Interobserver variability in the detection of cervical-thoracic Hodgkin's disease by computed tomography.

PURPOSE: Computed tomography (CT) scans of the neck and chest are obtained at diagnosis of Hodgkin's disease to establish disease extent, plan radiotherapy, and serve as baseline studies for subsequent evaluation of response to therapy. However, differences in interpretation may occur even among experienced radiologists. This study was designed to test the extent of variation among expert radiologists' interpretations and to assess how their interpretations differed from that of the primary (institutional) radiologists. MATERIALS AND METHODS: Five radiologists independently reviewed randomly selected CT scans of 59 patients enrolled onto two Pediatric Oncology Group Hodgkin's disease treatment protocols. For each patient, 31 potential disease sites were scored as positive, negative, uncertain, or unassessable. Agreement among the reviewers and between the reviewers and the primary readers was analyzed. RESULTS: For 58% of the sites, at least four of the five reviewers agreed in >/= 80% of the cases. Kappa analysis showed moderate agreement in approximately two thirds of the sites and poor agreement in the remainder. There was moderate agreement between a majority of the expert readers and the primary radiologist reports for approximately one third of the sites, and agreement was poor in two thirds. CONCLUSION: There are disparities among radiologists' interpretations of cervical-thoracic CT imaging of patients with Hodgkin's disease. This variability may affect patient care and the performance and results of multi-institutional clinical trials. We propose that a standardized method of reporting might improve the consistency of interpretation of CT scans in these patients.

Carboplatin/ifosfamide window therapy for osteosarcoma: results of the St Jude Children's Research Hospital OS-91 trial.

PURPOSE: To determine the activity of carboplatin/ifosfamide in patients with previously untreated osteosarcoma and to estimate patient outcomes after a multiagent chemotherapy protocol that eliminated cisplatin. PATIENTS AND METHODS: Sixty-nine patients with newly diagnosed, previously untreated osteosarcoma received three cycles of carboplatin (560 mg/m(2) x 1) and ifosfamide (2.65 g/m(2)/d x 3). Assessment of response was evaluated after two (week 6) and three (week 9) chemotherapy cycles. At week 9, histologic response was assessed. Adjuvant therapy comprised two additional carboplatin/ifosfamide cycles, doxorubicin, and high-dose methotrexate. Patients were stratified at enrollment: stratum A, resectable primary tumor without metastases; stratum B, unresectable primary tumor; and stratum C, metastatic disease at diagnosis. Week 6 response was compared with that of a historic group that received only ifosfamide during the initial window evaluation. RESULTS: The clinical and radiographic response rate to three cycles of carboplatin/ifosfamide was 67.7% (95% confidence interval, 55.0% to 78.8%). Compared with the historic population who received only ifosfamide, the combination of carboplatin and ifosfamide reduced the progressive disease rate at week 6 (31.9% v 9%, P: = .003). For patients in stratum A, the 3-year event-free survival and survival were 72.3% +/- 6.7% and 76.4% +/- 6.4%, respectively. Patients who received carboplatin-based therapy had less long-term renal toxicity and ototoxicity. CONCLUSION: This pilot trial suggests that carboplatin/ifosfamide combination chemotherapy has substantial antitumor activity. In the context of a multiagent chemotherapy protocol comprising high-dose methotrexate and doxorubicin, we found that the addition of carboplatin/ifosfamide resulted in patient outcomes comparable to trials using cisplatin-based therapy with less long-term toxicity.

Magnetic resonance imaging detection of avascular necrosis of the bone in children receiving intensive prednisone therapy for acute lymphoblastic leukemia or non-Hodgkin lymphoma.

The purpose of this study was to determine the frequency with which magnetic resonance (MR) imaging detects avascular necrosis of the bone (AVNB) in children with acute lymphoblastic leukemia (ALL) or advanced-stage non-Hodgkin lymphoma (NHL) who receive prednisone during remission induction, reinduction, and maintenance chemotherapy; to assess the clinical significance of these findings; and to identify factors predictive of AVNB. We prospectively obtained MR imaging of the hips and knees of 116 children who had completed at least 1 year of treatment for ALL or advanced-stage NHL on identical prednisone-containing regimens between December 1991 and October 1994. MR imaging findings of AVNB were compared with clinical outcomes, and the effect of therapeutic and patient factors on the frequency of AVNB was analyzed. The MR imaging findings of 17 of the 116 participating patients were consistent with AVNB. The most common clinical manifestation was joint pain (11 patients). Only one patient had progressive joint deterioration that necessitated surgical replacement. Only age 10 years or more at the time of the primary diagnosis was significantly associated with the development of AVNB (P = 0.004). MR imaging showed changes consistent with AVNB in approximately 15% of this patient population. However, most patients in this study who had MR imaging signs of AVNB did not experience progressive joint destruction, even with continued prednisone therapy. Therefore, the clinical usefulness of MR imaging as a screening tool for AVNB in this set of patients remains uncertain.

