Nomogram including pretherapeutic parameters for prediction of survival after SIRT of hepatic metastases from colorectal cancer.

OBJECTIVES: Pre-therapeutic prediction of outcome is important for clinicians and patients in determining whether selective internal radiation therapy (SIRT) is indicated for hepatic metastases of colorectal cancer (CRC). METHODS: Pre-therapeutic characteristics of 100 patients with colorectal liver metastases (CRLM) treated by radioembolization were analyzed to develop a nomogram for predicting survival. Prognostic factors were selected by univariate Cox regression analysis and subsequent tested by multivariate analysis for predicting patient survival. The nomogram was validated with reference to an external patient cohort (n = 25) from the Bonn University Department of Nuclear Medicine. RESULTS: Of the 13 parameters tested, four were independently associated with reduced patient survival in multivariate analysis. These parameters included no liver surgery before SIRT (HR:1.81, p = 0.014), CEA serum level ≥ 150 ng/ml (HR:2.08, p = 0.001), transaminase toxicity level ≥2.5× upper limit of normal (HR:2.82, p = 0.001), and summed computed tomography (CT) size of the largest two liver lesions ≥10 cm (HR:2.31, p < 0.001). The area under the receiver-operating characteristic curve for our prediction model was 0.83 for the external patient cohort, indicating superior performance of our multivariate model compared to a model ignoring covariates. CONCLUSIONS: The nomogram developed in our study entailing four pre-therapeutic parameters gives good prediction of patient survival post SIRT. KEY POINTS: • Four individual parameters predicted reduced survival following SIRT in CRC. • These parameters were combined into a nomogram of pre-therapeutic risk stratification. • The model provided good prediction of survival in two independent patient cohorts.

CT fluoroscopy-guided percutaneous fiducial marker placement for CyberKnife stereotactic radiosurgery: technical results and complications in 222 consecutive procedures.

PURPOSE: To evaluate technical outcome and safety of computed tomographic (CT) fluoroscopy-guided percutaneous fiducial marker placement before CyberKnife stereotactic radiosurgery. MATERIALS AND METHODS: Retrospective analysis was performed of 196 patients (106 men) undergoing CT fluoroscopy-guided fiducial marker placement in 222 consecutive procedures under local anesthesia from March 2006 to February 2012. Technical success was defined as fiducial marker location in the tumor or vicinity suitable for CyberKnife radiosurgery evaluated on postinterventional planning CT. Complications were classified per Society of Interventional Radiology (SIR). RESULTS: One hundred ninety-six patients (age, 61.5 y ± 13.1) underwent percutaneous placement of 321 fiducial markers (mean per tumor, 1.2 ± 0.5; range, 1-4) in 37 primary tumors and 227 metastases in the thorax (n = 121), abdomen (n = 122), and bone (n = 21). Fiducial marker placement was technically successful in all procedures: intratumoral localization in 193 (60.1%), at tumor margin in 50 (15.6%), and outside of tumor in 78 cases (24.3%; mean distance to marker, 0.4 cm ± 0.6; range, 0-2.9 cm). Complications were observed in 63 placement procedures (28.4%), including minor self-limiting pneumothorax (n = 21; SIR class B) and self-limiting pulmonary hemorrhage (n = 35; SIR class A), and major pneumothorax requiring thoracostomy/drainage insertion (n = 14; SIR class D) and systemic toxicity of local anesthetic drug (n = 1; SIR class D). CONCLUSIONS: CT fluoroscopy-guided percutaneous fiducial marker placement can be performed with high technical success under local anesthesia in various anatomic regions. Although self-limiting in most cases, pneumothorax and pulmonary hemorrhage are frequently observed during fiducial marker implantation into lung tumors.

Comparison of the survival and tolerability of radioembolization in elderly vs. younger patients with unresectable hepatocellular carcinoma.

