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This retrospective study investigated the usefulness of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) after interventional therapy for hepatocellular carcinoma (HCC).Between March 2007 and November 2010, 31 patients (24 men, 7 women; mean age, 61.8 ± 11.0 years) with 45 lesions underwent PET/CT within 1 month after interventional therapy for HCC. Twenty-six patients with 40 lesions underwent transcatheter arterial chemoembolization (TACE), two patients with 2 lesions underwent radiofrequency ablation (RFA), and three patients with 3 lesions underwent percutaneous ethanol injection therapy (PEIT). Patients with a history of previous interventional therapy were excluded. Visual analysis was graded as positive when FDG was observed as an eccentric, nodular, or infiltrative pattern, and negative in case of isometabolic, hypometabolic, or rim-shaped uptake. For quantitative analysis, the standardized uptake value (SUV) was measured by region of interest technique. Maximum SUV (SUVmax) was assessed, and the ratio of SUVmax of tumor to mean SUV of normal liver (TNR) was calculated. The patients were divided into two groups, with and without residual tumor, based on 6-month clinical follow-up with serum alpha-fetoprotein and contrast-enhanced abdominal CT.Of the 45 lesions, 24 were classified in the residual tumor group and the other 21 lesions in the no residual tumor group. No residual tumor was detected after RFA or PEIT. By visual analysis, the respective values for sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 87.5, 71.4, 77.8, 83.3, and 80.0 %. However, there were no significant differences in the SUVmax and TNR between the two groups.It is suggested that FDG PET/CT may play a role in the evaluation of early treatment response after interventional therapy for HCC. The results indicate that FDG PET/CT visual analysis may be more useful than quantitative analysis. Further prospective studies with a large number of patients and established protocol are needed to substantiate our results.

A 53-year-old man with fever of unknown origin underwent F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) as a workup for a fever of unknown origin. On presentation, he complained of fever, chills, and myalgia. The F-18 FDG PET/CT scan showed diffusely increased uptake of the liver with mild hepatomegaly. A liver biopsy then revealed fibrin-ring granulomas typically seen in Q fever. The patient was later serologically diagnosed as having acute Q fever as the titers for C. burnetii IgM and IgG were 64:1 and 16:1, respectively. He recovered completely following administration of doxycycline. This indicates that F-18 FDG PET/CT may be helpful for identifying hepatic involvement in Q fever as a cause of fever of unknown origin.

Langerhans cell histiocytosis (LCH) is a disorder of clonal proliferation of Langerhans-type cells. The imaging findings of LCH are not specific. A 27-year-old woman was admitted to our hospital because of liver enzyme elevation without other hepatic signs. Radiological studies were originally interpreted as possible metastatic disease to the liver. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) images demonstrated a diffuse pattern of nodules in the liver with hypermetabolic activity. LCH was diagnosed histopathologically with an ultrasound-guided liver biopsy. This case illustrates the importance of considering proliferative/benign conditions of the liver when interpreting PET/CT. Failure to do so could result in patient mismanagement.

PURPOSE The aim of this study was to assess the utility of positron emission tomography/computed tomography (PET/CT) for the investigation of patients with suspected paraneoplastic neurologic syndrome (PNS). MATERIALS AND METHODS We reviewed the whole-body fluorodeoxyglucose (FDG) PET/CT studies (ordered by the neurology department) performed at our hospital between December 2005 and November 2010; 27 cases (16 men, 11 women; mean age, 65 years) who were suspected of having PNS were selected. RESULTS Of the 27 patients, 6 (22%) had an abnormal FDG uptake. Of these 6 patients, 5 (19%) were histologically confirmed as having a malignancy. Of the 27 patients, 7 were tested for the presence of well-characterized paraneoplastic antibodies (anti-Hu, anti-Ri, anti-Yo); 1 had anti-Hu, but the patient did not have an abnormal FDG uptake or malignancy. CONCLUSIONS PET/CT may be a useful screening tool for patients with clinically suspected PNS who do not exhibit well-characterized paraneoplastic antibodies. Therefore, we recommended that PET/CT should be performed for patients with clinically suspicious PNS regardless of the presence of well-characterized paraneoplastic antibodies.

BACKGROUND: : The prevalence of bone involvement in sarcoidosis has been estimated to be 3% to 5%, mostly affecting the phalanges. The aim of this study was to assess the prevalence and distribution pattern of bone and bone marrow involvement as detected by positron emission tomography/computed tomography (PET/CT) in sarcoidosis patients. METHODS: : Between June 2006 and September 2010, 122 patients suffering from severe sarcoidosis who underwent a PET/CT and met the inclusion criteria were studied. In 94 (77%) patients, the PET/CT demonstrated positive findings associated with sarcoidosis. The 94 PET/CTs were screened for the presence of bone/bone marrow localizations. Additionally, low-dose CT scans were screened for other causes of increased bone uptake. Relevant clinical data were gathered retrospectively. RESULTS: : Evidence for bone/bone marrow localizations was found in 34% of the 94 patients with PET/CT-positive findings. Of these patients, 60% showed obvious focal bone lesions at various localizations: axial skeleton (47%), pelvis (40%), extremities (34%), and skull (2%). In 40% of patients, diffuse increased uptake in both axial and peripheral bone marrow, without focal lesions, was found. Both diffuse and focal uptake were seen in 34%, whereas only focal lesions were observed in 25%. In all but 2 (6%) patients, no bone abnormalities on low-dose CT were found. CONCLUSIONS: : More than one-third of PET/CT-positive sarcoidosis patients had osseous abnormalities on PET/CT. The majority of these lesions (94%) could not be detected on low-dose CT. No single localization of preference was found. These preliminary results stress the value of PET/CT imaging in the assessment of bone/bone marrow involvement in sarcoidosis patients.

