Transient seixure activity demonstrated by Tc-99m HMPAO SPECT and diffusion-weighted MR imaging

Cerebral perfusion single photon emission computed tomography (SPECT) has been used to confirm the localization of the epileptic focus and the evaluation of seizure. Recently, diffusion-weighted MR imaging (DWI) has been recognized for evaluation of seizure activity. We describe a case of transient seizure activity demonstrated by Tc-99m HMPAO SPECT and DWI. This patient was a 61-year-old woman with a 10-month history of right middle cerebral artery (MCA) infarction who had a generalized seizure during MRI. DWI immediately after seizure showed transient hyperintensity in the right frontal gray matter and the white matter, and these apparent diffusion coefficients (ADC) were transiently decreased. This transient hyperintensity on DWI corresponded to transient hyperperfusion identifying the epileptic focus on interictal Tc-99m HMPAO SPECT. Transient sustained seizure activity might cause these changes on DWI and SPECT. It was considered that interictal Tc-99m HMPAO SPECT showed the delayed hyperperfusion caused by excitatory neuronal overaction and DWI showed cytotoxic edema seizure-induced by energy failure of the membrane-bound Na/K-ATPase pump.     

Compare FDG-PET and Tc-99m tetrofosmin SPECT to detect metastatic thyroid carcinoma

RATIONALE AND OBJECTIVES: The effectiveness of 18-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) and technetium-99m tetrofosmin (Tc-99m TF) single photon emission computed tomography (SPECT) of neck and chest was evaluated to detect metastatic lesions in well-differentiated thyroid carcinoma after nearly total thyroidectomy and radioiodine (I-131) treatment who present with elevated serum human thyroglobulin levels but negative I-131 whole body scan. MATERIALS AND METHODS: Twenty-three patients with differentiated thyroid carcinoma who underwent nearly total thyroidectomy and I-131 treatments were included in this study. RESULTS: All of the 23 patients had negative I-131 whole body scan and elevated human thyroglobulin levels under thyroid-stimulating hormone stimulation. Metastatic lesions were detected by FDG-PET in 20 patients, while Tc-99m TF SPECT revealed metastatic lesions in only 11 of the 20 patients. Both FDG-PET and Tc-99m TF SPECT failed to demonstrate miliary pulmonary metastases in two of the remaining three patients. The other patient did not show any lesion on FDG-PET, Tc-99m TF SPECT, chest computed tomography, or other imaging techniques. CONCLUSION: This study demonstrated that FDG-PET is more sensitive than Tc-99m TF SPECT to detect metastatic lesions in differentiated thyroid carcinoma with elevated human thyroglobulin but negative I-131 whole body scan. However, miliary pulmonary metastases could be missed by the both techniques.     

Technical and analytical advances in pulmonary ventilation SPECT with xenon-133 gas and Tc-99m-Technegas

This paper describes the recent advances in technical and analytical methods in pulmonary ventilation SPECT studies, including a respiratory-gated image acquisition of Technetium-99m (99mTc)-labeled Technegas SPECT, a fusion image between Technegas SPECT and chest CT images created by a fully automatic image registration algorithm, and a three-dimensional (3D). display of xenon-133 (133Xe) gas SPECT data, and new analytical approaches by means of fractal analysis or the coefficient of variations of the pixel counts for Technegas SPECT data. The respiratory-gated image acquisition can partly eliminate problematic effects of the SPECT images obtained during non-breath-hold. The fusion image is available for routine clinical use, and provides complementary information on function and anatomy. The 3D displays of dynamic 133Xe SPECT data are helpful for accurate perception of the anatomic extent and locations of impaired ventilation, and the assessment of the severity of ventilation abnormalities. The new analytical approaches facilitate the objective assessment of the degrees of ventilation abnormalities.     