BACKGROUND & AIMS: The European Network on Radioembolization with Yttrium-90 resin microspheres study group (ENRY) conducted a retrospective study to evaluate the outcomes among elderly (≥ 70 years) and younger patients (<70 years) with unresectable hepatocellular carcinoma (HCC) who received radioembolization at 8 European centers. METHODS: Patients with confirmed diagnosis of unresectable HCC who either progressed following resection or locoregional treatment and/or who were considered poor candidates for chemoembolization were evaluated by a multidisciplinary team for radioembolization with (90)Y-resin microspheres (SIR-Spheres; Sirtex Medical). The survival outcome and all adverse events were compared between the two age groups. RESULTS: Between 2003 and 2009, 128 elderly and 197 younger patients received radioembolization. Patients in both groups had similar demographic characteristics. Many elderly and younger patients alike had multinodular, BCLC stage C disease, invading both lobes (p = 0.648). Elderly patients had a lower tumor burden, a smaller median target liver volume (p = 0.016) and appeared more likely to receive segmental treatment (p = 0.054). Radioembolization was equally well tolerated in both cohorts and common procedure-related adverse events were predominantly grade 1-2 and of short duration. No significant differences in survival between the groups were found (p = 0.942) with similar median survival in patients with early, intermediate or advanced BCLC stage disease. CONCLUSIONS: Radioembolization appears to be as well-tolerated and effective for the elderly as it is for younger patients with unresectable HCC. Age alone should not be a discriminating factor for the management of HCC patients.

CT fluoroscopy-guided vertebral augmentation with a radiofrequency-induced, high-viscosity bone cement (StabiliT(®)): technical results and polymethylmethacrylate leakages in 25 patients.

OBJECTIVE: To assess the technical results of CT fluoroscopy-guided, radiofrequency-induced vertebral augmentation (StabiliT®) in terms of vertebral height restoration and polymethylmethacrylate (PMMA) leakages, occurring in 25 individual patients with vertebral compression fractures and osteolysis. MATERIALS AND METHODS: From 07/2010 to 08/2011, 25 patients (16 women, nine men; age 71 ± 14; range 41-89) with painful vertebral compression fractures due to osteoporosis (n = 19), metastases (n = 2) or multiple myeloma (n = 4) underwent vertebral augmentation with a radiofrequency-activated, high-viscosity polymethylmethacrylate (PMMA) bone cement (StabiliT® Vertebral Augmentation system; DFINE Europe GmbH, Mannheim) under local anesthesia. Thirty-four vertebrae (Th5-L5) were treated in 27 sessions under CT fluoroscopy guidance (128-row CT, Somatom Definition AS, Siemens, Erlangen) using a unilateral access and a cavity-creating osteotome prior to remote-controlled, hydraulically driven cement injection. 1/2/3 levels were treated in 21/5/1 session(s). Vertebral height change in the midsagittal plane (anterior, midvertebral, posterior endplate distance) and PMMA leaks were retrospectively evaluated using the postinterventional CT. RESULTS: All patients were successfully treated in the first session. Mean (MV ± SD) procedure time and amount of injected PMMA were 56 ± 14 min and 4.5 ± 1.4 ml, respectively. Mean anterior/midvertebral/posterior height gain was +7.1/+9.7/+0.4%. Small local vertebral leaks were observed in 18/34 vertebrae (53%) without any clinical sequelae. No major complications occurred. CONCLUSIONS: CT fluoroscopy-guided, RF-induced vertebral augmentation with a high-viscosity bone cement (StabiliT®) was safe and technically successful in all patients. Using a hydraulic cement injection technique, a moderate restoration of anterior and midvertebral height was seen while the system was not markedly superior to standard vertebroplasty regarding the frequency of minor asymptomatic PMMA leaks.

CT fluoroscopy-guided percutaneous vertebroplasty in spinal malignancy: technical results, PMMA leakages, and complications in 202 patients.

OBJECTIVE: To retrospectively evaluate the incidence and clinical impact of local polymethylmethacrylate (PMMA) leaks and pulmonary cement embolisms occurring under CT fluoroscopy-guided vertebroplasty of symptomatic malignant vertebral osteolyses. MATERIALS AND METHODS: From December 2001 to June 2009, 202 cancer patients (116 women, 86 men; age 63.2±8.6 years) with painful malignant vertebral osteolyses underwent vertebroplasty, with or without vertebral compression fracture. A total of 331 vertebrae were treated in 231 sessions under CT fluoroscopy guidance (120 kV; 10­25 mA; single slice, 4-, 16-, and 128-row CT). In the pre-vertebroplasty CT, the following items were assessed: osteolytic destruction (0, ≤25, ≤50, ≤75, or ≤100%) of vertebral cross-sectional area, posterior wall, and circumference; presence of perivertebral and degree of epidural (no, mild, moderate) soft tissue involvement. Local PMMA leaks were analyzed using the post-vertebroplasty CT. Pulmonary cement embolisms were evaluated in all patients having undergone radiography (CR; n053) or CT (n088) of the chest after vertebroplasty due to their underlying disease. Patient charts were reviewed regarding adverse events. RESULTS: Of 331 treated vertebrae, 32, 20.2, and 15.7% showed more than 50% osteolytic involvement of the vertebral cross-sectional area, posterior wall, and circumference, respectively. Mild or moderate epidural involvement was seen in 13.0 and 8.4%. Local PMMA leakage rate was 58.6% (194 of 331 vertebrae). Pulmonary cement embolisms (segmental, n010; central, n01) were seen after 7.8% of the procedures with follow-up imaging of the chest. No major complications occurred within a 30-day period after vertebroplasty. CONCLUSION: Vertebroplasty of spinal malignancy can be safely performed under CT fluoroscopy guidance even in patients with substantial osteolytic involvement. In our patient collective, PMMA leaks and pulmonary cement embolisms visualized in post-procedural radiography and CT images had no clinical impact.

