Comparison of201Tl-chloride SPECT with99mTc-MIBI SPECT in the depiction of malignant head and neck tumors

OBJECTIVE: Comparison of 201Tl chloride SPECT (TI-SPECT) with 99mTc-MIBI SPECT (MIBI-SPECT) in the depiction of malignant head and neck tumors was prospectively studied. METHODS: Forty-one patients with various tumors of the head and neck were included in this prospective study. Histologically, 36 patients had squamous cell carcinomas, 3 undifferentiated carcinomas, 1 transitional cell carcinoma, and 1 MALT lymphoma. All patients underwent a simultaneous dual-isotope SPECT of the head and neck with 201Tl and 99mTc-MIBI. Dual-isotope SPECT for early (n=41) and delayed acquisition (n=21) was performed. Qualitatively, 3 observers evaluated both TI-SPECT and MIBI-SPECT individually. The interpretation criteria were graded as grade 1 (no abnormal increased uptake) to 5 (definitely increased uptake of a degree equal to or greater than that of normal salivary gland). Statistical analysis of the comparison of Tl-SPECT and MIBI-SPECT was performed. The interobserver difference was evaluated using the kappa-coefficient. Quantitatively, T/N ratio (the ratio of the counts in the tumor divided by that in the normal nuchal muscles) and retention index were compared between TI-SPECT and MIBI-SPECT. RESULTS: On both the early and delayed images, the grades of uptake of the tumor in TI-SPECT were significantly higher than those in MIBI-SPECT by three observers. The grade of Tl-uptake of the tumor on the delayed images was 5 for all observers (kappa-coefficient=1); however, the kappa-coefficient varied from 0.39 to 0.84 in early T1-SPECT, and in early and delayed MIBI-SPECT. Statistical differences in T/N ratio were noted between early TI-SPECT (2.87 +/- 1.19) and MIBI-SPECT (2.48 +/- 1.06), and between delayed Tl-SPECT (2.11 +/- 0.70) and MIBI-SPECT (1.20 +/- 0.48). The retention index or Tl-SPECT (0.81 +/- 0.24) was significantly higher than that of MIBI-SPECT (0.52 +/- 0.15). CONCLUSIONS: The present study qualitatively and quantitatively showed that 201Tl had higher accumulation in the tumor than 99mTc-MIBI in both early and delayed images.     

Detection of malignant thymoma in primary tumor and metastatic lesions using 99mTc-tetrofosmin scintigraphy

99mTc-tetrofosmin was developed as a myocardial perfusion imaging agent and can also be used to depict tumors. We have experienced five cases of malignant thymoma delineated on 99mTc-tetrofosmin SPECT. In one case significant activity was clearly detected in the primary tumor and metastatic lesions. In quantitative analysis, similar 99mTc-tetrofosmin and 201Tl-chloride uptake ratios were obtained (1.95+/-0.57 versus 2.27+/-0.85, respectively; n.s.). The ability of 99mTc-tetrofosmin to detect malignant thymoma was comparable to that of 201Tl-chloride. Therefore, 99mTc-tetrofosmin might be a useful tracer for the detection of malignant thymoma, although more studies will be required to evaluate its diagnostic accuracy.     

99mTc-MIBI SPECT in small cell lung cancer patients before chemotherapy and after unresponsive chemotherapy

We evaluated the accumulation of 99mTc-MIBI in small cell lung cancer patients before chemotherapy and after unresponsive chemotherapy. The pre-chemotherapeutic group included 22 newly diagnosed patients. These patients underwent a 99mTc-MIBI SPECT study before starting chemotherapy. After chemotherapy, based on changes in tumor size, three different patterns of response (complete remission: CR, partial remission: PR and no change: NC) were defined. The post-chemotherapeutic group included 11 patients after chemotherapy who did not respond to chemotherapy. These patients underwent a 99mTc-MIBI SPECT study after completion of chemotherapy. SPECT images were acquired 15 min (early) and 2 hr (delayed) after injection of 99mTc-MIBI. With a region of interest technique, the early ratio, delayed ratio and retention index were calculated. Early and delayed ratios in pre-chemotherapeutic patients were significantly higher than those in post-chemotherapeutic patients. There were no significant differences between the pre-chemotherapeutic and post-chemotherapeutic patients in the retention index. In the pre-chemotherapeutic patients, early and delayed ratios for the CR and PR groups were significantly higher than those for the NC group. There were no significant differences in the retention index with respect to the tumor response. 99mTc-MIBI might be useful for evaluating the tumor chemosensitivity in patients with small cell lung cancer.     

