Dynamic contrast-enhanced MR imaging evaluation of osteosarcoma response to neoadjuvant chemotherapy.

Assessment of osteosarcoma response to neoadjuvant chemotherapy has prognostic implications, but conventional imaging techniques have been unable to provide an accurate quantitative measure of tumor response. We developed an analysis of dynamic contrast-enhanced MR imaging (DEMRI) to render an image of dynamic vector magnitudes (DVM) and to summarize the result in a quantitative parameter, mean DVM for the lesion (mu DVM). We compared the mu DVM from the examination before surgery with histologic results from an en bloc resection of the tumor in 19 cases. The final mu DVM value provided an accurate (89.5%) measure of tumor necrosis in osteosarcoma. Further, we analyzed the findings in 17 patients with osteosarcoma who completed three DEMRI examinations during the course of therapy. Tumors with higher mu DVM values at presentation had greater decreases in the parameter over the course of therapy. These results are consistent with the distribution of DVM values in these lesions serving as an indicator of tumor perfusion and a possible surrogate variable for drug delivery.

A multicenter randomized trial comparing two surfactants for the treatment of neonatal respiratory distress syndrome. National Institute of Child Health and Human Development Neonatal Research Network.

OBJECTIVE: To compare the efficacy of two surfactants, Exosurf Neonatal (Burroughs Wellcome Co.) and Survanta (Ross Laboratories), for the treatment of neonatal respiratory distress syndrome. DESIGN: Multicenter randomized trial. SETTING: Eleven tertiary care university neonatal intensive care units participating in the National Institute of Child Health and Human Development Neonatal Research Network. PATIENTS: Newborn infants (n = 617) weighing 501 to 1500 gm with respiratory distress syndrome who were receiving assisted ventilation with 30% oxygen or more within 6 hours of birth were enrolled between January 1991 and January 1992. INTERVENTIONS: Infants were randomly assigned to receive up to four intratracheal doses of either Exosurf Neonatal (n = 309) or Survanta (n = 308). MAIN OUTCOME MEASURES: The occurrence of death or bronchopulmonary dysplasia 28 days after birth and the average fraction of inspired oxygen (FIO2) and mean airway pressure (MAP) during the first 72 hours after treatment. RESULTS: Death or bronchopulmonary dysplasia occurred in 67% of the infants in the Exosurf group and 62% of those in the Survanta group (adjusted relative risk, 1.07; 95% confidence interval, 0.96 to 1.20). During the 72 hours after the first surfactant dose, the average FIO2 (+/- SEM) was 0.50 +/- 0.01 for Exosurf and 0.42 +/- 0.01 for Survanta (difference, 0.08; 95% confidence interval, 0.05 to 0.11); the average MAP (+/- SEM) was 7.64 +/- 0.21 cm H2O for Exosurf and 6.93 +/- 0.21 cm H2O for Survanta (difference, 0.71 cm H2O; 95% confidence interval, 0.13 to 1.29 cm H2O). There was no difference between the groups in the incidence of other neonatal morbidities or in the duration of hospitalization, assisted ventilation, or supplemental oxygen administration. CONCLUSION: We found no difference between treatment groups in the incidence of death or bronchopulmonary dysplasia, although we did observe a difference in the initial response to treatment as measured by FIO2 and MAP.

Assessment of osteosarcoma response to preoperative chemotherapy using dynamic FLASH gadolinium-DTPA-enhanced magnetic resonance mapping.

RATIONALE AND OBJECTIVES: To improve the accuracy of magnetic resonance imaging (MRI) in evaluating the response of osteosarcomas to preoperative chemotherapy, the authors developed a technique of mapping tumor necrosis and viability by quantitating slope values of gadolinium-DTPA (Gd-DTPA) uptake on dynamic fast low-angle shot (FLASH) images. METHODS: Dynamic contrast-enhanced FLASH imaging of a single representative plane was performed on six osteosarcomas. Tumors were mapped by dividing resultant images into contiguous regions of interest and deriving slopes representing percentage increase in signal intensity (SI) per minute over the baseline for each region. The results were compared with estimations of viable tumor volume on subtracted Gd-DTPA-enhanced T1-weighted images and histologic maps of necrotic and viable tumor. RESULTS: Dynamic FLASH estimations of percent tumor necrosis using a critical slope value of 45% per minute correctly predicted histologic response to chemotherapy in all six patients. Comparison of dynamic FLASH and histologic maps showed a high degree of correlation. Static enhanced T1-weighted images overestimated the amount of residual viable tumor. CONCLUSIONS: Dynamic FLASH Gd-DTPA-enhanced mapping is a potentially useful noninvasive method of quantitating tumor response to chemotherapy.

Childhood chondrosarcoma: MR imaging with gadolinium-DTPA.

The radiologic, CT, MR, and histological features of a case of chondrosarcoma of the femur presenting in childhood are reported. This case emphasizes the use of correlative imaging in establishing the diagnosis as well as the value of MR supplemented by Gadolinium-DTPA enhancement in disclosing abundant necrosis within the tumor.

Comparison of radiolabeled monoclonal antibody and magnetic resonance imaging in the detection of metastatic neuroblastoma in bone marrow: preliminary results.

Magnetic resonance imaging (MRI) was compared with iodine-131-labeled monoclonal antibody scanning for ability to detect bone marrow metastases in the spine, pelvis, and femurs of children with disseminated neuroblastoma. The five patients in this study had received high-dose chemotherapy and radiation, either with (N = 2) or without (N = 3) bone marrow transplants. MRI disclosed marrow abnormalities at all sites detected with the radiolabeled antibody, which is highly specific for neuroblastoma. However, several diffuse and multifocal marrow changes apparent on MR scans were not present on scintigrams, indicating that MRI is probably less specific than monoclonal antibody imaging. Both methods were more useful than conventional radiography, computed tomography, and 99mTc-MDP bone scans for identifying sites of marrow involvement by neuroblastoma.

The use of glucagon in hydrostatic reduction of intussusception: a double-blind study of 30 patients.

Thirty patients were referred for hydrostatic reduction of ileocolic intussusception. Children with suspected gangrenous bowel or sensitivity to glucagon were excluded from the investigation. A standard protocol for the procedure was used in all patients, including the intravenous administration of glucagon or placebo (0.05 mg/kg) when the intussusception was encountered. Successful reduction was achieved in 53% of both control and glucagon-treated patients. Analysis of the length of the procedure and the ease of reduction of the intussusception indicated no difference in the two groups. This multicenter double-blind study failed to show any therapeutic value of glucagon in hydrostatic reduction of intussusception.

Vertebral agenesis: comprehensive care and outcome.

There is little information concerning long-term outcome of vertebral agenesis. In this series of eight patients with variable severity of vertebral agenesis, three died during infancy, two of associated congenital anomalies involving the cardiorespiratory system and one of unknown causes. The remaining five have had no life-threatening problems. They have normal intellect, and the developmental achievements are adequate for their age. The five patients with the highest lesions were those born to diabetic mothers. We also discuss current concepts of comprehensive team management of such infants.