Combination of ablation and embolization for intermediate-sized liver metastases from colorectal cancer: what can we learn from treating primary liver cancer?

Colorectal cancer liver metastases (CRLMs) are common. Treating CRLMs with thermal ablation can prolong survival, but compared to lesions smaller than 3 cm, local control rates and overall survival are relatively worse with larger, intermediate (3-5 cm) lesions. Local recurrence rates range between 1.7%-20.2% and 6.7%-68.9% for CRLMs less than 3 cm and greater than 3 cm, respectively. Worse outcomes are also present when ablating intermediate size hepatocellular carcinoma (HCC) and there are some pathological similarities with CRLMs, namely the presence of micrometastatic disease. Combining ablation with transarterial chemoembolization is more effective in treating intermediate-size HCC than ablation alone. A meta-analysis of robust randomized controlled trials demonstrated long-term improved survival with combination therapy compared to ablation alone (odds ratio at 1, 3 and 5 years of 2.74, 2.77 and 5.23, respectively). There is, however, minimal evidence for combination therapy in CRLMs, limited to a handful of studies that are predominantly retrospective and have heterogeneous inclusion criteria. Given the difficulty in successfully treating intermediate CRLMs, the strong evidence for combination therapy in intermediate HCC and potential pathological similarities, formal evaluation of combination treatment in CRLM is merited. This review highlights existing evidence for treatment of intermediate-size liver lesions and highlights where trials in CRLMs should focus.

MR-lymphangiography at 3.0 T--a feasibility study.

The purpose of this study was to establish and evaluate contrast-enhanced MR-lymphangiography (MRL) at 3.0 T for detection and visualization of abnormalities of the peripheral lymphatic system. Sixteen patients were examined with a highly resolved isotropic T1w-3D-GRE-(FLASH) sequence (TR 3.76 ms/TE 1.45 ms/FA 30 degrees /voxel-size 0.8 x 0.8 x 0.8 mm(3)) at 3T after intracutaneous injection of gadolinium-diethylene-triamine-pentaacetic-acid. Two radiologists evaluated overall image quality, contrast between lymph vessels and background tissue, venous contamination, visualized levels, and fat-saturation-homogeneity on 3D maximum-intensity projections. Overall image quality was good to excellent, and all examinations were diagnostic except one, where contrast medium was injected subcutaneously instead of intracutaneously. Overall image quality was good to excellent in 12/16 cases, depiction of lymph vessels was good to excellent in 15/16 cases. Venous contamination was always present, but diagnostically problematical in only one case. Instant lymphatic drainage was observed in unaffected extremities, reaching the pelvic level after approximately 10 min. Lymphatic drainage was considerably delayed in lymphedematous extremities. Ectatic lymph vessels, entrapment, and diffuse drainage of contrast medium correlated with impaired lymphatic drainage. In conclusion, MRL at 3.0 T provides very high spatial resolution and anatomical detail of normal and abnormal peripheral lymph vessels. MRL may thus become a valuable tool for microsurgical treatment planning and monitoring.

CT fluoroscopy-guided percutaneous vertebroplasty for the treatment of osteolytic breast cancer metastases: results in 62 sessions with 86 vertebrae treated.

