Technetium-99m hexamethylpropylene amine oxime leucocyte scintigraphy in the differential diagnosis of cerebral abscesses

The diagnosis of brain abscess is often difficult, as the clinical symptoms are not specific. Computed tomography (CT) and magnetic resonance imaging (MRI) are highly sensitive, but different cerebral lesions, especially neoplasms, can have the same ring-like contrast enhancement. Brain abscess is a severe illness requiring rapid diagnosis to choose the most appropriate therapy. Technetium-99m hexamethylpropylene amine oxime (HMPAO)-labelled leucocyte scintigraphy is commonly used to detect an inflammatory process. The aim of this study was to present the results obtained with leucocyte scintigraphy in 65 patients with intracranial mass lesions and clinical findings compatible to or suggestive of brain abscess. The final diagnosis, based on surgery, clinical findings and stereotatic puncture, was brain abscess in 17 patients, primary brain neoplasm in 22, brain metastasis in 16, lymphoma in 2, cysticercosis in 2, hematoma in 2 and cerebral infarction in 4. ^99mTc-HMPAO leucocyte scintigraphy was positive in all abscess cases. The scan was negative in the rest of the patients examined, with the exception of one lesion, which was finally diagnosed as a tumour (1 false-positive). All patients who did not have false-negative scans were treated with steroids. The sensitivity, specificity and diagnostic accuracy of leucocyte scintigraphy was 100%, 97.8% and 98.4%, respectively. In conclusion, in our experience, leucocyte scintigraphy is a valuable aid in the differential diagnosis between abscess and neoplasm. Received 25 April and in revised form 12 August 1999     

Diagnosis of pyogenic pelvic inflammatory diseases by 99mTc-HMPAO leucocyte scintigraphy

Pelvic inflammatory disease (PID) is one of the major health problems of women of child-bearing age. Among the most serious complications of PID is the formation of a tubo-ovarian abscess (TOA). Early diagnosis of this condition may prevent serious surgical complications such as peritonitis and sepsis, which may be fatal. The purpose of this study was to investigate the efficacy of technetium-99m hexamethylpropylene amine oxime (HMPAO) leucocyte scintigraphy in the diagnosis of TOA. Twenty women with high clinical suspicion of TOA underwent ^99mTc-HMPAO leucocyte scintigraphy. The labelling of leucocytes with ^99mTc-HMPAO was performed according to a standard protocol. Scans were obtained at 1, 3 and 24 h following the injection of the labelled leucocytes. In eight cases the early and/or late scan was positive, in 11 cases it was negative, and in one case of ovarian cyst torsion, confirmed by laparoscopy, it showed slight uptake in the capsule of the cyst (false-positive). The sensitivity of ^99mTc-HMPAO leucocyte scintigraphy was 100%, specificity 91.6%, positive predictive value 89%, negative predictive value 100% and overall accuracy 95%. It is concluded that leucocyte scintigraphy is a non-invasive, safe, physiological and accurate procedure for the diagnosis of TOA. The 24-h scan is crucial, since in some cases the abscess was not clearly visualized on the early scan. Leucocyte scintigraphy may reduce the need for CT, diagnostic laparoscopy and unnecessary invasive surgical procedures.     

Diagnosis of pyogenic pelvic inflammatory diseases by 99mTc-HMPAO leucocyte scintigraphy

