Fludeoxyglucose Positron Emission Tomography Research Articles

Malignant transformation surrounding iodine-125 beads after treatment of a low grade glioma.

Permanent iodine-125 beads have been used in the treatment of low- and high-grade gliomas with good results. On computed tomography (CT) and magnetic resonance imaging (MRI), increased enhancement around these beads is common and is usually thought to represent radiation necrosis or disruption of the blood brain barrier. Further investigation of these areas of enhancement is warranted due to the rare possibility of malignant transformation occurring around these beads. Advances in radiological imaging, such as Fludeoxyglucose Positron Emission Tomography (FDG PET), have been useful in differentiating malignant transformation from benign entities. We present the first reported case of a 33-year-old lady with malignant transformation occurring around these beads approximately three years post-resection of a low-grade glioma.

Pediatric Burkitt's Lymphoma and Diffuse B-Cell Lymphoma: Are Surveillance Scans Required?

Outcomes in pediatric B-Non-Hodgkin Lymphoma (B NHL) have improved with intensive chemotherapy protocols, with long-term survival now over 80%. However, long-term adverse effects of therapy and poor outcomes for patients who relapse remain challenges. In this study, we aimed to evaluate the potential risks and benefits of routine relapse surveillance imaging after the completion of therapy. We reviewed 44 B NHL patients diagnosed and treated at Texas Children's Cancer Center in the period between 2000 to 2011. All cross-sectional diagnostic imaging examinations performed for disease assessment after completion of chemotherapy were reviewed and cumulative radiation dosage from these examinations and the frequency of relapse detection by these examinations were recorded. Only 3 patients of the 44 relapsed (6.8%), though none of the relapses were initially diagnosed by computed tomography (CT) or fludeoxyglucose positron emission tomography (FDG-PET) scans. Median effective dose of ionizing radiation per patient was 40.3 mSv with an average of 49.1 mSv (range 0–276 mSv). This single-institution study highlights the low relapse rate in pediatric B-NHL with complete response at the end of therapy, the low sensitivity of early detection of relapse with surveillance CT or FDG-PET imaging, and the costs and potential increased risk of secondary malignancies from cumulative radiation exposure from surveillance imaging. We propose that routine surveillance CT or FDG-PET scans for these patients may not be necessary.

Yttrium-90 Microsphere-selective Internal Radiation Therapy With Chemotherapy (Chemo-SIRT) for Colorectal Cancer Liver Metastases

Selective internal radiation therapy (SIRT) with yttrium-90 (Y) microspheres has emerged as an effective liver-directed therapy with a favorable therapeutic ratio for treatment of colorectal cancer liver metastases. The aim of this study was to investigate the objective responses obtained by Y microsphere treatment when combined with contemporary chemotherapy in the front-line (first or second line) setting in patients with CRCLM. This study used an in vivo comparison between the right and left liver lobes; systemic chemotherapy was supplied to both liver lobes by virtue of systemic administration, whereas SIRT was administered selectively to the target liver lobe only. Response to treatment was evaluated by serial fludeoxyglucose positron emission tomography computed tomography performed at 4 weeks, 2 to 4 months, and 6 to 8 months. Standard uptake value, anatomic volume, functional tumor volume, and total lesion glycolysis (TLG) calculations were obtained at each time point. A decrease in TLG on fludeoxyglucose positron emission tomography computed tomography imaging was seen in 19 of the 20 patients. The mean decrease in TLG values in the tumors receiving chemo-SIRT and chemo-only treatment were 86.26%±18.57% and 31.74%±80.99% (P<0.01), 93.13%±11.81% and 40.80%±73.32% (P=0.01), and 90.55%±19.75% and 54.91%±38.55% (P<0.01) at 4 weeks, 2 to 4 months, 6 to 8 months posttreatment, respectively. Functional and anatomic tumor volume changes were in concordance with the TLG changes. The study demonstrated that, under near identical conditions in terms of patient and tumor characteristics, the chemo-SIRT combination produced superior objective responses compared with chemo-only treatment in a front-line treatment setting in patients with colorectal cancer liver metastases.