PURPOSE: This retrospective study aimed to assess the results of computed tomographic (CT) fluoroscopy-guided percutaneous vertebroplasty (PV) of painful osteolytic spinal metastases from breast cancer, focusing on the frequency and clinical impact of polymethylmethacrylate (PMMA) leaks. MATERIALS AND METHODS: Within 48 months, 53 patients (52 women; mean age of 62 y +/- 13) with painful osteolytic breast cancer metastases underwent vertebroplasty. Eighty-six vertebrae were treated in 62 sessions under CT fluoroscopy guidance (single slice and four- and 16-row CT). In the planning CT scan, osteolytic destruction (ie, none, < or =25%, < or =50%, < or =75%, or < or =100%) was assessed regarding the vertebral cross-sectional area, the cortical border of the spinal canal, and the outer circumference. CT performed after vertebroplasty was used to detect local PMMA leaks (intradiscal, intraspinal, paravertebral, intercostovertebral/posterolateral, and vascular). Patient charts were reviewed with respect to adverse events. Clinical outcome was assessed on a visual analog scale (VAS) 24 hours before, immediately after, and 6 months after PV. RESULTS: Overall, 37.2%, 12.8%, and 1.2% of vertebrae (N = 86) showed at least a 50% osteolytic involvement of the cross-sectional area, spinal canal, and outer vertebral cortex, respectively. Intradiscal, intraspinal, paravertebral, and intercostovertebral/posterolateral leaks were seen in 31.3%, 26.9%, 26.9%, and 14.9% of vertebrae, respectively. The ratio of basivertebral to segmental venous leaks was 22.4%/23.9%. No major complications (eg, radiculopathy or pulmonary embolism) occurred. VAS scores decreased significantly (P < .05) from 6.4 at 24 hours before PV to 3.4 at a mean follow-up of 9.2 months. CONCLUSIONS: PV of osteolytic breast cancer metastases can be performed safely under CT fluoroscopic guidance even with substantial involvement of the vertebral cross-sectional area or cortical bone. A high clinical success rate was achieved and cortical and vascular PMMA leaks had no impact.

Hepatic yttrium-90 radioembolization of chemotherapy-refractory colorectal cancer liver metastases.

PURPOSE: To present data for radioembolization with yttrium-90 ((90)Y) resin microspheres in patients with colorectal cancer liver metastases in whom currently available therapies had failed. MATERIALS AND METHODS: Retrospective review was conducted of case files of patients with colorectal cancer liver metastases in whom chemotherapy had failed, prompting hepatic (90)Y radioembolization administered as a single-session, whole-liver treatment. Imaging and laboratory follow-up results were available for 36 patients. Response and toxicity were assessed by computed tomography/magnetic resonance imaging with the Response Evaluation Criteria in Solid Tumors and the National Cancer Institute's Common Terminology Criteria for Adverse Events, version 3.0. RESULTS: Forty-one patients (mean age, 61 years; 30 men) received hepatic (90)Y radioembolization with resin microspheres (mean activity, 1.9 GBq). At a median interval of 2.9 months after radioembolization, partial response, stable disease, and progressive disease were demonstrated in seven, 25, and four patients, respectively. Median overall survival was 10.5 months, with improved survival for patients with a decrease in carcinoembryonic antigen level (19.1 months vs 5.4 months) and imaging response (29.3 months vs 4.3 months; P = .0001). Except for one instance of treatment-associated cholecystitis (grade 4 toxicity) and two gastric ulcers (grade 2 toxicity), no severe toxicities were observed. CONCLUSIONS: Hepatic (90)Y radioembolization can be performed with manageable toxicity in patients with colorectal cancer liver metastases whose disease is refractory to chemotherapy. The antitumoral effect is supported by imaging and tumor marker responses. Further investigation is warranted to determine the optimal use of this emerging therapeutic modality.

RFA of renal cell carcinoma in a solitary kidney.

The incidence of renal cell carcinoma (RCC) is increasing worldwide and diagnosis is made in an earlier stage due to increasing use of CT and ultrasound. Patients with a history of RCC have a high risk to develop another RCC within their remaining kidney. Especially, patients after tumor nephrectomy have to undergo follow-up examinations regularly allowing an early detection of new RCCs. Especially in patients with solitary kidney gold standard therapy (nephron-sparing surgery) can often account for consecutive renal failure with the need for hemodialysis. Percutaneous radiofrequency ablation (RFA) gained worldwide acceptance for the treatment of liver tumors in patients unable to undergo surgery. Furthermore, during the past few years, there is an increasing amount of publications dealing with the effectiveness of minimally invasive therapies like RFA in patients with renal masses. However, in the subgroup of patients with solitary kidney suffering from RCC, there are only case reports regarding safety and midterm outcome available so far. Therefore, the aim of this article is to briefly describe the basic technical principles of RFA and then focus on indications, technique, safety and the midterm outcome after treatment in terms of renal function and relapse.

