Dosimetric Comparison of Manual and Beam Angle Optimization of Gantry Angles in IMRT

Dosimetric comparison of manual beam angle selection (MBS) and beam angle optimization (BAO) for IMRT plans is investigated retrospectively for 15 head and neck and prostate patients. The head and neck and prostate had planning target volumes (PTVs) ranging between 96.0 and 319.9 cm³ and 153.6 and 321.3 cm³, whereas OAR ranged between 8.3 and 47.8 cm³ and 68.3 and 469.2 cm³, respectively. In MBS, a standard coplanar 7–9 fields equally spaced gantry angles were used. In BAO, the selection of gantry angle was optimized by the algorithm for the same number of beams. The optimization and dose-volume constraints were kept the same for both techniques. Treatment planning was performed on the Eclipse treatment planning system. Our results showed that the dose-volume histogram for PTV are nearly identical in both techniques but BAO provided superior sparing of the organs at risk compared with the MBS. Also, MBS produced statistically significant higher monitor units (MU) and segments than the BAO; 13.1 ± 6.6% (p = 0.012) and 10.4 ± 13.6% (p = 0.140), and 14.6 ± 5.6% (p = 1.003E-5) and 12.6 ± 7.4% (p = 0.76E-3) for head and neck and prostate cases, respectively. The reduction in MU translates into the reduction in total body and integral dose. It is concluded that BAO provides advantage over MBS for most intenisty-modulated radiation therapy cases.     

Use of tissue water as a concentration reference for proton spectroscopic imaging

A strategy for using tissue water as a concentration standard in ¹H magnetic resonance spectroscopic imaging studies on the brain is presented, and the potential errors that may arise when the method is used are examined. The sensitivity of the method to errors in estimates of the different water compartment relaxation times is shown to be small at short echo times (TEs). Using data from healthy human subjects, it is shown that different image segmentation approaches that are commonly used to account for partial volume effects (SPM2, FSL's FAST, and K‐means) lead to different estimates of metabolite levels, particularly in gray matter (GM), owing primarily to variability in the estimates of the cerebrospinal fluid (CSF) fraction. While consistency does not necessarily validate a method, a multispectral segmentation approach using FAST yielded the lowest intersubject variability in the estimates of GM metabolites. The mean GM and white matter (WM) levels of N‐acetyl groups (NAc, primarily N‐acetylaspartate), choline (Ch), and creatine (Cr) obtained in these subjects using the described method with FAST multispectral segmentation are reported: GM [NAc] = 17.16 ± 1.19 mM; WM [NAc] = 14.26 ± 1.38 mM; GM [Ch] = 3.27 ± 0.47 mM; WM [Ch] = 2.65 ± 0.25 mM; GM [Cr] = 13.98 ± 1.20 mM; and WM [Cr] = 7.10 ± 0.67 mM. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.     

Pretransplant diabetes, not donor age, predicts long-term outcomes in cardiac transplantation

BACKGROUND AND AIM: Accepting donors of advanced age may increase the number of hearts available for transplantation. Objectives were to review the outcomes of using cardiac donors 50 years of age and older and to identify predictors of outcome at a single institution. METHODS: A retrospective analysis of all adult cardiac transplants (n = 338) performed at our institution between 1988 and 2002 was conducted. RESULTS: Of these, 284 patients received hearts from donors <50 years old and 54 received hearts from donors > or =50 years old. Recipients of hearts from older donors had a greater frequency of pretransplant diabetes (19% vs 33%), renal failure (16% vs 30%), and dialysis (3% vs 9%). There were no differences in ICU or postoperative length of stay, days ventilated, or early rejection episodes. Recipients of older donor hearts, however, had increased perioperative mortality (7% vs 17%; p = 0.03). Multivariate analysis identified older donors (OR 2.599; p = 0.03) and donor ischemia time (OR 1.006; p = 0.002) as significant predictors of perioperative mortality. Actuarial survival at 1 (87% vs 74%), 5 (76% vs 69%), and 10 (59% vs 58%) years was similar (p = 0.08) for the two groups. Separate multivariate analyses identified pretransplant diabetes as the sole predictor of long-term survival (HR 1.659; p = 0.02) and transplant coronary disease (HR 2.486; p = 0.003). CONCLUSIONS: Despite increased perioperative mortality, donors > or =50 years old may be used with long-term outcomes similar to those of younger donor hearts. This has potential to expand the donor pool. Pretransplant diabetes has a significant impact on long-term outcomes in cardiac transplantation and requires further investigation.     

