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Purpose: Head CT and MRI show characteristic changes in the syndrome of acute bilateral basal ganglia lesions in patients with diabetic uremia. However, they do not provide further insight into the underlying pathophysiology. To further clarify the biologic mechanism of the syndrome, F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) was used in 2 patients., Methods: PET studies were performed in 2 diabetic uremic patients with acute movement disorders. The cerebral glucose metabolic rates in these 2 patients were compared with 11 normal age-matched controls. The images were further analyzed with statistical parametric mapping to identify regions of significant metabolic abnormality., Results: The cases showed markedly reduced glucose metabolism in the bilateral basal ganglia, especially in the bilateral putamens, where the glucose uptake was nearly absent., Conclusions: FDG-PET correlates better with the clinical conditions and provides more pathophysiological information than head CT or MRI scans in bilateral basal ganglia lesions in patients with diabetic uremia. We propose that acute exacerbation of a long-term glucose utilization failure in the basal ganglia cells produced these lesions.

This study was to evaluate the clinical impact of whole body positron emission tomography (PET) with 18F-fluoro-2-deoxyglucose (FDG) to detect recurrent cervical cancer based on asymptomatically elevated tumor marker levels. Whole-body FDG-PET was performed in 20 patients with suspected recurrent squamous cell carcinoma (SCC) of the cervix and asymptomatic tumor marker of SCC antigen increased serum levels but negative or equivocal other imaging modality results. All of these 20 asymptomatic patients have serum levels of SCC antigen > 1.5 ng/mL. The final diagnosis of recurrent cervical cancer was established by operation/biopsy histopathological findings or clinical follow-up after more than 1 year by additional morphological imaging techniques. Among the 20 patients, the final diagnosis of recurrent cervical cancer was established in 81 lesions of 19 patients. The FDG-PET accurately detected 78/81 lesions. With asymptomatically elevated SCC antigen serum levels, the diagnostic sensitivity and accuracy of FDG-PET to detect recurrent cervical cancer lesions were 97.5% and 94.0%, respectively. The FDG-PET is a useful technique to detect recurrent cervical cancer for patients with asymptomatically elevated SCC antigen serum levels.

Background/aims: The differentiation of hepatocellular carcinoma from benign liver diseases in hepatitis B virus carriers by imaging studies based upon morphological aspects can be difficult., Methodology: FDG-PET (18F-2-deoxyglucose positron emission tomographies) were performed in 48 hepatitis B virus carriers to detect hepatocellular carcinoma and differentiate other benign liver diseases. In each patient, the focal liver lesion was visible by ultrasound and an elevated serum alpha-fetoprotein level was noted. Definite diagnosis was established after ultrasound-guided liver biopsy followed by histopathological examination., Results: The histopathological examination revealed hepatocellular carcinoma in 36 patients and benign liver diseases in the remaining 12 patients. Twenty of 36 hepatocellular carcinomas were detectable by FDG-PET and none of 12 benign liver diseases were visualized by FDG-PET. The detection sensitivity of FDG-PET was not related to the echogenicity and size of hepatocellular carcinoma., Conclusions: FDG-PET is not sensitive to but is more specific than ultrasound and serum alpha-feto-protein level to detect hepatocellular carcinoma and differentiate from other benign liver diseases in hepatitis B virus carriers.

It is well-known that fluorodeoxyglucose (FDG) is taken up by different tumors and active inflammation. Focal uptake of FDG may cause false-positive results in certain benign or physiologic conditions. However, the misdiagnosis of laryngeal cancer resulting from FDG secretion in saliva has not been reported previously. In the current report, a 34-year-old man was admitted for a checkup and was misdiagnosed as having laryngeal cancer as a result of FDG secretion in saliva before the patient rinsed his mouth with a glass of water and swallowed the saliva with water.

The purpose of this preliminary study is to evaluate the characteristics of solitary pulmonary lesions in patients using extrapulmonary neoplasmas with 18F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET). Thirty-two patients with extrapulmonary neoplasmas who had solitary pulmonary lesions and were suspected for pulmonary metastasis underwent an oncological survey with FDG-PET. Standard uptake value (SUV) and the ratio of lesion-to-background (L/B ratio) were used as parameters to differentiate and characterize the solitary pulmonary lesions. Using SUV > 2.5 or L/B ratio > 3 as the cutoff to diagnose malignancy, FDG-PET correctly identified 29 true-positive cases. However, FDG-PET failed to interpret two false-positive and one false-negative cases. The accuracy of FDG-PET was 91%. We concluded that FDG-PET is an accurate modality to differentiate solitary pulmonary lesions in patients with extrapulmonary neoplasmas.