201Tl, 99mTc-MIBI, 99mTc-tetrofosmin and 99mTc-furifosmin: relative retention and clearance kinetics in retrogradely perfused guinea pig hearts

Myocellular kinetics of 201Tl, 99mTc-MIBI, 99mTc-tetrofosmin and 99mTc-furifosmin were investigated using retrogradely-perfused guinea-pig hearts. Relative retention decreased in the order 99mTc-MIBI ==> 99mTc-tetrofosmin ==> 99mTc-furifosmin. 201Tl and 99mTc-MIBI exhibited bi- (t1,t2), 99mTc-tetrofosmin and 99mTc-furifosmin triexponential (t1,t2,t3) time-activity-curves. Latest-phase elimination-half-life increased from 201Tl (t2) ==> 99mTc-MIBI (t2) ==> 99mTc-tetrofosmin (t3) ==> 99mTc-furifosmin (t3), showing a significant increase in deteriorating myocardium for all tracers but 99mTc-furifosmin. Delayed elimination in deteriorating myocardium explains at least partly the redistribution phenomenon of 201Tl, and suggests a similar phenomenon for 99mTc-MIBI and 99mTc-tetrofosmin.     

Characteristics of the myocardial SPECT images of 99mTc-MIBI and 99mTc-teboroxime]

Characteristics of the myocardial distribution of 99mTc-MIBI and 99mTc-Teboroxime was compared with the myocardial distribution of 201Tl. We made summed myocardial images, in which central three short-axis SPECT slices were added. Rectangular region of interest (ROI) was set on each myocardial segment, and mean counts of each myocardial region was obtained using summed short-axis images. The ratio of inferior-to-anterior mean counts (I/A) was 0.69 +/- 0.20 in 99mTc-MIBI and 0.62 +/- 0.16 in 201Tl. The ratio of inferior-to-lateral mean counts was 0.70 +/- 0.18 and 0.65 +/- 0.13, respectively. Both ratios in 99mTc-MIBI were significantly higher than those in 201Tl (p less than 0.05). 201Tl to 99mTc-MIBI ratios of these two values were 1.11 +/- 0.17 (I/A) and 1.08 +/- 0.16 (I/L). The ratios of I/A and I/L of 99mTc-MIBI were about 10 percent higher than those of 201Tl. 99mTc-Teboroxime dynamic short-axis SPECT images of every three-minute were obtained. The ratios of counts in each wall were calculated similarly. After about 8 minutes, gradual increase in hepatic activity can be a cause of quantitative error in the assessment of SPECT images. We obtained the data with a human cardiac phantom. The myocardial phantom filled with 99mTc or 201Tl was placed in the mediastinal portion that is surrounded by the lung (saw dust) and vertebra (plastic bar). The ratio of I/A was 0.79 and I/L was 0.85 in 201Tl. The I/A ratio was 0.93 and I/L was 0.97 in 99mTc. Both ratios in 99mTc were about 15 percent higher than those in 201Tl.(ABSTRACT TRUNCATED AT 250 WORDS)     

Myocardial uptake characteristics of three99mTc-labeled tracers for myocardial perfusion imaging one hour after rest injection

