Daniel Czerny

To evaluate liver tumor motion and how well reference measurement predicts motion during treatment. This retrospective study included 20 patients with colorectal cancer that had metastasized to the liver who were treated with stereotactic ablative radiotherapy. An online respiratory tumor tracking system was used. Tumor motion amplitudes in the superior-inferior (SI), latero-lateral (LL), and anterior-posterior (AP) directions were collected to generate patient-specific margins. Reference margins were generated as the mean motion and 95th percentile of motion from measurements recorded for different lengths of time (1, 3, and 5 min). We analyzed the predictability of tumor motion in each axis, based on the reference measurement and intra-/interfraction motions. About 96,000 amplitudes were analyzed. The mean tumor motions were 9.9 ± 4.2 mm, 2.6 ± 0.8 mm, and 4.5 ± 1.8 mm in the SI, LL, and AP directions, respectively. The intrafraction variations were 3.5 ± 1.8 mm, 0.63 ± 0.35 mm, and 1.4 ± 0.65 mm for the SI, LL, and AP directions, respectively. The interfraction motion variations were 1.32 ± 0.79 mm, 0.31 ± 0.23 mm, and 0.68 ± 0.62 mm for the SI, LL, and AP directions, respectively. The Pearson's correlation coefficients for margins based on the reference measurement (mean motion or 95th percentile) and margins covering 95% of the motion during the whole treatment were 0.8-0.91, 0.57-0.7, and 0.77-0.82 in the SI, LL, and AP directions, respectively. Liver tumor motion in the SI direction can be adequately represented by the mean tumor motion amplitude generated from a single 1 min reference measurement. Longer reference measurements did not improve results for patients who were well-educated about the importance of regular breathing. Although the study was based on tumor tracking data, the results are useful for ITV delineation when tumor tracking is not available.

Cholangiocarcinoma (CC) is a rare malignant tumour arising from cholangiocytes, and its prognosis is usually unfavourable, mostly as a result of late diagnosis of the tumour. The current incidence of cholangiocarcinoma in the Czech Republic is 1.4/100,000 inhabitants per year; in less than 30 % of patients with CC, one of the known risk factors can be identified, most frequently, primary sclerosing cholangitis. Only patients with early diagnosed and surgically amenable cholangiocarcinoma are likely to have a longer survival time; in their case, survival for more than five years has been achieved in 20 % to 40 %. From the perspective of the need for early diagnosis of CC, a significant part is played by imaging and histopathologic evaluation; the early diagnostic significance of oncomarkers is limited. The rational early diagnosis of CC consists in effective use of differentiated advantages of different imaging modalities - MRI with DSA appears to be the optimal method, endosonography is a sensitive method for the identification of malignancy in the hepatic hilum or distal common bile duct, MRCP (magnetic resonance cholangiopancreatography) is used to display pathological changes in the biliary tree, ERCP (endoscopic retrograde cholangiopancreatography) allows material removal for histopathological examination. Other new approaches are also beneficial, such as IDUS - intraductal ultrasonography of biliary tract or SPY-GLASS, enabling examination of the bile ducts by direct view with the possibility of taking targeted biopsies. Sensitivity and specificity of histology and cytology can be increased by using the molecular cytogenetic FISH method, i.e. fluorescence in situ by hybridization, with a specificity of 97 %.

To evaluate pancreatic tumor motion and its dynamics during respiration. This retrospective study includes 20 patients with unresectable pancreatic cancer who were treated with stereotactic ablative radiotherapy. An online respiratory tumor tracking system was used. Periodical maximum and minimum tumor positions with respiration in superior-inferior (SI), latero-lateral (LL), and anterior-posterior (AP) directions were collected for tumor motion evaluation. The predictability of tumor motion in each axis, based on reference measurement, was analyzed. The use of a 20-mm and 5-mm constant margins for SI and LL/AP directions, avoids target underdosage, without the need for reference measurement. Pearson’s correlation coefficient indicated only a modest correlation between reference and subsequent measurements in the SI direction (r = 0.50) and no correlation in LL (r = 0.17) and AP (r = 0.35) directions. When margins based on the reference measurement of respiratory tumor motion are used, then 30% of patients have a risk zone of underdosage >3 mm (in average). ITV (internal target volume) optimization based on the reference measurement is possible, but allows only modest margin reduction (approximately from 20 mm to 16-17 mm) in SI direction and no reduction in AP and LL directions. Our results support the use of 20-mm margin in the SI direction and 5-mm margins in the LL and AP directions to account for respiratory motion without reference measurement. Single measurement of tumor motion allows only modest margin reduction. Further margin reduction is only possible when there is on-line tumor motion control according to internal markers.

