The role of Tc-99m MDP and Ga-67 citrate in predicting the cure of osteomyelitis

Twenty rabbits with chronic osteomyelitis of the tibia were treated for eight weeks and then scanned with Tc-99m MDP and Ga-67 citrate. All were sacrificed and bacteriologic cultures of the tibia were obtained. All rabbits had positive Tc-99m MDP scans at the end of treatment despite thirteen cures of osteomyelitis. Eight had negative gallium scans and negative cultures. Five of the twelve positive gallium scans had negative cultures, while seven had positive cultures. Tc-99m MDP alone is not sensitive enough to be useful in predicting the cure of osteomyelitis, and combining Tc-99m MDP and Ga-67 citrate scintigrams offers no additional information over the Ga-67 citrate scintigram alone in follow-up of osteomyelitis.     

Detectability of metastatic bone tumor by Ga-67 scintigraphy

Ga-67 scintigrams in patients with malignant diseases sometimes reveal uptake of the tracer in the bone metastases. Detectability of Ga-67 scintigraphy for metastatic bone tumors and benign bone lesions was compared with that of Tc-99m bone scintigraphy. Countable bone metastases detected by bone scintigraphy were evaluated whether the lesion showed apparent, faint, or negative Ga-67 uptake. Of 47 lesions 23 (49%) showed apparent uptake and 17 (36%) showed negative uptake. On the other hand, of 71 benign bone lesions, only 7 (10%), mostly fracture/osteotomy, showed apparent uptake of the tracer. Uptake in the other benign lesions such as trauma of the ribs, spondylosis deformans, and arthrosis deformans was rather faint. In patients with multiple bone metastases, 9 patients (82%) out of 11 showed more prominent abnormal findings in Tc-99m MDP bone scintigraphy than in Ga-67 scintigraphy; that is, Ga-67 scintigraphy was not able to reveal all metastatic bone lesions. In patients with untreated or recurrent tumors, relation between Ga-67 uptake in the tumors and that in the bone metastases was evaluated. Of 7 patients with negative Ga-67 uptake in the primary tumors, 5 showed positive Ga-67 uptake in the bone metastases; that is, there seemed to be little relation between Ga-67 affinity to the primary tumors and that to the bone metastases. Mechanisms of the Ga-67 uptake in the bone metastases were discussed. Not only the tumor cells or tissues in the bone metastases but also bone mineral or osteoclasts might be the deposition sites of Ga-67.     

Comparison of Tc-99m HIG and Ga-67 citrate in the evaluation of bacterial abscess in a rat model

Tc-99m labeled polyclonal human immunoglobulin (HIG) has been shown to be able to localize an inflammatory site. There are several possible explanations for HIG accumulation at focal infection sites such as increased vascular permeability, binding of the Fc part of Ig to Fc receptors of leucocytes and binding directly to bacteria. In this study, we compared Tc-99m HIG and Ga-67 citrate scintigraphy in localizing acute bacterial abscesses induced byE. coli andS. aureus. Serial scintigrams were performed at 1, 4, 24 hr after injection. Tc-99m HIG showed greater accumulation at all times with both infectious agents than Ga-67 citrate (p < 0.05). While Tc-99m HIG showed greater accumulation inS. aureus thanE. coli (p < 0.05), there was no statistically significant difference betweenE. coli andS. aureus (p > 0.05) by Ga-67 citrate. Our study suggests that Tc-99m HIG is a superior agent to Ga-67 and bacterial affinity can be a factor responsible for HIG accumulation at focal sites of inflammation.     

Combined bone marrow and gallium imaging. Differentiation of osteomyelitis and infarction in sickle hemoglobinopathy

The clinical records and scintigrams of patients with sickle hemoglobinopathy who underwent combined Tc-99m bone marrow imaging and Ga-67 imaging to differentiate osteomyelitis from bony infarction were reviewed. Of 18 paired examinations in 15 patients, osteomyelitis was diagnosed correctly in six cases; in all six, gallium uptake at the symptomatic site was incongruently increased relative to the bone marrow activity. Of the 12 episodes of infarction, 11 showed congruent activity on both Tc-99m and Ga-67 images. The remaining study was interpreted incorrectly as osteomyelitis due to incongruent Tc-99m and Ga-67 uptake. The use of sequential Tc-99m bone marrow and Ga-67 imaging is an effective means of distinguishing osteomyelitis from bony infarction in patients with sickle hemoglobinopathy.     