Estimation of coronary flow reserve with the use of dynamic planar and SPECT images of Tc-99m tetrofosmin

BACKGROUND: We developed a noninvasive method to examine coronary flow reserve with technetium 99m tetrofosmin based on the microsphere model. According to the microsphere model, myocardial blood flow (MBF) can be calculated by MBF = q / integral C(t)dt, where q is myocardial activity and C(t) is tracer concentration in blood. Because the ratio of integral C(t)dt at stress to rest is equal to the ratio of the first transit count in the pulmonary artery (PA) and attenuation factors were canceled out, we calculated the increase ratio of MBF (MBF(IR)). METHODS AND RESULTS: After injection of dipyridamole, tetrofosmin was injected as a bolus and serial dynamic planar images were obtained to measure the first transit count in PA (PAC). Myocardial single photon emission computed tomography was performed to measure the regional myocardial count (RMC). MBF(IR) was calculated as [(RMCs x PACr)/(RMCr x PACs) - 1] x 100, where r and s denote resting and stress conditions, respectively. In contrast, the increase in the myocardial uptake ratio (MUR(IR)) was defined as (RMCs x SCr/RMCr x SCs - 1) x 100, where SC is syringe count of tracer. The results were as follows: (1) The mean MBF of healthy subjects was 46.9% +/- 22.8%. (2) MBF(IR) of the infarcted region and ischemic region was significantly decreased (8.3% +/- 12.2% and 11.2% +/- 11.9%, respectively; P <.001). (3) MUR(IR) was significantly lower than MBF(IR) (14.1% +/- 21.2%; P <.001). (4) MBF(IR) decreased according to the heart rate at rest (r = 0.47; P <.05). CONCLUSIONS: MBF(IR) is a potential parameter with which to evaluate coronary flow reserve when the changes of arterial input function during stress are considered.     

Brain MRI,Tc-99m HMPAO SPECT and F-18 FP-CIT PET/CT Findings in a Patient with Wilson Disease: A Case Report

A 34-year-old female had experienced head and hand tremors with a dystonic component for 8 months. Brain MRI showed T2 high signal intensity in the periaqueductal region, dorsal midbrain and dorsal upper pons. No abnormal uptake was noted on Tc-99m HMPAO SPECT or F-18 FP-CIT PET/CT. Wilson disease was diagnosed according to the 2008 consensus guideline from the American Association for the Study of Liver Disease and 2012 guideline from the European Association for the Study of the Liver. This case demonstrates T2 signal change in the basal ganglia, excluding the putamen, in a Wilson disease patient with relatively severe clinical findings, but normal Tc-99m HMPAO SPECT and F-18 FP-CIT PET/CT.     

Added value of attenuation-corrected Tc-99m tetrofosmin SPECT for the detection of myocardial viability: Comparison with FDG SPECT

BACKGROUND: The aim of this study was to evaluate the value of attenuation correction of technetium 99m tetrofosmin single photon emission computed tomography (SPECT) imaging for the detection of myocardial viability. METHODS AND RESULTS: A head-to-head comparison between resting Tc-99m tetrofosmin SPECT and fluorine 18 fluorodeoxyglucose (FDG) SPECT was performed. Both the noncorrected and attenuation-corrected Tc-99m tetrofosmin SPECT images were compared with the FDG images that served as the reference for viability. Consecutive patients (n = 33) with chronic coronary artery disease and left ventricular dysfunction were included. Segmental Tc-99m tetrofosmin and FDG data were displayed in polar maps (17-segment model), and the segments were normalized to peak activity by use of the 4D-MSPECT software program. Segments with normalized FDG activity greater than 50% were considered viable. A similar cutoff value to assess viability was used for the noncorrected and attenuation-corrected Tc-99m tetrofosmin images. Regional contractile function was determined from the gated Tc-99m tetrofosmin images and scored as normokinesia, hypokinesia, or akinesia/dyskinesia. Of all segments, 482 (85%) were viable on FDG SPECT. Of these, 427 (89%) were classified as viable with noncorrected Tc-99m tetrofosmin. Thus 55 (11%) were underestimated with noncorrected Tc-99m tetrofosmin SPECT; these segments were mainly located in the inferior and inferoseptal regions. Attenuation correction changed the classification of 39 (70%) of the underestimated segments to viable. By use of attenuation correction, the agreement between Tc-99m tetrofosmin and FDG imaging improved from 84% to 90%. Similar observations were made when the analysis was restricted to the dysfunctional segments. CONCLUSION: The addition of attenuation correction to Tc-99m tetrofosmin SPECT significantly improved detection of myocardial viability in patients with chronic coronary artery disease, although minimal underestimation of viability remained as compared with FDG SPECT imaging.     