Objective: Relation between patient age and Hounsfield Unit (HU),which is the linear attenuation coefficient, and Standardized Uptake Values (SUV) which is the amount of 18F-fluorodeoxyglucose (F-18 FDG) uptake, measured in the areas of interest drawn to prostate, seminal vesicles and testicles in F-18 FDG Positron Emission Tomography/Computed Tomography (PET/CT) images was investigated. Material and Methods: Mean and maximum SUV and HU values were recorded from the areas of interest (min 12 mm in diameter) which showed FDG uptake in prostate, seminal vesicles and testicles from F-18 FDG PET-CT images of 21 male patients under 40 years without genitourinary cancer. The effect of patient age to SUV and HU values was examined with Pearson correlation test using SPSS program. Results: There was a negative insignificant correlation between patient age and SUV and HU values for prostate. For seminal vesicles, correlation between patient age and SUV values and HUmax were positive but insignificant, while correlation with HUmean was significant (r=0.459, p=0.00). Correlation between patient age and SUVmax and SUVmean values were significant for testicles (r=0.506, p=0.002 and r=0.467, p=0.005, respectively) but the correlation between patient age and HUmax and HUmean values was not significant. Conclusion: F-18 FDG uptake in testicles in males increases with age until 40, suggesting an increase in metabolic rate. The significant correlation between age and mean HU values is probably caused by thickening of the tissue without an increase in glucose metabolism in seminal vesicles. In prostate, the effect of patient age to SUV and HU values was not observed until the age 40. Conflict of interest:None declared.

This short review aims at summarizing the available data pertaining to the usefulness of F-18 FDG PET/CT in rectal cancer. It is specifically focused on the emerging role of F-18 FDG PET/CT in assessing the response to neoadjuvant combined radiochemotherapy in locally advanced rectal cancer. It also probes the possibility of finding standardized PET/CT parameters that are capable of differentiating responders from nonresponders in whom therapeutic approach could be modified.

A 66-year-old woman with long-standing multiple sclerosis presented with a several month history of diarrhea and weight loss. F-18 FDG PET/CT imaging revealed breast, rectal, and urinary bladder masses which were biopsied to reveal 3 different synchronous primary malignancies. PET/CT is able to detect a variety of synchronous malignancies; however, the situation of detecting 3 different synchronous primaries is extremely rare, and this case highlights the importance of paying close attention to anatomic areas that are difficult to evaluate on PET/CT, even after successfully identifying one or several FDG-avid primary malignancies.

About one-third of patients with Crohn disease develop intraabdominal fistulas, and of these, cholecystocolic fistulas are among the rarest. F-18 FDG PET/CT can detect a vast variety of fistulas, although most are discovered incidentally. We present a very unusual case of a 79-year-old woman referred for an F-18 FDG PET/CT for evaluation of a solitary pulmonary nodule. A colon mass was detected incidentally that appeared to directly invade the gallbladder; however, histologic evaluation after surgery revealed a colon adenocarcinoma, with an adjacent cholecystocolic fistula arising from a transmural fissure ulcer in a nonneoplastic colon segment consistent with clinically silent Crohn disease.

Early and correct diagnosis of tumor recurrence and its differentiation from therapy-related changes is crucial for prompt and adequate management of glioma patients. The purpose of this study was to compare the efficacies of Tc-99m glucoheptonate (GHA) single photon emission tomography (SPECT) and F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in detection of recurrence in patients with glioma.A total of 90 patients with histopathologically proven glioma who had suspicion of recurrence clinically or on magnetic resonance imaging were evaluated using Tc-99m GHA SPECT and FDG PET/CT. Combination of clinical follow-up, repeat imaging, and biopsy (when available) was taken as gold standard.On the basis of gold standard, 59 patients were positive and 31 were negative for tumor recurrence. The sensitivity, specificity, and accuracy of GHA SPECT were 85%, 97%, and 89%, respectively, whereas those of FDG PET/CT were 70%, 97%, and 80%, respectively. On subgroup analysis, GHA SPECT performed better than FDG PET/CT in all grades except for grade II gliomas, where both were equally effective. In all, 15 patients had intermodality discordance, with GHA SPECT being correct in 13 of them.GHA SPECT appears to be a better imaging modality than FDG PET/CT for detection of recurrent gliomas.

Xerostomia is a significant morbidity of radiation treatment in the management of head and neck cancers. To preserve salivary function, a surgical technique has been developed that involves the transfer of one submandibular gland to the ipsilateral submental space, where it can be shielded during radiation therapy. F-18 FDG PET/CT imaging characteristics of recently or remotely transferred submandibular glands have not been previously described in the literature. We report 2 cases of patients with surgically transferred submandibular glands, which highlight a potential pitfall in the interpretation of PET/CT of the head and neck region in oncologic patients.

