Relationship between deep vein thrombosis and pulmonary embolism following THA and TKA

Patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA) are at risk for venous thromboembolisms, including deep vein thrombosis and pulmonary embolism. Most deep vein thromboses are asymptomatic, but they can lead to long-term morbidity to the same extent as symptomatic events. The risk of complications of venous thromboembolisms depends on the location of thrombi; potential long-term complications include recurrent venous thromboembolism, postthrombotic syndrome, and chronic thromboembolic pulmonary hypertension. Risk of recurrence persists for several years after the initial event. Approximately 20% of recurrent events are pulmonary embolisms, and approximately half of those are fatal. The causal relationship between deep vein thrombosis and pulmonary embolism remains controversial. Some consider them distinct clinical entities, while others have found asymptomatic distal deep vein thrombosis to be associated with elevated risk of developing pulmonary embolism. Unique coagulation factors may be associated with orthopedic surgery patients that differentiate them from patients undergoing other types of surgery. Symptomatic and asymptomatic deep vein thrombosis can lead to the development of recurrent venous thromboembolism, pulmonary embolism, postthrombotic syndrome, and chronic thromboembolic pulmonary hypertension, all of which are associated with reduced quality of life and increased health care expenditures. Thromboprophylaxis is therefore important in patients undergoing THA or TKA. However, traditional anticoagulants are not ideal, particularly for long-term use. Orthopedic surgeons should be aware of the causes and potential sequelae of venous thromboembolism and of the new thromboprophylactic agents that can help prevent it.     

FDG imaging

F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) imaging is being increasingly utilized in the detection of malignancy and in following the effects of therapy. FDG-PET imaging has been demonstrated to be accurate in the diagnosis of several malignancies including lung cancer, lymphoma, recurrent colorectal cancer, and recurrent melanoma. The initial studies evaluating FDG-PET in determining the effect of therapy reveal promising results. The clinical images are interpreted subjectively like other clinical nuclear medicine imaging studies. Semiquantitative indices such as the standardized uptake value may be used for research purposes to provide a quantitative parameter from the study.     

Report of the 1997 SCAROP survey on resident training. Society of Chairmen of Academic Radiation Oncology Programs

RATIONALE AND OBJECTIVES: Members of the Society of Chairmen of Academic Radiation Oncology Programs (SCAROP) were surveyed in November 1997 to evaluate the current status of radiation oncology training in the United States and to help determine how it should be carried out in the coming decade. MATERIALS AND METHODS: A detailed questionnaire was sent to all members of SCAROP; 68 of 82 questionnaires were returned, for a response rate of 83%. RESULTS: The responses to the survey show a serious shortage of radiation oncologists in university settings, despite an apparent surplus in private practice. Although recent changes in health care have added additional clinical responsibilities for radiation oncologists in university practices, approximately 75% of the chairpersons answering the survey continue to give their faculty protected time for research. Even with additional research and teaching responsibilities, the average radiation oncologist in university practice saw 206 patients per year in 1997, a number similar to that reported by the Patterns of Care Study for radiation oncologists overall. Approximately two-thirds of respondents believe that academic chairs should strive to have all clinical faculty members participating in research. Nevertheless, most think that basic research is better performed by dedicated researchers with PhD degrees rather than radiologists with MD degrees. Most respondents believe that the training programs adequately prepare radiation oncologists for a career in academic medicine but do not provide good training in research. Eighty-four percent agreed that resident performance on the American Board of Radiology examination should be considered in the accreditation of residency programs in radiation oncology but should not be the major criterion. CONCLUSION: There is a shortage of academic radiation oncologists in the United States despite the large number of radiation oncologists completing training. This probably is due to a variety of factors, including a relatively small pool of candidates for academic positions, increasing demands for performance from academic physicians (to see more patients, perform research, publish, write grants, and teach), and competition from the private sector for recruitment of these individuals.     