OBJECTIVE: 99mTc-tetrofosmin and 99mTc-sestamibi are approved tracers for myocardial perfusion studies. Recently, a 99mTc-MIBI preparation from a different manufacturer (99mTc-cardiospect-MIBI) has been introduced to the market. Therefore, the aim of this study was the evaluation of 99mTc-tetrofosmin as well as of two different 99mTc-labeled MIBI tracers with regard to differences in imaging quality under resting conditions. METHODS: Sixty patients (mean age 63.8 years +/- 1.25) with known or suspected coronary artery disease but without evidence of rest-ischemia were included. Twenty patients in each group were examined by a two-day-rest-stress protocol using the three 99mTc-labeled tracers. Visual analysis of all images was performed by two experienced physicians blinded with regard to the applied tracer. Regions of interest (ROI) were defined over the heart, lung and whole body only in the rest imaging in order to calculate heart-to-lung, lung-to-whole body-, and heart-to-whole body-ratios. RESULTS: The heart-to-lung ratio was statistically significant higher for 99mTc-cardiospect-MIBI as compared to 99mTc-sestamibi as well as to 99mTc-tetrofosmin. Furthermore, a significantly higher heart-to-lung ratio was found for 99mTc-sestamibi as compared to 99mTc-tetrofosmin. The heart-to-whole body-ratio and the lung-to-whole body-ratio were equivalent between all tracers. Visual analysis revealed only slight differences regarding image quality between all tracers. CONCLUSIONS: ROI analysis surprisingly revealed a significant higher myocardial uptake and consequently a higher heart-to-lung ratio for 99mTc-cardiospect-MIBI. Whether this leads to a better visual image quality has to be evaluated in future studies with larger study populations as well as semiquantitative segmental analysis of the myocardial perfusion images.     

Comparison of 99Tcm-MIBI with 201Tl chloride SPET in patients with malignant brain tumours

The purpose of this study was to evaluate the usefulness of 99Tcm-MIBI accumulation for the differentiation of histological diagnosis of malignant brain tumours in comparison with the findings obtained using 201Tl chloride. A total of 25 patients with malignant brain tumours were investigated. The histological categories of tumours included glioblastoma multiforme (n = 5), anaplastic astrocytoma (n = 4), malignant lymphoma (n = 5), and metastatic tumour (n = 11). Simultaneous dual single photon emission tomography (SPET) images with 99Tcm-MIBI and 201Tl were acquired 15 min (early) and 2 h (delayed) after injection, and the early ratio, delayed ratio and retention index were measured. The new indices 201Tl/99Tcm-MIBI ratios and 201Tl/99Tcm-MIBI retention index were also calculated. With respect to the histological type, a higher retention index using 99Tcm-MIBI was noted in glioblastoma multiforme compared with metastatic tumour. Higher values of both ratios using 201Tl were noted in glioblastoma multiforme compared to metastatic tumour. The value of the delayed ratio obtained using 201Tl was higher in glioblastoma multiforme than in anaplastic astrocytoma, and the value was also higher in malignant lymphoma than in metastatic tumour. The 201Tl/99Tcm-MIBI early ratio of glioblastoma multiforme was significantly higher than that of metastatic brain tumour. The 201Tl/99Tcm-MIBI retention index of malignant lymphoma was significantly higher than that of glioblastoma multiforme. In the histological type of tumour, 99Tcm-MIBI is not superior to 201Tl, but the combined indices using 201Tl/99Tcm-MIBI may add new information about differential diagnosis.     

Extraosseous accumulation of bone scanning agents in malignant brain tumors: Comparison to semi-quantitative evaluation with<Superscript>99m</Superscript>Tc SPECT/<Superscript>201</Superscript>Tl SPECT and histological findings

Although 201Tl chloride (Tl) SPECT has been used in the differential diagnosis between recurrence of malignant brain tumor and necrosis after treatment, it is not generally recognized as a definite modality to distinguish them. We conducted a preliminary study using Tl SPECT and 99mTc-MDP or 99mTc-HMDP (Tc) SPECT because it has been said that extraosseous accumulation was caused by calcium deposits in necrotic tissues. In our study, for the purposes of clarifying the mechanism of extraosseous uptake and the correlation between extraosseous accumulation of bone-scanning agent and tumor viability in malignant brain tumors, we compared whether Tc uptake was correlated with the histopathological findings and further performed semi-quantitative evaluation between Tc SPECT and Tl SPECT. The correlation coefficients between the ratio of tumor to normal skull count obtained from Tc SPECT (Tc-T/N) and those of tumor to normal brain count (T/N) and to normal scalp count (T/S) both obtained from Tl SPECT were calculated. Using contrast enhanced CT (CE-CT) or contrast enhanced MRI (CE-MRI), 8 of 10 cases showed intensely ring-enhanced tumor with necrotic lesion. Histopathologically, 7 of 8 cases whose tumor had been resected before treatment had necrosis with increased vascularity or bleeding. Of the remaining 2 cases one case, malignant lymphoma had only hypervascularity by biopsy, while the other one was excluded for resection after treatment. Three of these 8 cases whose CE-CT or CE-MRI showed necrotic lesions exhibited Tc and Tl accumulations in the area corresponding to necrosis. In contrast, 2 showed no Tc nor Tl uptake. Tc-T/N had no significant correlation with any of early-, delayed-T/N or T/S. In conclusion, there was no significant correlation between Tc and Tl uptakes by malignant brain tumors in semi-quantitative evaluation.     