Malignant extrarenal rhabdoid tumor (ERRT) is a very rare type of soft-tissue sarcoma with a reported incidence of 0.3% of all soft-tissue sarcomas. Only 7 cases of spinal malignant ERRT have been reported in the literature, and to our knowledge, F-18 FDG PET/CT imaging for staging and evaluation of response to therapy for these tumors has not been previously described. This is a case of an 8-month-old boy with malignant ERRT of the spine, who was staged with F-18 FDG PET/CT, and had his tumor burden assessed with PET/CT after chemotherapy, which altered the subsequent chemotherapy regimen.

Until now, serum tumor markers, physical examination, and conventional imaging modalities, such as CT or MRI, have been used in assessment of recurrence of cervical cancer after treatment. However, CT and MRI provide only anatomical data, which makes analysis of post-treatment change difficult. This study aims to explore the effectiveness of PET/CT, a new scanning device that combines PET and CT, in evaluation of cervical cancer lesions in patients with suspected recurrence.We studied 51 patients suspected of recurrence among those who underwent F-18 FDG PET/CT for cervical cancer follow-up at Gachon University Gil Hospital between June 2006 and August 2009. Patients were considered to be at risk for recurrence if they reported symptoms that were clinically suggestive of recurrence, or if physical examination showed abnormalities, serum tumor marker levels rose, or follow-up images revealed changes, such as new lesions or swelling of previous sites. Sensitivity, accuracy, specificity, and positive and negative predictive values of PET/CT were measured.A total of 37 patients were confirmed with recurrence or metastasis, 13 of whom were diagnosed histologically. Measured across all patients, PET/CT scored 97.3% on sensitivity, 71.4% on specificity, a positive predictive value of 90%, a negative predictive value of 90.9%, and an accuracy of 90.2%. PET/CT yielded only one false negative diagnosis and four false positives.As F-18 FDG PET/CT has high sensitivity and negative predictive value in diagnosis of recurrent cervical cancers, it is expected that it will be useful for clinical determination of recurrence and prevention of unnecessary additional treatments. The hope is that a future study on a larger scale will contribute further to determination of the efficacy of PET/CT.

Background: Survival with anaplastic thyroid cancer is dependent on how rapid multimodality treatment (chemotherapy, radiotherapy and surgery) and thus accurate assessment of the extent of the disease critical to predict prognosis and therapy planning. Methods & Results: We present a case of anaplastic cancer in a 54-year-old woman who presented with a supra-sternal lump which has decreased in size in response to chemo- and radiotherapy. CT and FDG-PET/CT scan were performed after therapy. CT demonstrated supra-sternal and lung metastases. FDG-PET/CT demonstrated the primary lesion and its distant widespread metastases, beyond the lung and supra-sternal mass. Conclusion: This case emphasizes the need for FDG PET/CT if there is equivocal clinical, laboratory, and radiological evidence of recurrence and metastases, especially if the suspected finding seems can be very unusual for metastatic lesions.

We present the pattern of metabolic brain abnormalities detected in patients undergoing whole body (WB) F-18 flurodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) examination for non-central nervous system (CNS) malignancies. Knowledge of the PET/CT appearance of various intracranial metabolic abnormalities enables correct interpretation of PET scans in oncological patients where differentiation of metastasis from benign intracranial pathologies is important and improves specificity of the PET study. A complete clinical history and correlation with CT and MRI greatly helps in arriving at a correct imaging diagnosis.

We report 2 cases of pyothorax-associated lymphoma that underwent 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) examinations during pre- and post-treatment states. The FDG PET/CT examinations were able to define the massive lesions as areas of intensive FDG uptake. After radiotherapy, follow-up PET/CT examinations showed the disappearance of the abnormal FDG uptake, although the residual masses remained in the original regions. Finally, we concluded that these lesions had entered remission based on the PET/CT findings. These cases indicate that PET/CT is a useful modality for detecting pyothorax-associated lymphoma and for evaluating the efficacy of treatments.

Extraosseous osteosarcomas account for less than 5% of all osteosarcomas. Primary osteosarcoma of the thyroid is a very rare tumor, with only 28 cases described in the published data. This is a case of a 40-year-old woman, 3 months postpartum, who presented with a rapidly growing mass in the neck, causing airway obstruction. An F-18 FDG PET-CT showed a large intensely FDG-avid mass in the thyroid gland, which was histopathologically confirmed to be a primary thyroid osteosarcoma. The patient was treated with tracheostomy, radiation therapy, and 2 cycles of chemotherapy. A posttherapy F-18 FDG PET-CT scan showed that the thyroid osteosarcoma was responding to therapy; however, the patient had developed new lung metastases.