Comparative evaluation of technetium-99m glucoheptonate and gallium-67 citrate thoracic imaging in detection of mediastinal and hilar involvement in primary lung cancer

Fifty-two patients with proven primary lung cancer who were referred for mediastinoscopy were prospectively studied with Tc-99m glucoheptonate and Ga-67 citrate thoracic scintigraphy. Primary lung tumors concentrated Ga-67 in 92% of cases, compared to 88% for Tc-99m glucoheptonate. Mediastinoscopy confirmed the presence of mediastinal metastases in 23 patients. The sensitivity of Tc-99m glucoheptonate and Ga-67 scans for mediastinal involvement detection is respectively 52% and 83%, for a specificity of 100% (Tc-99m glucoheptonate) and 88% (Ga-67). Twenty-nine patients underwent thoracotomy after a negative mediastinoscopy. Hilar metastatic involvement was present in eight patients. The sensitivity and the specificity for detection of hilar involvement were respectively 63% and 95% for Tc-99m glucoheptonate and 88% and 78% for Ga-67. Although more specific than Ga-67 scan, Tc-99m glucoheptonate thoracic imaging cannot be recommended in the staging of lung cancer because of its low sensitivity in the detection of intrathoracic metastatic spread of primary lung carcinoma.     

Accumulation of Tc-99m MIBI in breast lymphoma: Comparison with Ga-67 citrate

We report 2 cases of malignant lymphoma of the breast which were clearly shown on total body imaging as well as on SPECT with Ga-67 and Tc-99m MIBI. Tumor accumulation of Ga-67 was seen in all cases including a recurrent tumor. Ga-67 scintigraphy is useful for follow up in detecting relapse, as well as in predicting responses to therapy. Tc-99m MIBI was found to accumulate in the malignant lymphoma of the breast, and especially SPECT images of breast lesions provided better contrast than planar images, and Tc-99m MIBI SPECT could diagnose localization of the tumor because there was no uptake by the breast. But the Tc-99m MIBI accumulation of the tumor was lower than Ga-67.     

Primary Ewing sarcoma: follow-up with Ga-67 scintigraphy

While avid accumulation of gallium-67 citrate and technetium-99m methylene diphosphonate (MDP) occurs initially in most cases of primary Ewing sarcoma, uptake after therapy is less well defined. Thirty patients with Ewing sarcoma who underwent Ga-67 and bone scintigraphy at diagnosis, at completion of therapy, and at relapse from 1978 to 1988 were evaluated. All 30 patients showed less primary site Ga-67 activity following therapy. Twenty-three of 28 patients who underwent corresponding bone scintigraphy showed less uptake, but residual activity was usually more intense than with Ga-67. Avid reaccumulation of Ga-67 occurred in four of five patients with primary site relapse, while patients who underwent bone scintigraphy showed less change. It was concluded that a greater decrease in Ga-67 than in Tc-99m MDP uptake often occurs in patients successfully treated for primary Ewing sarcoma. Information obtained at Ga-67 scintigraphy is most likely to be helpful if results of bone scintigraphy remain abnormal or if occult relapse is suspected.     

Multifocal Pott's disease (tuberculous spondylitis) incidentally detected on Tc-99m MDP bone and Ga-67 citrate scintigraphy in a patient with diabetes

Pott's disease is an uncommon extrapulmonary form of tuberculosis. Delay in diagnosis and management may cause serious complications. The authors describe Pott's disease incidentally detected on Tc-99m MDP bone and Ga-67 imaging in a patient with diabetes. Tc-99m MDP bone scintigraphy showed intensely increased uptake in the lower cervical spine and lumbosacral regions. Ga-67 scintigraphy revealed intensely increased uptake corresponding to the areas noted on Tc-99m MDP bone scintigraphy. Magnetic resonance imaging showed destructive lesions in the C5-C6 and L5-S1 intervertebral discs with destruction of adjacent end plates. Biopsy of the lumbosacral area was guided by computed tomography, and histologic examination of the bone specimen showed caseation, giant cells, and acid-fast bacilli. Posterior decompression and posterolateral spinal fusion with bone grafts were performed. Antituberculous chemotherapy with isoniazid, rifampicin, pyrazinamide, and ethambutol was started. The patient showed remarkable relief of symptoms during a period of 9 months of therapy. Both Tc-99m MDP bone and Ga-67 imaging can offer the convenience of screening the entire body to detect multiple sites of Pott's disease.     

