Prospective evaluation of CT-guided HDR brachytherapy as a local ablative treatment for renal masses: a single-arm pilot trial.

PURPOSE: In this pilot trial, we investigate the safety of CT-guided high-dose-rate brachytherapy (HDR-BT) as a local ablative treatment for renal masses not eligible for resection or nephrectomy. METHODS: We investigated renal function after irradiation by HDR-BT in 16 patients (11 male, 5 female, mean age 76 years) with 20 renal lesions (renal cell carcinoma n = 18; renal metastases n = 2). Two patients had previous contralateral nephrectomy and two had ipsilateral partial nephrectomy. Six lesions had a hilar localization with proximity to the renal pelvis and would have not been favorable for thermal ablation. Renal function loss was determined within 1 year after HDR-BT by renal scintigraphy and laboratory parameters. Further investigations included CT and MRI every 3 months to observe procedural safety and local tumor control. Renal function tests were analyzed by Wilcoxon's signed rank test with Bonferroni-Holm correction of p-values. Survival and local tumor control underwent a Kaplan-Meier estimation. RESULTS: Median follow-up was 22.5 months. One patient required permanent hemodialysis 32 months after repeated HDR-BT and contralateral radiofrequency ablation of multifocal renal cell carcinoma. No other patient developed a significant worsening in global renal function and no gastrointestinal or urogenital side effects were observed. Only one patient died of renal tumor progression. Local control rate was 95% including repeated HDR-BT of two recurrences. CONCLUSION: HDR-BT is a feasible and safe technique for the local ablation of renal masses. A phase II study is recruiting to evaluate the efficacy of this novel local ablative treatment in a larger study population.

The impact of local control on overall survival after stereotactic body radiotherapy for liver and lung metastases from colorectal cancer: a combined analysis of 388 patients with 500 metastases.

BACKGROUND: The aim of this analysis was to model the effect of local control (LC) on overall survival (OS) in patients treated with stereotactic body radiotherapy (SBRT) for liver or lung metastases from colorectal cancer. METHODS: The analysis is based on pooled data from two retrospective SBRT databases for pulmonary and hepatic metastases from 27 centers from Germany and Switzerland. Only patients with metastases from colorectal cancer were considered to avoid histology as a confounding factor. An illness-death model was employed to model the relationship between LC and OS. RESULTS: Three hundred eighty-eight patients with 500 metastatic lesions (lung n = 209, liver n = 291) were included and analyzed. Median follow-up time for local recurrence assessment was 12.1 months. Ninety-nine patients with 112 lesions experienced local failure. Seventy-one of these patients died after local failure. Median survival time was 27.9 months in all patients and 25.4 months versus 30.6 months in patients with and without local failure after SBRT. The baseline risk of death after local failure exceeds the baseline risk of death without local failure at 10 months indicating better survival with LC. CONCLUSION: In CRC patients with lung or liver metastases, our findings suggest improved long-term OS by achieving metastatic disease control using SBRT in patients with a projected OS estimate of > 12 months.

[Clinical target volume : Principles and limits]. / Klinisches Zielvolumen : Grundsätze und Grenzen.

BACKGROUND: The clinical target volume (CTV) is regarded fundamental for radiotherapy planning by the International Commission on Radiation Units and Measurements (ICRU). OBJECTIVES: The aim of this article is to give an overview on the basics and problems of defining the CTV for radiotherapy planning. MATERIALS AND METHODS: After briefly defining CTV, a short description of the process to homogenize CTV in intraindividual comparisons is given, where special attention is paid to radiological requirements. This information is summarized in a number of tables. RESULTS: CTV is the most complex volume among the target volumes that have been defined by the ICRU. A survey of the determinants of the definition of CTV is given. CONCLUSIONS: This overview on the basic rules of how to define CTVs can help to increase the understanding of the radiological requirements for optimum imaging to support radiotherapy planning regardless of the specialty of the physician.

Stereotactic body radiotherapy (SBRT) for multiple pulmonary oligometastases: Analysis of number and timing of repeat SBRT as impact factors on treatment safety and efficacy.