The role of Tc-99m (V) DMSA scintigraphy in the diagnosis and follow-up of lung cancer lesions

Objective To define the role of Tc-99m (V) dimercaptosuccinic acid (DMSA) scanning in the detection of lung cancer (LC) and its metastases, and monitoring the response of LC lesions (LCL) to chemo/radiotherapy (TH). Methods Tc-99m (V) DMSA whole-body scans, planar thorax views, and thorax Single-photon emission computed tomography (SPECT) images were obtained both 30 min (early) and 5 h (late) after Tc-99m (V) DMSA administration in 12 small/nonsmall cell LC patients (11 men, 1 woman; mean age 59 years). Five patients also had bone scans. The same scintigraphic protocol was performed in 7 of 12 patients, 3 weeks after first-line TH. TH response was evaluated visually in all LCL and semiquantitatively in primary tumors (PT) of six patients, by comparing the tumor uptake ratios (TUR) of pre-TH and post-TH Tc-99m (V) DMSA SPECT [TUR = mean counts of region of interests (ROI) in PT/mean counts in contralateral ROI]. In seven patients, a 6-month survival was determined. Results Tc-99m (V) DMSA accumulated in 34 LCL (11 PT, 19 bone metastases, 1 suprarenal mass, 1 axillary node, 2 supraclavicular nodes). A total of 11 patients displayed Tc-99m (V) DMSA uptake in LCL and one patient did not show uptake. In six patients, SPECT imaging showed deeply located PT in the lung parenchyma better than planar views. In five patients, both planar and SPECT views revealed peripherally located PT in the lungs. Early scans showed 18 LCL and late scans displayed all the LCL. Nine bone metastases on pre-TH Tc-99m (V) DMSA scans revealed matched areas of increased Tc-99m methylene diphosphonate (MDP) uptake on bone scans; six bone metastases were additionally detected on Tc-99m (V) DMSA scans when compared with bone scans, and four bone metastases on Tc-99m (V) DMSA scans could not be compared with bone scans because bone scan was not performed. In one patient, Tc-99m (V) DMSA scans became positive for bone metastases on post-TH later than the bone scans for some of the bone metastases. Neither planar nor SPECT imaging showed mediastinal lesions defined on thorax CT in nine patients. On TH monitoring, 17 LCL showed diminished Tc-99m (V) DMSA uptake, one disappeared, four were unchanged, three displayed increased uptake, and five new lesions were established. Of the six patients, TUR in PT increased in two (one survived), decreased in one (exitus), was unchanged in two (two exitus) on post-TH scans, and PT totally disappeared in one (survived) patient. Conclusions Tc-99m (V) DMSA scans are useful in detecting LCL, except for those around the blood pool regions, making it a promising modality to monitor TH response. Obtaining a single fifth hour late Tc-99m (V) DMSA scan is appropriate. SPECT should be applied to all patients for the detection of deeply located lesions.     