Planning and intraoperative visualization of liver catheterizations: new CTA protocol and 2D-3D registration method.

RATIONALE AND OBJECTIVES: Two-dimensional and three-dimensional (2D-3D) registration for angiographic liver interventions is an unsolved problem mainly because of two reasons. First, a suitable protocol for computed tomography angiography (CTA) to contrast liver arteries is not used in clinical practice. Second, in spite of a valuable body of research results in the neuroradiology community, an adequate registration algorithm that addresses the difficult task of 2D-3D alignment of abdominal vessel structures has not been developed yet. MATERIALS AND METHODS: We address the first issue by introducing an angiographic computed tomography (CT) scanning phase. The scan visualizes arteries similar to the vasculature captured with an intraoperative C-arm acquiring digitally subtracted angiograms. Furthermore, we propose a registration algorithm using the new CT phase that aligns arterial structures in two steps: 1) Initialization of one corresponding feature using diameter information and 2) optimization on three rotational and one translational parameters to register vessel structures that are represented as centerline graphs. We form a space of good features by iteratively creating new graphs from projected centerline images and by restricting the correspondence search only on branching points (the vertices) of the vessel tree. RESULTS: We show convergence and robustness of the proposed algorithm on synthetic data, as well as head phantom and four consistent patient data sets. We compare our results with those of a recently proposed method. Moreover, we evaluate different visualization techniques and show that a transfer of planning information to intraoperative data is a benefit for interventional workflow. CONCLUSIONS: Introducing a new CTA protocol and a two-step 2D-3D registration algorithm, the proposed method creates a strong link between radiologists and interventionalists by bringing preoperative patient and planning information to interventional workflow.

Clinical value of MDCT in the diagnosis of coronary artery disease in patients with a low pretest likelihood of significant disease.

OBJECTIVE: The aim of this study was to evaluate the clinical value of MDCT in the diagnosis of coronary artery disease in a population having a low pretest likelihood of significant disease. SUBJECTS AND METHODS: Sixty-four patients with suspected coronary artery disease and a low pretest likelihood of significant disease according to the criteria of the American Heart Association underwent both MDCT of the heart and quantitative conventional coronary angiography (QCA). MDCT examinations were performed on a 16-MDCT scanner. CT data sets were evaluated on a per-patient basis and a per-segment basis and were classified as indicating no disease, nonsignificant disease (stenoses 50%). Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of 16-MDCT in the detection or exclusion of significant and nonsignificant coronary artery disease were evaluated on both per-patient and per-segment bases. RESULTS: Regarding the success rate of 16-MDCT, 94% (60/64) of patients and 92% (388/420) of vessel segments were of sufficient quality for diagnosis. In the remaining 60 patients evaluated, QCA revealed significant coronary artery disease, nonsignificant disease, and no disease in 8.3% (5/60), 75.0% (45/60), and 16.7% (10/60) of cases, respectively, on a per-patient basis, and in 1.3% (5/388), 23.2% (90/388), and 75.5% (293/388) of cases, respectively, on a per-segment basis. The sensitivity, specificity, NPV, and PPV of 16-MDCT for the detection of significant coronary artery disease were 80.0%, 94.5%, 98.1%, and 57.1%, respectively, on a per-patient basis, and 80.0%, 99.2%, 99.7%, and 57.1% on a per-segment basis. CONCLUSION: In a population having a low pretest likelihood of significant coronary artery disease, 16-MDCT shows a moderate to high sensitivity and high NPV for the detection or exclusion of significant disease, but has a somewhat reduced PPV compared with QCA.

Radiofrequency ablation of colorectal liver metastases: mid-term results in 68 patients.

UNLABELLED: The aim of this retrospective study was to evaluate the efficacy and medium-term survival, after percutaneous radiofrequency ablation (RFA), in patients suffering from hepatic metastases of colorectal cancer. PATIENTS AND METHODS: Between 2000 and 2004, 68 patients (42 men, 26 women; mean age 63 years, range: 38-87 years), with non-resectable liver metastases from colorectal cancer, were treated by RFA subsequently or parallel to chemotherapy. The procedures were mainly performed under conscious sedation and local anesthesia using computed tomography fluoroscopy guidance. The number of lesions, the primary success rate, complications, follow-up time and disease-free survival, as well as the local recurrence rate, were evaluated. RESULTS: One-hundred and eighty-three metastases with a mean diameter of 22.8 mm (5-50 mm) in 68 patients (2.7 +/- 1.1 lesions / patient) were successfully treated using RFA. No major complications and only 4 minor complications were noted. Over an average follow-up period of 21.4 +/- 10.6 months (range, 8 to 38 months), Kaplan-Meier analysis demonstrated a probability of 82% of remaining locally disease-free and a probability of 68% of surviving the first 38 months after treatment. CONCLUSION: For patients with non-resectable hepatic metastases of colorectal cancer, RFA is a safe option in a multimodal treatment concept and may lead to an improvement in survival.