BACKGROUND: Stereotactic body radiotherapy (SBRT) for oligometastatic disease is characterized by an excellent safety profile; however, experiences are mostly based on treatment of one single metastasis. It was the aim of this study to evaluate safety and efficacy of SBRT for multiple pulmonary metastases. PATIENTS AND METHODS: This study is based on a retrospective database of the DEGRO stereotactic working group, consisting of 637 patients with 858 treatments. Cox regression and logistic regression were used to analyze the association between the number of SBRT treatments or the number and the timing of repeat SBRT courses with overall survival (OS) and the risk of early death. RESULTS: Out of 637 patients, 145 patients were treated for multiple pulmonary metastases; 88 patients received all SBRT treatments within one month whereas 57 patients were treated with repeat SBRT separated by at least one month. Median OS for the total patient population was 23.5 months and OS was not significantly influenced by the overall number of SBRT treatments or the number and timing of repeat SBRT courses. The risk of early death within 3 and 6 months was not increased in patients treated with multiple SBRT treatments, and no grade 4 or grade 5 toxicity was observed in these patients. CONCLUSIONS: In appropriately selected patients, synchronous SBRT for multiple pulmonary oligometastases and repeat SBRT may have a comparable safety and efficacy profile compared to SBRT for one single oligometastasis.

Radioablation of adrenal gland malignomas with interstitial high-dose-rate brachytherapy : Efficacy and outcome.

PURPOSE: To assess the efficacy, safety, and outcome of image-guided high-dose-rate (HDR) brachytherapy in patients with adrenal gland metastases (AGM). MATERIALS AND METHODS: From January 2007 to April 2014, 37 patients (7 female, 30 male; mean age 66.8 years, range 41.5-82.5 years) with AGM from different primary tumors were treated with CT-guided HDR interstitial brachytherapy (iBT). Primary endpoint was local tumor control (LTC). Secondary endpoints were time to untreatable progression (TTUP), time to progression (TTP), overall survival (OS), and safety. In a secondary analysis, risk factors with an influence on survival were identified. RESULTS: The median biological equivalent dose (BED) was 37.4 Gy. Mean LTC after 12 months was 88%; after 24 months this was 74%. According to CTCAE criteria, one grade 3 adverse event occurred. Median OS after first diagnosis of AGM was 18.3 months. Median OS, TTUP, and TTP after iBT treatment were 11.4, 6.6, and 3.5 months, respectively. Uni- and multivariate Cox regression analyses revealed significant influences of synchronous disease, tumor diameter, and the total number of lesions on OS or TTUP or both. CONCLUSION: Image-guided HDR-iBT is safe and effective. Treatment- and primary tumor-independent features influenced survival of patients with AGM after HDR-iBR treatment.

Nomogram based overall survival prediction in stereotactic body radiotherapy for oligo-metastatic lung disease.

BACKGROUND: Radical local treatment of pulmonary metastases is practiced with increasing frequency due to acknowledgment and better understanding of oligo-metastatic disease. This study aimed to develop a nomogram predicting overall survival (OS) after stereotactic body radiotherapy (SBRT) for pulmonary metastases. PATIENTS AND METHODS: A multi-institutional database of 670 patients treated with SBRT for pulmonary metastases was used as training cohort. Cox regression analysis with bidirectional variable elimination was performed to identify factors to be included into the nomogram model to predict 2-year OS. The calibration rate of the nomogram was assessed by plotting the actual Kaplan-Meier 2-year OS against the nomogram predicted survival. The nomogram was externally validated using two separate monocentric databases of 145 and 92 patients treated with SBRT for pulmonary metastases. RESULTS: The median follow up of the trainings cohort was 14.3months, the 2-year and 5-year OS was 52.6% and 23.7%, respectively. Karnofsky performance index, type of the primary tumor, control of the primary tumor, maximum diameter of the largest treated metastasis and number of metastases (1 versus >1) were significant prognostic factors in the Cox model (all p<0.05). The calculated concordance-index for the nomogram was 0.73 (concordance indexes of all prognostic factors between 0.54 and 0.6). Based on the nomogram the training cohort was divided into 4 groups and 2-year OS ranged between 24.2% and 76.1% (predicted OS between 30.2% and 78.4%). The nomogram discriminated between risk groups in the two validation cohorts (concordance index 0.68 and 0.67). CONCLUSIONS: A nomogram for prediction of OS after SBRT for pulmonary metastases was generated and externally validated. This tool might be helpful for interdisciplinary discussion and evaluation of local and systemic treatment options in the oligo-metastatic setting. KEY MESSAGE: A nomogram for prediction of overall survival after stereotactic body radiotherapy (SBRT) for pulmonary metastases was developed and externally validated. This tool might be helpful for interdisciplinary discussion and evaluation of local and systemic treatment options in the oligo-metastatic setting.