Evaluation of the effects of methylprednisolone pulse therapy in patients with systemic lupus erythematosus with brain involvement by Tc-99m HMPAO brain SPECT

Methylprednisolone pulse therapy (MPT) was introduced to avoid life-threatening complications in patients with systemic lupus erythematosus (SLE) with brain manifestations; however, the efficacy of MPT in SLE patients with brain involvement is still uncertain and needs to be objectively evaluated. We enrolled 15 female SLE patients with neuropsychiatric manifestations in this study. All patients had normal brain MRI and abnormal brain HMPAO-SPECT findings. Follow-up HMPAO-SPECT studies were conducted 2 weeks after MPT. Serum levels of anticardiolipin antibodies (ACA) and anti-ribosomal P antibodies (anti-P) were measured before and after MPT. Before MPT, 7 patients were positive for ACA and 7 patients were positive for anti-P. After MPT, none of the 15 patients demonstrated positive serologic findings or neuropsychiatric manifestations. Based on the follow up brain HMPAO-SPECT images following MPT, 13 patients showed disappearance of the perfusion defects and 2 patients showed partial recovery of rCBF. Brain HMPAO-SPECT imaging is a logical and objective tool for measuring the effects of MPT in SLE patients with brain involvement by determining of changes in rCBF.     

Different findings in Tc-99m MDP bone scintigraphy of patients with sickle cell disease: report of three cases

Objective Sickle cell anemia is an inherited disorder caused by abnormal hemoglobin, the S hemoglobin. Although vaso-occlusive crises can occur virtually in any organ, they are particularly common in the bony skeleton of affected patients. Bone marrow necrosis, bone infarcts, osteomyelitis, and aseptic necrosis are common complications in patients with sickle cell disease. Beside these abnormalities of the skeletal system, diffuse micro or macro calcification resulting from both splenic infarction and repeated vaso-occlusive episodes in the kidneys can be shown by technetium-99m methylenediphosphonate (Tc-99m MDP) bone scintigraphy. We present here the different osseous and extraosseous abnormalities noted on bone scintigraphies of three patients with sickle cell anemia. Methods Whole-body bone scan was performed after injecting 740 MBq of Tc-99m MDP in three patients with sickle cell disease. Results Tc-99m MDP whole-body image of the first patient showed non-uniform uptake in the anterior and posterior aspects of multiple ribs and bilateral femurs and tibias that was attributed to repetitive infarcts. Additionally, increased activity in shoulders, right elbow, and right knee was consistent with arthritis. Tc-99m MDP image of the second patient demonstrated avascular necrosis of the left femoral head and diffuse activity in the enlarged kidneys. Increased activity in the spleen that was attributed to repetitive infarcts was visualized in bone scan of the third patient. Conclusions In light of the findings in these cases, bone scintigraphy is a reliable imaging method in detecting both osseous and extraosseous abnormalities of sickle cell disease and may be used initially.     

Clinical experience with Tc-99m HM-PAO high resolution SPECT of the brain in patients with cerebrovascular accidents

In order to evaluate the diagnostic contribution of brain SPECT imaging with ^99mTc-HMPAO in cerebrovascular disease, we examined 92 stroke cases (144 lesions), 2 hematoma cases and 30 cases with transient neurologic symptoms. Abnormal tracer distribution is visible as zones of either hypoactivity or hyperactivity (border zone hyperemia or luxury perfusion). Remote vascularization changes could also be found (crossed cerebellar diaschisis or ipsilateral cortical perfusion reduction in thalamic or capsula interna lesions). Both X-ray CT and blood flow SPECT have comparable sensitivity in the exploration of cerebral infarction, with detection in, respectively, 89.5% and 87.5% of the lesions. False negative scintitomographic images are frequently recorded in small lacunar infarcts within the basal ganglia and white matter (capsula interna). Some early infarcts and asymmetry of brain perfusion in patients with transient neurologic symptoms are frequently not detected by CT. An additional advantage of blood flow SPECT is its ability to visualize remote blood flow changes and the changing pattern of vascularization of ischemic lesions and their surrounding areas including hyperemia.     

