Extensive morbidity related to hemodialysis vascular access exists among end-stage renal disease (ESRD) patients, but the risk factors for this morbidity have not been extensively studied. Medicare ESRD patient data were obtained from 1984, 1985, and 1986. Hospitalization for vascular access morbidity (ICD-996.1, 996.6, or 996.7) was analyzed among prevalent patients and, using survival analysis, among incident patients to assess sex, age, race, and underlying cause of renal failure as risk factors. We found that 15 to 16% of hospital stays among prevalent ESRD patients were associated with vascular access-related morbidity. Black race, older age, female sex, and diabetes mellitus as a cause of kidney failure were all independent risk factors for access-related morbidity. The rate ratio comparing Blacks to Whites was 1.12 (95% C.I., 1.09, 1.16); > 64 years to 20 to 44 years, 1.53 (1.46, 1.59); men to women, 0.81 (0.79, 0.84); and diabetes to glomerulonephritis, 1.29 (1.24, 1.35). We conclude that hemodialysis vascular access malfunction causes much hospitalization among ESRD patients. Women, Blacks, the elderly, and diabetics appear to be at particularly high risk, and additional studies are needed to understand these patterns.

The purpose of this study was to test the accuracy of a commercially available deformable image registration tool in a clinical situation. In addition, to demonstrate a method to evaluate the resulting transformation of such a tool to a reference defined by multiple experts. For 16 patients (seven head and neck, four thoracic, five abdominal), 30‐50 anatomical landmarks were defined on recognizable spots of a planning CT and a corresponding fraction CT. A commercially available deformable image registration tool, Velocity AI, was used to align all fraction CTs with the respective planning CTs. The registration accuracy was quantified by means of the target registration error in respect to expert‐defined landmarks, considering the interobserver variation of five observers. The interobserver uncertainty of the landmark definition in our data sets is found to be 1.2±1.1thinmathspacemm. In general the deformable image registration tool decreases the extent of observable misalignments from 4‐8 mm to 1‐4 mm for nearly 50% of the landmarks (to 77% in sum). Only small differences are observed in the alignment quality of scans with different tumor location. Smallest residual deviations were achieved in scans of the head and neck region (79%,≤thinmathspace4thinmathspacemm) and the thoracic cases (79%,≤thinmathspace4thinmathspacemm), followed by the abdominal cases (59%,≤thinmathspace4thinmathspacemm). No difference is observed in the alignment quality of different tissue types (bony vs. soft tissue). The investigated commercially available deformable image registration tool is capable of reducing a mean target registration error to a level that is clinically acceptable for the evaluation of retreatment plans and replanning in case of gross tumor change during treatment. Yet, since the alignment quality needs to be improved further, the individual result of the deformable image registration tool has still to be judged by the physician prior to application.PACS numbers: 87.57.nj, 87.57.N‐, 87.55.‐x

BackgroundTo evaluate the effectivity of fractionated radiotherapy in adolescent and adult patients with pineal parenchymal tumors (PPT).MethodsBetween 1982 and 2003, 14 patients with PPTs were treated with fractionated radiotherapy. 4 patients had a pineocytoma (PC), one a PPT with intermediate differentiation (PPTID) and 9 patients a pineoblastoma (PB), 2 of which were recurrences. All patients underwent radiotherapy on the primary tumor site with a median total dose of 54 Gy. In 9 patients with primary PB treatment included whole brain irradiation (3 patients) or irradiation of the craniospinal axis (6 patients) with a median total dose of 35 Gy.ResultsMedian follow-up was 123 months in the PC patients and 109 months in the patients with primary PB. 7 patients were free from relapse at the end of follow-up. One PC patient died from spinal seeding. Among 5 PB patients treated with radiotherapy without chemotherapy, 3 developed local or spinal tumor recurrence. Both patients treated for PB recurrences died. The patient with PPTID is free of disease 7 years after radiotherapy.ConclusionLocal radiotherapy seems to be effective in patients with PC and some PPTIDs. Diagnosis and treatment of patients with more aggressive variants of PPTIDs as well as treatment of PB needs to be further improved, since local and spinal failure even despite craniospinal irradiation (CSI) is common. As PPT are very rare tumors, treatment within multi-institutional trials remains necessary.

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Background: While IMRT is widely used in treating complex oncological cases in adults, it is not commonly used in pediatric radiation oncology for a variety of reasons. This report evaluates our 9 year experience using stereotactic-guided, inverse planned intensity-modulated radiotherapy (IMRT) in children and adolescents in the context of the current literature.