A versatile strategy for grafting polymers to wood cell walls.

The hierarchical structure of wood is composed of a cellulose skeleton of high structural order at various length scales. At the nanoscale and microscale the specific structural features of the cells and cell walls result in a lightweight structure with an anisotropic material profile of excellent mechanical performance. By being able to specifically functionalize wood at the level of cell and cell walls one can insert new properties and inevitably upscale them along the intrinsic hierarchical structure, to a level of large-scale engineering materials applications. For this purpose, however, precise control of the spatial distribution of the modifying substances in the complex wood structure is needed. Here we demonstrate a method to insert methacryl groups into wood cell walls using two different chemistry routes. By using these methacryl groups as the anchor points for grafting, various polymers can be inserted into the wood structure. Strikingly, depending on the methacryl precursor, the spatial distribution of the polymer differs strongly. As a proof of concept we grafted polystyrene as a model compound in the second modification step. In the case of methacryloyl chloride the polymer was located mainly at the interface between the cell lumina and the cell wall covering the inner surface of the cells and being traceable up to 2-3 µm in the cell wall, whereas in the case of methacrylic anhydride the polymer was located inside the whole cell wall. Scanning electron microscopy, Fourier transform infrared spectroscopy and especially Raman spectroscopy were used for an in-depth analysis of the modified wood at the cell wall level.

[Update on interstitial brachytherapy]. / Update interstitielle Brachytherapie.

CLINICAL/METHODICAL ISSUE: Minimally invasive treatment procedures, such as image-guided local tumour ablation have gained increasing relevance in oncologic concepts. Limitations of thermal ablation procedures have led to the development of percutaneous, computed tomography (CT) guided brachytherapy. STANDARD RADIOLOGICAL METHODS: Thermal ablation procedures, such as radiofrequency ablation (RFA) and laser-induced thermotherapy (LITT) show limitations regarding maximum tumour size (<5 cm), cooling effects of adjacent vessels and surrounding risk structures. METHODICAL INNOVATIONS: The image-guided interstitial brachytherapy allows the single application of high-dose rate (HDR) irradiation with an extensive protracted cytotoxic effect. Adjacent risk structures play a minor role due to the steep dose gradient outside the clinical target volume. PERFORMANCE: Studies using CT-guided brachytherapy resulted in a local tumour control rate of approximately 90% after 12 months in the treatment of hepatocellular carcinoma (HCC) and 70-90% in the treatment of colorectal metastases or cholangiocellular carcinoma (CCC). Similar response rates were also seen in the treatment of metastases of renal cell carcinoma (RCC), non-small cell lung cancer (NSCLC) or neuroendocrine tumours. In colorectal liver metastases and HCC the method has proven to have a positive impact on prognosis. ACHIEVEMENTS: In contrast to thermal ablation the method can be used without restriction with respect to tumour location. Cooling effects do not play a role. It has already been applied in more than 5,000 cases and it is used in clinical routine. PRACTICAL RECOMMENDATIONS: Image-guided brachytherapy is safe and effective and has found its way into the clinical routine.

Identification of an angiogenic mitogen selective for endocrine gland endothelium.

