F-18 Sodium Fluoride Positron Emission Tomography/Computed Tomography for Detection of Thyroid Cancer Bone Metastasis Compared with Bone Scintigraphy

OBJECTIVE: The aim of the study was to compare the diagnostic performances of F-18 sodium fluoride positron emission tomography/computed tomography (bone PET/CT) and bone scintigraphy (BS) for the detection of thyroid cancer bone metastasis. MATERIALS AND METHODS: We retrospectively enrolled 6 thyroid cancer patients (age = 44.7 ± 9.8 years, M:F = 1:5, papillary:follicular = 2:4) with suspected bone metastatic lesions in the whole body iodine scintigraphy or BS, who subsequently underwent bone PET/CT. Pathologic diagnosis was conducted for 4 lesions of 4 patients. RESULTS: Of the 17 suspected bone lesions, 10 were metastatic and 7 benign. Compared to BS, bone PET/CT exhibited superior sensitivity (10/10 = 100% vs. 2/10 = 20%, p = 0.008), and accuracy (14/17 = 82.4% vs. 7/17 = 41.2%, p 0.05). CONCLUSION: Bone PET/CT may be more sensitive and accurate than BS for the detection of thyroid cancer bone metastasis.

Costo-efectividad de 18FDG-PET/CT vs CT al final del tratamiento en pacientes pediátricos con Linfoma Hodgkin / 18FDG-PET/CT cost-effectiveness compared to CT at the end of treatment in pediatric Hodgkin's lymphoma patients

Objetivo Estimar la costo-efectividad de 18FDG-PET/CT comparado con CT seguido de 18FDG-PET/CT como prueba confirmatoria de un caso positivo en la evaluación al final del tratamiento en pacientes menores de 18 años con Linfoma Hodgkin (LH). Métodos Se construyó un árbol de decisión donde se comparó el uso de 18FDG-PET/CT con CT seguido de 18FDG-PET/CT como prueba confirmatoria de un caso positivo en la detección de lesión residual. El resultado se midió en Años de Vida Ganados (AVG). Se calculó la razón de costo-efectividad incremental. Se utilizó como umbral 3 veces el PIB per cápita por año AVG. Valores expresados en pesos colombianos de 2010 (1 US dólar = $ 1 897,89) Se realizaron análisis de sensibilidad univariados, bivariados y probabilísticos. Resultados Suponiendo un diferencial en AVG entre verdaderos positivos y falsos negativos de 13 meses, el costo de un AVG adicional con 18FDG-PET/CT comparado con CT seguido de 18FDG-PET/CT como prueba confirmatoria de un caso positivo en la evaluación al final del tratamiento en pacientes pediátricos con LH fue $ 34 508 590. Conclusión Si el diferencial de esperanza de vida entre verdaderos positivos y falsos negativos es de al menos un 1,03 años, el uso de 18FDG-PET/CT en la evaluación al final del tratamiento de pacientes pediátricos con LH, es una estrategia costo-efectiva para Colombia.

Objective Estimating the cost-effectiveness of 18FDG-PET/CT (positron emission tomography) compared to computer tomography (CT) followed by 18FDG-PET/CT as a confirmatory test for a positive case at the end of treatment in Hodgkin's lymphoma (HL) patients under 18 years-old. Methods A decision tree was built for comparing 18FDG-PET/CT to CT followed by 18FDG-PET/CT as a confirmatory test for a positive case in detecting residual lesions; outcome was measured in life years gained (LYG). The cost-effectiveness ratio was calculated; the threshold was 3 times the per capita GDP per LYG. Values were expressed in Colombian pesos for 2010 (1 US dollar=$ 1,897.89) and submitted to deterministic and probabilistic sensitivity analysis. Results Assuming a difference of 13 months in true positives' life expectancy compared to that for false negatives, the cost of an additional LYG with 18FDG-PET/CT compared to CT followed by 18FDG-PET/CT as a confirmatory test for a positive case when evaluating the end of pediatric HL patients' treatment was $ 34,508,590 (COP). Conclusion If differential life-expectancy between true positives and false negatives is at least 1.03 years, then using 18FDG-PET/CT for evaluating the end of HL pediatric patients' therapy is a cost-effective strategy for Colombia.