Brown adipose tissue: Evaluation with<Superscript>201</Superscript>Tl and<Superscript>99m</Superscript>Tc-sestamibi dual-tracer SPECT

Brown adipose tissue is one kind of adipose tissue and regulates body temperature and balance of energy via non-shivering thermogenesis. The authors present a case that strongly suggested the presence of activated brown adipose tissue in the neck, shoulders and axillary space by increased 18F-FDG uptake. 99mTc-sestamibi and 201Tl dual-tracer SPECT study showed increased 99mTc-sestamibi uptake and non-increased 201Tl uptake in the corresponding 18F-FDG uptake sites. Brown adipose tissue has dense mitochondria in the cells, which play an important role in thermogenesis. 99mTc-sestamibi uptake and retention depend on the mitochondrial activity but 201Tl uptake does not. Therefore, the activity of mitochondria in activated brown adipose tissue may explain the discrepant uptake between 99mTc-sestamibi and 201Tl.     

The retention indices of 201Tl-SPECT in brain tumors

OBJECTIVE: The aim of this study was to assess the utility of 201Tl SPECT in the differential diagnosis of intracranial tumors and to determine the relationship between 201Tl uptake and histological types. METHODS: Thirty-eight patients (19 males and 19 females) with thirty-eight brain tumors were evaluated with 201Tl-SPECT. The early and delayed 201Tl uptake ratio was calculated, and the retention index (RI) was applied as follows; RI = delayed uptake ratio/early uptake ratio. RESULTS: The RI of malignant tumors was higher (0.72 +/- 0.18) than that of benign tumors (0.50 +/- 0.16) and the difference was statistically significant (p = 0.00045). The difference between high-grade glioma (0.80 +/- 0.15) and metastatic tumors (0.64 +/- 0.19) was statistically significant (p = 0.039). CONCLUSION: 201Tl-SPECT may add useful biochemical information and could differentiate malignant brain tumors from benign lesions, but the RI of metastatic tumors varied depending on the organs with the primary lesion and histological types.     

Evaluation of radiotherapeutic response in non-small cell lung cancer patients by technetium-99m MIBT and thallium-201 chloride SPET

The purpose of this study was to investigate the relationship between technetium-99m hexakis-2-methoxyisobutylisonitrile (99mTc-MIBI) accumulation in tumours and response to radiotherapy in non-small cell lung cancer patients in comparison with the findings obtained using thallium-201 chloride (201Tl). Simultaneous dual single-photon emission tomography (SPET) imaging with 600 MBq 99mTc-MIBI and 111 MBq 201Tl was performed in 31 patients with biopsy- or sputum cytology-proven lung cancer. SPET images were acquired 15 min (early) and 2 h (delayed) after injection, and the early ratio, delayed ratio and retention index were measured. The tumours were classified into two groups on the basis of follow-up computed tomography (CT): responders (at least 50% reduction in tumour size) and non-responders (little or no change in tumour size). The mean (+/-SD) values of early ratio, delayed ratio and retention index using 99mTc-MIBI SPET were 3.0+/-1.1, 2.7+/-1.0 and -9.5+/-12.7, respectively, in responders and 2.4+/-0.7, 2.0+/-0.5 and -18.4+/-9.0, respectively, in non-responders. The corresponding values using 201Tl chloride SPET were 3.7+/-1.0, 4.7+/-1.5 and 24.2+/-22.1 in responders and 3.3+/-1.2, 4.0+/-1.3 and 20.4+/-20.5 in nonresponders. Using 99mTc-MIBI, the delayed ratio and retention index in responders were significantly higher than those in non-responders (P<0.01 and P<0.05, respectively). The results of this study indicate that patients with higher delayed ratio and retention index values using 99mTc-MIBI SPET are likely to respond better to radiotherapy than those with lower values. 99mTc-MIBI SPET may give an indication of the short-term response to radiotherapy in patients with non-small cell lung cancer.     