The known endothelial mitogens stimulate growth of vascular endothelial cells without regard to their tissue of origin. Here we report a growth factor that is expressed largely in one type of tissue and acts selectively on one type of endothelium. This molecule, called endocrine-gland-derived vascular endothelial growth factor (EG-VEGF), induced proliferation, migration and fenestration (the formation of membrane discontinuities) in capillary endothelial cells derived from endocrine glands. However, EG-VEGF had little or no effect on a variety of other endothelial and non-endothelial cell types tested. Similar to VEGF, EG-VEGF possesses a HIF-1 binding site, and its expression is induced by hypoxia. Both EG-VEGF and VEGF resulted in extensive angiogenesis and cyst formation when delivered in the ovary. However, unlike VEGF, EG-VEGF failed to promote angiogenesis in the cornea or skeletal muscle. Expression of human EG-VEGF messenger RNA is restricted to the steroidogenic glands, ovary, testis, adrenal and placenta and is often complementary to the expression of VEGF, suggesting that these molecules function in a coordinated manner. EG-VEGF is an example of a class of highly specific mitogens that act to regulate proliferation and differentiation of the vascular endothelium in a tissue-specific manner.

Use of phage display for the generation of human antibodies that neutralize factor IXa function.

The use of libraries of phage-displayed human single-chain antibody fragments (scFv) has become a new, powerful tool in rapidly obtaining therapeutically useful antibodies. Here, we describe the generation of human scFv and F(ab')2 directed against the gamma-carboxyglutamic acid (Gla) domain of coagulation factor IX. A large library of human scFv, displayed either on M13 phage or expressed as soluble proteins, was screened for binding to human Gla-domain peptide (Tyr1-Lys43). Among a panel of scFv that bound to the factor IX-Gla domain, six scFv clones recognized full-length factor IX and exhibited strong inhibitory activity of factor IX in vitro. After reformatting as F(ab')2, the affinity for factor IX of three selected clones was determined: 10C12 Kd = 1.6 nmol/l, 13D1 Kd = 2.9 nmol/l, and 13H6 Kd = 0.46 nmol/l. The antibodies specifically bound to factor IX and not to other coagulation factors, as assessed by enzyme-linked immunosorbent-type and human plasma clotting assays. The complementarity determining region amino acid sequences of clones 10C12 and 13D1 only differed at a single residue, whereas 13H6 showed little homology, suggesting that 13H6 binds to a different epitope within the factor IX-Gla domain. Despite the slightly lower affinity of 10C12 F(ab')2 versus 13H6 F(ab')2, 10C12 was consistently more potent than 13H6 in prolonging the activated partial thromboplastin time (APTT), in inhibiting platelet-mediated plasma clotting, and in inhibiting factor X activation by the intrinsic Xase complex. Finally, 10C12 F(ab')2 also recognized and neutralized factor IX/factor IXa of different species, as demonstrated by the specific APTT prolongation of dog, mouse, baboon and rabbit plasma. In summary, the results validate the usefulness of scFv phage-displayed libraries to rapidly generate fully human antibodies as potential new therapeutics for thrombotic disorders.

Differentiation and diagnosis of jaundice.

Bilirubin metabolism is a complex and fascinating example of the body's ability to discard, renew, and recycle vital elements. Jaundice is the warning sign for derangements in this system. As is true of pain, jaundice is a powerful impetus for visiting a healthcare provider. Usually associated with hepatitis by a nonclinician, the origins of jaundice can range from benign to fatally malignant. Patients may have any number of idiopathic or nosocomial conditions that can contribute to an icteric state. This review delineates the steps of bilirubin metabolism, enumerates the sources of bilirubin derangement, and examines elements of patient condition and therapeutics that can contribute to hyperbilirubinemia and jaundice.

An agonist murine monoclonal antibody to the human c-Mpl receptor stimulates megakaryocytopoiesis.