Tumor targeting efficacy of a novel PET radiotracer (1)8F-AlF-NOTA-PRGD2 in mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the tumor targeting efficacy of (18)F-AlF-NOTA-PRGD2, a novel radiotracer of Arginine-glycine-aspartic acid (RGD) peptides.</p><p><b>METHODS</b>(18)F-AlF-NOTA-PRGD2 was synthesized in one-step by conjugating NOTA-PRGD2 with (18)F-AlF at 100 degrees celsius;. The tumor targeting efficacy and in vivo biodistribution profile of (18)F-AlF-NOTA-PRGD2, following intravenous injection via the tail vein, were evaluated in a nude mouse model bearing subcutaneous U87MG glioblastoma xenograft by radioactivity biodistribution assessment, PET/CT and microPET/CT.</p><p><b>RESULTS</b>NOTA-PRGD2 was (18)F-fluorinated successfully in one-step with a yield of 17%-25% within 15-20 min. Radioactivity biodistribution study confirmed the tumor-targeting ability of (18)F-AlF-NOTA-PRGD2 in the tumor-bearing mice. At 1 and 2 h following injection, (18)F-AlF-NOTA-PRGD2 uptake in the tumor reached 4.14∓1.44 and 2.80∓1.18 % ID/g (t=1.910, P=0.070) with tumor/brain ratios of 2.95∓0.61 and 5.21∓2.62, respectively (t=-1.686, P=0.167). Both PET/CT and microPET/CT were capable of showing the radioactivity biodistribution of (18)F-AlF-NOTA-PRGD2 in the mouse model and clearly displayed the tumor, but microPET/CT showed a much better image quality.</p><p><b>CONCLUSION</b>(18)F-AlF-NOTA-PRGD2 prepared by one-step radiosynthesis can selectively target to the tumor, demonstrating its potential as a good radiotracer for tumor imaging.</p>

Bone Positron Emission Tomography with or without CT Is More Accurate than Bone Scan for Detection of Bone Metastasis

OBJECTIVE: Na18F bone positron emission tomography (bone PET) is a new imaging modality which is useful for the evaluation of bone diseases. Here, we compared the diagnostic accuracies between bone PET and bone scan for the detection of bone metastasis (BM). MATERIALS AND METHODS: Sixteen cancer patients (M:F = 10:6, mean age = 60 +/- 12 years) who underwent both bone PET and bone scan were analyzed. Bone PET was conducted 30 minutes after the injection of 370 MBq Na18F, and a bone scan was performed 3 hours after the injection of 1295 MBq 99mTc-hydroxymethylene diphosphonate. RESULTS: In the patient-based analysis (8 patients with BM and 8 without BM), the sensitivities of bone PET (100% = 8/8) and bone scan (87.5% = 7/8) were not significantly different (p > 0.05), whereas the specificity of bone PET (87.5% = 7/8) was significantly greater than that of the bone scan (25% = 2/8) (p < 0.05). In the lesion-based analysis (43 lesions in 14 patients; 31 malignant and 12 benign), the sensitivity of bone PET (100% = 31/31) was significantly greater than that of bone scan (38.7% = 12/31) (p < 0.01), and the specificity of bone PET (75.0% = 9/12) was also significantly higher than that of bone scan (8.3% = 1/12) (p < 0.05). The receiver operating characteristic curve analysis showed that bone PET was significantly more accurate than the bone scan in the patient (p = 0.0306) and lesion (p = 0.0001) based analyses. CONCLUSION: Na18F bone PET is more accurate than bone scan for BM evaluation.

Metabolic Super Scan in 18F-FDG PET/CT Imaging

A 50-yr-old man presented with intermittent hemoptysis and was diagnosed small cell lung cancer. 18F-FDG PET/CT for staging demonstrated extensive hypermetabolic lesions throughout the skeleton and liver. Interestingly, skeletal muscles of limbs, mediastinum, bowel, and especially brain showed very low FDG uptake. Because of some characteristics in common with super scan on skeletal scintigraphy, this case could be considered as 'metabolic super scan'.

