Gallium-67 Citrate Scintigraphy Research Articles

Clinical outcomes of patients with isolated cardiac sarcoidosis confirmed by clinical diagnostic criteria

BackgroundAlthough isolated cardiac sarcoidosis (CS) is not uncommon, little is known about the prognosis. We aimed to clarify clinical features and clinical outcomes in patients with isolated CS. MethodsTwo-hundred eighty-six patients with suspected CS were enrolled. Systemic CS (SCS) was diagnosed by histological or clinical confirmation of sarcoidosis according to the guidelines. Isolated CS was diagnosed by histological or clinical confirmation in the heart alone. The endpoint was cardiac death, hospitalization for heart failure, or fatal ventricular arrhythmia. ResultsTwenty-one patients were diagnosed with isolated CS, and 63 were diagnosed with SCS. The frequencies of diagnostic criteria, such as high-grade atrioventricular block or fatal ventricular arrhythmia, basal thinning of the ventricular septum, left ventricular contractile dysfunction, positive myocardial uptake of gallium-67 citrate scintigraphy or fluorine-18 fluorodeoxyglucose positron emission tomography, and delayed contrast enhancement of cardiac magnetic resonance, were higher or equivalent in patients with isolated CS, compared to those with SCS. Over a median follow-up of 31 months (range: 1–175 months), cardiac death, hospitalization for heart failure, or fatal ventricular arrhythmia occurred in 14 (67%) patients with isolated CS, 24 (38%) patients with SCS, and 63 (31%) patients without CS. The rate of cardiac events was higher in patients with isolated CS (log-rank test, p = 0.01). Cox proportional hazard analysis showed that isolated CS, age, and New York Heart Association functional class were independently associated with cardiac events. ConclusionsPatients with isolated CS have clinical features compatible with SCS, and have cardiac events at a higher rate.

Muscular Sarcoidosis

Muscular sarcoidosis is a granulomatous myopathy of unknown etiology characterized by the presence of non-caseating granulomas associated with sarcoidosis. Asymptomatic muscle involvement is revealed by imaging findings in majority of the patients with muscular sarcoidosis. Symptomatic muscular sarcoidosis, namely sarcoid myopathy, is a rare condition, and three distinct clinical types are recognized: nodular myopathy, acute myopathy, and chronic myopathy. Patients often present with myalgia, progressive weakness, and atrophy of the proximal muscles of the extremities. In order to confirm a diagnosis of sarcoid myopathy and distinguish it from other muscle disorders, muscle biopsy is the most effective and useful method even in the absence of weakness or myalgia. In addition, magnetic resonance imaging, gallium-67 citrate scintigraphy, and fluorodeoxyglucose-positron emission tomography provide significant information for diagnosis. Immunomodulatory therapy, including corticosteroids, plays an important role in preventing progression. However, effective therapeutic strategies for sarcoid myopathy have not been established yet and need to be explored in the future.

Positron Emission Tomography and Single-Photon Emission Computed Tomography Imaging in the Diagnosis of Cardiac Implantable Electronic Device Infection: A Systematic Review and Meta-Analysis.

The use of cardiac implantable electronic devices (CIED) is increasing, and their associated infections result in significant morbidity and mortality. The introduction of better cardiac imaging techniques could be useful for diagnosing this condition and guiding therapy. Our objective was to systematically assess the diagnostic accuracy of Fluor-18-fluorodeoxyglucose positron emission tomography and computed tomography, labeled leukocyte scintigraphy (LS), and Gallium-67 citrate scintigraphy for the diagnosis of CIED infection. A systematic review of the literature and meta-analysis on the use of all 3 modalities in CIED infection were conducted. Pooled sensitivity, specificity, and summary receiver operating characteristic curves of each imaging modalities were determined. The literature search identified 2493 articles. A total of 13 articles (11 studies for 18F-FDG PET-CT and 2 for LS), met the inclusion criteria. No studies for 67Ga citrate scintigraphy met the inclusion criteria. The pooled sensitivity of 18F-FDG PET-CT for the diagnosis of CIED infection was 87% (95% CI, 82%-91%) and pooled specificity was 94% (95% CI, 88%-98%). The summary receiver operating characteristic curve analysis demonstrated good overall accuracy, with an area under the curve of 0.935. There were insufficient data to do a meta-analysis for LS, but both studies reported sensitivity above 90% and specificity of 100%. Both 18F-FDG PET-CT and LS yield high sensitivity, specificity, and accuracy, and thus seem to be useful for the diagnosis of CIED infection, based on robust data for 18F-FDG PET-CT but limited data for LS. When available,18F-FDG PET-CT may be preferred.