Vertebroepidural metastasis of an ethmoid adenocarcinoma: A case report

Ethmoid adenocarcinoma is the most frequent ethmoid tumor. To date, only a single case of spinal cord compression resulting from ethmoid adenocarcinoma has been reported. The current case study presents a recent case of vertebroepidural metastasis of an ethmoid adenocarcinoma leading to spinal cord compression. Modern imaging studies, including magnetic resonance imaging (MRI) and 18 fludeoxyglucose positron emission tomography (FDG PET), as well as histological and immunohistochemical analyses, have led to diagnoses of a metastasis of an ethmoid adenocarcinoma, which is a mucinous variant, dedifferentiated when compared to the primary tumor. The present case discusses current diagnostic and treatment protocols of this condition. Since survival rates associated with the primary tumor are improving, the incidence of spinal metastasis of ethmoid carcinomas is likely to increase in the future, therefore requiring appropriate diagnostic and therapeutic management.

Utilisation of combined18F-FDG PET/CT scan for differential diagnosis between benign and malignant adrenal enlargement

To assess the properties of adrenal lesions with and without known primary cancer and investigate predictors for differential diagnosis between benign and malignant adrenal enlargement. This retrospective study used fluorine-18 fludeoxyglucose positron emission tomography (PET)/CT in 325 patients with adrenal lesions (229 with known primary cancer and 96 without primary cancer). Age, sex, the presence of right and left masses, nodules or hyperplasia, unenhanced attenuation, maximum standardised uptake value (SUVmax) ratio, and the presence of metastasis in other body parts and locations of the primary cancer were assessed. Univariate and multivariate analyses were used to assess variables associated with risk of adrenal metastasis. Patients with adrenal metastasis vs those without had a higher frequency of primary lung cancer (52.3% vs 30.7%) but a lower frequency of gastrointestinal cancer (7.9% vs 16.6%). The frequency of other abnormalities, including adenoma and hyperplasia, was similar between patients with and without known primary cancer. A higher proportion of patients with adrenal metastasis regardless of primary cancer site were younger, had a nodule or a mass, had an unenhanced attenuation of >10 HU, had an SUVmax ratio of >2.5, and had metastasis in other body parts. Analysis found independent associations of age, unenhanced attenuation of >10 HU, SUVmax ratio of >2.5 and the presence of metastasis in other body parts with adrenal metastasis. The combination of the four variables was strongly associated with adrenal metastasis. PET/CT was useful in characterising adrenal lesions as benign or malignant and helpful in identifying adrenal metastasis and cancer severity. PET/CT can help in the differential diagnosis between benign and malignant adrenal enlargement.

Cardiac Sarcoidosis: F18FDG-PET/CT as the Most Helpful Tool in the Decision Making of Medical Management, and Assessment of Response to Treatment

We describe the case of a 32-year-old healthy man who presented to the Emergency Department (ED) with vomiting, dizziness, and diaphoresis in addition to transient episodes of loss of consciousness on the day of admission. The patient’s past medical history was unremarkable. Once in the ED triage vitals showed a heart rate of 254 beats per minute and an initial Electrocardiogram (EKG) showing stable monomorphic ventricular tachycardia. After conversion to sinus rhythm the patient was admitted where and after a long array of tests, the patient was diagnosed with cardiac sarcoidosis. Implantable Cardioverter-Defibrillators (ICD) was implanted and he was started on corticosteroids. The medical management of the patient’s treatment with corticosteroids was very challenging. Fludeoxyglucose positron emission tomography/ computed tomography (FDG-PET/CT) was the most helpful tool and the test of choice for the follow up in his medical management.

