Radionuclide imaging of soft tissue neoplasms.

Two classes of radiopharmaceuticals may be used for imaging tumors of the musculoskeletal system. The first is comprised of soft tissue or tumor specific agents such as gallium-67, bleomycin, and radionuclide-labeled antibodies, which may be useful for detecting and localizing these tumors. The other class of tracer is comprised of those with avidity for bone. The 99mTc-labeled-phosphate skeletal imaging compounds have been found to localize in a variety of soft tissue lesions, including benign and malignant tumors. In 1972, Enneking began to include bone scans in the preoperative evaluation of soft tissue masses. Later, he and his associates reported that these scans were useful in planning operative treatment of sarcomas by detecting involvement of bone by the tumors. Nearly all malignant soft tissue tumors take up bone-seeking radiopharmaceuticals, and bone involvement was indicated in two-thirds of the scans we reviewed. About half of benign soft tissue lesions had normal scans, but the other half showed uptake within the lesion and a few also showed bone involvement. Careful, thorough imaging technique is essential to proper evaluation. Multiple, high-resolution static gamma camera images in different projections are necessary to adequately demonstrate the presence or absence of soft tissue abnormality and to define the precise relationship of the tumor to the adjacent bone.

The management of primary lymphoma of bone.

From October 1962 through April 1982, 21 patients with the diagnosis of primary lymphoma of bone (18 monostotic, stages IE and IIE; 3 polyostotic) were treated with curative intent. A combination of chemotherapy and radiation therapy was used in 11 patients, local treatment alone in 9 patients, and chemotherapy alone in one patient. Overall 5-year survival for the patients treated with curative intent was 56%. Standard work-up has changed over the 20-year study period. Five-year survival for the subset of eight stage I and II patients with full pretherapy staging was 83%. Prognosis was significantly correlated with extent of pretherapy staging. Treatment parameters that also seemed to predict outcome were the aggressiveness of chemotherapy and the use of irradiation or surgery for local-regional disease; the only local failure occurred in the patient who received chemotherapy alone. Complications of radiation therapy alone and in combination with chemotherapy are discussed and correlated with irradiation dose. Radiation therapy techniques are described, and a management approach is recommended.

Elbow arthrography.

Arthrography of the elbow is performed infrequently, but may be quite useful in demonstrating the presence, number, and location of intra-articular loose bodies, and in evaluating articular cartilaginous surfaces. Such information may be valuable in the selection of an operative versus a nonoperative course of treatment, and, if surgery is elected, it may be useful to the surgeon in planning the operative approach and in locating the position of all of the abnormalities present. Elbow arthrography is also of occasional value in demonstrating synovial disease, evaluating certain traumatic disorders, and verifying needle position during aspiration. A useful and accurate elbow arthrogram requires careful planning and may require considerable time to perform completely. Plain radiographs should be carefully examined. Fluoroscopic observation before injection may be extremely helpful, and thoughtful selection of the type and amount of contrast medium is necessary. Adequate arthrographic films may be obtained only after careful consideration of the abnormalities to be demonstrated and their location in the joint. Tomography is almost always necessary for a thorough evaluation.

Fibrous lesions of bone.

Fibrous lesions of bone include entities with a wide range of radiographic appearance and clinical behavior. Many benign fibrous lesions, such as medial supracondylar defects, fibrous cortical defects, and nonossifying fibromas have typical radiographic appearances and usually are self-limited. Desmoplastic fibromas and benign fibrous histiocytomas are less common, behave more aggressively, and usually require biopsy and surgical management. Fibrous dysplasia varies from solitary clinically unimportant lesions to wide-spread, deforming skeletal involvement that can lead to severe functional impairment and, rarely, even to death. Malignant fibrous lesions, including malignant fibrous histiocytomas and fibrosarcoma, produce aggressive lytic lesions, which require careful anatomic staging, accurate biopsy, and aggressive and appropriate treatment.

The comparative value of bone scintigraphy and computed tomography in determining bone involvement by soft-tissue sarcomas.

In seventeen patients with a soft-tissue sarcoma, bone scintigrams were found to be more useful than computed tomograms for evaluating bone involvement. The scintigrams had higher predictive value and higher sensitivity, as there were no false-negative or false-positive scintigrams, while there were three false-positive computed tomograms. Accurate scintigraphy requires the use of high-resolution static gamma-camera images that show the tangential relationship between tumor and bone. The images that are usually made in surveying the skeleton for metastatic disease--routine whole-body bone scans, or even gamma-camera images that provide only anterior and posterior views--are inadequate. They did not demonstrate the true relationship of the tumor to bone in the patients in this study when activity within the tumor itself was superimposed over bone. In such patients, properly selected oblique views sometimes showed that the tumor was clearly separate from normal bone activity. Determination of the relationship of the soft-tissue tumor to bone is an important part of the accurate anatomical staging that is required to select appropriate surgical management.