SPECT/CT with radiolabeled somatostatin analogues in the evaluation of systemic granulomatous infections.

ObjectiveTo evaluate SPECT/CT with radiolabeled somatostatin analogues (RSAs) in systemic granulomatous infections in comparison with gallium-67 (67Ga) citrate scintigraphy.Materials and MethodsWe studied 28 patients with active systemic granulomatous infections, including tuberculosis, paracoccidioidomycosis, pneumocystosis, cryptococcosis, aspergillosis, leishmaniasis, infectious vasculitis, and an unspecified opportunistic infection. Of the 28 patients, 23 had started specific treatment before the study outset. All patients underwent whole-body SPECT/CT imaging: 7 after injection of 99mTc-EDDA-HYNIC-TOC, and 21 after injection of 111In-DTPA-octreotide. All patients also underwent 67Ga citrate imaging, except for one patient who died before the 67Ga was available.ResultsIn 20 of the 27 patients who underwent imaging with both tracers, 27 sites of active disease were detected by 67Ga citrate imaging and by SPECT/CT with an RSA. Both tracers had negative results in the other 7 patients. RSA uptake was visually lower than 67Ga uptake in 11 of the 20 patients with positive images and similar to 67Ga uptake in the other 9 patients. The only patient who did not undergo 67Ga scintigraphy underwent 99mTc-EDDA-HYNIC-TOC SPECT/CT-guided biopsy of a lung cavity with focal RSA uptake, which turned to be positive for aspergillosis.ConclusionSPECT/CT with 99mTc-EDDA-HYNIC-TOC or 111In-DTPA-octreotide seems to be a good alternative to 67Ga citrate imaging for the evaluation of patients with systemic granulomatous disease.

Fast and simple one-step preparation of 68Ga citrate for routine clinical PET

The imaging of infectious and inflammatory diseases using gallium-67 (⁶⁷Ga) citrate scintigraphy has been a well-established diagnostic tool for decades. In recent times, interest has focused on PET using the short-lived positron emitting radioisotope ⁶⁸Ga. ⁶⁸Ga is not only more readily available, it also provides better quality images whose high resolution permits quantitative analyses, thus improving the management of patients suffering from infections or inflammation. The purpose of our study was to develop a fast and reliable synthesis protocol for the preparation of ⁶⁸Ga citrate under good manufacturing practice aspects without the use of organic solvents. A commercially available synthesis module was used to perform 10 syntheses with an average yield of 768 ± 31 MBq (mean ± SD) within 10 min; 92.04 ± 1.23% of the radioactivity was located in the product vial, and the rest on the cation exchange cartridge (7.48 ± 1.23%) and in the waste vial (0.47 ± 0.28%). The radiochemical purity of the product determined by instant thin-layer chromatography was greater than 99%. The products have been proven to be sterile and pyrogen-free. Variations were made in several critical synthesis parameters, and the results are presented herein. By eliminating the use of organic solvents, the previously required quality control testing of the final product by gas chromatography can be abandoned. This novel, high-yielding method allows for a more efficient synthesis of ⁶⁸Ga citrate with both shorter production time and high radiochemical purity.

Value of Gallium-67 Scanning in Monitoring Therapeutic Effectiveness in a Patient with Relapsing Polychondritis

We present a 57-year-old man who had low-grade fever and painful, swollen and erythematous ears. Gallium-67 citrate scintigraphy (gallium scan) performed prior to the commencement of treatment showed increased gallium uptake in bilateral external ears, neck, mediastinum and bilateral pulmonary hili. The results of ultrasonography of both ears were compatible with the diagnosis of chondritis. The patient's clinical condition and laboratory data improved after a course of nonsteroidal anti-inflammatory drugs and steroids. Gallium scan performed after treatment showed a diminished uptake in the external ears, neck, and mediastinum. Gallium scintigraphy is a valuable tool for evaluating inflammatory activity and monitoring therapeutic response in patients with relapsing polychondritis.

