Transarterial chemoembolization is effective palliative treatment in achieving local control in selected patients with liver metastases from ovarian cancer.

Transarterial chemoembolization in the treatment of patients with unresectable cholangiocarcinoma: Results and prognostic factors governing treatment success

The aim of the study was to evaluate the effectiveness of transarterial chemoembolization (TACE) with four chemotherapeutic protocols in terms of local tumor control and survival of patients with unresectable cholangiocarcinoma (CCC) and to identify the prognostic factors governing treatment success. In the single-centre study, 115 patients (mean ages = 60.4 years) with unresectable CCC were repeatedly treated with TACE. In total, 819 chemoembolization sessions were performed in 4 week intervals with a mean of 7.1 (range, 3-30) sessions per patient. The chemotherapeutic used was Mitomycin C only in 20.9% of patients, Gemcitabine only in 7%, Mitomycin C with Gemcitabine in 47% and combination of Gemcitabine, Mitomycin C and Cisplatin in 25.1%. Local tumor response was evaluated by MRI according to RECIST. Survival data were calculated according to the Kaplan-Meier method. Prognostic factors for patient's survival were evaluated using log-rank-test. The local tumor controls were: partial response 8.7%, stable disease 57.4% and progressive disease 33.9% of patients. The median and mean survival times from the start of TACE were 13 and 20.8 months. Survival rate from the start of TACE was 52% after 1-year, 29% after 2-years and 10% after 3-years. Initial tumor response, high tumor vascularity and Child-Pugh class A were statistically significant factors for patient's survival. No statistically significant difference between patients treated with different chemotherapy protocols was noted. In conclusion, TACE is a palliative and safe treatment option for patients with unresectable CCC. Child Pugh class B, tumor hypovascularity and initially progressive disease were poor prognostic factors for patient survival.

Transarterial chemoembolization (TACE) with mitomycin C and gemcitabine for liver metastases in breast cancer

The purpose of this study was to evaluate the efficacy of transarterial chemoembolization (TACE) using different drug combinations in the treatment of breast cancer liver metastases in terms of local tumor control and survival rate. A total of 208 patients (mean age 56.4 years, range 29-81) with unresectable hepatic metastases of breast cancer were repeatedly treated with TACE at 4-week intervals. In total, 1,068 chemoembolizations were performed (mean 5.1 sessions/patient, range 3-25). The chemotherapy protocol consisted of mitomycin-C only (8 mg/m(2); n = 76), mitomycin-C with gemcitabine (n = 111), and gemcitabine only (1,000 mg/m(2); n = 21). Embolization was performed with lipiodol and starch microspheres. Tumor response was evaluated by MRI according to RECIST criteria. Survival rates were calculated using Kaplan-Meier method. For all protocols, local tumor control was partial response 13% (27/208), stable disease 50.5% (105/208), and progressive disease 36.5% (76/208). The 1-, 2-, and 3-year survival rates after TACE were 69, 40, and 33%. Median and mean survival times from the start of TACE were 18.5 and 30.7 months. Treatment with mitomycin-C only showed median and mean survival times of 13.3 and 24 months, with gemcitabine only they were 11 and 22.3 months, and with a combination of mitomycin-C and gemcitabine 24.8 and 35.5 months. TACE is an optional therapy for treatment of liver metastases in breast cancer patients with better results from the combined chemotherapy protocol.

Uterine artery embolization: optimization with preprocedural prediction of the best tube angle obliquity by using 3D-reconstructed contrast-enhanced MR angiography

PURPOSE

To evaluate the effect of preprocedural prediction of the best tube angle obliquity for visualization of the uterine artery origin by using three-dimensional (3D)-reconstructed contrast material-enhanced magnetic resonance (MR) angiography on the radiation dose, fluoroscopy time, and contrast medium volume during uterine artery embolization (UAE).

MATERIALS AND METHODS

The study was approved by the institutional review board. Informed consent was obtained. The prospective study included 20 consecutive prospective patients (age range, 37-56 years) for whom preprocedural prediction of the best tube angle obliquity was determined by using 3D-reconstructed contrast-enhanced MR angiography; the best tube angle obliquity was provided to the interventionist. Three-dimensional reconstruction was performed by using an application of the angiographic unit. The radiation dose, fluoroscopy time, and contrast medium volume for those patients were compared with those data in 20 retrospectively assessed control patients (age range, 39-56 years) from the prior 20 procedures performed by the same interventionist.

RESULTS

Tube angle prediction resulted in a significant reduction in the radiation dose utilized (P < .001), fluoroscopy time (P = .002), and contrast medium volume (P < .001) for the sample patients compared with those for the control patients. Overall radiation dose was reduced from a mean of 11 044 microGy per square meter to a mean of 4172.5 microGy per square meter. Fluoroscopy time was reduced from a mean of 15 minutes 30 seconds to 8 minutes 49 seconds. Contrast medium volume was reduced from a mean of 135 mL to 75 mL.

CONCLUSION

Preprocedural prediction of the best tube angle obliquity for visualization of the origin of the uterine artery by using 3D-reconstructed contrast-enhanced MR angiography results in significant reductions in radiation dose, fluoroscopy time, and contrast medium volume during UAE.