Assessment of myocardial washout of Tc-99m-sestamibi in patients with chronic heart failure: comparison with normal control

BACKGROUND: In contrast to 201TlCl, 99mTc-sestamibi shows very slow myocardial clearance after its initial myocardial uptake. In the present study, myocardial washout of 99mTc-sestamibi was calculated in patients with non-ischemic chronic heart failure (CHF) and compared with biventricular parameters obtained from first-pass and ECG-gated myocardial perfusion SPECT data. METHODS AND RESULTS: After administration of 99mTc-sestamibi, 25 patients with CHF and 8 normal controls (NC) were examined by ECG-gated myocardial perfusion SPECT and planar data acquisition in the early and delayed (interval of 3 hours) phase. Left ventricular ejection fraction (LVEF, %), peak filling rate (PFR, sec(-1)), end-diastolic volume (LVEDV, ml) and end-systolic volume (LVESV, ml) were automatically calculated from the ECG-gated SPECT data. Myocardial washout rates over 3 hours were calculated from the early and delayed planar images. Myocardial washout rates in the CHF group (39.6+/-5.2%) were significantly higher than those in the NC group (31.2+/-5.5%, p < 0.01). The myocardial washout rates for the 33 subjects showed significant correlations with LVEF (r = -0.61, p < 0.001), PFR (r = -0.47, p < 0.01), LVEDV (r = 0.45, p < 0.01) and LVESV (r = 0.48, p < 0.01). CONCLUSION: The myocardial washout rate of 99Tc-sestamibi is considered to be a novel marker for the diagnosis of myocardial damage in patients with chronic heart failure.     

Usefulness of<Superscript>201</Superscript>Tl and<Superscript>99m</Superscript>Tc MIBI scintigraphy in a case of oncogenic osteomalacia

A 45-year-old male was admitted with difficulty in walking due to leg pain. At the time of the first visit, a reduced serum phosphorus concentration and an increased serum alkaline phosphatase concentration of unknown etiology were observed. Either a whole body bone scintigraphy or CT of the neck, chest and abdominal region did not reveal any underlying disease. However both the whole body 201Tl scintigraphy and 99mTc MIBI SPECT showed accumulation in the right knee region, and a small tumor was detected by MRI examination. After a diagnosis of oncogenic osteomalacia due to this tumor was determined the tumor was surgically removed, and turned out to be a hemangiopericytoma. By removal of the tumor, either the symptoms or the laboratory data were improved significantly. In this case, both 201Tl scintigraphy and 99mTc scintigraphy MIBI were useful in identifying the location of the tumor which caused oncogenic osteomalacia.     

Segmental analysis of SPECT 99mTc-methoxy isobutyl isonitrile and 201Tl myocardial imaging in ischaemic heart disease

To study the potential usefulness of 99mTc-methoxy isobutyl isonitrile (99mTc-MIBI) as a substitute for 201Tl in assessing patients with ischaemic heart disease, 24 patients underwent 1 day rest and exercise 99mTc-MIBI single photon emission computerised tomography (SPECT) 1 week after SPECT exercise 201Tl. All patients were catheterized within 1 month after myocardial imaging. In 17 patients, resting first pass radionuclide angiography (FPRNA) was performed with 99mTc-MIBI. The heart to lung ratio for 99mTc-MIBI and 201Tl was calculated both at rest and exercise. The segmental analysis for myocardial perfusion reveals that 87/96 segments (91%) were correctly classified by SPECT 201Tl and 84/96 segments (88%) were correctly classified by 99mTc-MIBI. A significant correlation was present between LVEF measured by 99mTc-MIBI FPRNA and contrast ventriculography (r = 0.85, P less than 0.0001). The heart to lung ratio both at rest and exercise for 99mTc-MIBI is significantly higher than 201Tl (P less than 0.01 and less than 0.001 respectively). We conclude that 99mTc-MIBI is a promising agent for simultaneous evaluation of myocardial perfusion and cardiac function.     