Dyslipidemia,carotid intima-media thickness and endothelial dysfunction in children with chronic kidney disease

Background

Chronic kidney disease (CKD) predisposes to accelerated atherosclerosis that is measured by carotid artery intima-media thickness (cIMT) and brachial artery flow-mediated dilation (FMD). Information on the association of these parameters with dyslipidemia in pre-dialysis pediatric CKD is limited.

Methods

Eighty patients aged 9.9?±?3.2 years, with estimated glomerular filtration rate of 38.8?±?10.8 ml/1.73 m²/min, and 42 pediatric controls underwent cross-sectional analysis of lipid profile, cIMT, and brachial artery FMD. Significant differences in these parameters between patients and controls were analyzed using Student’s t test. Predictors of cIMT and dyslipidemia were assessed using linear and logistic regression respectively.

Results

Patients had elevated blood levels of triglyceride and of total and LDL cholesterol than controls (P?≤?0.001); 73.8 % were dyslipidemic. Mean cIMT was higher (0.421?±?0.054 mm vs 0.388?±?0.036 mm, P?=?0.001) and brachial artery FMD was reduced (10.6?±?4.9 % vs 18.9?±?4.1 %, P?<?0.0001) in patients compared with controls. On multivariate analysis, hypertension (OR 3.68, P?=?0.044) and male gender (OR 10.21, P?=?0.004) were associated with dyslipidemia; cIMT was significantly associated with LDL cholesterol (β?=?28.36, P?=?0.033).

Conclusion

Dyslipidemia was prevalent and cIMT significantly elevated in pre-dialysis pediatric CKD, indicating increased cardiovascular risk. Elevated LDL cholesterol predicted increased cIMT, strengthening the association between dyslipidemia and atherosclerosis in early CKD.

     

Infected retroperitoneal cystic lymphangioma masquerading as psoas abscess

A 2-year-old male is described who presented with fever, fixed flexion deformity of the right hip and a tender mass in the right iliac fossa. A clinical diagnosis of psoas abscess was made. Abdominal ultrasound was suggestive of an echogenic retroperitoneal cyst but could not accurately determine the nature of the cyst. A contrast CT scan showed a retroperitoneal cyst. At laparotomy, a large retroperitoneal cyst containing turbid fluid was found and was excised completely. Histopathological examination was suggestive of cystic lymphangioma. Clinical presentation of retroperitoneal lymphangioma may be variable and misleading, therefore complex imaging studies are necessary in the evaluation of this condition.     

Pretransplant laparoscopic nephrectomy in adult polycystic kidney disease: a single centre experience

OBJECTIVE

To report our experience with pretransplant laparoscopic nephrectomy in patients with autosomal dominant polycystic kidney disease (ADPKD), as ADPKD often progresses to end‐stage renal disease and most azotaemic patients with ADPKD have enlarged kidneys, making graft placement difficult.

MATERIAL AND METHODS

We retrospectively reviewed the medical records of 13 patients with renal failure attributable to ADPKD who underwent pretransplant laparoscopic nephrectomy (21 renal units) from August 2002 to December 2006. Five patients had a unilateral nephrectomy, seven had a staged bilateral nephrectomy, and one had a simultaneous bilateral nephrectomy. All patients underwent subsequent living‐related renal transplantation. The operative duration, haemoglobin decrease, blood transfusion, hospital stay, analgesic requirement and time to receipt of a transplant were compared with those of patients who underwent open pretransplant nephrectomy (14 patients) from 1984 to 2001.

RESULTS

Kidneys of a size to interfere with graft placement were the commonest indication for surgery (eight patients). In comparison with open surgery, the mean (sd ) hospital stay at 9.26 (2.9) vs 4.86 (0.9) days, analgesic requirement at 320 (120) vs 221 (120.5) mg of tramadol, blood transfusion rate at 1.3 (0.5) vs 0.9 (0.6) units, period to receive a graft kidney at 29.77 (4.6) vs 9.14 (3.38) days, were significantly less with laparoscopy. The complications noted were single instances of splenic capsular tear, pleural tear, sub‐acute intestinal obstruction and vena caval injury.

CONCLUSION

Pretransplant laparoscopic nephrectomy in patients with ADPKD has all the benefits of minimally invasive surgery such as reduced intraoperative blood loss and minimal postoperative pain leading to early and faster convalescence. These benefits help in decreasing the period between nephrectomy and transplantation. The surgeon needs to have considerable experience in laparoscopy before embarking on laparoscopic pretransplant nephrectomy.     