Relationship between arrhythmogenesis and disease activity in cardiac sarcoidosis

In patients with cardiac sarcoidosis, ventricular arrhythmias and/or conduction disturbances are frequently observed and sometimes fatal. However, few reports on disease activity and arrhythmic events in cardiac sarcoidosis are available. The purpose of this study was to investigate the relationship between disease activity and arrhythmic events in cardiac sarcoidosis and the effect of corticosteroid therapy. The study population consisted of 15 cardiac sarcoidosis patients with new-onset symptomatic arrhythmia, including eight patients admitted once for complete atrioventricular block (CAVB), five patients admitted once for sustained ventricular tachycardia (VT), and two patients admitted twice for two arrhythmic events (one for CAVB and the other for sustained VT). Disease activity was evaluated by gallium-67 citrate (Ga) scintigraphy. All patients with positive Ga uptake were treated with corticosteroids, and arrhythmic events were evaluated by repeat Holter recordings. Positive uptake of Ga was observed in 8 (80%) of the 10 CAVB events and in 1 (14%) of the 7 sustained VT events (80% vs 14%, P = .02). Corticosteroids abolished myocardial Ga uptake in all nine patients with positive Ga uptake. After corticosteroid therapy was started, AV conduction improved in 5 of 9 CAVB patients (including 8 patients with new-onset CAVB and one patient with history of CAVB). However, ventricular arrhythmias were not improved after corticosteroid therapy. In cardiac sarcoidosis patients, CAVB develops mainly during the active phase of the disease. Early treatment with corticosteroids might improve AV conduction disturbance. However, sustained VT is not closely linked with disease activity and frequently develops in the advanced stage of disease.

Adult-onset Still's Disease: Evaluation by Gallium-67 Citrate Scintigraphy

Adult-onset Still's Disease: Evaluation by Gallium-67 Citrate Scintigraphy

Mismatch between gallium-67 uptake and CT findings in a case of pulmonary alveolar proteinosis

Gallium-67 citrate (67Ga) scintigraphy has been used as an indicator of activity of diffuse interstitial lung diseases. However, little has been mentioned in pulmonary alveolar proteinosis (PAP). Here we present a 53-year-old man with PAP showing patchy 67Ga uptake by single photon emission computed tomography (SPECT). Interestingly, the strong 67Ga uptake was observed in areas where ground-glass opacities were faint on chest CT. The uptake persisted after whole-lung lavage while the ground-glass opacity improved markedly. Although the precise mechanism of 67Ga uptake remains unclear, 67Ga SPECT findings may reflect the different pathological condition of PAP than that shown by CT.

FDG PET and Gallium Scintigraphy for Diagnosis of An Advanced Jejunal Adenocarcinoma With Distant Metastases

The authors report a case of jejunal adenocarcinoma with distant metastases for which FDG PET succeeded in detecting the primary lesion and metastatic deposits. There were metastatic lymph nodes in the thorax and abdomen,but the primary lesion was unknown. Gallium-67 citrate scintigraphy was useful for visualizing the metastases in the thorax, but imaging was limited by physiologic accumulation in the liver and intestine. FDG PET showed all the metastases and suggested the primary site. FDG PET appears to be helpful in the diagnosis of jejunal adenocarcinomas.

Comparison of FDG-PET and Ga-67 Scintigraphy in the Evaluation of Lymphoma and Its Relationship to the Pathologic Diagnosis Using WHO Classification System.

In the management of lymphoma patients, 18fluoro-2-deoxyglucose positron emission tomography (FDG-PET) has emerged as an important tool. However there are conflicting results that have been reported concerning its usefulness in different histological subtypes, especially in indolent lymphomas. The aim of this study was to retrospectively assess and compare the sensitivity of FDG-PET with gallium-67 citrate scintigraphy (Ga-67) with regard to the capacity for identification of disease involvement in patients with malignant lymphoma, and to investigate the relationship with the World Health Organization's (WHO) classification system for pathological diagnosis of such cases.We contemporaneously performed 100 cases of FDG-PET and Ga-67 in addition to CT scans and/or MRIs prior to the treatment. Histological diagnoses included diffuse large B-cell lymphoma (DLBCL; n=38), MALT lymphoma (MALT; n=29), follicular lymphoma (FL; n=14), Hodgkin lymphoma (HL; n=8), NK lymphoma (NK; n=2), mantle cell lymphoma (MCL; n=2), Burkitt lymphoma (Burkitt; n=2), splenic marginal zone lymphoma (SMZL; n=2), and one case each with anaplastic large cell lymphoma (ALCL), peripheral T cell lymphoma (PTCL) and small lymphocytic lymphoma (SLL).In the 100 lymphoma cases, FDG-PET was unable to detect at least one of the disease involvement sites for 2/38 in DLBCL, 3/14 in FL, 1/8 in HD, 11/29 in MALT, 2/2 in SMZL, and 1/1 in SLL. FDG-PET detected more involvement sites than Ga-67 with 11/38 in DLBCL, 6/14 in FL, 4/8 in HL, 7/29 in MALT, 2/2 in MCL, and 1/2 in NK. In contrast, Ga-67 was more informative in two cases of MALT and in one case of SMZL, in which the regions included the eyelid, pleura and spleen.During the lymphoma imaging that was done before therapy, FDG-PET was highly sensitive in aggressive and high-grade lymphoma patients as compared to seen for Ga-67. In contrast, FDG-PET seemed to be more informative in FL with regard to indolent lymphomas, but was especially less reliable in MALT and SMZL. Anatomical imaging from CT scans and MRIs were useful in that they provided additional helpful information for the FDG-PET results in the lymphoma subgroups.Result of FDG-PET and Ga scintigraphyCT positiveCT positiveHistologyNo. of casesPET negativeGa negativeALCL100Burkitt201DLBCL38213FL1438HL815MALT291114MCL202NK201peripheral T100SLL111SMZL221

