Concurrent weekly cisplatin and simultaneous integrated boost intensity-modulated radiotherapy of locally advanced squamous cell carcinoma of the head and neck.

BACKGROUND: Radiotherapy of locally advanced head and neck cancer represents a major clinical challenge. Any treatment intensification aiming at improved treatment outcomes poten-tially results in a higher toxicity. The search for optimal treatment schedule involving conventional or altered fractionation of radiotherapy and the frequency and dose of concomitant cisplatin or other systemic agents has been spanning over several decades. PURPOSE: To evaluate long-term outcomes and toxicity of accelerated chemoradiotherapy of locally advanced squamous cell carcinoma of the head and neck (LA SCCHN). PATIENTS AND METHODS: Forty patients with stage III and IVA (TNM, 7th Ed.) LA SCCHN were treated with accelerated radiotherapy with a total dose of 67.5 Gy in 6 weeks delivered with simultaneous integrated boost intensity-modulated radiotherapy (SIB IMRT) and concomitant weekly cisplatin 40mg/m2. Five-year outcomes and early and late toxicity were evaluated. RESULTS: With the median follow-up of 47.8 months, a 5-year locoregional control rate (LCR) was 56.5%, distant control rate (DCR) was 87% and 5-year progression-free survival (PFS) and overall survival (OS) were 37 and 45%, respectively. Cisplatin cumulative dose of 200mg/m2 was administered in 83% of patients. Grade 2 late toxicity with dietary change was observed in 21 (53%) patients. Human papillomavirus (HPV) status determined by p16 immunohistochemistry was the only significant factor in 5-year treatment outcomes analysis with LCR 100 vs. 41% (P < 0.01), DCR 100 vs. 78% (P = 0.154), PFS 80 vs. 23% (P = 0.01) and OS 80 vs. 34% (P = 0.03) for HPV positive oropharyngeal cancer (OPC) and other HPV negative LA SCCHN. CONCLUSION: High proportion of patients with LA SCCHN received an adequate cumulative dose of concurrent cisplatin with accelerated radiotherapy with SIB IMRT. This study demonstrated that chemoradiotherapy with weekly cisplatin resulted in favorable local control rate and survival in patients with HPV+ OPC.

Prediction of toxicities of prostate cancer radiotherapy.

UNLABELLED: We treated a cohort of 116 patients with prostate cancer with three-dimensional conformal hypofractionated radiotherapy to a total dose of 52.8 Gy in 16 fractions (3.3 Gy per fraction). The correlation between acute and late gastrointestinal (GI) and genitourinary (GU) toxicity and dose-volume parameters was analysed. Comparison of observed incidence of toxicity and normal tissue complication probability calculated from dose-volume histograms (DVH) of all patients using radiobiological Lyman-Kutcher-Burman model was performed. The results of our study suggest that acute gastrointestinal toxicity ≥ grade 2 (G2) is the significant predictor of late toxicity ≥ G2 (p=0.006). Observed incidence of acute and late GI toxicities ≥ G2 was 9.7% and 11.5%, respectively. NTCPs of acute and late GI complications ≥ G2 were 11.3% and 2.5%. Observed incidence of late GU toxicity ≥ G2 was 14.2%, NTCP was 0.8%. Comparison of calculated probability of acute GI toxicity ≥ G2 and observed incidence indicates that parameters of radiobiological models are set appropriately. Comparison of observed incidence of late GI and GU complications ≥ G2 and calculated NTCPs shows the need of refinement of LKB model parameters for acute and late GI and GU complications ≥ G2. KEYWORDS: prostate cancer, radiotherapy, acute and late toxicity, radiobiological modeling.

Visualizing stable features in live cell nucleus for evaluation of the cell global motion compensation.