Assessment of myocardial viability using F-18 fluorodeoxyglucose/Tc-99m sestamibi dual-isotope simultaneous acquisition SPECT: Comparison with Tl-201 stress-reinjection SPECT

BACKGROUND: This study compared technetium 99m sestamibi/fluorine 18 fluorodeoxyglucose dual-isotope simultaneous acquisition (DISA) with stress-reinjection thallium 201 single photon emission computed tomography (SPECT) with regard to their ability to detect myocardial viability. METHODS AND RESULTS: The study cohort consisted of 42 angiographically significant coronary artery disease patients with symptomatic congestive heart failure or regional wall motion abnormalities. In total, 398 dysfunctional segments in 40 patients were analyzed (2 patients were excluded because of poor-quality F-18 fluorodeoxyglucose images). Of the segments, 217 were diagnosed as viable and 144 as nonviable by both DISA and Tl-201, 33 were viable by DISA but nonviable by Tl-201, and 4 were viable by Tl-201 but nonviable by DISA. Most discrepancies were in the inferior wall. Of the 40 patients, 16 underwent revascularization. From the follow-up results for the 105 dysfunctional segments in these 16 patients, DISA viability appears to be a significant predicting factor (P = .014) for functional recovery after revascularization statistically whereas Tl-201 viability does not (P = .09). CONCLUSION: Our study suggests that DISA viability provides more accurate prediction of postrevascularization functional recovery than Tl-201 viability. Given the small number of patients who underwent revascularization, the superiority of DISA over Tl-201 in detecting myocardial viability may be firmly established by further study on a large scale for patients with profound left ventricular dysfunction.     

Diagnostic performance of Tc-99m HMPAO SPECT for early and late onset Alzheimer’s disease: a clinical evaluation of linearization correction

Objective  This study examined the influence of linearization correction (LC) on brain perfusion single-photon emission computed tomography (SPECT) for the diagnosis of Alzheimer’s disease (AD). Methods  The early onset group (<65 years old) consisted of 10 patients with AD, and the late onset group (≥65 years old) of 13 patients with AD. Age-matched controls included seven younger and seven older normal volunteers. Tc-99m hexamethyl propyleneamine oxine (HMPAO) SPECT images were reconstructed with or without LC [LC (+) or LC (−)] and a statistical analysis was performed using a three-dimensional stereotactic surface projection (3D-SSP). In addition, a fully automatic diagnostic system was developed, which calculated the proportion of the number of abnormal pixels in the superior and inferior parietal lobule, as well as in the precuneus and posterior cingulate gyrus. Results  The areas under the receiver-operating characteristic curve (AUCs) of the early onset group for conventional axial SPECT images, SPECT + 3D-SSP images and the fully automatic diagnostic system were 0.71, 0.88, and 0.92 in LC (−) and 0.67, 0.85, and 0.91 in LC (+), respectively. The AUCs of the late onset group were 0.50, 0.61, and 0.79 in LC (−) and 0.49, 0.67, and 0.85 in LC (+), respectively. Conclusion  LC on Tc-99m HMPAO SPECT did not significantly influence the diagnostic performance for differentiating between AD and normal controls in either early or late onset AD. Further examination with individuals suffering from very mild dementia is, therefore, expected to elucidate the effect of LC on minimally hypoperfused areas.     

The relationship between the percentage of lung shunting on Tc-99m macroaggregated albumin (Tc-99m MAA) scan and the grade of hepatocellular carcinoma vascularity

Background

Hepatocellular carcinoma (HCC) stands for the majority of primary liver malignancy. HCC has variable grade of vascularity according to the histological tumor grade and underlying liver damage. Yttrium-90 radioembolization is a promising catheter-based hepatic intra-arterial therapy for HCC that necessitates proper planning. Technetium-99m macroaggregated albumin (Tc-99m MAA), a simulation of the treatment, is used to identify the shunting of microspheres to the lungs or gastrointestinal tract.