Pelvic inflammatory disease (PID) is one of the major health problems of women of child-bearing age. Among the most serious complications of PID is the formation of a tubo-ovarian abscess (TOA). Early diagnosis of this condition may prevent serious surgical complications such as peritonitis and sepsis, which may be fatal. The purpose of this study was to investigate the efficacy of technetium-99m hexamethylpropylene amine oxime (HMPAO) leucocyte scintigraphy in the diagnosis of TOA. Twenty women with high clinical suspicion of TOA underwent 99mTc-HMPAO leucocyte scintigraphy. The labelling of leucocytes with 99mTc-HMPAO was performed according to a standard protocol. Scans were obtained at 1, 3 and 24 h following the injection of the labelled leucocytes. In eight cases the early and/or late scan was positive, in 11 cases it was negative, and in one case of ovarian cyst torsion, confirmed by laparoscopy, it showed slight uptake in the capsule of the cyst (false-positive). The sensitivity of 99mTc-HMPAO leucocyte scintigraphy was 100%, specificity 91.6%, positive predictive value 89%, negative predictive value 100% and overall accuracy 95%. It is concluded that leucocyte scintigraphy is a non-invasive, safe, physiological and accurate procedure for the diagnosis of TOA. The 24-h scan is crucial, since in some cases the abscess was not clearly visualized on the early scan. Leucocyte scintigraphy may reduce the need for CT, diagnostic laparoscopy and unnecessary invasive surgical procedures.     

Clinical validation of the avidin/indium-111 biotin approach for imaging infection/inflammation in orthopaedic patients.

We report here the results of a validation study of the avidin/indium-111 biotin approach in patients with skeletal lesions. This study involved 54 patients with orthopaedic conditions: 20 patients with intermediate suspected osteomyelitis of the trunk, 19 patients with infection/inflammation of prosthetic joint replacements, and 15 patients with suspected osteomyelitis of appendicular bones. Avidin (3 mg) was injected as an i.v. bolus, followed 4 h later by 111In-biotin; imaging was acquired 30 min and 16-18 h after administration of 111In-biotin. Technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO)-labelled leucocyte scintigraphy was performed in 39/54 patients. The overall sensitivity of the avidin/111In-biotin scan was 97.7% (versus 88.9% for 99mTc-HMPAO leucocyte scintigraphy). While the diagnostic performance of avidin/111In-biotin scintigraphy was similar to that of 99mTc-HMPAO leucocyte scintigraphy in patients with prosthetic joint replacements or osteomyelitis of appendicular bones, the avidin/111In-biotin approach clearly performed better than 99mTc-HMPAO leucocyte scintigraphy in patients with suspected osteomyelitis of the trunk (100% sensitivity, specificity and accuracy versus 50% sensitivity, 100% specificity and 66.7% accuracy for 99mTc-HMPAO-leucocyte scintigraphy). These results demonstrate the feasibility of the avidin/111In-biotin approach for imaging sites of infection/inflammation in the clinical setting. Although no systematic advantages of avidin/111In-biotin scintigraphy were found versus 99mTc-HMPAO leucocyte scintigraphy, the newer scintigraphic method is more practicable and involves lower biological risk for the operators.     

99Tcm-labelled HSA-nanocolloid versus 111In oxine-labelled granulocytes in detecting skeletal septic process

Fifty-seven investigations of the skeletal system were performed on 54 patients, using a 99Tcm-labelled nanometer-sized HSA colloid in a crossover comparison with 111In oxine-labelled granulocytes for the detection of sites of infection. The findings were in agreement in 55 out of 57 investigations (96.5%). Based on 44 studies in which a final clinical diagnosis was obtained, both methods were found to display the same specificity (93%), whilst the sensitivity of 99Tcm nanocolloid scintigraphy (87%) was slightly higher than that obtained with 111In leucocyte scintigraphy (81%). In our opinion, 99Tcm nanocolloid is easier to use and the total duration of the investigation is considerably shorter. The use of 99Tcm is scintigraphically more advantageous and, with the dosage required, the absorbed radiation dose to the red bone marrow is three times lower than with 111In granulocytes. For the detection and therapy monitoring of osteomyelitis, as well as for the investigation of arthroplasties suspected of infective loosening, we consider scintigraphy with 99Tcm nanocolloid to be equivalent to leucocyte scintigraphy. Identical findings were obtained with both tracers in suspected spondylodiscitis.     