The use of radionuclide-labeled white blood cell scintigraphy and 67gallium scintigraphy in critically ill patients with sepsis

The usual diagnostic approach to patients with sepsis in an intensive care unit (ICU) or coronary care unit is based on clinical, biochemical, microbiologic and pathologic data and on radiologic imaging (radiograph, ultrasound and computed tomography), which are used to determine the most common sites of infection. In many cases, however, the site of infection is difficult to determine. Nuclear medicine provides various noninvasive scintigraphic methods for the imaging of focal sepsis, based on the intravenous administration of a radiotracer that accumulates at the site of infection or inflammation. The combined use of total body scintigraphy with ultrasound and computed tomography is considered a useful tool for the diagnosis of occult sepsis in ICU patients, and allows the targeting of aggressive measures against infections. The aim of this study is to evaluate the diagnostic value of technetium 99 m-white blood cell (99mTc-WBC)-labeled scintigraphy and gallium-67 citrate (67Ga) scintigraphy in the detection of focal sepsis in the ICU. We reviewed seven patients affected by sepsis of unknown origin. After the usual diagnostic approach, five patients were submitted to a total body scan using the 99mTc-WBC and two patients using 67Ga. The patients had complete clinical and instrumental data, but none of the radiological image detected the site of infection. The 99mTc-WBC scan showed typical patterns of increased tracer accumulation in six different sites. Four of these sites were studied histopathologically, confirming the infection: one case of left kidney abscess was associated with concomitant infection of the psoas muscle in the same patient, one frontoparietal osteomyelitis, and one acute cholecystitis. The other two sites corresponded to pulmonary accumulation of the tracer, which was interpreted as pneumonia. Of the two patients who underwent 67Ga scintigraphy, one had decubitus ulcerated infection associated with sacrum and left femoral osteomyelitis, and the other had clinical suspect of pulmonary vasculitis and diffuse pulmonary 67Ga accumulation.

Comparison of 18F-fluoro-2-deoxyglucose positron emission tomography and gallium-67 citrate scintigraphy for detecting malignant lymphoma

This study evaluates and compares the accuracy of positron emission tomography with 18F-fluoro-2-deoxyglucose (FDG-PET) and gallium-67 citrate (Ga-67) scintigraphy in identifying disease sites in patients with malignant lymphoma at initial diagnosis or relapse. Histology subgroups included low (n=5), intermediate (n=6), high-grade (n=5) non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD) (n=14). Ann-Arbor staging included 7 patients in stage I, 8 in stage II, 9 in stage II, 6 in stage IV and 11 extra-nodal. In this study, before any therapy, 25 contemporaneous FDG-PET and Ga-67 scintigraphies were performed on patients with either NHL (16) or HD (14). One hundred and eleven sites of disease were correlated on a site-by-site basis in corresponding areas of FDG-PET and Ga-67 scintigraphy. Discordant FDG-PET and Ga-67 scintigraphic findings were correlated with CT/MRI and clinical evaluation. FDG-PET detected malignant lymphoma in 24/25 patients (sensitivity: 96.0%). There was a false-negative FDG-PET result in only 1 patient with low-grade gastric malignant lymphoma. Ga-67 scintigraphy detected malignant lymphoma in 18/25 patients (sensitivity: 72.0%). There were false-negative Ga-67 scintigraphic results in 4 cases with low-grade non-Hodgkin's lymphoma, 2 cases with bone or bone marrow involvement, and 3 smaller disease sites. FDG-PET upstaged 6 patients in whom Ga-67 scintigraphy detected disease sites partially. In imaging lymphoma prior to therapy, FDG-PET had a higher sensitivity and detected significantly more disease sites when compared with Ga-67 scintigraphy in the initial evaluation of this group of patients. Upstaging of patients with FDG-PET may result in a change in treatment strategy. However, evaluation of the final sensitivity, specificity and accuracy of these imaging modalities will need a further study with a larger patient number.