This is a report of fluoro-deoxy-glucose positron emission tomography/computed tomography (F-18-FDG PET/CT) findings in a case of T-cell lymphoma-associated hemophagocytic syndrome, with “periportal low attenuation” and edematous gall-bladder wall thickening. FDG PET/CT showed diffuse inten

OBJECTIVE: The aims of this retrospective study were to evaluate the incidence of residual lymph node (LN) metastases in high-risk papillary thyroid cancer (PTC) patients receiving adjuvant I-131 therapy, especially in those without I-131 accumulation, and to evaluate the clinical usefulness of F-18 FDG PET/CT to detect those lesions. METHODS: The 37 PTC patients receiving adjuvant I-131 therapy were retrospectively evaluated. We examined the incidence of residual LN metastasis and compared the accumulation of F-18 FDG and I-131 in those lesions, and compared the serum thyroglobulin (Tg) levels between patients with and without residual LN metastases. RESULT: A total of 33 lesions were diagnosed as residual LN metastases in 9 patients. FDG accumulated in all of the lesions, but 19 lesions (57.6%) of them had no I-131 accumulation. The SUVmax was significantly higher in lesions without I-131 accumulation than in lesions with I-131 accumulation (6.6 +/- 2.8 vs. 4.2 +/- 1.8; P = 0.007). The serum Tg levels were significantly higher in patients with residual LN metastases than in patients without it (709.9 +/- 1470.8 vs. 25.6 +/- 37.1 ng/mL; P = 0.005). The incidence of residual LN metastasis was significantly higher in patients with a detectable serum Tg level than in patients without it (35.0% vs. 0%, P = 0.03). CONCLUSION: These results indicate that the residual LN metastasis was relatively common in high-risk PTC patients receiving adjuvant I-131 therapy whose serum Tg levels remained detectable, and those lesions often had no I-131 accumulation. FDG-PET/CT would be recommended for PTC patients with detectable serum Tg levels to detect residual LN metastases.

Two female patients aged 62 and 74 years underwent F-18 FDG PET/CT for evaluation of a large hepatic tumor. Subsequently, both patients underwent a partial hepatectomy which histopathologically revealed benign hepatic angiomyolipomas (AMLs). One patient with AML with a massive intratumoral hemorrhage presented with multiple foci demonstrating an increased FDG uptake along the margin of the cold defects that corresponded to low density areas within the tumor on contrast-enhanced CT, whereas the other patient with AML without any hemorrhage presented with a low FDG uptake in the tumor. This report demonstrates that benign hepatic AMLs may demonstrate increased FDG uptake if there is hemorrhage and a related inflammatory response.

To evaluate the usefulness of F-18 fluoro-fluorodeoxygulose positron emission tomography computed tomography (F-18 FDG PET-CT) in detecting clinically defined active disease in patients with Takayasu arteritis.F-18 FDG PET-CT was performed in 32 patients with Takayasu arteritis. Disease activity was assessed clinically by the National Institutes of Health (NIH) criteria. In 10 of the 32 patients, F-18 FDG PET-CT was performed while the patients were taking immunosuppressive drugs. Two nuclear physicians visually assessed the degree of F-18 FDG uptake in the walls of the aorta, its major branches and the pulmonary artery using a 4-point scale from grade 0 to III. F-18 FDG uptake greater than grade I in the thoracic aorta or greater than grade 0 in other areas were interpreted as active vasculitic lesions.Ten patients had active lesions on F-18 FDG PET-CT. According to the NIH criteria, 9 patients had active disease and 23 had inactive disease. Compared with disease activity assessed by the NIH criteria, F-18 FDG PET-CT had a sensitivity of 78% and a specificity of 87%. The erythrocyte sedimentation rate and CRP levels were significantly higher in F-18 FDG PET-CT-positive than in F-18 FDG PET-CT-negative patients. There was no significant difference in the proportion of positive PET scans according to the use of glucocorticoids.The sensitivity of F-18 FDG PET-CT for detecting active disease was higher in patients with higher erythrocyte sedimentation rate values. Although the specificity of F-18 FDG PET-CT was high, owing to the low sensitivity of the NIH criteria in detecting active disease, further studies are needed.

The "normal-sized ovary carcinoma syndrome (NOCS)" is defined as a clinical situation, in which diffuse metastatic malignant disease of the abdominal cavity of the female with normal-sized ovaries is noted, but no origin is assigned by preoperative or intraoperative evaluation. We report a case of ovarian serous surface papillary carcinoma with manifestation of NOCS, where F-18 FDG PET/CT scan correctly detected the site of origin, although computed tomography and magnetic resonance imaging failed to detect it. This technique may play a role to discern the site of origin of some malignancies.