Osteoblastic osteosarcoma of the mandible: findings on Tc-99m HMDP bone and Ga-67 citrate scintigraphy

A 25-year-old woman presented with a disturbance in the opening of her mouth 5 months before admission. On admission, painful swelling of the right preauricular region was revealed. Computed tomography (CT) demonstrated a soft tissue density mass around the right condylar process of the mandible. Tc-99m hydroxymethylene diphosphonate (HMDP) bone scintigraphy and Ga-67 citrate scintigraphy showed avid uptake in the mass. The tumor was histologically identified as an osteoblastic osteosarcoma of the right mandible. There are few reports of Ga-67 citrate scintigraphy findings of osteoblastic osteosarcoma of the mandible. The accumulation patterns on Tc-99m HMDP bone scintigraphy and Ga-67 citrate scintigraphy are possibly characteristic of osteoblastic osteosarcoma of the mandible.     

Observations on the sequential use of Tc-99m phosphonate and Ga-67 imaging in untreated primary and secondary malignant tumors of the head and neck

Scintigraphy using both Tc-99m phosphonate and Ga-67 was performed in 55 cases of untreated primary and secondary tumors of the head and neck. In 21 patients with primary tumors of jaws, eye, tongue, or parotid gland, Ga-67 scintigraphy visualized the primary tumor in all cases and metastases in 12. Scintigraphy using Tc-99m phosphonate disclosed primary bone involvement in 12 cases and skeletal metastases in two. In eight of 13 patients with metastatic lesions of jaws and skull, bone scintigraphy showed skeletal metastases. In seven of these patients, Ga-67 scintigraphy detected the primary tumor and in 11 cases detected metastases. Bone scintigraphy disclosed skeletal metastases in six of 21 patients with malignant neck tumors. In 13 of these patients, Ga-67 scintigraphy visualized the primary tumor, whereas it showed metastases in seven. It is concluded that Ga-67 scintigraphy should be used in the investigation of untreated primary or secondary malignant tumors of the head and neck. Bone scintigraphy may be indicated as an additional study in selected cases only.     

Gallium-67 myocardial imaging for the detection of adriamycin cardiomyopathy

To detect Adriamycin cardiomyopathy, radionuclide myocardial imagings with Tl-201, Tc-99m pyrophosphate, I-123 metaiodobenzylguanidine and Ga-67 were performed in a 49 year-old-woman receiving Adriamycin (a total dose of 230 mg/m2) for the treatment of breast cancer. This patient demonstrated symptoms of congestive heart failure 2 months after the last intravenous administration. At the period of performing the radionuclide studies, echocardiographic LV ejection fraction (EF) was 22%. Despite severe deterioration of cardiac function, Tl-201 SPECT demonstrated no defect and Tc-99m pyrophosphate (PYP) SPECT demonstrated no positive finding. I-123 metaiodobenzylguanidine (MIBG) scintigraphy demonstrated no regional defect. However, I-123 MIBG washout rate during 4 hours was markedly enhanced, probably reflecting abnormalities of norepinephrine kinetics due to the progression of heart failure. Compared to these pharmaceuticals, Ga-67 was diffusely accumulated in the heart. Then, 5 months after the first study, when LV EF improved to 30% and congestive symptoms disappeared probably owing to beta-blockade therapy, myocardial accumulation of Ga-67 markedly reduced. It has been reported that Ga-67 accumulates in malignant tumor cells and leukocytes. Since, in Adriamycin cardiomyopathy, myocardial accumulation of leukocytes with myocardial fibrotic changes have been histologically demonstrated, the results of Ga-67 scintigraphy may reflect the accumulation of leukocytes. Thus, this case indicates that Ga-67 scintigraphy is advantageous for detecting Adriamycin cardiomyopathy and may be more useful than Tl-201 and Tc-99m PYP scintigraphies.     

