Intradermal Indocyanine Green for In Vivo Fluorescence Laser Scanning Microscopy of Human Skin: A Pilot Study

BACKGROUND: In clinical diagnostics, as well as in routine dermatology, the increased need for non-invasive diagnosis is currently satisfied by reflectance laser scanning microscopy. However, this technique has some limitations as it relies solely on differences in the reflection properties of epidermal and dermal structures. To date, the superior method of fluorescence laser scanning microscopy is not generally applied in dermatology and predominantly restricted to fluorescein as fluorescent tracer, which has a number of limitations. Therefore, we searched for an alternative fluorophore matching a novel skin imaging device to advance this promising diagnostic approach. METHODOLOGY/PRINCIPAL FINDINGS: Using a Vivascope®-1500 Multilaser microscope, we found that the fluorophore Indocyanine-Green (ICG) is well suited as a fluorescent marker for skin imaging in vivo after intradermal injection. ICG is one of few fluorescent dyes approved for use in humans. Its fluorescence properties are compatible with the application of a near-infrared laser, which penetrates deeper into the tissue than the standard 488 nm laser for fluorescein. ICG-fluorescence turned out to be much more stable than fluorescein in vivo, persisting for more than 48 hours without significant photobleaching whereas fluorescein fades within 2 hours. The well-defined intercellular staining pattern of ICG allows automated cell-recognition algorithms, which we accomplished with the free software CellProfiler, providing the possibility of quantitative high-content imaging. Furthermore, we demonstrate the superiority of ICG-based fluorescence microscopy for selected skin pathologies, including dermal nevi, irritant contact dermatitis and necrotic skin. CONCLUSIONS/SIGNIFICANCE: Our results introduce a novel in vivo skin imaging technique using ICG, which delivers a stable intercellular fluorescence signal ideal for morphological assessment down to sub-cellular detail. The application of ICG in combination with the near infrared laser opens new ways for minimal-invasive diagnosis and monitoring of skin disorders

Prognostic scores in brain metastases from breast cancer

<p>Abstract</p> <p>Background</p> <p>Prognostic scores might be useful tools both in clinical practice and clinical trials, where they can be used as stratification parameter. The available scores for patients with brain metastases have never been tested specifically in patients with primary breast cancer. It is therefore unknown which score is most appropriate for these patients.</p> <p>Methods</p> <p>Five previously published prognostic scores were evaluated in a group of 83 patients with brain metastases from breast cancer. All patients had been treated with whole-brain radiotherapy with or without radiosurgery or surgical resection. In addition, it was tested whether the parameters that form the basis of these scores actually have a prognostic impact in this biologically distinct group of brain metastases patients.</p> <p>Results</p> <p>The scores that performed best were the recursive partitioning analysis (RPA) classes and the score index for radiosurgery (SIR). However, disagreement between the parameters that form the basis of these scores and those that determine survival in the present group of patients and many reported data from the literature on brain metastases from breast cancer was found. With the four statistically significant prognostic factors identified here, a 3-tiered score can be created that performs slightly better than RPA and SIR. In addition, a 4-tiered score is also possible, which performs better than the three previous 4-tiered scores, incl. graded prognostic assessment (GPA) score and basic score for brain metastases (BSBM).</p> <p>Conclusion</p> <p>A variety of prognostic models describe the survival of patients with brain metastases from breast cancer to a more or less satisfactory degree. However, the standard brain metastases scores might not fully appreciate the unique biology and time course of this disease, e.g., compared to lung cancer. It appears possible that inclusion of emerging prognostic factors will improve the results and allow for development and validation of a consensus score for broad clinical application. The model that is based on the authors own patient group, which is not large enough to fully evaluate a large number of potential prognostic factors, is meant to illustrate this point rather than to provide the definitive score.</p

Experimental concepts for toxicity prevention and tissue restoration after central nervous system irradiation

Several experimental strategies of radiation-induced central nervous system toxicity prevention have recently resulted in encouraging data. The present review summarizes the background for this research and the treatment results. It extends to the perspectives of tissue regeneration strategies, based for example on stem and progenitor cells. Preliminary data suggest a scenario with individually tailored strategies where patients with certain types of comorbidity, resulting in impaired regeneration reserve capacity, might be considered for toxicity prevention, while others might be "salvaged" by delayed interventions that circumvent the problem of normal tissue specificity. Given the complexity of radiation-induced changes, single target interventions might not suffice. Future interventions might vary with patient age, elapsed time from radiotherapy and toxicity type. Potential components include several drugs that interact with neurodegeneration, cell transplantation (into the CNS itself, the blood stream, or both) and creation of reparative signals and a permissive microenvironment, e.g., for cell homing. Without manipulation of the stem cell niche either by cell transfection or addition of appropriate chemokines and growth factors and by providing normal perfusion of the affected region, durable success of such cell-based approaches is hard to imagine

Experimental concepts for toxicity prevention and tissue restoration after central nervous system irradiation

Abstract Several experimental strategies of radiation-induced central nervous system toxicity prevention have recently resulted in encouraging data. The present review summarizes the background for this research and the treatment results. It extends to the perspectives of tissue regeneration strategies, based for example on stem and progenitor cells. Preliminary data suggest a scenario with individually tailored strategies where patients with certain types of comorbidity, resulting in impaired regeneration reserve capacity, might be considered for toxicity prevention, while others might be "salvaged" by delayed interventions that circumvent the problem of normal tissue specificity. Given the complexity of radiation-induced changes, single target interventions might not suffice. Future interventions might vary with patient age, elapsed time from radiotherapy and toxicity type. Potential components include several drugs that interact with neurodegeneration, cell transplantation (into the CNS itself, the blood stream, or both) and creation of reparative signals and a permissive microenvironment, e.g., for cell homing. Without manipulation of the stem cell niche either by cell transfection or addition of appropriate chemokines and growth factors and by providing normal perfusion of the affected region, durable success of such cell-based approaches is hard to imagine.</p