Safety, Efficacy, and Prognostic Factors After Radioembolization of Hepatic Metastases from Breast Cancer: A Large Single-Center Experience in 81 Patients.

UNLABELLED: The present study evaluated safety, efficacy, and prognostic factors for (90)Y-yttrium microsphere radioembolization of unresectable liver metastases from breast cancer. METHODS: Eighty-one patients were treated with radioembolization. Acute toxicity was monitored through daily physical examination and serum tests until 3 d after radioembolization; late toxicity was evaluated until 12 wk after radioembolization. Overall survival and response according to (18)F-FDG PET (>30% decrease of tracer uptake) and CA15-3 serum level (any decline) were recorded. Pretherapeutic characteristics, including pretreatment history, liver function tests, and PET/CT parameters, were assessed by univariate and subsequent multivariate Cox regression for predicting patient survival. RESULTS: A toxicity grade of 3 or more based on clinical symptoms, bilirubin, ulcer, pancreatitis, ascites, or radioembolization-induced liver disease occurred in 10% or less of patients. Two patients eventually died from radioembolization-induced liver disease. Sequential lobar treatment and absence of prior angiosuppressive therapy were both associated with a lower rate of serious adverse events. On the basis of PET/CA15-3 criteria, 52/61% of patients responded to treatment. Median overall survival after radioembolization was 35 wk (interquartile range, 41 wk). Pretherapeutic tumor burden of the liver greater than 50% or more (P< 0.001; hazard ratio, 5.67; 95% confidence interval, 2.41-13.34) and a transaminase toxicity grade of 2 or more (P= 0.009; hazard ratio, 2.15; 95% confidence interval, 1.21-3.80) independently predicted short survival. CONCLUSION: Radioembolization for breast cancer liver metastases shows encouraging local response rates with low incidence of serious adverse events, especially in those patients with sequential lobar treatment or without prior angiosuppressive therapy. High hepatic tumor burden and liver transaminase levels at baseline indicate poor outcome.

Predictive Value of 99mTc-MAA SPECT for 90Y-Labeled Resin Microsphere Distribution in Radioembolization of Primary and Secondary Hepatic Tumors.

UNLABELLED: This study analyzed the predictive value of (99m)Tc-labeled macroaggregated albumin ((99m)Tc-MAA) SPECT for (90)Y-labeled resin microsphere therapy (radioembolization) by comparing uptake on pretherapeutic (99m)Tc-MAA SPECT with uptake on posttherapeutic (90)Y-bremsstrahlung SPECT. METHODS: We included 502 patients (55% male; mean age ± SD, 62 ± 11 y) who underwent radioembolization between 2005 and 2013 because of primary or secondary liver malignancies (colorectal cancer [n = 195, 38.8%], neuroendocrine tumors [n = 77, 15.3%], breast cancer [n = 68, 13.5%], hepatocellular carcinoma [n = 59, 11.8%], cholangiocellular carcinoma [n = 40, 8.0%], or urologic tumors [n = 14, 2.8%]). Manually drawn regions of interest around tumors and adjacent healthy liver tissue for up to 3 lesions per patient on (99m)Tc-MAA and (90)Y-bremsstrahlung scans were used to quantify mean counts per pixel and evaluate the mean tumor-to-background ratio (TBR). Data were given as mean ± SD. Additionally, uptake in lesions on (99m)Tc-MAA and (90)Y-bremsstrahlung scans was graded visually as homogeneously higher than (grade 1), heterogeneously higher than (grade 2), equal to (grade 3), or lower than (grade 4) uptake in normal liver tissue. The Mann-Whitney U test and Spearman correlation were used to evaluate statistically significant differences between (99m)Tc-MAA and (90)Y-bremsstrahlung SPECT. RESULTS: In total, 1,008 lesions were analyzed. Of the 23% (230/1,008) of lesions that had grade 1 uptake on (99m)Tc-MAA SPECT, 81% (186/230) remained grade 1 after radioembolization whereas 16% (37/230) were grade 2. Of the lesions with grade 2 uptake on (99m)Tc-MAA SPECT, 16% had grade 1 uptake and 82% grade 2 uptake after radioembolization. Of the lesions with grade 3 uptake, however, 27% had grade 1 uptake and 47% grade 2 uptake after radioembolization. Even among the lesions with grade 4 uptake on (99m)Tc-MAA SPECT, 21% had grade 1 uptake and 46% grade 2 uptake after radioembolization. The mean TBR on (99m)Tc-MAA and (90)Y-bremsstrahlung SPECT showed a significant, though low, correlation in the total population (r = 0.26; P < 0.001) and in hepatocellular carcinoma (r = 0.4; P < 0.001), cholangiocellular carcinoma (r = 0.3; P < 0.05), breast cancer (r = 0.3; P < 0.001), colorectal cancer (r = 0.2; P < 0.001), and neuroendocrine tumors (r = 0.2; P < 0.01). CONCLUSION: Although significant for most lesions, the correlation between (99m)Tc-MAA and (90)Y-microsphere mean TBR was low. Classifying uptake into 4 grades revealed that lesions with high uptake on (99m)Tc-MAA SPECT maintain high uptake within radioembolization. More than 60% of lesions with a pretherapeutically lower uptake than in healthy liver tissue, however, showed high uptake within radioembolization. Patients with low tumor uptake on pretherapeutic (99m)Tc-MAA imaging should not be excluded from radioembolization.