Technetium-99m-DTPA aerosol scintigraphy in amiodarone induced pulmonary toxicity in comparison with Ga-67 scintigraphy

Amiodarone hydrochloride, which is used in life-threatening cardiac tachyarrhythmia, has been known to cause amiodarone induced pulmonary toxicity (AIPT) as a complication. In this study we aimed to investigate the clinical value of technetium-99m diethylene triamine penta-acetic acid (DTPA) aerosol lung scintigraphy in patients with AIPT in comparison with gallium-67 (Ga-67) scan. The study group included 26 cases, 7 patients with diagnosis of AIPT (Group A), 8 patients receiving amiodarone therapy but without AIPT (Group B) and 11 healthy subjects as a control group (Group C). All patients underwent Ga-67 and Tc-99m-DTPA aerosol scintigraphy in addition to various laboratory tests, Ga-67 scintigraphy was positive in 4 of 7 AIPT patients but quite normal in Group B. A positive correlation was found (r = 0.52, p < 0.05) between kep values determined by Tc-99m-DTPA aerosol scintigraphy and the cumulative dose of amiodarone. The mean kep values were 2.04% +/- 0.85%/min, 1.30% +/- 0.42%/min and 0.86% +/- 0.19%/min for groups A, B and C, respectively. The mean clearance rate of group A was significantly faster than that of normals (p < 0.0005) and group B (p = 0.028). In addition, there was a significant difference between groups B and C (p = 0.015). In conclusion, Ga-67 lung scintigraphy is a useful method for the detection of AIPT but Tc-99m-DTPA aerosol scintigraphy offers better results than Ga-67 scintigraphy. Early changes in Tc-99m-DTPA clearance may be observed in patients receiving amiodarone. The kep value in patients with AIPT is noticeably increased with respect to the control group. With its favorable physical properties, low cost, lower radiation burden and its ability to be used as an objective measure for the pulmonary clearance rate, Tc-99m-DTPA aerosol scintigraphy appears to be promising in patients receiving amiodarone therapy.     

Simultaneous demonstration of pleural effusion and ascites by technetium-99m sulfur colloid liver-spleen scintigraphy

Scintigraphic evidence of ascites has been observed in Tc-99m sulfur colloid studies of the liver and spleen, in Tc-99m HIDA hepatobiliary scans, in Ga-67 citrate scans, and in Tc-99m phosphonate bone images. Pleural effusion has been demonstrated in Tc-99m phosphonate bone scintigraphy. The case of a 48-year-old man whose Tc-99m sulfur colloid liver-spleen scintigram simultaneously demonstrated a right pleural effusion and ascites is presented.     

Poor accumulation of technetium-99m glucoheptonate in sarcoidosis and other diffuse infiltrative lung diseases as compared with gallium-67 citrate

Forty-two patients with diffuse infiltrative lung diseases were imaged with Ga-67 citrate and Tc-99m glucoheptonate (GH). Twenty patients had sarcoidosis, six had fibrosis, six had tuberculosis, nine had lung infiltration, and one had pleural empyema. The main difference between Ga-67 and Tc-99m GH was the much greater uptake of Ga-67 in sarcoidosis than that of Tc-99m GH. Fifteen patients with sarcoidosis had positive Ga-67 scans but only six had positive Tc-99m GH scans. The results in other diffuse infiltrative lung diseases were almost equal with Ga-67 and Tc-99m GH. Although Tc-99m GH is less expensive and simpler to use, it is not an adequate substitute for Ga-67 in diffuse infiltrative lung diseases.     

Scintigraphic findings in a primary cerebral amyloidoma

Bone, brain, and gallium scintigrams are presented of a 48-year-old man with biopsy-proven cerebral amyloidosis. Brain scintigraphy revealed a well-circumscribed accumulation of Tc-99m pertechnetate in the amyloidoma. Bone scintigraphy using Tc-99m methylenediphosphonate likewise exhibited increased activity in the same area. Gallium-67 citrate, however, failed to localize within the amyloidoma.     

Dual isotope scanning with gallium-67 citrate and technetium-99m radiopharmaceuticals

The interpretation of Ga-67 scans is limited by the complex anatomic and physiologic distribution of Ga-67 and by the low resolution possible with this isotope. The use of a second isotope Tc-99m, tagged to an appropriate pharmaceutical allows the identification of anatomic landmarks. Computer acquisition of both the Ga-67 and Tc-99m images allows for subtraction of the Tc-99m images from the Ga-67 images and leads to precise localization of abnormal Ga-67 accumulations. Only a small percentage of the counts in the Tc-99m window are due to Ga-67 scatter and do not degrade the Tc-99m images. Cases illustrating the value of the dual-isotope technique are presented.     