Radioactive excretion in human milk following administration of technetium Tc 99m macroaggregated albumin.

Albumin-tagged sodium pertechnetate (technetium) is routinely used in nuclear medicine for scanning procedures of the lung. The rate of excretion of this radionuclide into breast milk and the resultant potential radiation hazard to the nursing infant have received little attention. Therefore the milk from a nursing mother who required a lung scan because of suspected pulmonary emboli using an intravenous injection of 4 mCi of technetium Tc 99 macroaggregated human serum albumin was monitored. Albumin tagging severely limited the entrance of technetium into her milk and the radioactivity of the milk returned to base line by 24 hours. A total of 2.02 muCi of technetium was measured in the 24-hour milk collection after technetium injection and 94% of this amount was excreted by 15.5 hours. This amount of technetium administered orally to a newborn would deliver a total body radiation dose of .3 mrad. Therefore, an infant would receive trivial doses of radiation if breast-feeding were resumed 15.5 hours after administration of the radionuclide to the mother and nursing can clearly be resumed safely 24 hours after injection.

Evaluation of atrioventricular septal defect by magnetic resonance imaging.

Electrocardiographically gated magnetic resonance imaging (MRI) was successfully performed in 9 patients with atrioventricular (AV) septal defect: 6 had complete AV canal and 3 had partial AV canal. The defect was readily visualized in all patients on transverse scans taken at the level of the AV valve. The size and extent of the defect could be easily determined. All patients demonstrated a similar underlying morphologic pattern on MRI scans, consisting of deficiency of the primum atrial septum and inlet ventricular septum and a "common" AV valve ring with absence of the cardiac crux. The 3 patients with isolated atrial septal defect could be distinguished from the 6 with complete AV canal by the dense, fibromuscular bridging tissue, which coursed from the AV valve to the crest of the ventricular septum, obliterating the interventricular communication. Four patients had angiographically proved ventricular hypoplasia, which was also detected by MRI. AV valves and their patterns of chordal attachment were accurately imaged in 7 patients on systolic sections; accessory chordae were identified in 6 patients. MRI is a useful noninvasive imaging modality that can depict the underlying morphologic abnormalities in AV septal defect as well as important anatomic variations.

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.

Imaging pediatric bone sarcomas. Diagnosis and treatment-related issues.

The treatment of pediatric bone malignancies has undergone dramatic change in the past two decades. With the use of adjuvant chemotherapy, survival of patients with osteosarcoma and Ewing's sarcoma has greatly increased and most extremity lesions are now managed with an initial course of chemotherapy followed by limb-sparing surgery rather than amputation. Radiologists are called on not only to help diagnose and stage these tumors, but also to assess their extent, to determine response to preoperative chemotherapy, and to monitor patients for postoperative complications and recurrent disease. This article discusses imaging solutions to clinical issues that arise during the care of these children.

Changes in MR signal intensity and contrast enhancement of therapeutically irradiated soft tissue.

Increased MR signal intensity was observed on T2-weighted, STIR, and Gadolinium-DTPA-enhanced T1-weighted images of subcutaneous and muscular soft tissue in 9 of 10 children treated with combination chemotherapy and radiation therapy (RT) for malignancy in the pelvis or an extremity. Total radiation doses ranged from 59.5 to 65 Gy. Eight of the patients with these changes received hyperfractionated RT (seven for Ewing sarcoma and one for perineal rhabdomyosarcoma); one was treated for pelvic hemangiopericytoma with once-daily fractions. Evidence of soft tissue damage became apparent as early as the sixth week of RT and was seen for up to 69 wk post-RT. There was no clear MR evidence of RT-induced soft tissue damage in one patient, who underwent hyperfractionated RT for pelvic rhabdomyosarcoma. Other MR findings in this group included evidence of bladder wall thickening in three of the seven patients given pelvic RT and increased T1-weighted signal of irradiated marrow in nine patients. All patients had clinical evidence of skin, soft tissue, or epithelial radiation effects. Increased MR signal intensity secondary to RT-induced damage can be differentiated from widespread tumor by geometric borders that conform to the margins of the radiation field.