Objective: This preliminary study was to evaluate the characteristics of indeterminate solitary pulmonary lesions in patients with renal cell carcinomas (RCC) using (18)F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET)., Material and Methods: Fifteen patients with RCC were found to have solitary pulmonary lesions with indeterminate chest X-ray and CT findings. Pulmonary metastases were suspected in all cases so whole body surveys with FDG-PET were performed., Results: FDG-PET correctly identified 9 true-positive and 4 true-negative cases. However, FDG-PET failed to interpret 1 false-positive and 1 false-negative case. Standard uptake values (SUV) were used as parameters to differentiate the solitary pulmonary lesions. Using SUV >2.5 as the cutoff to diagnose malignancy, the sensitivity, specificity, and accuracy of FDG-PET were 90, 80, and 87%, respectively., Conclusion: We conclude that FDG-PET is an accurate modality to differentiate solitary pulmonary lesions in patients with RCC., (Copyright 2003 S. Karger AG, Basel)

Aim: To evaluate whether positron emission tomography (PET) with (18)F-2-deoxyglucose (FDG) can detect pelvic lymph node metastases in prostate cancer patients who had elevated serum prostate-specific antigen (PSA) levels after treatment., Methods: Twenty-four patients with a rising serum PSA level after treatment for localized prostate cancer were examined with FDG-PET before pelvic lymph node dissection. All patients had negative findings on whole body bone scan and equivocal pelvic computed tomography (CT) results. The results of FDG-PET were then compared to the histology of the pelvic lymph nodes obtained at surgery., Results: Lymph node metastases were detected by histopathological examination in 16/24 (66.7%) patients. At the sites with histopathologically proven metastases, increased FDG uptake was found in 12/16 (75.0%) patients. In addition, there were 4 patients with false-negative results, but no patient with a false-positive result on FDG-PET images. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FDG-PET in detecting metastatic pelvic lymph nodes were 75.0, 100.0, 83.3, 100.0, and 67.7%, respectively., Conclusions: These results suggest that FDG-PET may be a valuable diagnostic tool in the staging of pelvic lymph nodes in patients with PSA relapse after treatment of localized prostate cancer when the whole body bone scan is negative and pelvic CT findings are equivocal., (Copyright 2003 S. Karger AG, Basel)

The patient's prognosis is significantly related to para-aortic lymph node metastasis in advanced cervical cancer. Magnetic resonance imaging (MRI) has been widely performed to detect lymph node metastasis with a variable sensitivity. Therefore, in this prospective study, we evaluated FDG-PET to detec para-aortic lymph nodal metastasis in locally advanced cervical carcinoma with negative MRI findings. Forty-two women with advanced cervical cancer and negative abdominal MRI findings were included in this study. Para-aortic lymph node metastases were confirmed according to para-aortic lymph-adenectomy findings. Para-aortic lymphadenectomy findings showed 12 patients with para-aortic lymph nodal metastasis. Two patients had false-negative and 1 patient had false-positive FDG-PET findings. The FDG-PET showed sensitivity of 83.3%, specificity of 96.7%, and accuracy of 92.9%. As assessment of para-aortic lymph node metastases may be essential for therapy planning, FDG-PET is an alternative tool to detect para-aortic lymph node metastases in advanced cervical cancer with negative MRI findings.

Purpose: Conventional technetium-99m methylene diphosphate whole body bone scan (bone scan) has a high sensitivity but a poor specificity to detect bone metastases. However, positron emission tomography with 18F-2-deoxyglucose (FDG-PET) can offer superior spatial resolution and improved specificity. We have attempted to evaluate the usefulness of FDG-PET for detecting bone metastases in renal cell carcinomas (RCC) and to compare FDG-PET results with bone scan findings., Methods: Eighteen patients were selected for this study with biopsy-proven RCC. They were suspected of having bone metastases and were undergoing bone scan and FDG-PET to detect bone metastases. The final diagnoses of bone metastases were established by operative, histopathological findings or clinical follow-up longer than 1 year by additional radiographs or following FDG-PET/bone scan findings showing progressive and extensive widespread bone lesions., Results: A total of 52 bone lesions including 40 metastatic and 12 benign bone lesions found on either FDG-PET or bone scan were evaluated. FDG-PET could accurately diagnose all 40 metastatic and 12 benign bone lesions. Bone scan could accurately diagnose only 31 metastatic bone lesions. Diagnostic sensitivity and accuracy of FDG-PET were 100% and 100%, respectively,and bone scan were 77.5% and 59.6%, respectively., Conclusions: Our data suggest that FDG-PET has a higher sensitivity and a better accuracy than that of bone scan to detect bone metastases in patients with RCC.