Systematic evaluation of tumoral 99mTc-MAA uptake using SPECT and SPECT/CT in 502 patients before 90Y radioembolization.

UNLABELLED: The aim of this study was to evaluate the (99m)Tc-macroaggregated albumin ((99m)Tc-MAA) uptake of primary and secondary liver tumors in a large patient cohort before (90)Y radioembolization. METHODS: We included 502 patients during the years 2005-2013 (55% male; mean age, 62 ± 11 y), who were examined with (99m)Tc-MAA SPECT or SPECT/CT before planned radioembolization. The patients had colorectal cancer (CRC; n = 195, 38.8%), neuroendocrine tumors (NET; n = 77, 15.3%), mammary cancer (MAM; n = 68, 13.5%), hepatocellular carcinoma (HCC; n = 59, 11.8%), cholangiocellular carcinoma (CCC; n = 40, 8.0%), or urologic tumors (URO; n = 14, 2.8%). SPECT with coregistered contrast-enhanced CT or MR imaging and SPECT/CT images of these patients were analyzed using dedicated software with regard to the (99m)Tc-MAA uptake of the liver tumors. Regions of interest were drawn around the lesions manually and quantified the uptake of up to 3 lesions per patient and also adjacent healthy liver tissue without evidence of tumor. We quantified maximum and mean counts per pixel and calculated tumor-to-background ratio (TBR). Data are reported as mean ± SD. Lesion uptake was classified as being homogeneously high (grade 1), heterogeneously high (grade 2), equal to that of the liver (grade 3), or low (grade 4). RESULTS: Grade 1 uptake was seen in 230 of 1,008 lesions (with the highest rates in sarcoma [47%], MAM [37%], and NET [32%]), grade 2 in 706 lesions (with the highest rates in CRC [77%], HCC [75%], and CCC [74%]), grade 4 in 57 lesions (with the highest rates in pancreatic cancer [17%], sarcoma [SAR] [13%], and MAM [8%]), and grade 3 in only 15 lesions. In quantitative analysis, the mean TBRmax of all lesions was 4.8 ± 4.1 (range, 0.2-50.1), with the highest values in HCC (6.0 ± 4.7; range, 1.4-21.6), NET (5.4 ± 4.9; range, 0.8-43.0), pancreatic cancer (4.0 ± 2.8; range, 0.9-12.2), and CCC (4.7 ± 2.9; range, 0.9-11.6), and the lowest values in SAR (3.5 ± 1.8; range, 0.8-2.7) and MAM (3.6 ± 2.2; range, 0.9-11.6). The mean TBRmean was 1.9 ± 1.0 (range, 0.1-7.2), with the highest values in NET (2.2 ± 1.2; range, 0.2-7.2), HCC (2.1 ± 1.2; range, 0.3-6.3), and CCC (2.0 ± 1.0; range, 0.2-6.3) and the lowest values in MAM (1.7 ± 0.8; range, 0.2-4.1), CRC (1.8 ± 0.9; range, 0.4-6.6), and SAR (1.7 ± 1.1; range, 0.3-3.9). CONCLUSION: The (99m)Tc-MAA uptake of different tumor entities shows a wide variation, with generally highest values for NET, HCC, and CCC and lowest values for MAM, CRC, and SAR. However, the variation of uptake within the different tumor entities is high.