STUDY DESIGN Prospective study. OBJECTIVE To determine whether F-18 fluoro-deoxy-glucose positron emission tomography/computed tomography (F-18 FDG PET/CT) follow-up imaging after treatment in patients with spinal infection (SI) could provide useful prognostic information and determine the residual SI. SUMMARY OF BACKGROUND DATA There are seldom data on the capability of follow-up imaging methods to predict residual disease and treatment efficacy in patients with SI. METHODS Thirty patients with SI underwent F-18 FDG PET/CT at initial and during follow-up. From F-18 FDG PET/CT, quantitative indexes were obtained. The residual SI was determined by the presence of preoperative symptoms, hematological infection marker, and radiologic findings. RESULTS The SUVmax were significantly declined after treatment in both of residual (2.85 +/- 1.17 vs. 2.06 +/- 1.03; P < 0.0001) and nonresidual SI (4.31 +/- 2.07 vs. 1.44 +/- 0.46; P < 0.0001). The SUVmean were also decreased after treatment in both of residual (1.45 +/- 0.45 vs. 1.04 +/- 0.29; P = 0.0014) and nonresidual SI (2.09 +/- 1.03 vs. 0.81 +/- 0.25; P < 0.0001). By lesion-based analysis, when < or =43.01% of %deltaSUVmax was used as threshold value, the area under curve (AUC) was 0.879 (P = 0.0001). The sensitivity and specificity were 85.7% and 82.6%, respectively. When < or =44.12% of %deltaSUVmean was used as threshold value, AUC was 0.828 (P = 0.0001). The sensitivity and specificity were 85.7% and 68%, respectively. In patient-based analysis, when < or =46.14% of %deltaSUVmax was used as threshold value, AUC was 0.904 (P = 0.0001). The sensitivity and specificity were 100% and 76.9%, respectively. When < or =41.78% of %deltaSUVmean was used as threshold value, AUC was 0.923 (P = 0.0001). The sensitivity and specificity were 100%, 76.9%, respectively. CONCLUSION F-18 FDG PET/CT is useful for discrimination of residual and nonresidual SI after treatment. Among the various quantitative indexes, %deltaSUVmax is a potent predictor of residual SI in the current study.

Fibrosing mediastinitis is an uncommon benign disorder, and its pathogenesis and management remain unclear. Conventional imaging techniques (chest radiographs, CT, MRI) may suggest its diagnosis but are frequently nonspecific, and it frequently mimics a malignant process by presenting as a mediastinal mass without calcifications, encasing, and infiltrating adjacent mediastinal structures, and showing an overall aggressive behavior. The value of FDG PET imaging in this entity remains largely unknown with only a few case reports in the literature, and often, biopsy is necessary for definitive diagnosis. We report a case of biopsy proven fibrosing mediastinitis highlighting the utility of PET in the evaluation and management of the disease.

Elevated thyroglobulin (Tg) levels, along with a negative radioiodine scan, present a clinical problem for the diagnosis of recurrence in papillary thyroid cancer (PTC) patients. The purpose of this study was to assess (1) the usefulness of 18F-fluorodeoxyglucose (F-18 FDG) positron emission tomography (PET)/computed tomography (CT) for PTC patients with negative diagnostic radioiodine scan and elevated serum Tg level or positive anti-thyroglobulin antibody (TgAb), and (2) the effect of endogenous thyroid stimulating hormone (TSH) stimulation (ETS) on detecting recurrence in these circumstances. Eighty-four patients with negative diagnostic radioiodine scan and elevated serum Tg or positive TgAb under ETS were included. Correlation with clinicopathological features and recurrence, detectability of FDG PET/CT and cut-off value of serum Tg for recurrence in PTC patients with these circumstance were assessed. In addition, detectability of F-18 FDG PET/CT under ETS and suppression were compared. In Cox regression analysis, only serum Tg level was significantly associated with recurrence (P

We report a case of Kaposi sarcoma (KS) who presented with unusual clinical features. The unusual clinical features were abscence of detectable HIV, absence of cutaneous lesion and presence of a splenic mass. F-18 FDG PET/CT demonstrated a spleen mass lesion with FDG uptake with SUVmax 7.0. This lesion was confirmed by ultrasonography guided biopsy. The lesion was consistent with KS. F-18 FDG PET/CT may be instrumental in establishing a diagnosis of the splenic KS

Background. We evaluated the prognostic significance of standardized uptake value (SUVmax), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) in [F-18] FDG PET/CT findings in patients with inoperable non-small-cell lung cancer (NSCLC). Patients and methods. One hundred and three patients (mean age, 65.6 ± 16 years) underwent [F-18] FDG PET/CT before the chemotherapy. The SUVmax value, the MTV (cm3; 42% threshold) and the TLG (g) were registered. The patients were followed up to 18 months thereafter (range 12-55 months). Failure to respond without progression, progression and/or disease-related death constituted surrogate end-points. The optimal SUVmax, MTV and TLG cut-off to predict the patients’ outcome were estimated. PET/CT results were then related to disease outcome (progression free survival; PFS). Results. The Kaplan-Meier survival analysis for SUVmax showed a significant shorter PFS in patients presenting with lower values as compared to those with higher (p < 0.05, log-rank test). MTV and TLG were not suitable for predicting PFS apart from the subset of patients with mediastinal nodal involvement. Conclusions. Despite the availability of new tools for the quantitative assessment of disease activity on PET/CT, the SUVmax rather than MTV and TLG remains the only predictor for PFS in NSCLC patients. MTV holds a value only when concomitant nodal involvement occurs.