The compensation of cell motion is an important step in single-particle tracking analysis of live cells. This step is required in most of the cases, since the movement of subcellular foci is superimposed by the movement and deformation of the cell, while only the local motion of the foci is important to be analysed. The cell motion and deformation compensation is usually performed by means of image registration. There are a number of approaches with different models and properties presented in the literature that perform cell image registration. However, the evaluation of the registration approach quality on real data is a tricky problem due to the fact that some stable features in the images with a priori no local motion are needed. In this paper we propose a methodology for creating live cell nuclei image sequences with stable features imposed. The features are defined using the regions of fluorescence bleaching invoked by the UV laser. Data with different deformations are acquired and can be used for evaluation of the cell image registration methods. Along with that, we describe an image analysis technique and a metric that can characterize the quality of the method quantitatively. The proposed methodology allows building a ground truth dataset for testing and thoroughly evaluating cell image registration methods.

Sub-volume averaging of repetitive structural features in angularly filtered electron tomographic reconstructions.

Electron tomographic reconstructions suffer from a number of artefacts arising from effects accompanying the processes of acquisition of a set of tilted projections of the specimen in a transmission electron microscope and from its subsequent computational handling. The most pronounced artefacts usually come from imprecise projection alignment, distortion of specimens during tomogram acquisition and from the presence of a region of missing data in the Fourier space, the "missing wedge". The ray artefacts caused by the presence of the missing wedge can be attenuated by the angular image filter, which attenuates the transition between the data and the missing wedge regions. In this work, we present an analysis of the influence of angular filtering on the resolution of averaged repetitive structural motives extracted from three-dimensional reconstructions of tomograms acquired in the single-axis tilting geometry.

High dose rate versus low dose rate brachytherapy in the treatment of tongue carcinoma - a radiobiological study.

UNLABELLED: Low dose rate (LDR) brachytherapy is a well established treatment for the early stages of tongue cancer. High dose rate (HDR) afterloading devices have replaced LDR brachytherapy in many radiotherapy departments, but the effect and safety of HDR brachytherapy in comparison with LDR brachytherapy for interstitial applications is an unresolved question. The aim of our radiobiological study was to utilize dose volume histiograms from patients treated in our institution to simulate the risk of complication of LDR and HDR brachytherapy. Normal tissue complication probabilities (NTCP) of acute mucositis, late mucosal necrosis and osteoradionecrosis of two HDR brachytherapy schedules (18 x 3 Gy bid and 10 x 6 Gy bid) and of LDR brachytherapy with identical tumor control probability were compared using data from 8 brachytherapy applications. A linear quadratic (LQ) model was used to calculate the biologically equivalent doses, the effective volume method of Kutcher and Burman and Lyman's model was used to calculate NTCP. The Student's two-tailed test was used for statistical analysis. For 18 x 3 Gy bid the risk of acute mucositis and of late mucosal necrosis was 1.48 and 1.66 times higher with HDR in comparison with LDR brachytherapy. For 10 x 6 Gy bid the risk of acute mucositis, mucosal necrosis and osteoradionecrosis was 1.3, 3.44 and 13.18 times higher with HDR brachytherapy. All differences were statistically highly significant. Our radiobiological study supported the hypothesis that HDR has a higher risk of complication in comparison with LDR brachytherapy for the same tumor control probability. KEYWORDS: tongue cancer, brachytherapy, low dose rate, high dose rate.

Distinct patterns of histone methylation and acetylation in human interphase nuclei.

To study 3D nuclear distributions of epigenetic histone modifications such as H3(K9) acetylation, H3(K4) dimethylation, H3(K9) dimethylation, and H3(K27) trimethylation, and of histone methyltransferase Suv39H1, we used advanced image analysis methods, combined with Nipkow disk confocal microscopy. Total fluorescence intensity and distributions of fluorescently labelled proteins were analyzed in formaldehyde-fixed interphase nuclei. Our data showed reduced fluorescent signals of H3(K9) acetylation and H3(K4) dimethylation (di-me) at the nuclear periphery, while di-meH3(K9) was also abundant in chromatin regions closely associated with the nuclear envelope. Little overlapping (intermingling) was observed for di-meH3(K4) and H3(K27) trimethylation (tri-me), and for di-meH3(K9) and Suv39H1. The histone modifications studied were absent in the nucleolar compartment with the exception of H3(K9) dimethylation that was closely associated with perinucleolar regions which are formed by centromeres of acrocentric chromosomes. Using immunocytochemistry, no di-meH3(K4) but only dense di-meH3(K9) was found for the human acrocentric chromosomes 14 and 22. The active X chromosome was observed to be partially acetylated, while the inactive X was more condensed, located in a very peripheral part of the interphase nuclei, and lacked H3(K9) acetylation. Our results confirmed specific interphase patterns of histone modifications within the interphase nuclei as well as within their chromosome territories.