Subacute and chronic bone infections: diagnosis using In-111, Ga-67 and Tc-99m MDP bone scintigraphy, and radiography

The usefulness of indium-111 white blood cell scintigraphy in the diagnosis of subacute or chronic bone infection was examined in 21 orthopedic patients. In-111 WBC imaging was compared with gallium-67 and technetium-99m methylene diphosphonate skeletal scintigraphy and bone radiography, all studies being performed within 1 week. In-111 WBC scintigraphy showed no definite advantage over Ga-67 scintigraphy in the identification of chronic bone infection. The two tests had the same sensitivity (80%) and similar specificity (In-111 WBC 75%, Ga-67 83%; difference not significant). Bone radiography had a sensitivity of 60% and a specificity of 67%. A negative Tc-99m MDP bone scintigram ruled out infection (sensitivity 100%), but because of low specificity (25%), final evaluation required performance of Ga-67 or In-111 WBC scintigraphy.     

Ga-67 citrate scintigraphy for the early detection of radiation pneumonitis.

To evaluate the usefulness of Ga-67 citrate scintigraphy in the early detection of radiation pneumonitis, scintigrams from 103 patients who were treated with radiation therapy for lung cancer were retrospectively analyzed with regard to abnormal Ga-67 uptake after radiation therapy in sites other than the original or recurrent tumors. Sixteen (20%) of the 80 asymptomatic cases showed positive Ga-67 scintigrams. All of the other 23 symptomatic cases showed positive Ga-67 scintigrams. Thirteen (57%) of these 23 cases had negative chest radiographs although their Ga-67 scintigrams were positive. Detection of radiation pneumonitis by Ga-67 scintigraphy was significantly earlier than that possible by chest radiography (P less than 0.01). These data suggest that Ga-67 scintigraphy is more useful and sensitive than chest radiography for the early detection of radiation pneumonitis.     

The value of Tc-99m (V) dimercaptosuccinic acid in detecting intra-abdominal infection: compared with gallium scan

Objective Gallium-67 (Ga-67) and labeled leukocytes are useful in the detection of an unknown infectious source. However, the delay in the diagnosis of a Ga-67 citrate scan (gallium scan) and the complicated labeling technique of a leukocyte scan are major drawbacks to their clinical use. Recently, Tc-99m (V) dimercaptosuccinic acid (DMSA) has been found to be very useful in the detection of infection. Tc-99m (V) DMSA is inexpensive, easy to prepare, and provides a result within hours. In this study, we evaluated the potential of Tc-99m (V) DMSA scan (DMSA scan) in the detection of intra-abdominal infection. Methods A total of 33 patients who suffered from an unknown cause of fever after colorectal surgery were enrolled in this study. All patients received both a gallium scan and a DMSA scan. DMSA scintigraphy was performed 3–4 h after an injection of 740 MBq (20 mCi) of Tc-99m DMSA. After completion of the DMSA image, 111 MBq (3 mCi) of Ga-67 citrate was injected intravenously. Gallium scintigraphy was performed after 24 h and later as needed. Results Of the 33 patients, 17 (51.5%) were diagnosed with intra-abdominal abscesses. For DMSA scans, the sensitivity, specificity, and overall accuracy were 88.2%, 93.7%, and 90.9%, respectively. For gallium scans, the diagnostic sensitivity, specificity, and accuracy were 100%, 87.5%, and 93.9%, respectively. No statistical difference was found in the diagnostic accuracy between these two diagnostic modalities using Fisher's exact test. Conclusions DMSA scan is a useful alternative to gallium scan in the detection of intra-abdominal infection in patients with colorectal surgery because Tc-99m DMSA is inexpensive, easy to prepare, and most importantly the result can be obtained within hours.     

Nonvisualization of an enlarged spleen on Ga-67 scintigraphy but demonstrated by CT after splenic irradiation

Presence of enlarged spleen using CT with absence of splenic visualization in Ga-67 citrate images in a patient with chronic myelogenous leukemia and splenomegaly after splenic irradiation was observed. Since Howell-Jolly bodies had not been identified in the peripheral circulation, the finding of splenic nonvisualization was explained by disassociated splenic functions, which are not tightly coupled, and some activities that can be suppressed by irradiation without impairing others. The Ga-67 splenic localization mechanism is probably more sensitive and liable to disruption by irradiation, and was independent of spleen size. Ga-67 scintigraphy and Tc-99m sulfur colloid liver-spleen scintigraphy are two organ function-dependent imaging procedures, while CT provides anatomic information.