The role of radionuclide bone-scanning in determining the resectability of soft-tissue sarcomas.

In sixty patients with soft-tissue sarcoma, radionuclide bone scans were 92 per cent accurate in evaluating the presence or absence of involvement of contiguous bone by the tumor itself, by the tumor's reactive pseudocapsule, or by tissue contaminated during inadequate excision. The scans were most helpful when the relationship of the tumor to the bone was crucial in determining the resectability of the tumor. Meticulous imaging technique is essential to a complete and accurate radionuclide study. High-resolution, high-count gamma-camera scans in multiple projections are required for precise localization of tumor.

Digital vascular imaging in children. A preliminary report.

Whereas digital subtraction angiography (DSA) has been extensively used in adults, few reports have dealt with its application in children. We utilized DSA in 52 children, studying various vascular territories. Technically satisfactory studies were obtained in 89%. Motion artifacts is the foremost technical problem. Extremity DSA with arterial injection was highly successful in a number of cases. Thoracic vascular studies were also successful, as were studies of the head and neck, whereas renal and abdominal vessel studies were somewhat less successful. DSA with arterial injection may be expected to replace conventional angiographic studies in selected cases and appears to be an excellent screening method also in children.

Perivascular soft tissue spread of osteosarcoma.

Skeletal scintigraphy of a distal femoral osteosarcoma revealed a band of soft-tissue uptake in the medial thigh extending to the groin, which corresponded to direct perivascular tumor extension.

Triple-phase bone scan findings in aggressive fibromatosis. Before and after radiation therapy.

The authors present comparative triple-phase bone scan findings in three cases of histologically proven aggressive fibromatosis both before (initial evaluation) and after radiation therapy. The purpose of the study was to compare triple-phase bone scan findings in aggressive fibromatosis both before and after radiation therapy and to determine whether any additional physiological information could be obtained. Before radiation therapy, the triple-phase bone scintigraphy demonstrated increased flow and radiotracer pooling in the areas of tumors on dynamic flow and immediate blood pool images, respectively. However, the delayed static images demonstrated variable radiotracer uptake. When compared to preradiation therapy triple-phase bone scan, decreased vascularity was well demonstrated in all three patients after radiation therapy. In addition, it also provided information regarding the changes in the size and extent of tumor, noninvaded underlying bone, and remainder of the skeleton. This additional information can be particularly useful in patients with equivocal or questionable histologic diagnosis especially from small, unrepresentative biopsies.

Fluid levels in aneurysmal bone cysts: a CT feature.

Review of 17 computed tomographic (CT) scans of aneurysmal bone cysts revealed fluid levels in six of the lesions; the fluid shifted after repositioning of two patients. Visibility of fluid levels did not correlate with the type of fluid found within the lesions. Detection of fluid levels depended partly on a period of immobilization before CT and on viewing the images with sufficiently narrow window settings.

Joint fluoroscopy before arthrography: detection and evaluation of loose bodies.

Fluoroscopy before injection of contrast medium increased the usefulness and accuracy of arthrography in 14 of 22 patients with possible intra-articular loose bodies. Although loose bodies wedged between articular surfaces deep within the joint were immobile, a typical tumbling motion on fluoroscopy reliably identified most free-floating loose bodies. Fluoroscopy sometimes revealed abnormalities more clearly than the plain radiographs or arthrograms.

Scintigraphy of aneurysmal bone cysts.

Bone scintigrams of 25 aneurysmal bone cysts showed abnormal activity in every case. In 22 cases, the activity was correlated with the true pathologic extent of the lesions; only three exhibited a false-positive extended pattern of uptake beyond the true tumor margins. Sixteen scintigrams (64%) revealed increased uptake, chiefly around the periphery of the lesions, with less activity in their centers. This feature could not be explained simply by the cystic nature of the lesions, since aneurysmal bone cysts may contain considerable fibrous tissue septa containing trabeculae of reactive new bone. However, there was no correlation between any specific anatomic or histologic pattern and the intensity and pattern of abnormal scintigraphic activity.

Radionuclide imaging of lipoma and liposarcoma.

