To evaluate the clinical usefulness of FDG-PET in the diagnosis of hepatocellular carcinima (HCC), cholangiocellular carcinoma (CCC), and gall bladder carcinoma (GBC), we performed multi-institutional questionnaire survey about the current status of diagnostic FDG-PET study for these tumors in Japan. The questionnaire was performed on individual-patient-basis, and the questionnaire items were the following; age, sex, the purpose of the study, assertion about the clinical usefulness of the study, and its reasons. Forty-two cases of HCC (male:33 cases, age:59.1±14.8, female:9 cases, age:69.8±6.2), fifty-one cases of CCC (male:37 cases, age:65.0±9.9, female:14 cases, age:67.9±6.2), and twenty cases of GBC (male:11 cases, age:66.5±8.4, female:9 cases, age:71.7±12.0). Clinical usefulness was evaluated as highly-useful (HU), useful (U), and not useful (NU) in each case in each group for A) initial diagnosis or for B) staging, recurrence, or treatment decision. Clinical usefulness was asserted as effective in all groups (HCC:A) HU/U/NU:4/0/2cases, B) HU/U/NU:30/7/2cases;CCC:A) HU/U/NU:11/9/5cases, B) HU/U/NU:21/17/5cases;GBC:A) HU/U/NU:6/2/2cases, B) HU/U/NU:10/3/1cases.) According to this survey, the clinical diagnosis of FDG-PET was useful in the diagnosis of hepatocellular carcinima, cholangiocellular carcinoma, and gall bladder carcinoma, for initial diagnosis or for staging, recurrence, or treatment decision.
The usefulness of [18F] FDG-PET for the diagnosis of bone and soft tissue tumors was evaluated using 75 cases(20 kinds of diseases)which were collected from7institutions in Japan by sending out questionnaires. The data of the study patients, who had osteosarcoma, Ewing′s sarcoma(including primitive neuroectodermal tumor), liposarcoma, leiomyosarcoma, Hemangiosarcoma, synovial sarcoma, rhabdomyosarcoma, giant cell tumor, schwannoma, malignant fibrous histiocystoma, chondrosarcoma, alveolar soft part sarcoma, epithelioid sarcoma, endometrial stromal sarcoma, hibernoma, fibrosarcoma, multiple osteochondroma, sacral chordoma, Langerhans cell histiocytosis, and neurofibromatosis, respectively, were analyzed. From the analytical results it was concluded that the usefulness of [18F] FDG-PET is high for the diagnosis of these tumors.
Multi-center survey has been conducted to evaluate a diagnostic accuracy of positron emission tomography using fluorine-18-fluorodeoxyglucose (FDG-PET) for gastric cancer (n=173), duodenal ampullary cancer (n=10), and GIST (gastrointestinal stromal tumor, n=15). For the diagnosis of gastric cancer, FDG-PET was superior in47.4% (82/173), similar in 45.1% (78/173) and inferior in7.5% (13/173), as compared to conventional morphological imaging modalities such as X-ray CT and MRI. FDG-PET was superior in20% (2/10), similar in70% (7/10) and inferior in10% (1/10) for the diagnosis of duodenal ampullary cancer, and was superior in40% (6/15), similar in46.7% (7/15) and inferior in13.3% (2/15) for the diagnosis of GIST, as compared to the conventional imaging modalities. FDG-PET was highly useful for the detection of primary tumor and moderately useful for the diagnosis of metastatic and recurrent diseases. The diagnostic result was better for primary tumor probably because most of patients had advanced gastric cancers. In patients with suspected metastasis or recurrence, FDG-PET was able to detect foci of diseases, which were not evident by morphological imaging modalities. Thus, FDG-PET may have a potential to afford important information for the management of such patients and yield cost-effectiveness by obviating unnecessary surgery.
The diagnostic accuracy of [18F]FDG-PET(FDG-PET) was analyzed for a total of 18 kinds of tumors and 133 cases, including neuroblastoma (n=3), pheochromocytoma (n=13), carcinoid (n=2), malignant mesothelioma (n=14, pleural or peritoneal), renal cell carcinoma (n=2), ureteral cancer (n=2), bladder cancer (n=4), Wilms' tumor (n=1), prostate cancer (n=24), testis tumor (n=16), mediastinal tumor (n=17), adrenal tumor (n=5), cutaneous tumor (n=5), extra-mammary Paget's disease (n=5), multiple myeloma (n=7), intracardiac tumor (left atrial malignant fibrous histocytoma) (n=1) and splenic tumor (splenic hemangioma) (n=1). FDG-PET was highly useful for the diagnosis of neuroblastoma, malignant peritoneal mesothelioma, Wilms' tumor, adrenal tumor, extra-mammary Paget's disease, intracardiac tumor and splenic tumor. FDG-PET was fairly useful for the diagnosis of carcinoid, malignant pleural mesothelioma, prostate cancer, cutaneous tumor and multiple myeloma. FDG-PET was useful for the diagnosis of pheochromocytoma, testis tumor and mediastinal tumor. In all cases of urological tumor, including renal cell carcinoma, ureteral cancer and bladder cancer, FDG-PET was performed for the purpose of detecting recurrence or metastasis after surgery. The results showed the usefulness of FDG-PET for follow-up of patients after treatment.
Effect of expansion of [18F] FDG-PET or PET/CT indication for all malignancy on reimbursement of the Japanese national health insurance system was calculated since the health insurance system is now facing with financial difficulties. The number of the PET examinations was estimated to be 275785/year at 2008 from results of the three consecutive surveys of questionnaire from 2004 to 2006. Reimbursement per PET or PET/CT examination was calculated as ¥78350 based on the frequency of 20%-discounted examination and PET to PET/CT study ratio. Stage shift brought by FDG-PET or PET/CT was assumed to decrease futile operations by 27%. Based on these figures, it was estimated that an annual reimbursement in 2008 would be reduced by ¥3164258753. Careful inspection and proper interpretation based on appropriate integration of clinical history, physical examination, laboratory data, and results of other imaging studies, particularly CT, is the key to attain improved patient care with reduced cost.
The gamma-gamma coincidence counting method with two coaxial Ge detectors was applied to the absolute measurement of radioactivity. To investigate the dependence of the calculated activity on the coincidence time, a 60Co standard point source was measured by a gamma-gamma coincidence counting system. As a result, it was confirmed that the coincidence time did not influence the calculated activity, which agreed with the calibrated value within 10%. To estimate measurable range of source disposition, two or nine 60Co sources were measured by this system. As a result, the measurable range was 3cm × 10cm × 10cm(thickness × width × height), when the detector-detector distance was 10cm.