A study on quantitative analysis of exposure dose caused by patient depending on time and distance in nuclear medicine examination

This study evaluated possible actions that can help protect against and reduce radiation exposure by measuring the exposure dose for each type of isotope that is used frequently in nuclear medicine before performing numerical analysis of the effective half-life based on the measurement results. From July to August in 2010, the study targeted 10, 6 and 5 people who underwent an 18F-FDG (fludeoxyglucose) positron emission tomography (PET) scan, 99mTc-HDP bone scan, and 201Tl myocardial single-photon emission computed tomography (SPECT) scan, respectively, in the nuclear medicine department. After injecting the required medicine into the subjects, a survey meter was used to measure the dose depending on the distance from the heart and time elapsed. For the 18F-FDG PET scan, the dose decreased by approximately 66% at 90 min compared to that immediately after the injection and by 78% at a distance of 1 m compared to that at 0.3 m. In the 99mTc-HDP bone scan, the dose decreased by approximately 71% in 200 min compared to that immediately after the injection and by approximately 78% at a distance of 1 m compared to that at 0.3 m. In the 201Tl myocardial SPECT scan, the dose decreased by approximately 30% in 250 min compared to that immediately after the injection and by approximately 55% at a distance of 1 m compared to that at 0.3 m. In conclusion, the dose decreases by a large margin depending on the distance and time. In conclusion, this study measured the exposure doses by isotopes, distance from the heart and exposure time, and found that the doses were reduced significantly according the distance and the time.

Primary hepatic choriocarcinoma in a 49-year-old man: Report of a case

We report a case of hepatic choriocarcinoma in a man diagnosed at autopsy after a rapid downhill clinical course. The patient was a 49-year-old man who presented with acute right-sided abdominal pain. There were no masses palpable on physical examination. Radiographic findings showed large multi-nodular tumors mainly in the right lobe of the liver. Fludeoxyglucose-positron emission tomography scan showed uptake only in the liver, and no uptake in the testes. We initially planned to perform a liver resection for the presumed diagnosis of intra-hepatic cholangiocarcinoma. However, the tumors grew rapidly and ruptured. Multiple lung metastases rapidly developed resulting in respiratory failure, preventing liver resection or even biopsy. He died 60 d after initial presentation with no pathological diagnosis. Postmortem studies included histopathological and immunohistological examinations which diagnosed a primary choriocarcinoma of the liver. Primary hepatic choriocarcinoma is very rare but should be considered in the differential diagnosis of a liver tumor in a middle aged man. Establishing this diagnosis may enable treatment of the choriocarcinoma. Liver biopsy and evaluation of serum human chorionic gonadotropin are recommended in these patients.

Oesophageal squamous cell carcinoma: relationship between fluorine-18 fludeoxyglucose positron emission tomography CT maximum standardised uptake value, metabolic tumour volume, and tumour, node and metastasis classification

We aimed to evaluate the relationships between primary tumour, maximum standardised uptake value, metabolic tumour volume and seventh edition American Joint Committee on Cancer (AJCC) classification in oesophageal squamous cell carcinoma (OSCC) patients. Fluorine-18 fludeoxyglucose ((18)F-FDG) positron emission tomography (PET)-CT scans of 41 consecutive newly diagnosed OSCC patients were retrospectively reviewed. Maximum standard uptake value (SUV(max)) and metabolic tumour volume (MTV) were recorded. Two-tailed Spearman's correlation was used to analyse the relationships between the metabolic parameters and the AJCC staging system. Positive correlations were observed between SUV(max), MTV and tumour (T) stage, in addition to node (N) stage and AJCC stage. Both metabolic parameters were independent variables that significantly affected the N stage and AJCC stage, and SUV(max) was the only independent variable that significantly affected the T stage. The metabolic parameters derived from (18)F-FDG PET-CT were positively correlated with T, N and AJCC stage in primary OSCC. Our findings may suggest a complementary role of these parameters to seventh-edition AJCC staging in the prognostication of OSCC patients.