Precise 3D image alignment in micro-axial tomography.

Micro (micro-) axial tomography is a challenging technique in microscopy which improves quantitative imaging especially in cytogenetic applications by means of defined sample rotation under the microscope objective. The advantage of micro-axial tomography is an effective improvement of the precision of distance measurements between point-like objects. Under certain circumstances, the effective (3D) resolution can be improved by optimized acquisition depending on subsequent, multi-perspective image recording of the same objects followed by reconstruction methods. This requires, however, a very precise alignment of the tilted views. We present a novel feature-based image alignment method with a precision better than the full width at half maximum of the point spread function. The features are the positions (centres of gravity) of all fluorescent objects observed in the images (e.g. cell nuclei, fluorescent signals inside cell nuclei, fluorescent beads, etc.). Thus, real alignment precision depends on the localization precision of these objects. The method automatically determines the corresponding objects in subsequently tilted perspectives using a weighted bipartite graph. The optimum transformation function is computed in a least squares manner based on the coordinates of the centres of gravity of the matched objects. The theoretically feasible precision of the method was calculated using computer-generated data and confirmed by tests on real image series obtained from data sets of 200 nm fluorescent nano-particles. The advantages of the proposed algorithm are its speed and accuracy, which means that if enough objects are included, the real alignment precision is better than the axial localization precision of a single object. The alignment precision can be assessed directly from the algorithm's output. Thus, the method can be applied not only for image alignment and object matching in tilted view series in order to reconstruct (3D) images, but also to validate the experimental performance (e.g. mechanical precision of the tilting). In practice, the key application of the method is an improvement of the effective spatial (3D) resolution, because the well-known spatial anisotropy in light microscopy can be overcome. This allows more precise distance measurements between point-like objects.

Combined confocal and wide-field high-resolution cytometry of fluorescent in situ hybridization-stained cells.

BACKGROUND: The recently developed technique of high-resolution cytometry (HRCM) enables automated acquisition and analysis of fluorescent in situ hybridization (FISH)-stained cell nuclei using conventional wide-field fluorescence microscopy. The method has now been extended to confocal imaging and offers the opportunity to combine the advantages of confocal and wide-field modes. METHODS: We have automated image acquisition and analysis from a standard inverted fluorescence microscope equipped with a confocal module with Nipkow disk and a cooled digital CCD camera. The system is fully controlled by a high-performance computer that performs both acquisition and related on-line image analysis. The system can be used either for an automatic two (2D) and three-dimensional (3D) analysis of FISH- stained interphase nuclei or for a semiautomatic 3D analysis of FISH-stained cells in tissues. The user can select which fluorochromes are acquired using wide-field mode and which using confocal mode. The wide-field and confocal images are overlaid automatically in computer memory. The developed software compensates automatically for both chromatic color shifts and spatial shifts caused by switching to a different imaging mode. RESULTS: Using the combined confocal and wide-field HRCM technique, it is possible to take advantage of both imaging modes. Images of some dyes (such as small hybridization dots or counterstain images of individual interphase nuclei) do not require confocal quality and can be acquired quickly in wide-field mode. On the contrary, images of other dyes (such as chromosome territories or counterstain images of cells in tissues) do require improved quality and are acquired in confocal mode. The dual-mode approach is two to three times faster compared with the single-mode confocal approach and the spectrum of its applications is much broader compared with both single-mode confocal and single-mode wide-field systems. CONCLUSIONS: The combination of high speed specific to the wide-field mode and high quality specific to the confocal mode gives optimal system performance.

An efficient algorithm for measurement and correction of chromatic aberrations in fluorescence microscopy.