Usefulness of 111In labeled leukocytes scintigraphy combined with 99mTc phytate liver scintigraphy for diagnosis of hepatic abscess comparing with CT and US]

111In labelled leukocyte scintigraphy (ILLS) was performed in five patients with hepatic abscess. For the accurate diagnosis of hepatic abscess, ILLS was superimposed on 99mTc phytate liver scintigraphy. The results of ILLS were compared with CT and US findings. Four of five patients (80%) showed abnormal accumulations in the liver. The smallest abscess detected was 46 mm x 43 mm. CT scan showed rim enhancement, which was a specific finding for hepatic abscess, in three patients. It was rather difficult to diagnose hepatic abscess by US. In two cases without definite rim enhancement on CT, the abscesses were diagnosed as hot spots by ILLS. We conclude that ILLS combined with 99mTc liver scintigraphy is useful for the diagnosis of hepatic abscess.     

Opportunistic intracranial infection in AIDS detection by technetium-99m DTPA brain scintigraphy

Radionuclide brain scintigraphy and computed tomography (CT) demonstrated cerebral lesions in two patients with acquired immunodeficiency disease syndrome (AIDS) complicated by opportunistic infection of the brain. In the detection of these cerebral lesions, [99mTc]DTPA radionuclide scintigraphy was as reliable as CT. Since malignant lymphoma involving the brain has been seen with increasing frequency in patients with AIDS, the positive brain scan alone is nonspecific and should be correlated appropriately with the clinical setting.     

CT and 99mTc-DMSA scintigraphy in adult acute pyelonephritis: a comparative study

PURPOSE: The aim of this prospective study was to evaluate the relative value of CT and (99m)Tc-DMSA scintigraphy in the diagnosis of acute pyelonephritis (APN) in adult patients suspected of having urinary tract infection. METHOD: The study was conducted in 36 patients presenting with symptoms suggestive of urinary tract infection. Plain B-mode sonography, CT with contrast medium, and (99m)Tc-DMSA scintigraphy of the kidneys were performed in all patients. Both CT and (99m)Tc-DMSA scintigraphy were performed within 72 h after admission. RESULTS: Twelve patients with clinical and biological signs of urinary tract infection had no CT or (99m)Tc-DMSA scintigraphy abnormalities. Among these patients, lower urinary tract infection was found in 10 patients and 2 patients had ureteral obstruction. In the 24 remaining patients, the diagnosis of APN was made. Among these patients, a correlation was found between CT and (99m)Tc-DMSA scintigraphy in 11 cases. In two cases, both examinations were normal, and in nine cases, both were abnormal. In 11 cases of the 13 remaining patients, abnormal CT was found with normal (99m)Tc-DMSA scintigraphy, whereas the 2 last cases had normal CT and abnormal (99m)Tc-DMSA scintigraphy results. In two cases, bilateral lesions found on CT manifested as unilateral abnormalities on (99m)Tc-DMSA scintigraphy images. CONCLUSION: The diagnosis of APN in adult patients is based on clinical presentation and biological findings. Few studies have compared (99m)Tc-DMSA scintigraphy with CT in the detection of parenchymal involvement in APN. We conclude that CT is more accurate than (99m)Tc-DMSA scintigraphy in the detection of APN lesions in adult patients.     

Technetium-99m hexamethylpropylene amine oxime leucocyte scintigraphy in the early course of mild acute pancreatitis following endoscopic retrograde cholangiopancreatography

We evaluated the diagnostic accuracy of technetium-99m hexamethylpropylene amine oxime (HMPAO) leucocyte scintigraphy in mild acute pancreatitis. A study design was chosen that gave us an opportunity to assess patients by leucocyte scintigraphy in the very early course of the disease. Thirty-two consecutive patients referred for endoscopic retrograde cholangiopancreatography were followed according to a very rigid protocol with laboratory tests and clinical examination before and after the endoscopic procedure and leucocyte scintigraphy [including single-photon emission tomography (SPET)] performed within 24 h. Planar and SPET images were examined by two observers who were blinded to each other and to the clinical history and diagnosis. Eight (25%) of the 32 patients developed mild acute pancreatitis, and only one of these patients had a positive scan. Sensitivity, specificity and accuracy of 13%, 79% and 63%, respectively, were achieved when both planar and SPET images were considered. When only planar images were considered the sensitivity, specificity and accuracy were 13%, 96% and 75%, respectively. No evidence of pathological leucocyte accumulation in mild acute pancreatitis was found despite the aforementioned very rigid protocol, allowing patients to be assessed by^99mTc-HMPAO leucocyte scintigraphy in the very early phase of the disease (this was true even when using SPET). From a clinical point of view, we believe that leucocyte scintigraphy should be used only when the disease is moderate or severe and serious intra-abdominal complications are suspected.     

