Preliminary results of this trial provide evidence that 18F-FDG PET/CT imaging is a highly accurate and reliable noninvasive test to decide for further investigation of differentiating malignant mesothelioma from benign pleural disease.

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High-grade brain tumors have increased Tc-99m MIBI uptake compared with that of low-grade tumors. Tc-99m MIBI uptake is correlated with the percentage of the S-phase fraction of the cell and the aneuploidy level of the brain tumor. This preliminary report suggests that Tc-99m MIBI imaging may be useful in the evaluation of the biologic characteristics of brain tumors.

Positron emission tomography (PET) has evolved into a technique that can accurately determine the distribution of positron-emitting radionuclides. The addition of a coincidence detection mode to a standard dual-head detector system has resulted in the option of single-photon and annihilation coincidence detection. This new device for imaging fluorine-18 2-fluoro-2-deoxy-D-glucose (18F-FDG) accumulation in neoplasms became commercially available in 1994. Besides conventional low-energy imaging in the collimated single-photon mode, it offers a relatively inexpensive opportunity to perform uncollimated PET by switching to the coincidence acquisition mode. This review summarises the clinical value of 18F-FDG detection with a dual-head coincidence camera in oncology. The results are compared with the overall results obtained using dedicated PET scanners. With respect to head and neck tumours, 18F-FDG coincidence mode gamma camera imaging (CGI) yields results that are in agreement with those obtained with dedicated PET scanners. With regard to other malignancies, such as lung cancer, lymphoma and brain tumours, data in the literature are too scarce to draw any definite conclusions. In general, the results of 18F-FDG CGI in tumours >15 mm seem to be comparable to those obtained with dedicated PET scanners, whereas in tumours <15 mm, the relative sensitivity of 18F-FDG CGI is approximately 80%. Using attenuation correction, the diagnostic yield of 18F-FDG CGI may increase. However, further clinical investigation is required to definitely establish its value in staging primary disease, therapy monitoring and assessment of tumour recurrence in clinical oncology.

The percentage of myeloma cells in bone marrow is subsequently an important index of disease in patients with multiple myeloma (MM). Bone marrow myeloma cells can be detected by strong CD38/CD138 positivity and light scatter characteristics using flow cytometry. The aim of the study was to evaluate the relationship between the degree of F-18 fluorodeoxyglucose (F-18 FDG) uptake and the percentage of CD38/CD138 expressing myeloma cells in the bone marrow of patients with MM. A total of 31 patients with MM (14 females and 17 males, mean age 59.5 ± 1.9 years, range 29-80 years) were included in the study. All patients underwent FDG-positron emission tomography/computed tomography (PET/CT) scan within 2 weeks after the completion of the usual staging workup for MM, consisting of X-ray skeletal survey and hematological/biochemical parameters including complete blood count, liver and kidney function test, erythrocyte sedimentation rate, serum immunoglobulins, urine light chain excretion, C-reactive protein, β2-microglobulin, and bone marrow plasma cell infiltration. In all patients, flow cytometry was performed for assessing the percentage of CD38/CD138 expressing myeloma cells in the bone marrow samples. The extent of bone marrow FDG uptake on PET/CT scans was visually graduated using a qualitative scoring system as extension score (E-score) and also a semiquantitative scoring system defined as mean standardized uptake value (mSUV) of both femora. There was a statistically significant positive correlation between the percentage of CD38/CD138 expressing plasma cells in bone marrow and both mean qualitative (r = 0.616) and semiquantitative (r = 0.755) results of F-18 FDG uptakes. mSUV and E-score of bone marrow FDG uptake values were also correlated with serum beta-2-microglobulin levels (r = 0.523 and r = 479, respectively). mSUV of bone marrow FDG uptake values were also negatively correlated with serum albumin levels (r = -0.424), whereas there was no correlation between E-score and albumin levels. In conclusion, our results indicate that increased F-18 FDG uptake of bone marrow is related to the percentage of plasma cell infiltration of bone marrow in patients with MM. Therefore, F-18 FDG-PET/CT study may be a useful tool for predicting the levels of myeloma cells in bone marrow, and an additional analysis of FDG uptake of bone marrow on FDG-PET/CT scans should be performed in patients undergoing PET studies during the initial staging, evaluating the therapy response, and monitoring patients with MM.

Uterine leiomyomas, benign tumours of the human uterus, are the most common uterine neoplasm and are composed of smooth muscle with varying amounts of fibrous connective tissue. As a functional imaging modality, 2-[F]fluoro-2-deoxy-D-glucose (F-FDG) positron emission tomography can be used to obtain information about glucose metabolism in tissues. In this study, the findings of the F-FDG scans of four patients who were suspected of having malignant gynaecological tumours because of clinical and radiological findings and finally diagnosed as uterine leiomyoma based on histopathological examination were evaluated. Moderately intense F-FDG accumulation was detected in uterine mass localization in lower pelvis. The reason for the accumulation of F-FDG in uterine leiomyomas is not known. It may be explained by the existence of higher levels of growth factors, including basic fibroblast growth factor, transforming growth factor beta, granulocyte-macrophage colony-stimulating factor and receptors, and proliferation of smooth muscle cells in leiomatous uterus.

Our data shows that due to its high sensitivity and accuracy, mediastinoscopy is still the most reliable method to evaluate mediastinal lymph nodes in patients with NSCLC.

Discordant findings of skeletal metastasis between Tc-99m MDP bone scans and F-18 FDG PET/CT imaging may be seen in 20% of the patients with NSCLC. F-18 FDG PET/CT could detect metastatic bone involvement more accurately than bone scintigraphy. Bone scans are insensitive to early bone marrow neoplastic infiltration. Assessment of glucose metabolism with FDG PET/CT can represent a more powerful tool to detect early bone metastases in lung cancer than with traditional bone scans.