Objective

To evaluate the relationship between the percentage of lung shunting on Tc-99m MAA scan performed in treatment planning of Yttrium-90 (Y-90) microsphere selective internal radiation therapy (SIRT) for HCC and the grade of tumor vascularity shown on digital subtraction hepatic angiography.

Materials and methods

This study was conducted on 19 patients diagnosed to have HCC, based on typical computed tomography (CT) criteria and/or elevated alpha-fetoprotein (AFP) ?200 ng/ml, and planned for Y-90 therapy. They were injected by Tc-99m MAA into the hepatic arterial territory with prior digital subtraction angiography. Tc-99m MAA scan was reviewed for extrahepatic shunting within the abdomen. Additionally, the hepatopulmonary shunt (HPS) fraction or the lung shunting (LS) percentage was calculated and further evaluated in relation to the grade of tumor vascularity shown on digital subtraction hepatic angiography.

Results

There was no extrahepatic accumulation of Tc-99m MAA related to umbilical, gastroduodenal or splenic shunting. The LS percentage assorted among patients and ranged between 0.8% and 42.9% with a median of 5.5%. LS more than 20% occurred in only 1 patient. Subsequent therapy plan was changed accordingly in 5% of patients. The more vascular the lesion was, the higher lung shunting percentage was detected.

Conclusion

Tc-99m MAA scan is fundamental prior to Y-90 microsphere SIRT as it minimizes the risk of post-radioembolization complications, hence, enhancing the safety of Y-90 microsphere subsequent administration. Moreover, the percentage of lung shunting varies considerably among patients with HCC relying on the grade of tumor vascularity.     

Baseline/post-nitrate Tc-99m tetrofosmin mismatch for the assessment of myocardial viability in patients with severe left ventricular dysfunction: Comparison with baseline Tc-99m tetrofosmin scintigraphy/FDG PET imaging

BACKGROUND: Positron emission tomography (PET) flow/metabolic mismatch is considered the nuclear medicine gold standard for the assessment of myocardial viability. The aim of this study was to investigate whether baseline/nitrate technetium 99m tetrofosmin single photon emission computed tomography (SPECT) mismatch may provide equivalent clinical information. METHODS AND RESULTS: We studied 23 patients (aged 62 +/- 10 years, 19 men) with previous myocardial infarction (16 anterior, 4 inferior, and 3 anterior plus inferior) and postischemic heart failure (gated SPECT [G-SPECT] ejection fraction, 26% +/- 8%). All patients underwent Tc-99m tetrofosmin G-SPECT at rest and after nitrates (intravenous isosorbide dinitrate, 0.2 mg/mL, 10 mL/h) as well as a fluorine 18 fluoro-2-deoxy-d-glucose (FDG) PET scan. Regional wall motion analysis was performed with quantitative G-SPECT (QGS). Myocardial dysfunction was defined as a regional QGS score of 2 or greater. Regional perfusion was assessed by quantitative perfusion score (QPS) providing percent Tc-99m tetrofosmin uptake in a 20-segment model. Semiquantitative analysis of FDG uptake was performed by use of polar maps generated by Siemens ECAT HR + software. In areas with a perfusion rate lower than 80%, PET viability was identified by a normalized FDG percent uptake/baseline Tc-99m tetrofosmin percent uptake ratio greater than 1.2. We analyzed 460 segments; 298 (64%) were dysfunctional by QGS analysis. Of these, 170 were viable by PET imaging whereas 128 were nonviable. Regional Tc-99m tetrofosmin uptake was higher in viable than in nonviable segments both at rest (60% +/- 24% vs 42% +/- 12%, P <.01) and after nitrates (67% +/- 20% vs 41% +/- 18%, P <.01). According to receiver operating characteristic curve analysis, a cutoff value of 63% for resting as well as post-nitrate G-SPECT provided the highest diagnostic accuracy for the detection of myocardial viability (67% and 72% at rest and after nitrates, respectively). When the same algorithm used for the comparison with PET (normalized nitrate percent uptake/baseline percent uptake) was applied to G-SPECT, we obtained the highest agreement with PET (accuracy, 93%; sensitivity, 95%; specificity, 92%). CONCLUSIONS: In patients with severe left ventricular dysfunction, perfusion data alone, both at rest and after nitrates, do not allow an accurate estimate of myocardial viability. In dysfunctioning segments, the analysis of rest/post-nitrate Tc-99m tetrofosmin mismatch provides results similar to those obtained by PET flow/metabolic mismatch.     

