Complications of total hip arthroplasty: MR imaging-initial experience

PURPOSE: To investigate the use of standard magnetic resonance (MR) imaging sequences with simple parameter modifications for the detection and characterization of total hip arthroplasty (THA) complications. MATERIALS AND METHODS: An initial phantom study was performed with cobalt-chrome and titanium prostheses to establish the imaging parameters for a subsequent clinical study. In the clinical study, coronal and transverse MR imaging of 14 THA prostheses was performed before and after intravenous contrast material administration in 12 patients who were being considered for revision arthroplasty. The images were reviewed for evidence of juxtaarticular or periprosthetic abnormalities, patterns of contrast enhancement, and quality of periprosthetic tissue depiction. RESULTS: Phantom study results showed improved periprosthetic tissue depiction with use of thin sections, increased frequency-encoding gradient strength, and fast spin-echo sequences. The clinical study results demonstrated periprosthetic abnormalities in 11 cases: mechanical loosening in two cases (including one case with an associated periprosthetic fracture); granulomatosis, eight; and infection, one. In 100% of cases, tissue depiction around the femoral component was judged to be of "diagnostic quality." Tissue depiction around the acetabular component was of diagnostic quality in five (36%) cases. In all seven surgically confirmed cases, a correct diagnosis was made preoperatively with MR imaging. CONCLUSION: By using simple modifications to standard MR imaging sequences, diagnostic-quality MR imaging of THA complications can be performed, particularly around the femoral prosthetic stem.     

Phase I clinical and pharmacokinetic study of NSC 655649, a rebeccamycin analogue, given in both single-dose and multiple-dose formats.

PURPOSE: NSC 655649 was given in both single- and multiple-dose formats, to characterize maximum tolerated dose (MTD), toxicity, and pharmacokinetic profile. Experimental Design: Patients with advanced malignancies were treated with escalating doses of NSC 655649 in either a single-dose format (step 1) or a multiple-dose format (step 2). In step 1, NSC 655649 was given as a 30-60 min infusion. In step 2, the NSC 655649 dose was divided into three consecutive daily doses. Plasma and urine were sampled to assess the pharmacokinetic and excretory characteristics of NSC 655649. A total of 12 patients were enrolled at the MTD for the purpose of gender equity. RESULTS: Forty-three patients were treated with NSC 655649 for a total of 108 cycles in step 1, and 26 patients were treated for a total of 41 cycles in step 2. The MTD for both steps 1 and 2 was determined to be 572 mg/m(2). Myelosuppression was the dose-limiting toxicity. Local venous irritation was generally grade 1-2 in severity but could only be adequately prevented by administration of study drug through central i.v. access. One patient with adenocarcinoma of unknown primary experienced a partial response on step 1. Four patients experienced stable disease of >100 days duration. CONCLUSIONS: NSC 655649 may be safely given at an MTD of 572 mg/m(2) in both single-dose and multiple-dose formats. Optimally, this drug should be administered through central i.v. access.     

Giant bronchial carcinoid tumors: a multidisciplinary approach

BACKGROUND: Bronchial carcinoid tumors account for approximately 2% of all lung tumors. Although they were considered benign lesions, they are now categorized malignant, occasionally with poor prognosis. The clinical symptoms can be highly variable and are often present for many years before diagnosis. Whereas some carcinoids are entirely asymptomatic, others are accompanied by carcinoid or paraneoplastic syndromes. METHODS: We describe the multidisciplinary management of a 34-year-old female patient with a massive actively secreting bronchial carcinoid tumor of the right lung. Furthermore, we provide a review of the literature regarding the operative treatment and the perioperative management of pulmonary carcinoid tumors with respect to surgical, anesthetic, radiologic, and pathologic considerations. RESULTS: In the reported case, the first symptoms were chronic watery diarrhea, skin flushing, progressive shortness of breath, and increasing right shoulder pain. When the patient initially presented at our institution, the tumor had already reached an enormous size and it involved the right and left atrium as well as the atrial septum. Using an evidence-based, multidisciplinary approach the patient was treated successfully with extended surgical resection. CONCLUSIONS: Carcinoid tumors are potentially curable even if they reach a significant size and thus an aggressive strategy is warranted. The management of such cases requires careful investigation, planning, and treatment with collaborative expertise provided by a multidisciplinary team. We demonstrated that this approach can lead to a favorable outcome in what first appeared to be a formidable and unresectable tumor.     

Hemangiopericytoma in children and infants

BACKGROUND: Hemangiopericytoma (HPC) is a soft-tissue neoplasm most commonly seen in adults; only 5-10% of cases occur in children. Childhood HPC comprises two distinct clinical entities. In children older than 1 year, it behaves in a manner similar to adult HPC. Infantile HPC, however, although histologically identical to adult HPC, has a more benign clinical course. The reasons for these differences in the natural history of HPC are not well understood. METHODS: The authors reviewed the clinicopathologic features of HPC as well as the treatment and outcomes of the 12 children (9 males and 3 females) treated for this disease at St. Jude Children's Research Hospital over a 35-year period. RESULTS: At diagnosis, 9 patients were older than 1 year and 3 were younger than 1 year. Among the 9 older patients, tumors were most commonly found in the lower extremities (n = 5). One patient had been treated for acute lymphoblastic leukemia 15 years earlier. One patient had metastatic disease at diagnosis, and three had unresectable tumors. Two patients experienced objective responses to chemotherapy. Three patients died of disease progression. Among the three infants, two had unresectable disease at diagnosis, and both experienced excellent responses to neoadjuvant chemotherapy. In one case, the response of the tumor to chemotherapy correlated with maturation to hemangioma. All three infants are alive without evidence of disease. CONCLUSIONS: HPC in children older than 1 year does not differ from adult HPC, and aggressive multimodality therapy is required. Infantile HPC, on the other hand, is characterized by better clinical behavior, with documented chemoresponsiveness and spontaneous regression, and requires a more conservative surgical approach. In some cases of infantile HPC, this benign behavior correlates with maturation to hemangioma.