Clinical PET in Oncology

The major utilization of clinical PET is in oncology, and oncologic PET utilizes FDG as the radiopharmaceutical. FDG imaging demonstrates the increased metabolism by malignant cells compared to normal cells. The initial clinical application of FDG-PET was demonstrated in brain tumors, and the gradation of accumulation of FDG related to the degree of malignancy. Subsequent studies have documented the accuracy of FDG-PET in detecting and staging several different malignancies. Whole-body imaging has made a major impact on the ability of PET to document the distribution of malignancy.FDG-PET imaging is very accurate in determining if an indeterminate solitary pulmonary nodule is malignant and in staging lung cancer. The cost-effectiveness of PET has been demonstrated for these indications. Third-party payers have policies for paying for PET scans performed in the evaluation of solitary pulmonary nodules and in staging lung cancer. The preliminary data on the use of FDG-PET imaging in other malignancies supports its use in detecting liver metastases from colorectal cancer and differentiating fibrosis from recurrent tumor after therapy for colorectal cancer; staging the axilla in primary breast cancer; staging melanoma and lymphoma; and staging and detecting recurrence of head and neck cancer. The initial reports on the use of FDG-PET are encouraging in its use in musculoskeletal malignancy, ovarian cancer, pancreatic cancer, and thyroid cancer.     

Clinical experience with alpha-particle emitting 211At: treatment of recurrent brain tumor patients with 211At-labeled chimeric antitenascin monoclonal antibody 81C6.

alpha-Particle-emitting radionuclides, such as (211)At, with a 7.2-h half-life, may be optimally suited for the molecularly targeted radiotherapy of strategically sensitive tumor sites, such as those in the central nervous system. Because of the much shorter range and more potent cytotoxicity of alpha-particles than of beta-particles, (211)At-labeled agents may be ideal for the eradication of tumor cells remaining after surgical debulking of malignant brain tumors. The main goal of this study was to investigate the feasibility and safety of this approach in patients with recurrent malignant brain tumors. METHODS: Chimeric antitenascin monoclonal antibody 81C6 (ch81C6) (10 mg) was labeled with 71-347 MBq of (211)At by use of N-succinimidyl 3-[(211)At]astatobenzoate. Eighteen patients were treated with (211)At-labeled ch81C6 ((211)At-ch81C6) administered into a surgically created resection cavity (SCRC) and then with salvage chemotherapy. Serial gamma-camera imaging and blood sampling over 24 h were performed. RESULTS: A total of 96.7% +/- 3.6% (mean +/- SD) of (211)At decays occurred in the SCRC, and the mean blood-pool percentage injected dose was < or = 0.3. No patient experienced dose-limiting toxicity, and the maximum tolerated dose was not identified. Six patients experienced grade 2 neurotoxicity within 6 wk of (211)At-ch81C6 administration; this neurotoxicity resolved fully in all but 1 patient. No toxicities of grade 3 or higher were attributable to the treatment. No patient required repeat surgery for radionecrosis. The median survival times for all patients, those with glioblastoma multiforme, and those with anaplastic astrocytoma or oligodendroglioma were 54, 52, and 116 wk, respectively. CONCLUSION: This study provides proof of concept for regional targeted radiotherapy with (211)At-labeled molecules in oncology. Specifically, the regional administration of (211)At-ch81C6 is feasible, safe, and associated with a promising antitumor benefit in patients with malignant central nervous system tumors.     

Validity and reliability of the Ergomopro powermeter

The aim of this investigation was to assess the validity and reliability of the Ergomopro powermeter. Nine participants completed trials on a Monark ergometer fitted with Ergomopro and SRM powermeters simultaneously recording power output. Each participant completed multiple trials at power outputs ranging from 50 to 450 W. The work stages recorded were 60 s in duration and were repeated three times. Participants also completed a single trial on a cycle ergometer designed to assess bilateral contributions to work output (Lode Excaliber Sport PFM). The power output during the trials was significantly different between all three systems, (p < 0.01) 231.2 +/- 114.2 W, 233.0 +/- 112.4 W, 227.8 +/- 108.8 W for the Monark, SRM and Ergomopro system, respectively. When the bilateral contributions were factored into the analysis, there were no significant differences between the powermeters (p = 0.58). The reliability of the Ergomopro system (CV%) was 2.31 % (95 % CI 2.13 - 2.52 %) compared to 1.59 % (95 % CI 1.47 to 1.74 %) for the Monark, and 1.37 % (95 % CI 1.26 - 1.50 %) for the SRM powermeter. These results indicate that the Ergomopro system has acceptable accuracy under these conditions. However, based on the reliability data, the increased variability of the Ergomopro system and bilateral balance issues have to be considered when using this device.     