Thrombopoietin (TPO) is a hematopoietic growth factor that stimulates megakaryocytopoiesis and platelet production in vivo and promotes the development of identifiable megakaryocytes in vitro. We have developed a murine monoclonal antibody, BAH-1, raised against human megakaryocytic cells, which specifically recognizes the c-Mpl receptor and shows agonist activity by stimulating megakaryocytopoiesis in vitro. BAH-1 antibody specifically binds to platelets and to recombinant c-Mpl with high affinity. Similar to TPO, BAH-1 alone supported the formation of colony-forming unit-megakaryocyte (CFU-MK) colonies. The combination of BAH-1 plus interleukin-3 or of BAH-1 plus human TPO significantly increased the number of human CFU-MK colonies. In addition, BAH-1 monoclonal antibody stimulated the proliferation and maturation of primary bone marrow megakaryocytes in a dynamic heterogeneous liquid culture system. Individual large megakaryocytes as well as small megakaryocytic cells were observed in cultures of CD34(+) CD41(+) cells in the presence of BAH-1 antibodies. Similar to TPO, BAH-1 antibody induced a significant response of murine immature megakaryocytes as observed by an increase in the detectable numbers of acetylcholinesterase-positive megakaryocytes. No effects of BAH-1 antibody were observed on colony-forming unit-granulocyte-macrophage, burst-forming unit-erythroid, or colony-forming unit-erythroid colonies. In vivo studies showed that BAH-1, alone or in combination with TPO, expands the numbers of megakaryocytic progenitor cells in myelosuppressed mice. This antibody should prove useful in understanding the structure-function aspects of the c-Mpl receptor as well as in evaluating the effects of the sustained activation of this receptor in preclinical models of severe thrombocytopenia.

Human platelets as a model for the binding and degradation of thrombopoietin.

Recent studies have shown that plasma thrombopoietin (TPO) levels appear to be directly regulated by platelet mass and that removal of plasma TPO by platelets via binding to the c-Mpl receptor is involved in the clearance of TPO in rodents. To help elucidate the role of platelets in the clearance of TPO in humans, we studied the in vitro specific binding of recombinant human TPO (rhTPO) to human platelet-rich plasma (PRP), washed platelets (WP), and cloned c-Mpl. Using a four-parameter fit and/or Scatchard analysis, the approximate affinity of rhTPO for its receptor, which was calculated from multiple experiments using different PRP preparations, was between 128 and 846 pmol/L, with approximately 25 to 224 receptors per platelet. WP preparations gave an affinity of 260 to 540 pmol/L, with approximately 25 to 35 receptors per platelet, and erythropoietin failed to compete with 125I-rhTPO for binding to WP. Binding and dissociation studies conducted with a BiaCore apparatus yielded an affinity of 350 pmol/L for rhTPO binding to cloned c-Mpl receptors. The ability of PRP to bind and degrade 125I-rhTPO was both time- and temperature-dependent and was blocked by the addition of excess cold rhTPO. Analysis of platelet pellets by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that 125I-rhTPO was degraded into a major fragment of approximately 45 to 50 kD. When 125I-rhTPO was incubated with a platelet homogenate at pH = 7.4, a degradation pattern similar to intact platelets was observed. Together, these data show that human platelets specifically bind rhTPO with high affinity, internalize, and then degrade the rhTPO.

Cognition-related EEG abnormalities in nondemented Down syndrome subjects.

Down syndrome (DS) subjects develop Alzheimer disease (AD) histopathology before they develop dementia. We compared the resting and flash stimulated electroencephalogram (EEG) of nondemented adult DS and age-matched control subjects, in search of EEG abnormalities that might correlate with AD histopathology. DS subjects had increased absolute power in all the EEG bands, independent of cognition functions measured by the Mini Mental State Examination and Picture Absurdities Test scores. In the power spectrum of the resting EEG, we found a cognition-related increase in power at 4.5 and 8.8 Hz, indicative of alpha-slowing, as in AD patients. In the stimulated EEG, we found several cognition-related abnormalities, such as decreased responses to 12-Hz stimulation and decreased integral of beta- and gamma-band responses, indicative of decreased responsiveness to photic stimulation, as in AD patients. Therefore, nondemented DS and AD patients share several cognition related EEG abnormalities which are probably due to AD histopathology.

Severity of dementia correlates with loss of broad-band visual cortical responses.

We have shown that the response to flash stimulation of the occipital electroencephalogram (EEG) in Alzheimer disease (AD) patients is smaller than in normal subjects. To ascertain whether this is a specific feature of AD or a nonspecific effect of dementia, we investigated in AD and multi-infarct dementia (MID) patients the relationship between cognitive function, measured as Mini-Mental State Examination score, and EEG power response, measured as the difference in spectral power between flash-stimulated EEG and resting EEG. Both variables were positively correlated and the regression equations of AD and MID patients were not significantly different, showing nonspecificity. The coupling between cognitive function and power response is discussed in relation to the dynamic binding hypothesis of cognition.

