Seiei Yasuda

Application of positron emission tomography imaging to cancer screening

Whole-body positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) is a diagnostic modality that can noninvasively survey the entire body and sensitively detect various cancers. In this study, we examined the potential application of whole-body PET for cancer screening in asymptomatic individuals. PET was performed in conjunction with conventional examinations including physical examination, laboratory study, ultrasonography and chest computed tomography. Between September 1994 and March 1999, 3165 asymptomatic individuals participated in 5575 screening sessions (2017 men and 1148 women; mean ± SD age, 52.2 ± 10.4 years). Follow-up periods were no less than 10 months. PET results were compared with the screening outcomes. Within 1 year after screening, malignant tumours were discovered in 67 of the 3165 participants (2.1%). PET findings were true-positive in 36 of the 67 cancers (54%). Most of the 36 patients underwent potentially curative surgery; thus a wide variety of cancers were detected by PET at potentially curable stages. However, PET findings were false-negative in 31 of the 67 patients (46%). 14 of these 31 (45%) were of urological origin. FDG PET imaging has the potential to detect a wide variety of cancers at potentially curable stages. However, PET imaging is not suited to screening test of general population because PET examination involves substantial cost.

Significance of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) for detection of renal cell carcinoma and immunohistochemical glucose transporter 1 (GLUT-1) expression in the cancer.

Abstract Objective: Positron emission tomography (PET) is now primarily used in oncological indication owing to the successful application of fluorine‐18 fluorodeoxyglucose (FDG) in an increasing number of clinical indications. Glucose transporter 1 (GLUT‐1) is recognized as a major early marker of cellular malignant transformation. The aims of this study were to assess whether FDG‐PET is a useful diagnostic tool for renal cell carcinoma and to compare the pathologic characteristics.

Detection of tumor cells in the portal and peripheral blood of patients with colorectal carcinoma using competitive reverse transcriptase-polymerase chain reaction

In spite of many reports, it remains unclear whether the presence of tumor cells in circulating blood flow predicts a poor prognosis.

F-18 FDG uptake in endometrial cancer.

Endometrial cancer, which is one of the most common malignant gynecologic diseases, was detected by F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) in a 60-year-old woman with abdominal distention. FDG PET revealed heterogeneous and marked accumulation in the endometrium, which was thought to represent endometrial cancer. In addition, focal intense accumulation of FDG in both lungs suggestive of lung metastases were noted. Endometrial cancer and lung metastases were confirmed by endometrial biopsy and computed tomography of the chest, respectively.

Four cases of Warthin’s tumor of the parotid gland detected with FDG PET

In the cancer screening with FDG PET for 1,872 medical health club members, high FDG accumulation in the parotid gland was found in four males (age, 57–70 years). Warthin’s tumor was confirmed by surgical pathology. The exact mechanism of high FDG accumulation in Warthin’s tumor is not yet known. This tumor may be found incidentally during FDG PET studies. When high FDG accumulation is found in the parotid gland, integrated consideration of the results of the physical examination, medical history and99mTc-pertechnetate scintigraphy makes it possible to differentiate Warthin’s tumor from other lesions.

Risk of lymph node and distant metastases in patients with early invasive colorectal cancer classified as Haggitt's level 4 invasion: Image analysis of submucosal layer invasion