Accuracy of exercise testing in the assessment of the severity of myocardial ischemia as determined by means of technetium-99m tetrofosmin SPECT scintigraphy

BACKGROUND: The separation of patients with suspected or known coronary artery disease into low- and high-risk subgroups by means of noninvasive testing is highly relevant in the selection of patients who require further diagnostic or therapeutic investigation. We evaluated whether exercise electrocardiographic variables during exercise testing might be a means of predicting the severity of myocardial ischemia as assessed with myocardial scintigraphy. METHODS AND RESULTS: We retrospectively reviewed 816 consecutive patients (mean age, 57+/-10 years) who underwent exercise technetium-99m tetrofosmin single photon emission computed tomography (SPECT) for the assessment of suspected or known coronary artery disease. Eight independent significant predictors of the extent and severity of reversible perfusion defects (ischemic perfusion score), which when integrated in a diagnostic algorithm satisfactorily discriminated patients with no reversible perfusion defects (sensitivity, 75%; specificity, 80%) and patients with severe impaired myocardial perfusion (> or =11 ischemic perfusion score; sensitivity, 77%; specificity, 82%), were identified by means of stepwise discriminant analysis. However, patients with mildly to moderately impaired myocardial perfusion (> or =21 but <11 ischemic perfusion score) were poorly discriminated (sensitivity, 50%; specificity, 78%). The set of variables that were significant (P<.0001) for prediction included sex, myocardial infarction, exercise angina, the maximal amount of ST segment depression, rate-pressure product threshold criteria, slope of ST segment depression, ST/heart rate index, and peak exercise heart rate. CONCLUSIONS: The results of the use of clinical and electrocardiographic exercise variables satisfactorily agrees with the results from scintigraphy only for patients with no reversible perfusion defects and with severely impaired myocardial perfusion. However, it fails as an approach with universal applicability.     

The role of thallium-201 whole body scan with pelvic SPECT in patients with uterine cervical cancer treated by radiation therapy: a preliminary report

Evaluation of tumor extent before treatment and its response to therapy is important. The aim of this report is to assess the usefulness with thallium-201 (Tl-201) imaging study including whole body scan and pelvic single photon emission computed tomography (SPECT) in patients with uterine cervical cancers treated by radiation therapy. Before irradiation, eleven patients received detailed physical examination and Tl-201 imaging studies. A 4-score grading system was set for evaluation. The interval between Tl-201 imaging follow-up and completion of radiotherapy is one to four months, and its findings were compared with those from CT scan and clinical evidence. Before radiation, left supraclavicular and paraaortic lymphadenopathy was identified in one patient from whole body scan. Accumulation of Tl-201 uptake is observed from pelvic SPECT in all patients. It seems that patients with more tumor bulk had more intense uptake, except for one case with history of suspected pelvic inflammatory disease (PID). After radiotherapy, complete or partial regression is observed. For 6 patients with complete regression (score=0), no evidence of recurrence is confirmed by follow-up examinations. For three patients with little residual uptake (score=1), one is suspected with residual density and she is under close follow-up, the other two patients seem due to uterine myoma or short latency. These three patients received another Tl-201 scan 6 months after irradiation completion and the score became zero. One patient with residual intense uptake (score=2) suffered from relapse in the pelvis and abdomen. This preliminary report indicates that Tl-201 whole body scan and pelvic SPECT has potential in the assessment of response to radiotherapy in patients with uterine cervical cancers. However, further studies including more cases and longer follow-up are needed.     