Gallium-67 citrate accumulation in sinonasal regions

A 55-YEAR-OLD MAN who manifesting nasal obstruction, nasal discharge/rhinorrhea, epistaxis, blurred vision, headache, toothache, fever, weight loss, and drenching night sweats was admitted to our hospital for survey and treatment. On admission, elevated serum lactic dehydrogenase level and Epstein-Barr virus immunoglobulin G (IgG) titer were found. Gallium-67 citrate scintigraphy was performed. The scintigraphic findings showed intense gallium-67 citrate accumulation in the sinonasal regions (48 hours) (Fig 1). Biopsies of the lesion in the nasal cavity were then performed. The final pathological diagnosis was sinonasal non-Hodgkin's lymphoma with diffuse large cells. Causes of gallium-67 citrate accumulation in sinonasal regions are as follows. Common 1. Normal distfibutionm 2. Sinusitis 3,4 Uncommon 1. Carcinoma 3-5 2. Osteomyelitis 4,6 3. Sarcoidosis 7,8 4. Sinonasal malignant lymphoma 1,9 Rare 1. Aspergillosis 1~

Primary malignant melanoma (clear cell sarcoma) of bone: Report of a case arising in the ulna

To the authors' knowledge, there has been no previous report of primary malignant melanoma of bone. A 33-year-old woman presented with a tumorous lesion in the olecranon of the right ulna. The histologic diagnosis was malignant melanoma with close similarity to clear cell sarcoma. To exclude the possibility of malignant melanoma metastatic to the bone, clinical investigations including gallium 67-citrate scintigraphy, brain, chest, and abdominal computed tomography, and upper and lower gastrointestinal endoscopic examinations were performed. Conventional histopathologic, immunohistochemical, and electron microscopic studies were also performed. Clinical investigations showed no lesion suggestive of a primary melanoma other than that in the right ulna. Histologically, the tumor was comprised of polygonal or fusiform cells with clear or granular cytoplasm and vesicular nuclei containing one or two prominent nucleoli. The features were similar to those of clear cell sarcoma (malignant melanoma of soft parts). Fontana preparations and immunohistochemical staining for S-100 protein and HMB-45 (melanoma specific antigen) also revealed that the tumor cells had the characteristics of malignant melanoma. The patient has remained alive and well for more than 5 years after the initial treatment. The clinicopathologic findings in this case strongly suggested that the lesion was a primary malignant melanoma of bone. Therefore, this is the first report to indicate that malignant melanoma and related diseases can occur even in bone tissue.

Myocardial gallium-67 citrate scintigraphy in patients with systemic sclerosis.

To detect myocardial involvement in 16 patients with systemic sclerosis using radiogallium scintigraphy Sixteen patients with systemic sclerosis were investigated by myocardial gallium-67 citrate scintigraphy. Echocardiographic studies and (in the positive cases) magnetic resonance imaging were also performed. Increased myocardial gallium uptake was found in five of the 16 patients. None of these positive cases exhibited any 'classical' clinical, electrocardiographic or laboratory signs characteristic of myocarditis. The mean age of the positive cases was 60.8 (SD 5.0) years compared with 44.6 (10.7) years for the negative cases; no difference was detected in the mean disease duration between these two groups. Two of the affected cases belonged to the limited scleroderma subgroup. In spite of the low number of patients investigated, it is tempting to speculate that elderly patients with a disease onset around 60 years tend to be the candidates in whom a positive gallium-67 scintigraphy test may best indicate a silent myocardial interstitial inflammation.