Clinical evaluation of the 99mTc-CPI myocardial perfusion imaging

^99mTc-CPI myocardial perfusion scintigraphy including planar images in 35 patients and SPECT images in 16 patients has been studied. Scintigraphic data revealed that high quality ^99mTc-CPI myocardial perfusion images were obtained. The sensitivity and specificity of ^99mTc-CPI planar images in detecting CAD was 92% and 80% respectively. There was no significant difference in sensitivity for detecting CAD between planar and SPECT. However, the specificity of SPECT was much better than that of planar imaging.     

Comparison of 99mTc-hexakis 2-methoxy-2-isobutyl isonitrile and 201Tl SPECT imaging for evaluation of coronary artery disease

To evaluate clinical value of 99mTc-hexakis 2-methoxy-2-isobutyl isonitrile (MIBI) imaging for assessing coronary artery disease (CAD), 99mTc-MIBI SPECT imaging at post-exercise and at rest was compared with 201Tl SPECT imaging at post-exercise and 3 hours redistribution in 27 patients suspected with CAD. The sensitivities for detecting CAD patients were 94% (17/18) by both studies. The specificities were 71% (5/7) by 99mTc-MIBI and 57% (4/7) by 201Tl (p = NS). The sensitivities for detecting stenosed coronary arteries (greater than or equal to 75% stenosis) were also similar between 99mTc-MIBI (78%) and 201Tl (74%) (p = NS). The similar specificity values were obtained by 99mTc-MIBI (84%) and by 201Tl (82%) (p = NS). The patterns of abnormality (normal, ischemia and scar) were similar between 99mTc-MIBI and 201Tl images in 22 of the 25 cases (88%) and 117 of the 125 segments (94%). However, these patterns were occasionally different particularly in patients who received PTCA or CABG. Thus, 99mTc-MIBI SPECT imaging seems to be as accurate as 201Tl SPECT imaging for the detecting and evaluating CAD.     

Accuracy of 99mTc-tetrofosmin myocardial tomography in the evaluation of coronary artery disease

BACKGROUND: Technetium 99m-labeled myocardial agents have been proposed as an alternative to thallium 201. The aim of this study was to assess retrospectively the accuracy of exercise myocardial 99mTc-tetrofosmin scintigraphy with tomographic imaging (SPECT) in a large group population in the evaluation of coronary artery disease. Furthermore we evaluated the relation between the severity of scintigraphic impaired myocardial perfusion and the angiographic coronary artery stenoses in patients without myocardial infarction and with stenosis localized exclusively in the proximal segment of the 3 main coronary arteries. METHODS AND RESULTS: The study group consisted of 235 consecutive patients, 204 (87%) of whom were men, with a mean age of 57+/-10 years, and with suspected or known coronary artery disease, who underwent 99mTc-tetrofosmin SPECT and coronary angiography. Furthermore, 61 patients in a low-likelihood group for coronary artery disease were also studied. Significant disease was defined by > or = 50% luminal coronary artery stenosis in > or = 1 native coronary artery or major branch or in a saphenous vein graft or arterial mammary graft. The overall sensitivity was 95%, specificity was 76%, and predictive accuracy was 95%. The normalcy rate for the low-likelihood group was 93%. Sensitivity was 71% for the left anterior descending artery, 61% for the left circumflex artery, and 73% for the right coronary artery. Specificity was 94% for the left anterior descending artery, 96% for the left circumflex artery, and 91% for the right coronary artery. Predictive accuracy was 79% for the left anterior descending artery, 78% for the left circumflex artery, and 81 % for the right coronary artery. In patients without myocardial infarction linear regression analysis between scintigraphy and angiography showed a significant correlation in patients with severe proximal coronary artery stenosis (r = 0.53, P < .002), but not in those with moderate proximal stenosis (r = 0.31, P = NS). CONCLUSIONS: This study shows that 99mTc-tetrofosmin SPECT is accurate in the detection of coronary artery disease. The relation of the severity of scintigraphic impaired myocardial perfusion and angiographic coronary artery stenosis, however, may differ significantly in patients with proximal stenosis of different severity.     