Retrospective review: usefulness of a number of imaging modalities including CT, MRI, technetium-99m pertechnetate scintigraphy, gallium-67 scintigraphy and F-18-FDG PET in the differentiation of benign from malignant parotid masses

Objective The aim of this study is to evaluate an imaging approach using computed tomography (CT), magnetic resonance imaging (MRI), technetium-99m pertechnetate scintigraphy (^99mTc pertechnetate scintigraphy), gallium-67 scintigraphy (⁶⁷Ga scintigraphy) and fluorine-18 fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET). Material and Methods We reviewed retrospectively 59 patients with parotid masses. CT, MRI,⁶⁷Ga scintigraphy,^99mTc pertechnetate scintigraphy, and¹⁸F-FDG PET were performed. Results All of the benign tumors had smooth margins on CT and MRI. Patients with inflammatory lesions and malignant lesions showed well-defined margins or ill-defined margins. All Warthin's tumors showed high technetium accumulation. Many of malignant tumors showed high FDG accumulation. Both pleomorphic adenomas and Warthin's tumors showed high accumulation in some cases on¹⁸F-FDG PET. Among 15 patients with pleomorphic adenoma, 14 patients showed marked hyperintensity relative to CSF on T2-weighted images and partial enhancement on contrast-enhanced T1-weighted images. Combination of several imaging modarity offered usefulness of differential diagnosis for parotid masses. Conclusion An efficient combination of imaging methods may be helpul for achieve the correct diagnosis.     

Comparative study of fluorodeoxyglucose positron emission tomography and magnetic resonance imaging for the detection of spinal bone marrow infiltration in untreated patients with multiple myeloma

Background: The presence and extent of osteolytic bone lesions in untreated patients with multiple myeloma are important factors in the staging of the disease, and the extent of bone lesions in multiple myeloma cases significantly influences decisions regarding therapy. Recently, fluorodeoxyglucose positron emission tomography (FDG-PET) and magnetic resonance imaging (MRI) have been used to detect bone marrow involvement in patients with multiple myeloma.

Purpose: To compare the efficacy of FDG-PET and MRI for the detection of bone marrow infiltration into the spine in untreated patients with multiple myeloma.

Material and Methods: Twenty-two patients with multiple myeloma underwent both FDG-PET and spine MRI. The examined spinal regions by MRI included 21 thoracic and lumbar spines, one lumbar spine, and 12 cervical spines. The following imaging sequences were performed: T1-weighted spin-echo MRI with and without fat suppression, and T2-weighted spin-echo MRI in the sagittal plane. In the patients with bone marrow abnormalities, an additional contrast-enhanced T1-weighted spin-echo MR image and a fat-suppressed T1-weighted spin-echo MR image were obtained. Patients were divided into three groups on the basis of the criteria defined by Durie and Salmon: stage I (n=9), stage II (n=3), and stage III (n=10). The number and location of lesions detected in both FGD-PET and MRI were recorded, and the lesions were compared using the McNemar test. Bone marrow biopsy results, the patient's clinical examinations, and other imaging findings (MRI, FDG-PET, etc.) were used as references.

Results: In stages I and II (37 lesions in 12 patients), FDG-PET and MRI detected lesions in 78% (29 of 37 lesions) and 86% (32 of 37 lesions), respectively. However, the difference between the abilities of FDG-PET and MRI to detect lesions was not statistically significant (P=0.317). In stage III (101 lesions in 10 patients), FDG-PET and MRI detected lesions in 80% (81 of 101 lesions) and 92% (93 of 101 lesions), respectively. The difference between the abilities of FDG-PET and MRI to detect lesions was statistically significant (P=0.038).

Conclusion: MRI is superior to FDG-PET in detecting bone marrow involvement in the spine of patients with advanced multiple myeloma.