Cost-effectiveness of Adding FDG-PET or CT to the Diagnostic Work-up of Patients With Stage III Melanoma

The aim of this prospective study was to assess predictive value of fludeoxyglucose-positron emission tomography (FDG-PET) and computed tomography (CT) and to analyze their cost-effectiveness in several diagnosis-treatment combinations. The incidence of melanoma continues to rise. A proportion will present or recur with lymph node metastases (American Joint Committee on Cancer/Union for International Cancer Control stage III). To detect distant metastases, CT and/or FDG-PET are available. However, few studies have assessed their value and costs in stage III. All consecutive patients with melanoma with palpable, proven lymph node metastases (2003-2008) referred for examination with FDG-PET and CT were prospectively included. Sensitivity, specificity, and accuracy, and positive predictive value (PPV) and negative predictive value (NPV) were calculated. In economic evaluation, the costs of diagnostic work-up with and without FDG-PET and CT were compared. Overall, 253 patients with melanoma were included. FDG-PET showed a higher sensitivity than CT: 86.1% compared with 78.2%. Specificity was higher for CT (93.7%) compared with FDG-PET (93.1%). Overall, FDG-PET showed a higher PPV and NPV. Cost-consequence analysis showed that adding CT (True-Positive upstaging in 61 patients) to diagnostic work-up decreased cost by 5.5%, adding FDG-PET (True-Positive upstaging in 68 patients) increased cost by 7.2%, and adding both (True-Positive upstaging in 78 patients) increased cost by 15.1%. In this study, FDG-PET had higher sensitivity and predictive value, whereas CT had a higher specificity. Adding one of these diagnostic tools improved the staging of stage III patients with less than 10% cost increase. A proposal for stage-specific use of imaging modalities for clinicians caring for patients with melanoma is presented.

Malignant transformation of exophytic Schneiderian papilloma of the nasal cavity

Schneiderian papilloma (SP) is classified into three types: inverted, oncocytic, and exophytic. Malignant transformation occurs in 10% of SP; most are inverted and oncocytic types. Malignant transformation of polypoid exophytic SP is exceptional; only two cases have been reported in the English literature. A 58-year-old man consulted our hospital because of nasal obstruction. Nasal endoscopy and imaging modalities showed a polyp in the right nasal cavity. Biopsy findings showed compatibility with SP. However, since fludeoxyglucose positron emission tomography (FDG-PET) showed signals, polypectomy was performed. Grossly, the polyp was reddish white and measured 2 cm. Histologically, the polyp consisted of a non-invasive squamous cell carcinoma (SCC) component (70%), a mature squamous component (20%), and Schneiderian epithelium (10%). Vague koilocytosis was present in the SCC component. The three components were arranged in an exophytic papillary pattern. Immunohistochemically, the non-invasive SCC component was positive for cytokeratins (AE1/3, CAM5.2, CK5/6), p63, p53, and Ki67 (labeling 50%). The mature squamous component was positive for cytokeratins (AE1/3, CAM5.2 and CK5/6), p63, and Ki67 (labeling 6%). The Schneiderian component was positive for cytokeratins (AE1/3, CAM5.2, and CK5/6), p63, and Ki-67 (labeling 4%). The tumor was HPV negative in the three components. The polyp was diagnosed as exophytic Schneiderian carcinoma arising from exophytic SP. The patient is now free from tumor 4 years after the operation.

Applying new clinicopathological characteristics to prognostication in advanced thyroid carcinoma

In the February 2011 issue of Endocrine-Related Cancer, Deandreis et al. reported that increased FDG uptake was prognostic in patients with metastatic thyroid cancer. Fludeoxyglucose-positron emission tomography (FDG-PET) is routinely used in the staging and follow-up of patients with cancer. This study gives further evidence for the role of FDG-PET scanning in metastatic thyroid cancer, especially to identify patients with aggressive disease requiring systemic therapy.