Clinical validation of the avidin/indium-111 biotin approach for imaging infection/inflammation in orthopaedic patients

We report here the results of a validation study of the avidin/indium-111 biotin approach in patients with skeletal lesions. This study involved 54 patients with orthopaedic conditions: 20 patients with intermediate suspected osteomyelitis of the trunk, 19 patients with infection/inflammation of prosthetic joint replacements, and 15 patients with suspected osteomyelitis of appendicular bones. Avidin (3 mg) was injected as an i.v. bolus, followed 4 h later by ¹¹¹In-biotin; imaging was acquired 30 min and 16–18 h after administration of ¹¹¹In-biotin. Technetium-99m hexamethylpropylene amine oxime (^99mTc-HMPAO)-labelled leucocyte scintigraphy was performed in 39/54 patients. The overall sensitivity of the avidin/¹¹¹In-biotin scan was 97.7% (versus 88.9% for ^99mTc-HMPAO leucocyte scintigraphy). While the diagnostic performance of avidin/¹¹¹In-biotin scintigraphy was similar to that of ^99mTc-HMPAO leucocyte scintigraphy in patients with prosthetic joint replacements or osteomyelitis of appendicular bones, the avidin/¹¹¹In-biotin approach clearly performed better than ^99mTc-HMPAO leucocyte scintigraphy in patients with suspected osteomyelitis of the trunk (100% sensitivity, specificity and accuracy versus 50% sensitivity, 100% specificity and 66.7% accuracy for ^99mTc-HMPAO-leucocyte scintigraphy). These results demonstrate the feasibility of the avidin/¹¹¹In-biotin approach for imaging sites of infection/inflammation in the clinical setting. Although no systematic advantages of avidin/¹¹¹In-biotin scintigraphy were found versus ^99mTc-HMPAO leucocyte scintigraphy, the newer scintigraphic method is more practicable and involves lower biological risk for the operators. Received 9 November 1998 and in revised form 1 February 1999     

Prospective investigation of radiologic methods in the diagnosis of intra-abdominal abscesses

A prospective investigation of conventional abdominal radiography, ultrasonography, computed tomography and 111In-labelled leucocyte scintigraphy was performed in 40 patients suspected of having an intra-abdominal abscess. There were 23 confirmed abscesses in the material. When conventional abdominal radiography indicated an abscess, such a lesion was usually present. The ability of abdominal radiography to exclude an abscess was, however, low. Both ultrasonography and 111In-labelled leucocyte scintigraphy detected 65 to 85 per cent of the confirmed abscesses, but both also revealed many abscess-like areas in patients where no unequivocal abscess was confirmed at follow-up. Computed tomography was, when employed as a single method, the most reliable one both to show and to exclude an abscess, However, the combination of ultrasonography and 111In-labelled leucocyte scintigraphy disclosed all the lesions demonstrated by any one of the four methods used in the investigation.     

Contribution of technetium-99m hexamethylpropylene amine oxime labelled leucocyte scintigraphy to the diagnosis of diabetic foot infection