Superimposed dual-isotope SPECT using99mTc-hydroxymethylene diphosphonate and201Tl-chloride to assess cartilage invasion in laryngohypopharyngeal cancer

OBJECTIVE: Cartilage invasion in laryngohypopharyngeal cancer has a significant impact on the choice of treatment modality and outcome of the disease. We examined invasion of cartilage in laryngohypopharyngeal cancer by simultaneous bone and tumor dual-isotope SPECT using 99mTc-hydroxymethylene diphosphonate and 201Tl-chloride. METHODS: Early and delayed simultaneous bone and tumor dual-isotope SPECT were performed on 19 patients with laryngohypopharyngeal cancer. Dual-isotope SPECT images were superimposed to project tumor location from tumor SPECT onto the osseous structures shown by bone SPECT. The presence or absence of cartilage invasion was evaluated histopathologically or by radiological studies such as CT and/or MRI. RESULTS: Histopathological or radiological examination of the cartilage revealed invasion in 5 patients and no invasion in 14 patients. The results of both early and delayed dual-isotope SPECT were exactly the same. Using dual-isotope SPECT, the sensitivity, specificity, and accuracy in detecting cartilage invasion by laryngohypopharyngeal cancer were: 80% (4/5), 92.9% (13/14), and 89.5% (17/19), respectively. CONCLUSIONS: Results of the present study suggest that superimposed early bone and tumor dual-isotope SPECT images may be sufficient for the diagnostic evaluation of cartilage invasion by laryngohypopharyngeal cancer. Superimposed dual-isotope SPECT imaging is a useful technique in the evaluation of cartilage invasion in laryngohypopharyngeal cancer.     

Tl-201 chloride and Tc-99m MIBI accumulation in lung adenocarcinoma in patients with and without distant metastases

PURPOSE: The relation between Tl-201 chloride accumulation by the tumor and its distant metastatic potential were evaluated in patients with lung adenocarcinoma and compared with the same parameters achieved using Tc-99m MIBI. METHODS: Fifty-six patients with primary lung adenocarcinoma were examined before therapy was begun. They were classified according to the radiologic findings and pathologic diagnosis into two groups: distant metastases and no distant metastases. All patients underwent dual-isotope imaging with Tl-201 chloride and Tc-99m MIBI. Regions of interest were placed over the tumor uptake (T) and contralateral normal lung tissue (N) areas on one transverse view with clearly defined lesions, and the T:N ratio and retention index were calculated. RESULTS: The early and delayed T:N ratios and retention index using Tl-201 chloride SPECT in the distant-metastases group were significantly greater (P < 0.001 to P < 0.05) than were those in the no-distant-metastases group. There was no significant correlation between the T:N ratio and retention index and distant metastatic potential using Tc-99m MIBI SPECT. CONCLUSION: Tl-201 chloride SPECT may be more effective than Tc-99m MIBI SPECT for evaluating the distant metastatic potential of primary lung adenocarcinoma.     

Diaphyseal medullary stenosis with pleomorphic malignant fibrous histiocytoma of the bone:99mTc hydroxymethylenediphosphonate and201Tl chloride scintigraphy findings

Diaphyseal medullary stenosis (DMS) is an extremely rare hereditary bone dysplasia, which was first described by Arnold in 1973. DMS has a high incidence of pleomorphic malignant fibrous histiocytoma (MFH). In this paper, we report the imaging findings of DMS with pleomorphic MFH of the bone, mainly describing 99mTc hydroxymethylenediphosphonate (HMDP) and thallium-201 (201Tl) chloride scintigraphy findings. On 99mTc HMDP scintigraphy, focal increased uptake area of the right femur corresponded to the area of bone marrow invasion of the tumor and bone infarction. The mechanism of the uptake of 99mTc HMDP to the extraosseous lesion was not clear. On 201Tl chloride scintigraphy, the increased uptake of the periphery of the mass seemed to reflect the aggressiveness of invasion and the cellularity.