(18)FDG PET/CT en linfoma primario de mama y cáncer de mama / (18)FDG PET/CT imaging in primary breast lymphoma and breast cancer

BACKGROUND: Of women between 15 and 29 years of age, 13.6% will die from breast cancer. For women between 30 and 64 years of age, 19% will die from breast cancer. METHODS: We studied 1728 oncological patients and 295 patients were included, 293 with breast cancer (17%) and two patients with primary breast lymphoma (0.1%). RESULTS: There were 98% females and 2% males. SUVmax for the primary tumor was 4.2 +/- 2.6 SD. Mean SUVmax for patients with primary breast lymphoma were 3.2 and 1.4. Sites of metastases were lymph nodes in the neck (4.4% SUVmax 2.7), internal mammary lymph nodes (5% SUVmax 5.3), mediastinum (8.3% SUVmax 5.0), retroperitoneal (6 % SUVmax 5.4), ipsilateral axilla (94% SUVmax 4.5), contralateral axilla (4.4% SUVmax 2.8), pectoral muscle (10.2% SUVmax 2.6), pleura (4.4% SUVmax 3.9), lung (32.3% SUVmax 2.9), liver (19.1% SUVmax 4.5), bone (36.7%), adrenal gland (4.4% SUVmax 2.4), brain (4.4%), spleen and contralateral breast, one case each. One patient presented thymic hyperplasia after chemotherapy. Mean SUVmax for blastic lesions was 5.4 +/- 2.9 SD, for lytic lesions it was 6.7 +/- 2.4 SD and for lesions not apparent on the CT it was 4.6 +/- 2.4 SD. The incidence of a second primary was 4.7%, 2.1% ovarian, 1.4% lung, 0.3% lymphoma, 0.3% endometrium, 0.3% pancreas and 0.3% thyroid. CONCLUSIONS: Mean SUVmax for the primary tumor was similar to that reported in the literature. Values for metastatic bone lesions are higher in this study. Inclusion of PET/CT in the followup of breast lesions is cost efficient.

CT and (18F)FDG PET/CT Findings of Esophageal Squamous Cell Papillomatosis: A Case Report

Esophageal squamous cell papillomatosis is a rare disorder that is usually found incidentally on an upper gastrointestinal endoscopy examination or autopsy. A 70-year-old woman presented with a two-month history of dysphagia and abdominal discomfort. A chest CT scan showed diffuse marked thickening of the esophageal wall along the entire length and multiple small enhancing polypoid projections in the distal esophagus. Diffuse circumferential FDG uptake in the entire esophagus was seen on [18F] FDG PET/CT. Squamous papillomatosis was diagnosed by an endoscopic biopsy. We report a case of extensive esophageal papillomatosis with imaging features on CT and [18F] FDG PET/CT, with a review of the clinical literature.

Biodistribution of (18)F-NaF as an imaging agent in osteoporotic rats for position emission tomography / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the biodistribution of (18)-NaF as an imaging agent for position emission tomography (PET) in rat models of osteoporosis.</p><p><b>METHODS</b>Osteoporosis was induced in 10 rats via injection with an excess of dexamethasone phosphate sodium, and the biodistribution of (18)-NaF in the rats was studied, with another 10 normal rats as the control group. (18)-NaF PET was also performed in 8 healthy volunteers, and the uptakes of (18)-F- in the bone tissues were measured.</p><p><b>RESULTS</b>Compared with the control rats, the osteoporotic rats showed significantly decreased (18)-F- uptake, especially in the femoral neck, lumbar vertebrae, the 7th rib and the tibia (P<0.05). Dynamic chest PET scanning in the volunteers revealed obvious (18)-F- uptake in the spine, ribs and humerus 20 s after injection of the imaging agent. (18)-F- uptake significantly increased with time in the bones, reaching the peak level 60 min after the injection, and whole-body PET at this point demonstrated obvious skeletal (18)-F- uptake, with high skeletal-to-muscle (STM) ratio that averaged 8.12.</p><p><b>CONCLUSION</b>(18)-NaF is an excellent skeletal imaging agent for clinical skeletal blood flow and metabolism measurements. The uptake of (18)-NaF has significant difference between normal and osteoporotic bone tissues, indicating the value of (18)-NaF PET for study of osteoporosis.</p>