This study aimed to evaluate the possibility that Bacillus Calmette-Guérin (BCG)-induced granulomatous prostatitis can be a potential cause of benign F-18 FDG uptake.A total of 395 bladder cancer patients who underwent F-18 FDG PET/CT (PET/CT) were retrospectively evaluated. Patients were divided into two groups according to BCG therapy status. Elapsed time after BCG therapy, serum PSA level, results of prostate biopsy, and the SUVmax and uptake pattern in the prostate gland were reviewed. For patients who underwent follow-up PET/CT, the changes in SUVmax were calculated.While 35 % of patients showed prostate uptake in the BCG therapy group, only 1 % showed prostate uptake in the non-BCG therapy group (p 0.001). Among 49 patients with FDG-avid prostate lesions, none had suspected malignancy during the follow-up period (median: 16 months). Five patients revealed granulomatous prostatitis on biopsy. The incidence of FDG-avid prostate lesions was significantly higher if the elapsed time after BCG therapy was less than 1 year compared to more than 1 year (p 0.001). Serum PSA was normal in 88 % of patients. All patients with incidental F-18 FDG uptake in the prostate gland showed focal or multifocal prostate uptake, and median SUVmax was 4.7. In 16 patients who underwent follow-up PET/CT, SUVmax was decreased in 14 patients (88 %) without treatment, and no patients demonstrated further increased prostate uptake (p 0.001).BCG-induced granulomatous prostatitis can be a potential cause of benign F-18 FDG uptake, especially in those with a history of bladder cancer treated with BCG. In BCG-induced granulomatous prostatitis, focal or multifocal prostate uptake is frequently seen within 1 year after BCG therapy, and the intensity of prostate uptake is decreased on the follow-up PET/CT without any treatment.

Objective: Many radiopharmaceuticals have been evaluated extensively in both preclinical and clinical studies as potential diagnostic agents to identify the sites of infection. There is a definite role of FDG-PET in diagnosis, extent of assessing the disease, evaluation of treatment response and disease activity in patients with infections and inflammation. The aim of the study, the process of formation and development of infection and inflammation is monitored using (18 F) 2’-deoxy-2-fluoroD-glucose (F-18 FDG) by Positron Emission Computed Tomography (PET-CT). Methods: In this study, sterile abscess was induced by using turpentine and infected abscess was induced by using Staphylococcus aureus atcc 25923 strain on rats. In the abscess formation on rats, three grups rats were used as sterile, infected and control grups. There were examined male White Wistar Rats, the clinical healthy animals were 150-220 gr body weight. Bacterial strain and rat model for abscess formation for infected abscess formation on rats (n=7), S. aureus 0.5 ml 107 CFU/ml was inoculated in the right arm of the rats as subcutaneous. For sterile abscess formation on rats (n=7) 0.2-0.4 ml turpentine (sigma-aldrich) was injected into the right arm of the rats as subcutaneous. In control group (n=6), 0.5 ml 0.9% NaCl was injected into the right arm of the rats as subcutaneous. First day imsaging was acquired 24 hours after inoculation of S.aureus and turpentine. 1 mCi 18F-FDG was injected intravenously via the tail vein. Prior to 18F-FDG injection, rats fasted at least 4 hours and well hydrated. Imaging was done using PET-CT (PHILIPS Gemini TF), beginning 1 hour following injection of 18F-FDG IV in the first day and at intervals of 24 hours for five days. First day imaging was performed 1. hour after IV injection of 18F-FDG to obtain optimum imaging time. PET/CT images were visually and semiquantitatively assessed. For semiquantitative analysis of the PET images, a region of interest (ROI) was drawn around the abscess area in the right arm and the noninfected contralateral for control as background. Results: SUVmaxs were obtained from the images for evaluation glucose meatabolism of infection and inflammation detected by 18F-FDG, PET/CT. A soft tissue infection developed in the right arm site of the rats within 24 hours after bacterial inoculation. Swelling and redness of the abscess area was apparently seen in all rats. Abscess in rats were visualized by 18F-FDG, PET/CT. The higher abscess/ background rate was seen 1. hour than 2. hour after injection 18F-FDG. Imaging time was chosen as 1. hour post injection 18F-FDG for the following days. In the first day of the formation of S.aureus abscess SUVmax was about 3.9±0.9 while SUVmax was 1.5±0.2 in the control site. In sterile abscess, SUVmax of the first day was 2.2±0.8, while the SUVmax was 1.3±0.5 for control site. First day 2. hours following the injection of 18F-FDG SUVmax values were 2.8±0.6 for infected abscess, 1.2±0.09 for infected abscess control site and 1.9±0.9 for sterile abscess, 1.3±0.3 for sterile abscess control site. Conclusion: Steril and infected abscess differantiation can be evaulated by imaging with 18F-FDG PET. The rate of SUV(max) explores the correlation between sterile abscess and infected abscess. 18F-FDG PET is also useful technique to understand the extent of the infection and inflammation process. In addition 18F- FDG PET imaging method has rapid diagnosis and local availability of equipment and labeled agent.