We conducted a prospective study in order to evaluate the contribution of technetium-99m hexamethylpropylene amine oxime (HMPAO) labelled leucocyte scintigraphy to the diagnosis and follow-up of osteomyelitis in the diabetic foot. The study was conducted between October 1992 and November 1996 and included 42 patients (30 men and 12 women; mean age 63 years) with diabetes mellitus (type 1, n = 22, type 2, n = 20) who had a total of 56 diabetic foot ulcers. The initial exploration included standard radiography, three-phase bone scintigraphy and ^99mTc-HMPAO labelled leucocyte scintigraphy (HMPAO-LS), performed within a 3-day interval. For the 56 ulceration sites, 26 cases of osteomyelitis were diagnosed: ten on the basis of radiographic and histological/bacteriological criteria after bone biopsy, 11 after radiographic follow-up and five on the basis of biopsy results alone. No osteomyelitis was present at 30 sites, there were seven cases of cellulitis. The sensitivity and specificity of ^99mTc-HMPAO-LS were 88.4% and 96.6% respectively (23 true-positives, 29 true-negatives, one false-positive, three false-negatives). The accuracy of radiography, ^99mTc-methylene diphosphonate and HMPAO-LS was 69.6%, 62.5%, and 92.9%, respectively. Follow-up scintigraphy (n = 14) 4 months after initial diagnosis and 1 month after antibiotic withdrawal confirmed cure of osteomyelitis despite the absence of complete clinical regression of the ulcers. In conclusion, ^99mTc-HMPAO labelled leucocyte scintigraphy was found to be an excellent method for the diagnosis of osteomyelitis in the diabetic foot. It can contribute to follow-up, particularly when clinical regression of perforating ulcers is incomplete and cure of osteomyelitis must be confirmed in order that antibiotic treatment may be discontinued. Received 10 July and in revised form 1 October 1997     

99mTc-MIBI scintigraphy in untreated stage III multiple myeloma: comparison with X-ray skeletal survey and bone scintigraphy

Technetium-99m 2-methoxyisobutylisonitrile (99mTc-MIBI) is a lipophilic agent that has been proposed as a useful tracer for the detection of disease sites in patients with multiple myeloma (MM). We performed a prospective study to determine the potential of 99mTc-MIBI imaging for the evaluation of the extent of primary disease in patients with advanced stage MM, compared with skeletal survey and bone scintigraphy. Twenty patients with advanced stage MM at initial diagnosis underwent whole-body 99mTc-MIBI imaging, together with contemporaneous skeletal survey and bone scintigraphy. The findings of 99mTc-MIBI imaging were correlated with the results of skeletal survey and bone scan. All 99mTc-MIBI scans were positive for the presence of active MM, whereas skeletal surveys were positive in 18 patients (90%) with osteolytic lesions. Bone scintigraphy demonstrated MM in only 15 patients (75%). In two patients with no detectable lesions on skeletal survey, 99mTc-MIBI imaging revealed uptake in the spine, corresponding to the abnormalities seen on magnetic resonance imaging (MRI). With respect to the localization of bone lesions, 99mTc-MIBI imaging was superior to bone scintigraphy in 15 patients (75%) and had concordant results with bone scintigraphy in four (20%). 99mTc-MIBI imaging is a very sensitive imaging modality for the identification of the extent of disease in patients with advanced MM. It is clearly superior to bone scintigraphy and complements the results of skeletal survey by finding additional disease sites. Hence, in active MM patients, 99mTc-MIBI imaging has the potential to detect bone marrow disease that cannot be detected by skeletal survey and bone scintigraphy.     

Whole-body scintigraphy in melanoma patients: comparison of 99Tcm-tetrofosmin and 201Tl