To compare safety and utility of intraarterial revascularization with use of stents to no revascularization in patients who either failed to respond to intravenous thrombolysis (IVT) or have contraindications to IVT. The case-control study was approved by local ethics committees; all patients signed informed consent. One hundred thirty-one patients (74 men; mean age, 65.9 years ± 12.3; range, 25-86 years) with acute ischemic stroke (AIS) due to middle cerebral artery (MCA) occlusion were enrolled; 75 underwent IVT. No further recanalization therapy was performed in 26 (35%) IVT-treated patients with MCA recanalization (group 1). Patients with IVT failure after 60 minutes were allocated to endovascular treatment (group 2A) or no further therapy (group 2B). Patients with contraindication to IVT were allocated to endovascular treatment within 8 hours since AIS onset (group 3A) or to no recanalization therapy (group 3B). Neurologic deficit at admission, MCA recanalization, symptomatic intracerebral hemorrhage (SICH), and 3-month clinical outcome were evaluated. Favorable clinical outcome was defined as modified Rankin scale score 0-2 at 3 months after stroke onset. Two-sided Mann-Whitney U test, independent samples t test, Fisher exact test, multivariate logistic regression analysis of baseline variables, and complete MCA recanalization for the prediction of favorable clinical outcome were used for statistical evaluation. Median National Institutes of Health Stroke Scale score at admission was 13.5, 16.0, 15.5, 15.0, and 16.0 in groups 1, 2A, 2B, 3A, and 3B, respectively (P > .05); SICH occurred in one of 26 (3.8%), one of 23 (4.3%), one of 26 (3.8%), one of 31 (3.2%), and one of 25 (4.0%) patients, respectively (P > .05). MCA recanalization after endovascular treatment was achieved in 50 of 54 (92.6%) patients. Favorable outcome was significantly different between groups 2A and 2B (10 of 23 [43.5%] and four of 26 [15.4%], respectively; P = .03) and groups 3A and 3B (14 of 31 [45.2%] and two of 25 [8.0%], respectively; P = .004) and was dependent on MCA recanalization (odds ratio, 5.55; P = .006). In this controlled trial, intraarterial revascularization with stents was an effective and safe-effective treatment option in patients with acute MCA occlusion with contraindication to IVT or after IVT failure.

BACKGROUND AND PURPOSE: In CTP, an arterial input function is used for cerebral blood volume measurement. AIFs are often influenced by partial volume effects resulting in overestimated CBV. A venous output function is manually selected to correct for partial volume. This can introduce variability. Our goal was to develop a CTP protocol that enables AIF selection unaffected by partial volume. MATERIALS AND METHODS: First, the effects of partial volume on artery sizes/types including the MCA were estimated by using a CTP phantom with 9 protocols (section thicknesses of 1, 1.8, and 5 mm and image resolutions of 0.5, 1, and 1.5 mm). Next, these protocols were applied to clinical CTP studies from 6 patients. The influence of the partial volume effect was measured by comparison of the time-attenuation curves from different artery locations with reference veins. RESULTS: AIFs from MCAs were unaffected by partial volume effects when using high image resolution (1 mm) and medium section thickness (1.8 mm). For the clinical data, a total of 104 arteries and 60 veins was selected. The data confirmed that high image resolution and thin section thickness enable selection of MCAs for AIFs free of partial volume influences. In addition, we found that large veins were not insusceptible to partial volume effects relative to large arteries, questioning the use of veins for partial volume correction. CONCLUSIONS: A CTP protocol with 1.8-mm section thickness and 1-mm image resolution allows AIF selection unaffected by partial volume effects in MCAs.

During the pandemy caused by novel influenza A virus (subgroup H1N1), a significant number of patients became critically ill from respiratory failure. In the most severe cases of primary pneumonia, patients develop refractory hypoxemic acute respiratory distress syndrome (ARDS) with typical computed tomographic findings of multi-lobar alveolar opacities and extremely reduced pulmonary airspace. To reduce the risk of injurious ventilation and promote survival, some authors recommend the use of extracorporeal membrane oxygenation (ECMO). Unfortunately, ECMO is expensive, associated with serious complications, and available at very few centers. Other therapeutic options are clearly needed. Here we report three patients with severe influenza pneumonia who recovered following treatment with porcine surfactant (Tab. 1, Fig. 3, Ref. 6) . Full Text in free PDF www.bmj.sk .

Decompressive surgery 3 [interquartile (IQR, 250–350)]; mean shift on CT was 10.6 ± 3.6 mm and size of hemicraniectomy was 125 cm² (IQR, 110–154). A favorable outcome was achieved in 45% of the patients. The number of procedures increased from 39 in 2,006 to 2,056 in 2009. Based on data from one stroke center, 10% suffered from malignant supratentorial infarction and 2.3% met the criteria for decompressive surgery. In 2009, as compared to 2006, the volume of decompressive surgery carried out moderately increased. However, procedures remained underutilized because only ~10% of those who needed decompressive surgery underwent surgery.

Fifty percent of diabetics (7% of general population) suffer from peripheral arterial occlusive disease, which may lead to amputation due to critical limb ischemia (CLI). The aim of our study was to prevent major limb amputation (MLA) in this group of patients using a local application of autologous bone marrow stem cells (ABMSC) concentrate. A total of 96 patients with CLI and foot ulcer (FU) were randomized into groups I and II. Patients in group I ( n = 42, 36 males, 6 females, 66.2 ± 10.6 years) underwent local treatment with ABMSC while those in group II ( n = 54, control, 42 males, 12 females, 64.1 ± 8.6 years) received standard medical care. The frequency of major limb amputation in groups I and II was 21% and 44% within the 120 days of follow up, respectively ( p < 0.05). Only in salvaged limbs of group I both toe pressure and toe brachial index increased (from 22.66 ± 5.32 to 25.63 ± 4.75 mmHg and from 0.14 ± 0.03 to 0.17 ± 0.03, respectively, mean ± SEM). The CD34⁺ cell counts in bone marrow concentrate (BMC) decreased (correlation, p = 0.024) with age, even though there was no correlation between age and healing. An unexpected finding was made of relative, bone marrow lymphopenia in the initial bone marrow concentrates in patients who failed ABMSC therapy (21% of MLA). This difference was statistically significant ( p < 0.040). We conclude ABMSC therapy results in 79% limb salvage in patients suffering from CLI and FU. In the remaining 21% lymphopenia and thrombocytopenia were identified as potential causative factors, suggesting that at least a partial correction with platelet supplementation may be beneficial.