Radionuclide imaging with technetium-99m phosphate compounds was performed in 18 patients with deep-seated soft-tissue masses. The histologically established diagnosis was intra- or intermuscular lipoma in 13 patients and liposarcoma in five. Radionuclide scans demonstrated disparate scintigraphic characteristics in these two often clinically similar lesions. Soft-tissue radionuclide accumulation occurred in two lipomas and corresponded to radiographically evident calcification. All liposarcomas were uncalcified and demonstrated intense radionuclide activity. This activity may be related to the angiographic and histologic hypervascularity of liposarcomas, which is also demonstrable on computed tomography as contrast enhancement; hence, these modalities offer the same nonspecific diagnostic information. It is concluded, however, that plain radiography and radionuclide scaning should suffice to establish the diagnosis of lipoma.

Radiological evaluation of chondroblastoma.

Eleven new and six recurrent chondroblastomas were studied with multiple radiological imaging methods (plain radiography, conventional tomography, computed tomography, radionuclide bone scanning, and angiography). When the plain radiographic appearance was typical, conventional tomography or computed tomography (CT) was helpful, but other studies were not. Periosteal reaction and angiographic hypervascularity were common and did not indicate cortical breakthrough. For large, aggressive, or atypical lesions, conventional tomography and CT were helpful in delineating anatomic extent, and angiography was of value in demonstrating major vessel displacement. Radionuclide bone scanning was not useful.

Radiology of sacrococcygeal chordoma. Difficulties in detecting soft tissue extension.

Plain radiographs of seven patients with sacrococcygeal chordomas showed sacral destruction, enlarged sacral neural foramina, and, usually, a presacral mass. Conventional tomograms clarified these bone abnormalities, which were often poorly visible on the plain radiographs. Two radionuclide bone scans showed increased peripheral uptake around the lesion, and one showed decreased uptake in the area of destroyed bone. Angiograms demonstrated only vessel displacement, and barium enemas showed only displacement of bowel by large soft tissue masses. Five myelograms were normal. Adequate surgical treatment of sacral chordomas requires a wide radical resection that avoids contaminating the wound with tumor. Therefore, thorough preoperative radiologic evaluation of the anatomic extent of a chordoma is essential. Although computed tomograms in three patients provided the best delineation of the total extent of bone and soft tissue involvement, tumor extension into gluteal muscles and other tissues eluded radiographic detection. The widespread infiltrative growth pattern along soft tissue planes and nerves and into vessels, undetectable by the above listed studies, mandates a cautious approach and a wide surgical margin, to prevent wound contamination and subsequent recurrence.

Radionuclide bone scanning of osteosarcoma: falsely extended uptake patterns.

The pathologic specimens of 18 osteosarcomas of long bones were examined to correlate histologic abnormalities with abnormalities seen on preoperative 99mTc pyrophosphate or methylene diphosphonate bone scans. Seven scans accurately represented the extent of the tumor. Eleven scans disclosed increased activity extending beyond the radiographic abnormalities. In eight of these, there was no occult tumor extension and in the other three, the scan activity did not accurately portray the skip metastases that were present. Therefore, these 11 scans demonstrated the falsely extended pattern of uptake beyond the true limits of the tumors. Pathologic slides were available for 10 of the 11 areas of bone that exhibited extended uptake. In two instances, there was no pathologic abnormality. In the other eight cases we found marrow hyperemia, medullary reactive bone, or periosteal new bone. This is the first description of these histologic abnormalities of medullary bone in areas of extended uptake on radionuclide bone scans.

Myositis ossificans: radiologic evaluation of two cases with diagnostic computed tomograms.

Although most physicians associated myositis ossificans with recent, acute trauma, only 40%-60% of patients give such a history. The appearance of a soft tissue mass without a clear history of trauma may suggest a diagnosis of sarcoma, especially because results of a biopsy of the central portion of an area of myositis ossificans may yield immature, undifferentiated tissue resembling a sarcoma. Pain and rapid growth of a mass are more usual in myositis ossificans than in sarcomas, and careful inquiry may reveal stretching injury or chronic trauma associated with normal, vigorous, physical activities. Recognizing the characteristic histologic zoning phenomenon (immature tissue centrally surrounded by more mature tissue and a peripheral shell of benign bone) during the biopsy procedure permits the correct diagnosis of myositis ossificans. Plain radiographs or conventional tomograms may reflect this histologic zoning by demonstrating the typical, mature, outer shell of bone. Although additional radiographic studies are not usually necessary, they may be obtained when the mass is suspected to be a sarcoma. In two patients computed tomographic scans clearly demonstrated well-defined, peripheral shells of mature bone, diagnostic of myositis ossificans.