The aim of this study was to determine the diagnostic value of 99Tcm-tetrofosmin whole-body imaging in comparison to 201Tl scintigraphy in patients with metastatic melanoma. In 27 patients with known or suspected melanoma metastases we performed 201Tl scintigraphy and 99Tcm-tetrofosmin scintigraphy using a 1-day protocol. In five patients with known locoregional metastasis the in vivo uptake kinetics of both radiotracers were compared. The final diagnosis was confirmed by surgical histology in 39 lesions (group I) and computed tomography (CT) and clinical course in 14 lesions (group II). In group I, containing mainly locoregional metastases, 201Tl scintigraphy correctly identified 36 of 39 metastases and 99Tcm-tetrofosmin 35 of 39 resulting in a sensitivity of 92% and 90% respectively. The T/B ratios of 201Tl (1.4-4.0, mean 2.15) were statistically significantly higher in comparison to tetrofosmin (1.3-3.0, mean 1.88). However, both radiotracers showed similar uptake and washout kinetics with a maximum of tracer uptake between 1 and 5 min p.i. In group II, containing mainly cerebral and pulmonary metastases, both methods correctly identified six of 14 metastases resulting in a sensitivity of only 43%. We conclude that the uptake of 99Tcm-tetrofosmin and 201Tl in melanoma metastases is very similar. The T/B ratios with 99Tcm-tetrofosmin are significantly lower than with 201Tl. In locoregional melanoma metastases the sensitivity of tetrofosmin scintigraphy is identical with 201Tl imaging and amounts to 90%. In cerebral and lung metastases the sensitivity of both methods is limited when using whole-body scintigraphy.     

Extended combined 99mTc-white blood cell and bone imaging improves the diagnostic accuracy in the detection of hip replacement infections

Although the diagnosis of hip prosthesis infection is clinically important, X-ray studies, blood chemistry and synovial fluid aspiration may be unreliable for this purpose. The aim of this study was to evaluate whether extending the time for technetium-99m labelled leucocyte imaging to 24 h post injection improves the accuracy of diagnosis of hip replacement infections. We studied 64 symptomatic patients with hip prostheses. The presence of infections was verified by intraoperative bacterial cultures, and infection was excluded either by negative operative findings or by follow-up for at least 1 year. Leucocyte imaging was done with 99mTc-hexamethylpropylene amine oxime (HMPAO)-labelled leucocytes at 2-4 h (routine images) and at 24 h (late images) after the injection of the leucocytes. In addition, bone imaging was carried out with 99mTc-hydroxydiphosphonate (HDP) at the arterial, soft tissue and metabolic phases. A standardised method was used to compare leucocyte images with bone metabolic images. In this material, there were six confirmed infections. All the bone imaging methods had a sensitivity of 100% in detecting prosthesis infections whereas the specificity varied from only 2% to 82%. Routine leucocyte imaging was less sensitive (50% vs 83%) and less specific (90% vs 100%) than late leucocyte imaging. All tests had a high negative predictive value for excluding infection (95%-100%). However, both bone (10%-38%) and routine leucocyte imaging (33%) showed a poor positive predictive value (PPV), whereas late leucocyte imaging had a PPV of 100% and a diagnostic accuracy of 98%. We conclude that late leucocyte imaging improves the specificity of diagnosis of infected hip prostheses. This type of imaging procedure should be combined with three-phase bone scintigraphy in studies of patients with painful joint replacement.     

Clinical significance of abdominal scintigraphy using 99mTc-HMPAO-labelled leucocytes in patients with seronegative spondyloarthropathies

Abdominal scintigraphy shows silent gut inflammation in patients with spondyloarthropathies (Sp) without clinical evidence of gut inflammation. Abdominal scintigraphy images are different than those obtained in patients with ulcerative colitis or Crohn's disease and are not related to the anti-inflammatory drugs administered. The aim of this study was to examine the clinical associations of findings on abdominal scintigraphy in patients with Sp. A total of 204 Sp patients (European Spondylarthropathy Study Group 1991 criteria) and 54 non-Sp controls receiving non-steroidal anti-inflammatory drugs were studied. Abdominal scintigraphy images were obtained at 30 and 120 min after injection of technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO)-labelled leucocytes. 99mTc-HMPAO-labelled leucocyte scans were positive in 104 Sp patients (50.9%) and in six non-Sp controls (2.9%) (P<0.001; OR=8.32; 95% CI=3.23-22.67). Silent gut inflammation was not associated with any of the following: age of onset, duration of evolution, sex, family history of Sp or psoriasis, articular manifestations, extra-articular manifestations, radiological findings or HLA-B27 positivity. Positive abdominal scintigraphy was associated with active disease (P < 0.0001; OR=52.7; 95% CI=19-145.6) and an increase in the C-reactive protein (P < 0.005; OR = 3.4; 95% CI = 1.5-7.4). It is concluded that (a) abdominal scintigraphy using 99mTc-HMPAO-labelled leucocytes is of value in detecting the silent gut inflammation in Sp patients, and (b) silent gut inflammation is related to the clinical activity, but is not associated with any particular type of illness or with HLA-B27.     