MR imaging findings in recurrent primary osseous Ewing sarcoma.

The objective of this study was to determine the value of magnetic resonance (MR) imaging in diagnosing local recurrence of Ewing sarcoma. We retrospectively reviewed radiographs, Tc99m-methylene diphosphonate (MDP) skeletal scintigraphy, computed tomography scans, and MR studies of 11 patients who had local recurrences of osseous Ewing sarcoma following initial responses to chemotherapy and local radiation. The MR images were compared to those of a control group of nine patients who had no evidence of relapse. T1- and T2-weighted MR images identified 9 of the 11 recurrences. Computed tomography was diagnostic in 4 of 6 cases evaluated, Tc99m-MDP bone scintigraphy in 4 of 11 cases, and plain radiographs in 2 of 10. MR findings at relapse included changes in signal intensity, increased extent of abnormal marrow signal on T1- and T2-weighted images, and identification of a new soft tissue mass. These findings suggest that MR imaging is valuable in the routine follow-up of primary osseous Ewing sarcoma.

Increased confidence of diagnosis of Ewing sarcoma using T2-weighted MR images.

To assess whether magnetic resonance imaging could assist in diagnosing Ewing sarcoma, we retrospectively analyzed T1- and T2-weighted images of 24 consecutive solitary lytic bone lesions, including 18 cases of histologically proven Ewing sarcoma, and six aggressive-appearing benign lesions including eosinophilic granuloma and osteomyelitis (3 cases each). Images were obtained using a (1.0T) Siemens GBSII system. No signal intensity differences were noted among the various lesions on T1-weighted images. The observed differences in T2-weighted marrow signal intensities were scored on a 5-point scale (5 = water, 3 = fat, and 1 = muscle) and then histologically correlated. Sixteen of 18 Ewing sarcomas showed homogeneous T2-weighted signal isointense with fat and two were heterogeneous. Signals for all 6 benign lesions were homogeneous and more intense than fat on T2-weighted images. All Ewing sarcomas had associated soft tissue masses whereas, only one benign lesion, an eosinophilic granuloma had a small soft tissue component. In our patient population, a homogeneous intramedullary T2-weighted signal isointense with fat, and the presence of an associated soft tissue mass helped differentiate Ewing sarcoma from benign lytic lesions. The reproducibility of these results requires testing in larger series of patients using a variety of MR imaging equipment of differing field strengths.

Subtraction technique for contrast-enhanced MR images of musculoskeletal tumors.

Vascularized malignant tissue, fat and hemorrhage may have similar intensities on Gd-DTPA-enhanced, T1-weighted MRI performed to evaluate musculoskeletal tumors. We describe a simple, rapid post-processing subtraction technique which resulted in improved definition of these tissues in 33 of 42 examinations. While the subtraction process is susceptible to complex patient motion, the improved contrast can be obtained without modifying standard pulse sequences.

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.

MR imaging of malignant soft-tissue tumors.

Nearly 6000 cases of soft-tissue sarcoma are diagnosed annually. Many are evaluated with MR imaging, which, because of its superior tissue contrast, has become the most important tool for detecting, staging, and monitoring treatment of the primary tumor. Although irregular margins, invasion of bone, and vascular encasement are indicators of soft-tissue malignancy, sarcomas may also be localized and well-circumscribed. Regardless of their histology, most soft-tissue sarcomas are similar in intensity to muscle on T1-weighted images and intermediate to high signal relative to fat on T2-weighted images. The addition of paramagnetic contrast agents can help differentiate between recurrent primary tumor and postoperative fluid collections.

Pediatric musculoskeletal lesions simulating neoplasms.

Radiologists who interpret images of pediatric oncology patients may also be presented with nonneoplastic lesions that bear a clinical or radiographic resemblance to a malignant bone or soft-tissue sarcoma. In these cases, it is often desirable to avoid biopsy. Although not always specific, MR imaging can, in many instances, increase the confidence with which the radiologist is able to rule out malignancy. This article describes the common developmental, infectious, traumatic, and iatrogenic lesions in which the initial presentation is that of a malignant, musculoskeletal neoplasm.