Mucosa-Associated Lymphoid Tissue Lymphoma of the Rectum Cured by Radiotherapy

Primary rectal mucosa-associated lymphoid tissue (MALT) lymphoma is a particularly rare disease, comprising <1% of gastrointestinal lymphomas. Although antibiotic therapy has been demonstrated effective for gastric MALT lymphoma, the optimal treatment for MALT lymphoma of the rectum is unknown. Radiotherapy or surgery is often used to treat limited stage MALT lymphoma of the rectum. Here, we describe a case of a 44-year-old-man, who was diagnosed with primary MALT lymphoma of the rectum through colonoscopy. Other staging evaluations, including upper gastrointestinal endoscopy, abdomino-pelvic CT, chest CT, 18F fludeoxyglucose-positron emission tomography, and a bone marrow examination showed no other abnormalities, except stage IA para-rectal lymphadenopathy. The patient received 2 months of radiotherapy without major toxicity. A follow-up abdomino-pelvic CT scan revealed marked improvement in the volume of rectal lymphoma and adjacent lymph nodes. Mucosal nodularity of the lower rectum had completely regressed at the follow-up endoscopy and complete remission was confirmed with a biopsy. (Intest Res 2012;10:201-205) 󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏

Molecular imaging of potential bone metastasis from differentiated thyroid cancer: a case report

IntroductionMolecular imaging of the spine is a rarely used diagnostic method for which only a few case reports exist in the literature. Here, to the best of our knowledge we present the first case of a combination of molecular imaging by single photon emission computer tomography and positron emission tomography used in post-operative spinal diagnostic assessment.Case presentationWe present the case of a 50-year-old Caucasian woman experiencing progressive spinal cord compression caused by a vertebral metastasis of a less well differentiated thyroid cancer. Following tumor resection and vertebral stabilization, total thyroidectomy was performed revealing follicular thyroid carcinoma pT2 pNxM1 (lung, bone). During follow-up our patient underwent five radioiodine therapy procedures (5.3 to 5.7 GBq each) over a two-year period. Post-therapeutic I-131 scans showed decreasing uptake in multiple Pulmonary metastases. However, following an initial decrease, stimulated thyroglobulin remained at pathologically increased levels, indicating further neoplastic activity. F18 Fludeoxyglucose positron emission tomography, which was performed in parallel, showed remaining hypermetabolism in the lungs but no hypermetabolism of the spinal lesions correlating with the stable neurological examinations. While on single photon emission computer tomography images Pulmonary hyperfixation of I-131 disappeared (most likely indicating dedifferentiation), there was persistent spinal hyperfixation at the operated level and even higher fixation at the spinal process of L3. Based on the negative results of the spinal F18 fludeoxyglucose positron emission tomography, a decision was made not to operate again on the spine since our patient was completely asymptomatic and the neurological risk seemed to be too high. During further follow-up our patient remained neurologically stable.ConclusionsMolecular imaging by F18 fludeoxyglucose positron emission tomography helps to exclude metabolically active spinal metastases and to spare further risky surgery.

Progress in diagnosis and treatment of cervical postoperative infection

Postoperative infection is the commonest complication that causes failure of spinal surgery. Although the rate of infection after cervical surgery is lower than that after lumbar surgery, the absolute number of cases is increasing. In recent years, new techniques, such as serum amyloid A and fludeoxyglucose ((18) F) positron emission tomography (18F-FDG PET), have emerged and gradually been employed in the diagnosis of postoperative infection, updating the ability to identify the presence of infection. Most patients with cervical postoperative infection require re-operation. There are three principles for such surgery: thorough debridement, adequate drainage and ensuring stability of the spine. Some severe cases even need emergency surgery. This article aims to discuss the controversial issues in diagnosis and treatment of cervical postoperative infection, as well as progress in related studies.