In vitro megakaryocytopoietic and thrombopoietic activity of c-mpl ligand (TPO) on purified murine hematopoietic stem cells.

Recently, the ligand for c-mpl has been identified and cloned. Initial studies of this molecule indicate that it is the platelet regulatory factor, thrombopoietin (TPO). Previous work has indicated that c-mpl is expressed in very immature hematopoietic precursors and thus raised the possibility that TPO may act directly on the hematopoietic stem cell. Therefore, in these studies, we investigate the effects of TPO on hematopoietic stem cell populations isolated from the murine fetal liver and bone marrow. Cocultivation of stem cells with fetal liver stroma give rise to multilineage expansion of the stem cells but with little or no megakaryocytopoiesis. Addition of TPO to these cocultures gives significant megakaryocyte production. This production is enhanced in combination with Kit ligand or interleukin-3. The addition of TPO to stem cell suspension cultures produces a dynamic thrombopoietic system in which stem cells undergo differentiation to produce megakaryocytes and proplatelets. These experiments show that the megakaryocytopoietic and thrombopoietic activities of TPO are initiated at the level of an early progenitor cell or upon the hematopoietic stem cell.

Stimulation of megakaryocytopoiesis and thrombopoiesis by the c-Mpl ligand.

Physiological platelet synthesis is thought to require the humoral activities of meg-CSF and thrombopoietin, which respectively promote proliferation and maturation of megakaryocytic cells. A meg-CSF/thrombopoietin-like protein that is present in plasma of irradiated pigs has been purified and cloned. This protein binds to and activates the c-mpl protein, a member of the cytokine receptor superfamily. The isolated Mpl ligand shares homology with erythropoietin and stimulates both megakaryocytopoiesis and thrombopoiesis.

Quinolinate and kainate facilitate magnesium penetration into brain tissue.

To study the penetration of magnesium ions from blood into brain tissue, magnesium content in serum and hippocampus of normal and of excitotoxically affected rats was estimated after a single subcutaneous injection of magnesium sulphate (600 mg kg-1). In normal rats Mg2+ levels in serum rose from 1 to 6 mM, while that of the hippocampus remained constant, provided the brains were perfused before magnesium measurement. Following unilateral intracerebroventricular injection of the excitotoxic glutamate analogues, quinolinate or kainate acid, Mg2+ levels increased up to 38% on the (unaffected) contralateral side. Since magnesium is known to prevent glutamate-mediated neurodegeneration, our findings on the accessibility of exogenously applied magnesium may justify further investigations on the utility of magnesium for a therapeutic approach to limiting excitotoxic brain injury in human patients.

Mg2+ antagonizes alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-induced brain damage and convulsions.

alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), an agonist of the non-N-methyl-D-aspartate (NMDA) subtype of the glutamate receptor, was used to imitate glutamate-induced brain injury. A single intracerebroventricular injection of AMPA (9 nmol; 1.7 micrograms) induced convulsive reactions and heavy neurodegeneration in the hippocampal formation. MgSO4 (600 mg/kg), administered 20 min prior to or simultaneously with AMPA exposure, was able to protect completely against this non-NMDA-induced neurotoxicity. Magnesium is suggested to be a hopeful therapeutic principle for glutamate-mediated brain disorders.

Decreased alpha bandwidth responsiveness to photic driving in Alzheimer disease.

The power spectra of the photically activated occipital EEGs of 9 mildly to moderately demented probable Alzheimer disease (AD) patients (according to NINCDS-ADRDA criteria), 9 normal age-matched control and 27 normal subjects of different ages were compared. In normal subjects, photic stimulation with rhythmic flashes ranging between 2 and 20 Hz elicited a characteristic response in each EEG bandwidth (delta, theta, alpha, beta1 and beta2). The magnitude of each bandwidth response was a function of the frequency of the photic stimulus. In AD patients the alpha bandwidth response curve was significantly smaller than that of age-matched controls (MANOVA main effect of group, P = 0.018); all the other bandwidth response curves were normal. Therefore, in AD there is a selective abnormality in the alpha bandwidth responsiveness to photic stimulation, probably due to AD pathology in the neuronal generator of the alpha rhythm.