Normative bone mineral density data at multiple skeletal sites in Indian subjects

Summary

Age-related change in bone mineral density (BMD) varied according to skeletal site in Indian subjects. A larger proportion of subjects was classified as osteoporotic and osteopenic using the Caucasian database than newly derived peak BMD values at most skeletal sites. Results establish useful normative data for reliable interpretations of individual dual-energy X-ray absorptiometry (DEXA) values

Introduction

Osteoporosis is believed to occur at a relatively younger age in the Indian population. With increasing knowledge on significant differences in BMD between various racial groups, there is increased emphasis for the use of population-specific reference database.

Methods

BMD at multiple skeletal sites was measured using DEXA (Prodigy, Lunar) in 615 Indian women (20–86 years) and 489 Indian men (20–83 years). Best-fit models were drawn for each skeletal site. Osteopenia and osteoporosis diagnosis rates were calculated using Caucasian and derived Indian peak BMD values.

Results

Age-related change in BMD varied with skeletal site in both sexes. Peak BMD in women was observed between 31 and 40 years of age at the hip, spine, and radius 33% and between 20 and 30 years at the ultradistal radius. Peak BMD in men was attained between 20 and 30 years at the hip and radius 33% and between 31 and 40 years at the spine and ultradistal radius. A larger proportion of Indian subjects was classified as osteoporotic and osteopenic based on the Caucasian database than newly derived Indian peak BMD values at all skeletal sites except radius 33% and femoral neck in females above 40 years of age.

Conclusion

Results establish useful normative data for the Indian population for reliable interpretations of individual DEXA values.     

Connective tissue growth factor expression is increased in biliary epithelial cells in biliary atresia

Background/Purpose

Connective tissue growth factor (CTGF) has been implicated in the pathogenesis of hepatic fibrosis and is elevated in the serum of children with biliary atresia (BA). The objective of this study was to evaluate hepatic CTGF messenger RNA (mRNA) expression and its relationship to hepatic histology in children with BA.

Methods

Connective tissue growth factor mRNA expression was evaluated by in situ hybridization in 26 liver biopsies from 11 patients with BA, 11 with other diseases, and 4 autopsy controls. Serial sections were immunostained with cell-specific markers to characterize the cells expressing CTGF. Biopsies were scored for CTGF expression (0-4) and inflammation and fibrosis (1-4).

Results

High levels of CTGF expression were observed in 9 of 11 BA with localization to biliary epithelial cells and vascular endothelial cells. Connective tissue growth factor mRNA expression was correlated with fibrosis in BA and all livers. In the 11 patients with other liver diseases, 7 had CTGF expression limited to hepatic stellate cells and vascular endothelial cells. None of the 4 livers in children without liver disease had significant levels of CTGF.

Conclusions

In BA livers, novel biliary epithelia CTGF mRNA expression is high and correlates with severity of fibrosis. These data support a role for biliary epithelial cell signaling in fibrogenesis.     

Cystic adventitial disease: a case report and literature review

Cystic adventitial disease (CAD) is a rare non-atherosclerotic cause of peripheral vascular disease (PVD). We describe a 54-year-old man who presented with calf claudication and catheter angiography showed the typical scallop appearances of CAD. Surgery involved resection of the diseased segment with a femoral popliteal venous bypass graft. A literature review revealed the different theories for pathogenesis, the investigation of choice being catheter angiography and the treatment excision with bypass grafting.     

Discovery of Novel 1,2,4‐Triazol‐5‐Ones as Tumor Necrosis Factor‐Alpha Inhibitors for the Treatment of Neuropathic Pain

In this work, synthetic integration of substituted semicarbazides and various aliphatic, aryl and heteroaryl acids into 1,2,4‐triazol‐5‐ones was accomplished. Following the assessment of neurotoxicity and peripheral analgesic activity, the compounds were evaluated in two peripheral models of neuropathic pain, the chronic constriction injury and partial sciatic nerve ligation to assess their antihyperalgesic and antiallodynic potential. ED₅₀ studies undertaken for selected compounds exhibiting promising efficacies ( 1c , 3c and 4a ) revealed values ranging from 13.21 to 39.85 mg/kg in four behavioral assays of hyperalgesia and allodynia (spontaneous pain, tactile allodynia, cold allodynia, and mechanical hyperalgesia). Mechanistic studies revealed that the compounds suppressed the inflammatory component of the neuropathic pain inhibiting tumor necrosis factor‐alpha and preventing oxidative and nitrosative stress.