PURPOSE Tumor invasion in patients with early invasive colorectal cancer has been classified into four levels proposed by Haggitt. Level 4 invasion into the submucosa has been defined as a risk factor for lymph node metastasis; however, the false-positive rate remains high. This study was designed to determine risk factors for lymph node and distant metastases in addition to Haggitt’s Level 4 invasion. METHODS Seventy-one of 142 patients with submucosa-invasive colorectal cancer underwent intestinal resection as an initial surgical treatment between 1975 and 2000. The subjects of this study were 65 of these 71 patients, all of whom were diagnosed as having Haggitt’s Level 4 invasion. The depth, width, and area of submucosal invasion were measured with an image analyzer. RESULTS Lymph node metastasis was noted in 11 (16.9 percent) of the 65 patients. There were no significant differences in the depth or area of submucosal invasion between node-positive and node-negative patients. However, the width of submucosal invasion was significantly greater in node-positive than in node-negative patients (P = 0.001). When 5-mm-wide submucosal invasion was used as an indicator for intestinal resection, 37 patients were found to have indications for bowel resection, and 11 (29.7 percent) of the 37 had lymph node metastases. Distant metastasis was noted in five patients (7.7 percent). The depth, width, and area of submucosal invasion in patients with distant metastasis did not differ significantly from those without distant metastasis. CONCLUSION Although further prospective investigation is required, the positive predictive value increases from 17 to 30 percent when the width of submucosal invasion is added to Haggitt’s Level 4 as an indicator for bowel resection.

High fluorine-18 labeled deoxyglucose uptake in sarcoidosis.

A 72-year-old man underwent a whole-body fluorine-18 labeled deoxyglucose (FDG) PET study for cancer screening. On the PET images, multiple foci of intense FDG uptake were noted in the mediastinum. CT scan showed enlarged mediastinal nodes. Chest X-ray was normal. Mediastinoscopy and lymph node biopsy were performed. Histology results showed noncaseating granulomas and a diagnosis of sarcoidosis was obtained. The patient was asymptomatic and was observed without medications. Early reports have indicated that high FDG uptake can be observed in sarcoid granulomas. Inflammatory cells, especially macrophages, are characterized as cells with high glucose use. In interpreting multiple increased FDG accumulations in the mediastinum, sarcoidosis needs to be considered as a differential diagnosis.

Diffuse F-18 FDG uptake in chronic thyroiditis

A 52-year-old woman underwent whole-body F-18 FDG PET imaging for cancer screening. Diffuse F-18 FDG uptake was seen in the thyroid gland. A nodule with elevated F18 FDG uptake was seen protruding posteriorly in the right thyroid lobe. Ultrasonography also showed a thyroid nodule. Surgery was performed and histologically, the nodule was composed of atrophic thyroid tissue, fibrous stroma, and lymphoid cell infiltration; it was consistent with chronic thyroiditis. The patient had high antimicrosomal antibody titers. Thus, chronic thyroiditis may be found incidentally during FDG PET studies.

PET imaging for evaluation of metastatic colorectal cancer of the liver

Colorectal cancer is a major cause of cancer death in Western Europe and United States; the liver is the most common site for colorectal metastases. PET has an important role in the management of patients with colorectal liver metastases. It is an effective tool to detect hepatic metastases and to monitor the response to systemic and local therapy. The major impact of PET–CT over PET alone is the improvement in the certainty of lesion location. PET–CT has the unique advantage to combine functional and anatomic imaging in an integrated scanner; it allows a thoroughly evaluation of patients with colorectal liver metastases.

Comparative efficacy of positron emission tomography and ultrasonography in preoperative evaluation of axillary lymph node metastases in breast cancer

PurposeIn primary breast cancer, axillary nodal status is the most powerful predictive factor of recurrence. However, axillary lymph node dissection may cause surgical complications. If preoperative evaluation of axillary lymph node metastases is possible, unnecessary axillary lymph node dissections can be avoided. The purpose of this study was to evaluate the efficacy of positron emission tomography (PET) on detection of axillary lymph node metastases in breast cancer.MethodsPET scans of the axilla were obtained in 32 patients with primary breast cancer. All patients fasted for at least 4 hours before the examination. After transmission scans for attenuation correction were performed, emission scans after intravenous injection of 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) were obtained.ResultsOverall accuracy of PET alone, ultrasonography alone, and in combination in the detection of axillary metastases were 82%, 79%, and 85% respectively.ConclusionThere were no significant differences between PET, ultrasonography, and PET in combination with ultrasonography regarding sensitivity, specificity and accuracy in the detection of axillary metastases.