The aim of this study was to evaluate if effective radiation dose due to PET component in adult whole-body tumor imaging with time-of-flight F-18 FDG PET/CT could be significantly reduced. We retrospectively analyzed data for 10 patients with the body mass index ranging from 25 to 50. We simulated F-18 FDG dose reduction to 25% of the ACR recommended dose via reconstruction of simulated shorter acquisition time per bed position scans from the acquired list data. F-18 FDG whole-body scans were reconstructed using time-of-flight OSEM algorithm and advanced system modeling. Two groups of images were obtained: group A with a standard dose of F-18 FDG and standard reconstruction parameters and group B with simulated 25% dose and modified reconstruction parameters, respectively. Three nuclear medicine physicians blinded to the simulated activity independently reviewed the images and compared diagnostic quality of images. Based on the input from the physicians, we selected optimal modified reconstruction parameters for group B. In so obtained images, all the lesions observed in the group A were visible in the group B. The tumor SUV values were different in the group A, as compared to group B, respectively. However, no significant differences were reported in the final interpretation of the images from A and B groups. In conclusion, for a small number of patients, we have demonstrated that F-18 FDG dose reduction to 25% of the ACR recommended dose, accompanied by appropriate modification of the reconstruction parameters provided adequate diagnostic quality of PET images acquired on time-of-flight PET/CT.

Gun, A/0000-0001-7801-8081 WOS: 000351643000022 PubMed: 25835124 …

Purpose To determine the metabolically active whole-body tumor volume (WB-MTV) on F-18-fluorodeoxyglucose positron emission tomography/computed tomography (F-18-FDG PET/CT) in individuals with neurofibromatosis type 1 (NF1) using a three-dimensional (3D) segmentation and computerized volumetry technique, and to compare PET WB-MTV between patients with benign and malignant peripheral nerve sheath tumors (PNSTs). Patients and Methods Thirty-six NF1 patients (18 patients with malignant PNSTs and 18 age- and sex-matched controls with benign PNSTs) were examined by F-18-FDG PET/CT. WB-MTV, whole-body total lesion glycolysis (WB-TLG) and a set of semi-quantitative imaging-based parameters were analyzed both on a per-patient and a per-lesion basis. Results On a per-lesion basis, malignant PNSTs demonstrated both a significantly higher MTV and TLG than benign PNSTs (p < 0.0001). On a per-patient basis, WB-MTV and WB-TLG were significantly higher in patients with malignant PNSTs compared to patients with benign PNSTs (p < 0.001). ROC analysis showed that MTV and TLG could be used to differentiate between benign and malignant tumors. Conclusions WB-MTV and WB-TLG may identify malignant change and may have the potential to provide a basis for investigating molecular biomarkers that correlate with metabolically active disease manifestations. Further evaluation will determine the potential clinical impact of these PET-based parameters in NF1.

Introduction Osseous and soft tissue sarcomas (OSTS) represent a histologic heterogeneous group of malignant tumors. Most of the current clinical data on the role of F-18 FDG PET in sarcomas come from patients studied with dedicated PET and less frequently with hardware fusion PET/CT. Therefore, we were prompted to review our experience with F-18 FDG PET/CT in OSTS. Methods This is a retrospective study (January 2003-December 2005) of 44 patients with histologic diagnoses of OSTS who had F-18 FDG PET/CT at our institution. The group included 22 men and 22 women with an age range of 2 of 84 years (average, 37 +/- 20.2 years). The administered doses of F-18 FDG range 4.1 to 19.5 mCi (average, 14.3 +/- 3 mCi). Reinterpretation of the imaging studies for accuracy and data analysis from medical records was performed. Results The sensitivity and specificity of combined F-18 FDG PET/CT were 100% (95% confidence interval [CI] = 75.7-100) and 93.3% (95% CI = 78.7-98.1) for the primary OSTS, and 80% (95% CI = 58.4-91.9) and 86.4% (95% CI = 66.7-95.2) for metastases. When interpreted separately, CT outperformed PET for pulmonary metastases detection: CT was 76.5% sensitive and 88% specific, whereas PET was only 57.1% sensitive but 96.4% specific. For detection of other metastases, CT was 82.3% sensitive and 76% specific, with PET demonstrating 78.6% sensitivity and 92.8% specificity. Conclusion Relatively similar results (except better specificity for PET and PET/CT) were noted when examining the rate of metastases detection, excluding pulmonary lesions. However, CT had a better detection rate for pulmonary metastases when compared with PET alone. A negative PET scan in the presence of suspicious CT findings in the chest cannot reliably exclude pulmonary metastases from OSTS.

The vast majority of soft tissue sarcomas metastasize initially to the lungs. We report a 71-year-old woman with malignant fibrous histiocytoma of the right buttock and thigh that metastasized to the bilateral adrenal glands without development of pulmonary metastasis. Whole-body [F-18]FDG PET-CT showed abnormal tracer uptakes in the bilateral adrenal glands in addition to high accumulation in the primary soft tissue tumors. CT-guided needle biopsy revealed that both of the adrenal lesions were metastatic malignant fibrous histiocytoma. There was no pulmonary or other visceral metastasis. To the authors' knowledge, this is the first report of malignant fibrous histiocytoma metastatic to the bilateral adrenal glands without development of pulmonary metastases. This case illustrates the excellence of [F-18]FDG PET-CT scan for diagnosis of occult metastases from soft tissue sarcomas.