Comparison of Thallium-201 and Gallium-67 Citrate Scintigraphy in the Diagnosis of Pulmonary Disease

Gallium is presently used in the diagnosis of inflammatory, granulomatous, and neoplastic lung disease despite its many logistical problems. In contrast, thallium-201 scintigraphy, which was initially developed for myocardial imaging, offers the principal advantage of immediate imaging and diagnosis although it had not been investigated previously for use in pulmonary disease. In this study, thallium and gallium were prospectively compared with each other for the diagnosis of a variety of lung diseases. The overall concordance rate was 75%. Thallium was found to be significantly more sensitive than gallium for the entire group studied (N = 51, p < 0.006). In a subset of patients in whom a firm diagnosis was established, thallium was also found to be more sensitive, 86% vs 64%. The greater sensitivity of thallium-201 and its several inherent advantages suggest that thallium-201 should replace gallium-67 citrate as the radioisotope of choice for nuclear imaging of the chest.

Soft-tissue tumors: diagnosis with Tc-99m (V) dimercaptosuccinic acid scintigraphy.

To assess the potential of technetium-99m (V) dimercaptosuccinic acid (DMSA) scintigraphy for diagnosis of soft-tissue tumors. Tc-99m (V) DMSA scintigraphy was performed in 76 patients with histologic proof of soft-tissue tumors. In 57 of these patients, gallium-67 citrate scintigraphy was performed within 2 weeks after Tc-99m (V) DMSA scintigraphy. Uptake of Tc-99m (V) DMSA was clearly detected in almost all sarcomas, metastatic carcinomas, highly recurrent benign tumors (ie, extra-abdominal desmoids and tenosynovial giant cell tumors), superficial and deep hemangiomas, and granulomatous soft-tissue lesions but was not found in other benign solid tumors of soft tissue. Uptake of Ga-67 citrate was clearly detected in all inflammatory lesions and metastatic carcinomas, eight of 14 sarcomas (57%), and two of 10 highly recurrent benign tumors (20%) but was not found in hemangiomas or benign soft-tissue tumors. Low-grade malignant and highly recurrent benign lesions, which often recur after surgery, were detected more accurately with Tc-99m (V) DMSA scintigraphy than with Ga-67 citrate scintigraphy.

USEFULNESS OF 67Ga SCINTIGRAPHY IN LUNG CANCER

Gallium-67 citrate scintigraphy (67Ga scintigraphy) was evaluated in 305 patients with lung cancer. The positive rate among 135 patients, in whon the radiation doses were less than 10Gy when 67Ga scintigraphies were performed, was 76% ; positive rates for small cell carcinomas, poorly differentiated epidermoid carcinomas and large cell carcinomas were higher (>90%), while positive rate for well differentiated adenocarcinomas was the lowest (57%).The positive rates for poorly differentiated types of epidermoid carcinomas and adenocarcinomas were higher than those of well differentiated types. No relation between 67Ga accumulation and tumor diameter was recognized within the range of tumor diameter from 30 mm to 100mm. In small cell carcinomas and well differentiated adenocarcinomas, the cases that showed high 67Ga accumulation tended to decrease according to increase of radiation dose. But there were many cases that showed high 67Ga accumulation when radiation dose increased in other histologic types. In 86% of cases with atelectasis or pleural effusion or inflammatory change, 67Ga scintigraphy was useful for differentiating the extent of tumor from these changes. 67Ga scintigraphy appeared to assist the differential diagnosis of histologic types of lung cancer, and to be useful for evaluation of the extent of tumor.

Gallium-67 citrate scintigraphy in the pre-operative evaluation of soft tissue tumors of the extremities

We conducted a study of 90 patients with soft tissue tumor in their arms or legs, in order to determine the usefulness of scintigraphy with gallium-67 citrate as a diagnostic means. All patients had adequate scan images, and tumor tissues had been histologically confirmed by surgical resection. The subjects consisted of 19 patients with malignant tumors, 55 patients with benign tumors, and 16 patients with other disorders in which soft tissue tumor-like lesions occurred. When the activity of the tumor was more than the activity of the normal region of the contralateral extremity, it was estimated to be positive. The positive rate was found in 78% (15/19) of patients with malignant tumors, in 25% (14/55) of patients with benign tumors and in 31% (5/16) of patients with other disorders. Classified by diseases, high positive rates were observed in liposarcoma, leiomyosarcoma, malignant lymphoma, neurinoma, extra-abdominal desmoid and sarcoidosis. Out of 7 patients in which the activity of the tumor was equal to, or higher than that of the liver, 6 patients had malignant tumors and one patient was diagnosed as having an abscess. It seemed possible to distinguish between liposarcoma and lipoma by means of a gallium-67 scan. Furthermore, the gallium-67 scan was useful in detecting lesions of sarcoidosis as well as in evaluating the response to treatment.