The role of technetium-99m-labeled octreotide acetate scintigraphy in suspected breast cancer and correlates with expression of SSTR

PURPOSE: To evaluate the value of (99m)Tc-octreotide acetate (hereafter, (99m)Tc-octreotide) somatostatin receptor (SSTR) scintigraphy in the detection of primary breast cancer and to correlate with expression of SSTRs. MATERIALS AND METHODS: Fifty-four female and 1 male patients (range, 17-77 years; mean age, 48 years) with palpable breast lesion were included in this study. (99m)Tc-octreotide and (99m)Tc-MIBI scintigraphy were undertaken in all patients, and the region of interest was drawn around each lesion. Tumor uptake was measured and expressed as the ratio of tumor to normal tissue activity (T/NT). Final clinical diagnosis was confirmed by histopathological analysis. Expression of SSTR1-5 mRNA was measured with RT-PCR in 15 patients with malignant neoplasm, and protein level of SSTR-2 and SSTR-5 was measured using immunohistochemical staining in 15 patients with malignant neoplasm and 18 patients with benign lesion. RESULTS: Thirty-five patients were confirmed to have infiltrative ductal breast carcinoma, 1 patient with cellular cancer, 1 patient with adenocarcinoma and 18 patients had benign lesions. The sensitivity, specificity, positive predictive value and negative predictive value of (99m)Tc-octreotide in detection of primary lesion were 91.8%, 22.2%, 71.8% and 57.1%, respectively. No significant correlation was observed between T/NT of (99m)Tc-octreotide and (99m)Tc-MIBI. SSTR mRNA subtypes were variably expressed. SSTR3 was the most highly expressed, followed by SSTR1, SSTR2 and SSTR5; SSTR4 was the least expressed in the level of mRNA of SSTR. Significant correlation was shown between T/NT and the expression of SSTR2 mRNA (r=0.73, P<.01). CONCLUSION: (99m)Tc-octreotide acetate scintigraphy was sensitive for the detection of primary lesion of breast cancer; however, nonspecific breast tissue uptake hampered the specificity and clinical value in the detection of lymph node metastasis. Five subtypes of SSTR mRNA and protein SSTR2 and SSTR5 were expressed variably in breast cancer due to tumor heterogeneity. (99m)Tc-octreotide imaging may hold promise in the evaluation of the level of SSTR2 in vivo.     

Abdominal scintigraphy using99mTc-HMPAO-labelled leucocytes in patients with seronegative spondylarthropathies without clinical evidence of inflammatory bowel disease

Abdominal scintigraphy with technetium-99m hexamethylpropylene amine oxime (^99mTc-HMPAO)-labelled leucocytes is an excellent tool for evaluating disease extent and activity of intestinal lesions in patients with inflammatory bowel disease (IBD). In some cases of seronegative spondylarthropathies (SSp), IBD may remain subclinical. The aim of this study was to evaluate the presence of positive abdominal scintigraphy in patients with SSp and without clinical symptoms or signs of IBD. To this end we studied 32 patients with active SSp (European Spondylarthropathy Study Group 1991 criteria) without clinical evidence of IBD (eight had ankylosing spondylitis, four psoriatic arthritis, three reactive arthritis an 17 undifferentiated SSp) and 11 controls without SSp. All SSp and control patients received similar doses of non-steroidal anti-inflammatory drugs (NSAIDs). Abdominal scintigraphic images were obtained at 30 and 120 min after re-injection of^99mTc-HMPAO-labelled leucocytes. The^99mTc-HMPAO-labelled leucocyte scan was positive in 17 patients with SSp (53.1%) (six with ankylosing spondylitis, three with psoriatic arthritis, two with reactive arthritis and six with undifferentiated SSp). Fourteen patients scored from 2 to 4 on the intensity of uptake scale. The colon and terminal ileum were predominantly involved. Axial involvement was more frequent in patients with a positive scan than in patients with negative results (P<0.05) (64.7% vs 26.6%; odds ratio: 5). No control patient showed a positive scan. It is concluded that^99mTc-HMPAO-labelled leucocyte scan shows increased uptake among patients with SSp without evidence of IBD. These findings provide new evidence linking SSp with intestinal inflammation and suggest that in some cases a bowel-related process could contribute to the development of SSp. Longterm follow-up studies with more patients are necessary to evaluate the diagnostic and therapeutic implications of these results.     