Endovascular repair of abdominal aortic aneurysm with chronic dissection using an intravascular ultrasound-guided reentry catheter

The incidence of aortic dissection is rare (approximately 10 cases per 1 million inhabitants' year), and reports of an associated aortic dissection within an abdominal aortic aneurysm (AAA) are anecdotal. Historically, such a dissection was treated by operation, but operative risks often excluded patients from intervention. An endovascular approach appears to be more advantageous, but concerns regarding "true" versus "false" lumens and the presence of an intimal flap make an endovascular intervention potentially hazardous. In this report, the authors describe a novel endovascular repair of an AAA with an Excluder device and the successful treatment of a concomitant abdominal aortic dissection using intravascular ultrasound and a Pioneer guided reentry catheter.     

Hereditary leiomyomatosis and renal cell cancer: a syndrome associated with an aggressive form of inherited renal cancer

PURPOSE: Hereditary leiomyomatosis and renal cell cancer is a recently described hereditary cancer syndrome in which affected individuals are at risk for cutaneous and uterine leiomyomas, and kidney cancer. Our initial experience revealed the aggressive behavior of these renal tumors, often with early metastasis, despite small primary tumor size. We report the clinical characteristics and urological treatment of patients with hereditary leiomyomatosis and renal cell cancer associated renal tumors. MATERIALS AND METHODS: A total of 19 patients with hereditary leiomyomatosis and renal cell cancer associated renal tumors were evaluated. The 11 women and 8 men had a median age at diagnosis of 39 years (range 22 to 67), and a median clinical and radiological followup of 34 months (range 6 to 141). Hereditary leiomyomatosis and renal cell cancer manifestations in patients with renal tumors included cutaneous leiomyomas in 11 of 17 evaluable patients (65%) and uterine leiomyomas in 7 of 7 evaluable females (100%). RESULTS: Median pathological tumor size was 7.8 cm (range 1.5 to 20). Histological subtypes were consistent with hereditary leiomyomatosis and renal cell cancer renal carcinoma. Four of 7 patients with 2.0 to 6.7 cm T1 tumors had spread to regional lymph nodes or metastases at nephrectomy. Overall 9 of 19 patients (47%) presented with nodal or distant metastases. CONCLUSIONS: Renal tumors in patients with hereditary leiomyomatosis and renal cell cancer syndrome are significantly more aggressive than those in patients with other hereditary renal tumor syndromes. In contrast to other familial renal cancer syndromes, the observation of 3 cm or less renal tumors associated with hereditary leiomyomatosis and renal cell cancer is not recommended. Careful followup of affected and at risk individuals in families is necessary.     

Guidelines for the conduct of clinical trials for spinal cord injury (SCI) as developed by the ICCP panel: clinical trial outcome measures

An international panel reviewed the methodology for clinical trials of spinal cord injury (SCI), and provided recommendations for the valid conduct of future trials. This is the second of four papers. It examines clinical trial end points that have been used previously, reviews alternative outcome tools and identifies unmet needs for demonstrating the efficacy of an experimental intervention after SCI. The panel focused on outcome measures that are relevant to clinical trials of experimental cell-based and pharmaceutical drug treatments. Outcome measures are of three main classes: (1) those that provide an anatomical or neurological assessment for the connectivity of the spinal cord, (2) those that categorize a subject's functional ability to engage in activities of daily living, and (3) those that measure an individual's quality of life (QoL). The American Spinal Injury Association impairment scale forms the standard basis for measuring neurologic outcomes. Various electrophysiological measures and imaging tools are in development, which may provide more precise information on functional changes following treatment and/or the therapeutic action of experimental agents. When compared to appropriate controls, an improved functional outcome, in response to an experimental treatment, is the necessary goal of a clinical trial program. Several new functional outcome tools are being developed for measuring an individual's ability to engage in activities of daily living. Such clinical end points will need to be incorporated into Phase 2 and Phase 3 trials. QoL measures often do not correlate tightly with the above outcome tools, but may need to form part of Phase 3 trial measures.