Even the best optical microscopes available on the market exhibit chromatic aberrations to some extent. In some types of study, chromatic aberrations of current optics cannot be neglected and a software correction is highly desirable. This paper describes a novel method of chromatic aberration measurement and software correction using sub-resolution bead imaging and computer image analysis. The method is quick, precise and enables the determination of both longitudinal and lateral chromatic aberrations. Correction function can be computed in about half an hour, including image acquisition. Using this approach, chromatic aberrations can be reduced to 10-20 nm laterally and 10-60 nm axially depending on the type of optical set-up. The method is especially suitable for fluorescence microscopy, where a limited number of wavelengths are observed.

Topography of genetic loci in tissue samples: towards new diagnostic tool using interphase FISH and high-resolution image analysis techniques.

Using single and dual colour fluorescence in situ hybridisation (FISH) combined with image analysis techniques the topographic characteristics of genes and centromeres in nuclei of human colon tissue cells were investigated. The distributions of distances from the centre-of-nucleus to genes (centromeres) and from genes to genes (centromeres to centromeres) were studied in normal colon tissue cells found in the neighbourhood of tumour samples, in tumour cell line HT-29 and in promyelocytic HL-60 cell line for comparison. Our results show that the topography of genetic loci determined in 3D-fixed cell tissue corresponds to that obtained for 2D-fixed cells separated from the tissue. The distributions of the centre-of-nucleus to gene (centromere) distances and gene to gene (centromere to centromere) distances and their average values are different for various genetic loci but similar for normal colon tissue cells, HT-29 colon tumour cell line and HL-60 promyelocytic cell line. It suggests that the arrangement of genetic loci in cell nucleus is conserved in different types of human cells. The investigations of trisomic loci in HT-29 cells revealed that the location of the third genetic element is not different from the location of two homologues in diploid cells. We have shown that the topographic parameters used in our experiments for different genetic elements are not tissue or tumour specific. In order to validate high-resolution cytometry for oncology, further investigations should include more precise parameters reflecting the state of chromatin in the neighbourhood of critical oncogenes or tumour suppresser genes.

Total joint project: acute care to home care.

The advent of managed care, decreased reimbursement, and competition among providers has forced acute care institutions to examine care delivery. Clinical paths provide a method that manages patient care toward positive outcomes within a cost-effective environment. A collaborative project for total joint patients beginning with the office visit and continuing through the entire episode of care is described.

Clinical path coordinator: pulling it all together.

Institutions across the country are using different approaches to restructuring health care delivery systems. At Lehigh Valley Hospital collaborative practice was instituted to ensure the achievement of patient outcomes within appropriate time frames and with efficient use of resources. The role of the clinical path coordinator emerged from the collaborative practice model developed to manage the care of the patient with an abdominal aortic aneurysm. The step-by-step process for selecting, orienting, and implementing the role of the coordinator is discussed. Since the implementation of the coordinator role, patient satisfaction has been positive, length of stay and cost have decreased, and quality of care has improved for these patients.

Protein S deficiency: a case study.

Protein S deficiency, a life-threatening defect in the body's protective mechanism against activated coagulation, can result in recurrent or atypical patterns of thrombosis. A case study describing diagnosis and treatment of protein S deficiency and the nursing care of a patient requiring a vena cava filter is presented. It is important for nurses to be aware of the vital role they play in assessing, managing, and assisting both the patient and family as they adjust to this rare disorder.

Management of patients undergoing vascular surgery who are receiving epidural analgesia.

Epidural analgesia affords new opportunities for pain management in the acute and chronic arenas for patients undergoing vascular surgery. Effective and safe management of the patient receiving epidural analgesia requires careful integration of the skills and knowledge of the health care providers. Vascular surgeons in this institution use epidural analgesia almost exclusively in postoperative management of the patient undergoing vascular surgery, resulting in consistent pain relief with reduced narcotic requirements and earlier mobilization. Recognized complications are associated with epidural analgesia. Thus development of standardized nursing care plans to ensure safe and appropriate care of patients is imperative. Monitoring specific quality indicators ensures safe delivery of epidural analgesia and evaluates the effectiveness of the pain management program.