The relevance of aortic endograft prosthetic infection

Vascular prosthetic graft infection is a severe complication after open aortic aneurysm repair. Reports of infected endografts are scarce. General treatment consensus with infected graft material is that it should be removed completely. The objective of this study was to describe the incidence of endograft infection after endovascular repair of abdominal (EVAR) and thoracic aortic aneurysm (TEVAR) and to report treatment options and their outcome. A retrospective cohort study was performed of patients endovascularly operated for abdominal and thoracic aortic aneurysm in two large hospitals (one tertiary referral center and one large community hospital) between March 1996 and June 2009. Diagnosis of infected endograft was made based on clinical findings, blood tests and cultures, imaging studies (computed tomography, fludeoxyglucose positron emission tomography), and intraoperative findings at reoperation. Eleven patients with an infected endograft were identified in 1431 endovascular procedures. One other patient was referred from another hospital. Patients were aged 68 ± 9 years, and all but one were male. The median time from initial TEVAR/EVAR to the diagnosis of infection was 115 days (range, 7-3748 days), with 42% of patients presenting within 3 months after TEVAR/EVAR. Seven patients were diagnosed with endograft infection after elective TEVAR/EVAR and five after emergency TEVAR/EVAR. The incidence was significantly higher in patients that were treated in an emergency setting (0.56% vs 2.79%; P = .002), while there was no significant difference between TEVAR and EVAR procedures (1.37% vs 0.77%). All patients were initially treated with antibiotic therapy, which was complemented with surgical intervention in six patients. In four patients, the infected graft material was completely explanted. Isolated microorganisms included Staphylococcus species (n = 4), Streptococcus species (n = 4), Enterobacter cloacae (n = 1), Escherichia coli (n = 1), Pseudomonas aeruginosa (n = 1), and Listeria monocytogenes (n = 1). Median time of follow-up was 201 days (range, 6-2023 days). During the study period, three out of 12 patients died, of which two were treated conservatively (P = ns). At their last follow-up visit, seven of nine patients still used antimicrobial therapy. The incidence of endograft infection is below 1%, with a mortality rate of 25%. Although consensus is that infected graft material should always be removed, this study shows no significant difference in mortality between the conservatively- and the surgically-managed group, possibly related to the small sample size. There may be a role for conservative treatment in selected cases of patients with an infected endograft.

Metabolic and Receptor Imaging in Patients with Neuroendocrine Tumors: Comparison of Fludeoxyglucose-Positron Emission Tomography and Computed Tomography with Indium in 111 Pentetreotide

To determine whether positron emission tomography/computed tomography (PET/CT) and indium In 111 pentetreotide, individually or collectively, predict the outcome of patients with neuroendocrine tumors (NETs). Between July 31, 2002, and May 4, 2007, 29 patients with previously diagnosed NETs underwent both PET/CT and indium In 111 pentetreotide imaging at our institution. The images were evaluated for the presence of abnormalities. Clinical outcomes were classified as survival without major morbidities, survival with severe complications of disease, or death. Time to outcome was measured in months from the imaging date to outcome. Kaplan-Meier survival curves were calculated in which patient outcome was compared with results on PET/CT and indium In 111 pentetreotide imaging. Of the 29 patients, 9 had abnormalities on both PET/CT and indium In 111 pentetreotide imaging. Two patients had abnormal findings on PET/CT but normal findings on pentetreotide imaging. In 5 patients, findings were normal on PET/CT but abnormal on pentetreotide imaging. In 13 patients, normal findings were noted on both PET/CT and pentetreotide imaging. Kaplan-Meier analysis demonstrated a significant survival advantage for patients who had normal findings on PET/CT in comparison with abnormal PET/CT findings (P = .01). Patients with normal findings on indium In 111 pentetreotide imaging had a higher but insignificant survival advantage over those with abnormal results on pentetreotide imaging (P = .08). For evaluation of NETs, PET/CT and indium In 111 pentetreotide are complementary. Increased metabolic activity in tumor cells is reflected by abnormalities on PET/CT. Patients who had abnormal PET/CT findings had a generally poorer prognosis and a more rapid clinical deterioration than those with normal PET/CT findings.