Dual modality of 18F-Fluorodeoxyglucose-positron emission tomography / computed tomography in patients with cervical carcinoma of unknown primary

To evaluate an optimized F-18-flurodeoxyglucose-positron emission tomography/computed tomography [FDG-PET/CT] acquisition protocol for head and neck cancer and assess the usefulness of combined FDG-PET/CT in locating unknown primary tumors in patients with biopsy-proven cervical lymph node metastases. Subjects and Twenty-one patients with cervical lymph node metastases of unknown primary tumors underwent staging with FDG-PET/CT. The images of FDG-PET alone, CT alone, FDG-PET/CT read side by side and fused and FDG-PET/CT were evaluated separately by 2 physicians. Imaging results were correlated with either histology [n = 14] or clinical follow-up [n = 7]. On the fused FDG-PET/CT images, primary tumors were identified in 12 patients [57%]; with FDG-PET alone and FDG-PET and CT read side by side 11 [52%] primary tumors were found while CT alone identified 5 [23%] primary tumors. Our data indicate that fused FDG-PET and CT images increased the sensitivity of detecting carcinoma of unknown primary [CUP] tumors compared to CT alone, but not to FDG-PET alone or FDG-PET and CT read side by side. Hence accurate fusion of functional and morphologic data by FDG-PET/CT is a promising imaging modality in the clinical workup of patients with cervical CUP tumors

18FDG PET in the management of malignant lymphoma / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the role and prospect of 18FDG PET imaging in patients with malignant lymphoma.</p><p><b>METHODS</b>Forty-four patients (73 studies) with malignant lymphoma underwent 18FDG PET imaging. Final diagnoses were proved histopathologically. Images obtained were analyzed using visual and semiquantitative analysis (SUV).</p><p><b>RESULTS</b>Either nodal or extranodal tumor foci showed high 18FDG uptake. 18FDG PET led to correct diagnosis in 5 of 6 cases except 1 false negative case. PET imaging changed the staging in 4 of 6 cases pretherapeutically. Of the 16 cases in which either residual tumor mass or suspicious recurrence suggested by other imaging modalities, 18FDG PET confirmed relapse in 5, detected more lesions in 2 and showed no evidence of active tumor mass in 9. For the 3 patients with comparison between pre- or post-treatment PET imaging and 16 patients who only underwent post-treatment PET follow-up studies, therapeutic response was correctly evaluated.</p><p><b>CONCLUSIONS</b>18FDG PET is a valuable non-invasive metabolic imaging modality in facilitating diagnosis and staging, evaluating therapeutic response, assessing clinical outcome and predicting prognosis in patients with lymphoma.</p>

Synthesis and preliminary studies of O-(2-18F fluoroethyl)-L-tyrosine as a positron emission tomography imaging agent / 中国医学科学院学报

<p><b>OBJECTIVE</b>To develop a 18F-labeled amino acid, O-(2-[18F]fluoroethyl) - L-tyrosine(18F-FET), as a positron emission tomography (PET) tracer for imaging cerebral tumors.</p><p><b>METHODS</b>18F-FET was synthesized. Preclinical studies including sterility, endotoxin, and toxicity tests were performed. Two brain tumor cases were studied using 18F-FET and compared with 18F-FDG.</p><p><b>RESULTS</b>Radiochemical purity of 18F-FET was over 95% which remained stable for 6 hours. The 18F-FET injection was sterile and its endotoxin content accorded with the standards of Chinese Pharmacopoeia. The uptake of 18F-FET in the normal brain tissues was significantly lower than that of the tumor, and the images of the brain tumor were clearer than those of 18F-FDG.</p><p><b>CONCLUSION</b>18F-FET can accumulate in the tumor tissues to give high quality images. It suggests that 18F-FET may be a safe and effective tracer for brain tumor imaging.</p>