Introduction: During PET/CT chest interpretation, the radiologist may encounter non-malignant positive findings originating from physiologic variants, inflammation, infection, iatrogenic causes, post-surgical/post-therapeutic changes and benign tumors of different components of the thorax. This article illustrates and raises the awareness of these benign FDG-avid findings. Methods: We use a search engine to retrospectively review the 10-year PET/CT and pathology database of our institution for cases with thoracic findings linked to physiologic variations, and to benign processes and diseases. The keywords used for the search include all the entities presented in this article. We select the cases presenting with the most didactic value of benignity related to (1) established imaging patterns already published in the literature, which serves as reference articles in this paper, (2) final diagnosis from tissue sampling of ambiguous and difficult cases, and (3) long term monitoring based on clinical evaluation and anatomic and functional imaging. Results: Among the pool of cases fulfilling the required search criteria, we choose the most illustrative ones to present the different categories of benign findings encompassing the physiologic variants, inflammation, infection, iatrogenic causes, post-operative and post-therapeutic changes, and benign neoplasms. The most representative reference articles of the presented cases concerning all the benign thoracic entities are selected for the bibliography. Conclusion: The presented PET/CT cases raise the awareness and strengthen the interpretation confidence of the radiologist during the evaluation of cancer. The familiarity with these benign thoracic entities would obviate any suspicion of malignancy and avoid unnecessary additional assessment using expansive and potentially harmful procedures.

A 29-year-old male presented with a 6-month history of left hip pain. Radiography and CT demonstrated a 6-cm lytic lesion of the left acetabulum. F-18 FDG PET for staging of the biopsy-proven malignant PEComa demonstrated intense hypermetabolism corresponding to the lytic left acetabulum. The patient underwent left hemipelvectomy with reconstructive surgery. On a follow-up F-18 FDG PET scan 3 months after initial surgery, a left lung pleural-based 9-mm nodule with hypermetabolism (SUVmax 4.1) was discovered and pathologically proven to be metastases from the primary osseous PEComa.

Rectal carcinoma with metastasis to skeletal muscle is rare. So far, 16 cases of skeletal muscle metastasis from colorectal carcinoma have been documented of which only 5 were rectal carcinomas.[1] We discuss here the case of a 69-year old male, a known case of mucinous adenocarcinoma status post neoadjuvant chemoradiotherapy and abdomino perineal resection, who presented with low backache 4 months post surgery. He was found to have metastasis to multiple skeletal muscles without the involvement of common sites, such as liver and lung. The role of 18-FDG–PET/CT in such cases is rarely reported in the literature. This case highlights the importance of utilizing 18-FDG-PET/CT in detecting sites of skeletal muscle metastasis and thereby guides appropriate management.

During PET/CT acquisition, respiratory motion generates artifacts in the form of breath-related blurring, which may impair lesion detectability and diagnostic accuracy. This observational study was undertaken to verify whether breath-hold F-18-FDG-PET/CT (bhPET) detects additional foci compared to free-breathing PET/CT (fbPET) in cases of malignant melanoma, and to assess the impact of breath-holding on standard uptake values (SUV) and metabolic isocontoured volume (mVic40). Thirty-four patients with melanoma were examined. BhPET and fbPET findings of 117 lesions were compared and correlated with standard contrast-enhanced (ce) CT and MRI for lesion verification. Quantitative parameters (SUVmax, SUVmean, and mVic40) were assessed for both methods and evaluated by linear regression and Spearman correlation. The impact of lesion size and time interval between investigations was analyzed. In 1 patient, a CT-confirmed liver metastasis was seen only on bhPET but not on fbPET. At bhPET, SUVmax, and SUVmean proved significantly higher and mVic40 significantly lower than at fbPET. The positive effect on SUVmax and SUVmean was more pronounced in smaller lesions, whereas the time interval between bhPET and fbPET did not influence SUV or mVic40. In our patient cohort, bhPET yielded significantly higher SUV and provided improved volumetric lesion definition, particularly of smaller lesions. Also one additional liver lesion was identified. Breath-hold PET/CT is technically feasible, and may become clinically useful when fine quantitative evaluations are needed.

A 67-year-old man, previously operated for a pancreatic neuroendocrine tumor (NET), had progressive increase of serum chromogranin A during follow-up. Sequential 68Ga-DOTA-NOC and F-18 FDG PET/CT were performed. 68Ga-DOTA-NOC imaging was negative, whereas F-18 FDG PET/CT showed 2 hypermetabolic hepatic lesions demonstrated at CT-guided biopsy as metastatic deposits from a high-grade (G3) aggressive NET. Despite the large consensus of SPECT or PET with radiolabeled somatostatin analogs as first choice in functional imaging for detecting NETs metastasis, F-18 FDG may occasionally be the right tracer to provide accurate diagnostic and prognostic information in aggressive G3 NET.

Neuroblastoma is an embryonal tumor from the neural crest cell, which generally occurs in young children with a median age of about 17 months. The incidence of adult was only 0.12 cases per million per year. Because metastatic disease was present in approximately one-third of all adult patients at diagnosis, accurate staging was necessary before the initial therapy. We report F-18 FDG PET/CT findings a case of adult neuroblastoma in the anterior mediastinum with skeletal and pulmonary metastasis, which demonstrates the utility of F-18 FDG PET/CT in the staging of adult neuroblastoma.

Cholesterol granuloma (CG) is a foreign body-type granuloma formed in reaction to cholesterol crystals. CG usually develops in pneumatized bones because of inadequate drainage, especially in the middle ear cavity. We report a case of a patient with huge CG involving multiple ribs. A 66-year