Activity-based costing evaluation of a [18F]-fludeoxyglucose positron emission tomography study

The aim of the study is to use the activity-based costing approach to give a better insight in the actual cost structure of a positron emission tomography procedure (FDG-PET) by defining the constituting components and by simulating the impact of possible resource or practice changes. The cost data were obtained from the hospital administration, personnel and vendor interviews as well as from structured questionnaires. A process map separates the process in 16 patient- and non-patient-related activities, to which the detailed cost data are related. One-way sensitivity analyses shows to which degree of uncertainty the different parameters affect the individual cost and evaluate the impact of possible resource or practice changes like the acquisition of a hybrid PET/CT device, the patient throughput or the sales price of a 370MBq (18)F-FDG patient dose. The PET centre spends 73% of time in clinical activities and the resting time after injection of the tracer (42%) is the single largest departmental cost element. The tracer cost and the operational time have the most influence on cost per procedure. The analysis shows a total cost per FDG-PET ranging from 859 Euro for a BGO PET camera to 1142 Euro for a 16 slices PET-CT system, with a distribution of the resource costs in decreasing order: materials (44%), equipment (24%), wage (16%), space (6%) and hospital overhead (10%). The cost of FDG-PET is mainly influenced by the cost of the radiopharmaceutical. Therefore, the latter rather than the operational time should be reduced in order to improve its cost-effectiveness.

Ga-68 DOTATOC PET/CT Changed the Therapeutic Course of a Patient With the Sudden Onset of Vision Problems

A 61-year-old man presented with the sudden onset of blurry vision of the right eye. Conventional ophthalmologic examination and magnetic resonance index were suspicious for a choroidal melanoma. Fludeoxyglucose positron emission tomography imaging showed no increased uptake, rendering the diagnosis of melanoma most unlikely. Because of the patient had a history of bronchial carcinoid tumor (pT2N0Mx) 3 years ago, further work-up included ophthalmologic echography (A-scan) showing a probable metastatic lesion. Evaluation of the chromogranin blood level and Ga-68 Positron emission tomography-computed tomography DOTATOCPET/CT revealed high uptake in the ocular lesion and further tumor localization in the mediastinum, liver, and pancreas. The pattern was considered highly suspicious for metastases, and without further anatomopathological analysis, the patient was referred for external beam radiotherapy and additional radiopeptide receptor therapy with Lu-177-DOTATATE. This case illustrates the use of Ga-68 DOTATOC-PET/CT in a difficult clinical problem, where fludeoxyglucose-PET/CT did not provide a final diagnosis.

Positron-emission tomography with fluorine-18-fluoro-2-deoxy-D-glucose for gallbladder cancer diagnosis

Background Recent advances in hepatobiliary surgery have underscored the need for presurgical diagnosis of gallbladder cancer. Frequently, clinical presentation, biochemical analysis, and structural ultrasound or computed axial tomography images do not enable definitive differentiation of cholecystitis or cholethiasis from gallbladder cancer. The aim of this study was to evaluate the role of fludeoxy glucose–positron-emission tomography (FDG-PET) in establishing the benign or malignant nature of gallbladder lesions. Methods A case series of 16 patients with clinical symptoms suggestive of biliary colic or chronic cholecystitis and with inconclusive ultrasound and/or computed axial tomography findings for presence of gallbladder cancer were studied by FDG-PET. Results FDG-PET showed a sensitivity of 0.80, a specificity of 0.82, and positive and negative predictive values of 0.67 and 0.90, respectively. There was 1 false- negative result in 1 patient with mucinous adenocarcinoma and 2 false-positive results in 1 patient with tuberculoid granulomatous reaction and 1 patient with polypoid lesion with adenomyomatosis. Conclusions FDG-PET may be of utility to establish the diagnosis of gallbladder cancer in patients with nonspecific clinical and imaging findings.