Objective: To evaluate retrospectively the impact of [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) on the detection of recurrent breast cancer based on asymptomatically elevated tumor markers levels., Methods: Whole-body FDG-PET was performed in 30 patients with suspected recurrent breast cancer and asymptomatic tumor marker increase but negative or equivocal other imaging modality results. A blood sample was drawn in each case for marker assay (CA 15-3 and CEA) on the same day as the FDG-PET. All of these 30 asymptomatic patients had either CA l5-3 >32 U/ml or CEA >5 ng/ml. The final diagnosis of recurrent breast cancer was established by operation/biopsy histopathological findings or clinical follow-up for >1 year by additional morphological imaging techniques., Results: Among the 30 patients, the final diagnosis of recurrent breast cancer was established in 38 sites in 28 patients. FDG-PET accurately detected 35/38 sites in 25/28 patients with recurrence. The diagnostic sensitivity and accuracy of FDG-PET in patients with suspected recurrent breast cancer and asymptomatically elevated tumor markers were 96 and 90%, respectively., Conclusions: FDG-PET is a useful technique for detecting recurrent breast cancer suspected from asymptomatically elevated tumor markers levels and has an important clinical impact on the management of these patients.

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

Despite advances in morphological imaging, some patients with non-small cell lung cancer (NSCLC) are found to have non-resectable disease at surgery or die of recurrence within a year of surgery. At present, metastatic bone involvement is usually assessed using conventional technetium-99m methylene diophosphate (Tc-99m MDP) whole body bone scan (bone scan), which has a high sensitivity but a poor specificity. We have attempted to evaluate the usefulness of whole body positron emission tomography with 18F-2-deoxyglucose (FDG-PET) for the detection of malignant bone metastases of NSCLC, and to compare FDG-PET results with Bone Scan findings. Forty-eight patients with biopsy-proven NSCLC and suspected to have stage IV disease underwent whole body bone scan and FDG-PET to detect bone metastases. The final diagnoses of bone metastases were established by operative, histopathological findings or clinical follow-up longer than 1 year by additional radiographs or following FDG-PET/Tc-99m MDP bone scan findings showing progressively and extensively widespread bone lesions. A total of 138 bone lesions found on either FDG-PET or Tc-99m MDP bone scan were evaluated. Among the 106 metastatic and 32 benign bone lesions, FDG-PET and Tc-99m MDP bone scan could accurately diagnose 99 and 98, as well as 30 and 2 metastatic and benign bone lesions, respectively. Diagnostic sensitivity and accuracy of FDG-PET and Tc-99m MDP bone scan were 93.4% and 92.5%, as well as 93.5% and 72.5%, respectively. In conclusion, our data suggest that FDG-PET with the same sensitivity and a better accuracy than those of Tc-99m MDP bone scan to detect metastatic bone lesions in patients with biopsy-proven NSCLC and suspected to have stage IV disease.

The aim of this study was to evaluate practice usefulness of whole body positron emission tomography (PET) with 18F-fluoro-2-deoxyglucose (FDG) to detect recurrent ovarian cancer based on asymptomatically elevated tumor marker (CA-125) serum levels. Whole-body FDG-PET was performed in 28 patients with suspected recurrent ovarian cancers and asymptomatically increased serum levels of tumor marker (CA-125 antigen) but negative or equivocal other imaging modality results. All of these 28 asymptomatic patients had serum levels of CA-125 antigen >35 U/ml. The final diagnosis of recurrent ovarian cancer was established by operation/biopsy histopathological findings or clinical follow-up longer than 1 year by additional morphologic imaging techniques. Among the 28 patients, the final diagnoses of recurrent ovarian cancers and benign lesions were established in 20 and 8 patients, respectively. FDG-PET accurately diagnosed recurrent ovarian cancers in 19 patients and benign lesions in 7 patients. When asymptomatically elevated serum levels of CA-125 antigen, the diagnostic sensitivity, specificity, and accuracy of FDG-PET to detect recurrent ovarian cancers were 95.0%, 87.5%, and 92.9%, respectively. FDG-PET is a useful technique to detect recurrent ovarian cancers for patients suspected of recurrent ovarian cancers due to asymptomatically elevated serum levels of CA-125 antigen.

To evaluate the clinical value of whole body positron emission tomography (PET) with 18F-fluoro-2-deoxyglucose (FDG) in recurrent cervical cancer, the records of 20 patients who underwent FDG-PET scans were reviewed to detect local recurrence, pelvic/para-aortic lymph node metastases and distal metastases. The final diagnosis was based on operative, histopathological findings or clinical follow-up for longer than one year. FDG-PET accurately detected 18 patients with recurrent diseases (12 patients with local recurrences, 16 patients with pelvic lymph node metastases, 14 patients with para-aortic lymph node metastases and 4 patients with distal metastases of other sites). However, 2 patients with local recurrences had false- negative FDG-PET results as well as 1 patient without local recurrence and 1 patient without pelvic lymph node metastases who had false-positive FDG-PET results. The overall sensitivity and specificity of FDG-PET for patients were 90% and 100%, for local recurrence were 86% and 92%, for pelvic lymph node metastases were 100% and 94%, for para-aortic lymph node metastases were 100% and 100% and for distal metastases were 100% and 100%, respectively. In conclusion, whole body FDG-PET is a useful diagnostic tool in the evaluation of recurrent cervical cancer. It appears to be promising for detecting recurrent cervical cancer, lymph node metastases and distal metastases.