The usefulnes of99mTc-HMPAO-labeled leukocyte scintigraphy in the diagnosis of skeletal metastases of cancers

The usefulness of bone marrow scintigraphy with 99mTc-HMPAO-labeled leukocytes (leukocyte bone marrow scintigraphy) in the diagnosis of skeletal metastases of cancers was investigated in 70 lesions in 27 patients with various types of cancer. The final diagnosis of skeletal metastases was based on one or more criteria consisting of histological confirmation, typical findings of metastases by bone radiograph, CT and MRI, or progressive swellings of the lesions with severe pain due to nerve compression. Of the 70 lesions, 55 were finally diagnosed as metastases, and 15 as benign lesions. Leukocyte bone marrow scintigraphy showed photopenic defects in 52 of the 55 metastatic lesions (sensitivity 95%), and the remaining 3 negative lesions were found positive for metastases by MRI. In contrast, MRI could evaluate only 39 of the 55 lesions because 16 lesions in the ribs, scapula and sternum were not visualized. Of these 39 lesions, MRI showed positive findings for metastases in 33 (sensitivity 85%), and negative findings in 6 with photopenic defects found by leukocyte bone marrow scintigraphy. Of the 15 benign lesions, 3 were false positive for metastases on leukocyte bone marrow scintigraphy (specificity 80%). We conclude that 99mTc-HMPAO-labeled leukocyte bone marrow scintigraphy may be useful in the diagnosis of skeletal metastases of cancers, particularly when MRI fails to evaluate the lesions.     

Radiolabeled leucocyte imaging in diffuse granulomatous involvement of the meninges in Wegener's granulomatosis: scintigraphic findings and their role in monitoring treatment response to specific immunotherapy (humanized monoclonal antilymphocyte antibodies)

BACKGROUND AND PURPOSE: Diffuse involvement of the meninges by remote granulomas in Wegener's granulomatosis is rare. This study reports the radiolabeled leucocyte imaging findings in five such patients. The diagnosis was made by MR imaging in five patients and confirmed in four by findings at meningeal biopsy. The potential role of serial radiolabeled leucocyte examinations in assessing treatment response is discussed. METHODS: Three of the five patients underwent whole-body planar 111In-labeled leucocyte imaging. Two of these patients had serial imaging and one had, in addition, a 99mTc-HMPAO-labeled leucocyte single-photon emission CT brain examination. Two of the five patients had whole-body planar 99mTc-HMPAO-labeled leucocyte imaging. Of these, one patient had serial imaging. The radiolabeled leucocyte imaging findings were correlated with MR findings and with the patients' clinical course. RESULTS: In four patients there was a midline linear area of increased tracer uptake in the brain, and in one of these, tracer uptake also extended laterally over the brain convexity. In two patients linear tracer uptake extended in an inferolateral direction from the midline. These abnormalities correlated with meningeal thickening in the falx, over the brain convexity, and in the tentorium cerebelli on MR images. Serial imaging in three patients revealed a reduction or disappearance in tracer uptake after treatment with anti-CD52, which correlated with clinical improvement. CONCLUSION: In patients with Wegener's granulomatosis, abnormal uptake corresponding to meningeal thickening can be seen on planar radiolabeled leucocyte images. Leucocyte imaging may be useful for monitoring treatment response.