Multi-detector-row CT angiography of peripheral arteries.

The development of multi-detector-row CT (MDCT), within recent years, dramatically improved image quality and expanded the applications for non-invasive CT angiography. Since the introduction of four-detector-row CT (4-DCT) systems in 1998, MDCT technology has spread rapidly and is now widely available. This technique already meets the requirements for many vascular applications with respect to acquisition speed, anatomical coverage and spatial resolution. The newest MDCT scanners offer the advantages of up to 16 detector rows and gantry rotation as fast as 500 msec, further expanding the possibilities for CT angiography. For the assessment of the aorta and the iliac vessels MDCT has already proven to be superior to single detector CT and comparable to conventional angiography. This article reviews the status of MDCT angiography, including technical aspects, reformation methods and limitations, and clinical applications at the current state of the art.

MDCT-imaging of peripheral arterial disease.

With the design and development of advanced computed tomography (CT) techniques and applications, like the newest generation of 16-detector-row CTs, CT angiography of the lower limb becomes a feasible tool for imaging peripheral vascular disease. Due to several advantages, compared with conventional digital subtraction angiography (DSA), including minimal invasiveness, CT angiography competes against diagnostic DSA in several clinical situations. 16-DCT offers the possibility to acquire thin slices from the diaphragm to the ankle in less than 40 sec. Easily, a data set of 800 to 1200 transverse slices may be created. To use transverse reconstructions alone to read these volumetric data sets is not appropriate. Powerful post-processing tools for volumetric analysis are required so that routine interpretation can be performed as efficiently and accurately as transverse section review. Because of its widespread availability and applicability, CT angiography of the lower extremities may be applied to patients in a pre- or post-procedural situation and also serves as a first line modality in patients with acute onset of clinical symptoms. Although multidetector CT arteriography is rapidly achieving clinical acceptance, further studies need to be performed to fully evaluate the clinical value of this method of peripheral arterial imaging. This article reviews the current status of multidetector CT peripheral arteriography, including indications, technical details, image post-processing, radiation exposure, and clinical results.

Validation of several SUV-based parameters derived from 18F-FDG PET for prediction of survival after SIRT of hepatic metastases from colorectal cancer.

UNLABELLED: (90)Y radioembolization (selective internal radiation therapy [SIRT]) is a valuable therapeutic option for unresectable hepatic metastases arising from primary colorectal cancer. The present study evaluated the prognostic value of (18)F-FDG PET/CT metabolic parameters for predicting survival after SIRT. METHODS: Eighty patients with hepatic metastases of colorectal cancer were treated with SIRT. (18)F-FDG PET/CT was performed at baseline and 3 mo after the treatment. Metabolic volume, total lesion glycolysis, and maximum and peak standardized uptake value (SUV(max) and SUV(peak), respectively) according to PET Response Criteria in Solid Tumors (PERCIST 1.0) were obtained from 3 liver lesions in each patient, and the corresponding percentage changes from baseline to follow-up were calculated. Tumor response was defined as more than a 30% decrease in these parameters. Furthermore, response was evaluated in accordance with Response Evaluation Criteria in Solid Tumors (RECIST 1.1). Toxicity events and survival were recorded. RESULTS: Overall median survival after SIRT was 60 wk. Responders who had a change in metabolic volume or total lesion glycolysis had significantly longer survival (92 vs. 49 wk [P = 0.006] and 91 vs. 48 wk [P = 0.025], respectively). However, neither RECIST 1.1 criteria nor changes in SUV(peak) or SUV(max) after treatment predicted outcome (P = 0.086 for RECIST; P = 0.310 for change in SUV(peak); P = 0.155 for change in SUV(max)). CONCLUSION: Changes in metabolic volume and total lesion glycolytic rate as measured by (18)F-FDG PET predicted survival in patients with hepatic metastases from colorectal cancer, whereas changes in SUV(peak) or SUV(max) and RECIST 1.1 criteria did not predict survival.