BackgroundTo evaluate the impact of image-guided radiation therapy (IGRT) versus non-image-guided radiation therapy (non-IGRT) on the dose to the clinical target volume (CTV) and the cervical spinal cord during fractionated intensity-modulated radiation therapy (IMRT) for head-and-neck cancer (HNC) patients.Material and MethodsFor detailed investigation, 4 exemplary patients with daily control-CT scans (total 118 CT scans) were analyzed. For the IGRT approach a target point correction (TPC) derived from a rigid registration focused to the high-dose region was used. In the non-IGRT setting, instead of a TPC, an additional cohort-based safety margin was applied. The dose distributions of the CTV and spinal cord were calculated on each control-CT and the resulting dose volume histograms (DVHs) were compared with the planned ones fraction by fraction. The D50 and D98 values for the CTV and the D5 values of the spinal cord were additionally reported.ResultsIn general, the D50 and D98 histograms show no remarkable difference between both strategies. Yet, our detailed analysis also reveals differences in individual dose coverage worth inspection. Using IGRT, the D5 histograms show that the spinal cord less frequently receives a higher dose than planned compared to the non-IGRT setting. This effect is even more pronounced when looking at the curve progressions of the respective DVHs.ConclusionsBoth approaches are equally effective in maintaining CTV coverage. However, IGRT is beneficial in spinal cord sparing. The use of an additional margin in the non-IGRT approach frequently results in a higher dose to the spinal cord than originally planned. This implies that a margin reduction combined with an IGRT correction helps to maintain spinal cord dose sparing best as possible. Yet, a detailed analysis of the dosimetric consequences dependent on the used strategy is required, to detect single fractions with unacceptable dosimetric deviations.

BackgroundTo analyse the frequency of re-planning and its variability dependent on the IGRT correction strategy and on the modification of the dosimetric criteria for re-planning for the spinal cord in head and neck IG-IMRT.MethodsDaily kV-control-CTs of six head and neck patients (=175 CTs) were analysed. All volumes of interest were re-contoured using deformable image registration. Three IGRT correction strategies were simulated and the resulting dose distributions were computed for all fractions. Different sets of criteria with varying dose thresholds for re-planning were investigated. All sets of criteria ensure equivalent target coverage of both CTVs, but vary in the tolerance threshold of the spinal cord.ResultsThe variations of the D95 and D2 in respect to the planned values ranged from -7% to +3% for both CTVs, and -2% to +6% for the spinal cord. Despite different correction vectors of the three IGRT strategies, the dosimetric differences were small. The number of fractions not requiring re-planning varied between 0% and 11% dependent on the applied IGRT correction strategy. In contrast, this number ranged between 32% and 70% dependent on the dosimetric thresholds, even though these thresholds were only gently modified.ConclusionsThe more precise the planned dose needs to be maintained over the treatment course, the more frequently re-planning is required. The influence of different IGRT correction strategies, even though geometrically notable, was found to be of only limited relevance for the re-planning frequency. In contrast, the definition and modification of thresholds for re-planning have a major impact on the re-planning frequency.

Study Design Clinical measurement study. Background Computer adaptive testing (CAT) methods may allow detection of change across the continuum of osteoarthritis (OA) care. Objective To evaluate the sensitivity to change of a self-report OA CAT instrument (OA-CAT) following surgery. Methods Core measures consisted of the 5-item OA-CAT function, pain, and disability scales; the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC); the University of California at Los Angeles activity rating scale; and the Medical Outcomes Study 12-Item Short-Form Health Survey (SF-12), which were administered in 3 samples. Fifty-three patients with hip dysplasia completed the core measures, the Hip disability and Osteoarthritis Outcome Score physical function short form (HOOS-PS), and the Modified Harris Hip Score (MHHS) before periacetabular osteotomy, and at 6 months, 1 year, and 2 years after periacetabular osteotomy. The hip (n = 62) and knee (n = 66) arthroplasty samples completed core measures and the MHHS or the Knee Society's Knee Scoring System at baseline and at 3-month follow-up. Mean change, floor and ceiling effects (percent), and effect size were calculated. Results For osteotomy, the 6-month physical function effect sizes for the OA-CAT, WOMAC, HOOS-PS, MHHS, and SF-12 physical component summary scores were 0.66 (95% confidence interval [CI]: 0.08, 1.61), 0.78 (95% CI: 0.56, 1.10), 0.91 (95% CI: 0.70, 1.21), 0.64 (95% CI: 0.22, 1.07), and 0.87 (95% CI: 0.53, 1.38), respectively. Effect-size trends were all increased at 1 year, and most were level at 2 years. For hip arthroplasty, the OA-CAT, WOMAC, MHHS, and SF-12 effect sizes were 1.27 (95% CI: 0.88, 1.84), 1.50 (95% CI: 1.20, 1.80), 0.68 (95% CI: 0.35, 1.04), and 0.56 (95% CI: 0.29, 0.88), respectively. For knee arthroplasty, the OA-CAT, WOMAC, Knee Society Knee Scoring System, and SF-12 effect sizes were 0.81 (95% CI: 0.56, 1.14), 0.85 (95% CI: 0.61, 1.10), 0.09 (95% CI: -0.22, 0.40), and -0.01 (95% CI: -0.39, 0.31), respectively. The OA-CAT and SF-12 demonstrated smaller ceiling effects than the HOOS-PS and other instruments, especially at 1 and 2 years. Administration time was less for the OA-CAT than for the WOMAC physical function subscale. Conclusion The OA-CAT shows potential for outcome measurement after hip and knee surgery. Larger studies are needed to better understand relative performance. J Orthop Sports Phys Ther 2016;46(9):756-767. Epub 5 Aug 2016. doi:10.2519/jospt.2016.6442.