Positron Emission Tomography-computed Tomography Examination Research Articles

Undiagnosed Borrmann type IV gastric cancer despite repeated endoscopic biopsies and PET-CT examination: A case report.

Borrmann type IV gastric cancer is a particular histological type of carcinoma, which has the characteristic of diffused infiltration that invades the entire stomach, resulting in the thickening and stiffness of the stomach wall. Borrmann type IV gastric cancer is known for the difficulty of detecting tumor cells in endoscopic biopsy specimens. This is crucial in obtaining the pathological results to make a therapeutic decision. The case reported in the present study was highly suspected to be Borrmann type IV gastric cancer according to the clinical manifestations and gastrointestinal barium meal examinations, but demonstrated negative results in multiple endoscopic biopsies and positron emission tomography-computed tomography (PET-CT) examination. The patient was discharged as no affirmative diagnosis was specified. Two weeks after discharge, the patient was administered to another hospital under emergency treatment due to frequent urination. Cystoscopy examination revealed marked thickening of the right bladder wall over a large area. Biopsy specimens were sampled. Pathological consultation suggested a gastrointestinal original of the lesion, which was most likely poorly differentiated gastric adenocarcinoma with neuroendocrine metastasis to the bladder.

Simultaneous whole body (18)F-fluorodeoxyglucose positron emission tomography magnetic resonance imaging for evaluation of pediatric cancer: Preliminary experience and comparison with (18)F-fluorodeoxyglucose positron emission tomography computed tomography.

To describe our preliminary experience with simultaneous whole body (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography and magnetic resonance imaging (PET-MRI) in the evaluation of pediatric oncology patients. This prospective, observational, single-center study was Health Insurance Portability and Accountability Act-compliant, and institutional review board approved. To be eligible, a patient was required to: (1) have a known or suspected cancer diagnosis; (2) be under the care of a pediatric hematologist/oncologist; and (3) be scheduled for clinically indicated (18)F-FDG positron emission tomography-computed tomography (PET-CT) examination at our institution. Patients underwent PET-CT followed by PET-MRI on the same day. PET-CT examinations were performed using standard department protocols. PET-MRI studies were acquired with an integrated 3 Tesla PET-MRI scanner using whole body T1 Dixon, T2 HASTE, EPI diffusion-weighted imaging (DWI) and STIR sequences. No additional radiotracer was given for the PET-MRI examination. Both PET-CT and PET-MRI examinations were reviewed by consensus by two study personnel. Test performance characteristics of PET-MRI, for the detection of malignant lesions, including FDG maximum standardized uptake value (SUVmax) and minimum apparent diffusion coefficient (ADCmin), were calculated on a per lesion basis using PET-CT as a reference standard. A total of 10 whole body PET-MRI exams were performed in 7 pediatric oncology patients. The mean patient age was 16.1 years (range 12-19 years) including 6 males and 1 female. A total of 20 malignant and 21 benign lesions were identified on PET-CT. PET-MRI SUVmax had excellent correlation with PET-CT SUVmax for both benign and malignant lesions (R = 0.93). PET-MRI SUVmax > 2.5 had 100% accuracy for discriminating benign from malignant lesions using PET-CT reference. Whole body DWI was also evaluated: the mean ADCmin of malignant lesions (780.2 + 326.6) was significantly lower than that of benign lesions (1246.2 + 417.3; P = 0.0003; Student's t test). A range of ADCmin thresholds for malignancy were evaluated, from 0.5-1.5 × 10(-3) mm(2)/s. The 1.0 × 10(-3) ADCmin threshold performed best compared with PET-CT reference (68.3% accuracy). However, the accuracy of PET-MRI SUVmax was significantly better than ADCmin for detecting malignant lesions compared with PET-CT reference (P < 0.0001; two-tailed McNemar's test). These results suggest a clinical role for simultaneous whole body PET-MRI in evaluating pediatric cancer patients.

The Role of PET-CT in Evaluation of Cervical Lymph Node Metastases in Oral Cavity Squamous Cell Carcinomas.

The aim of this study is to determine the sensitivity and specificity of positron emission tomography-computed tomography (PET-CT) in the evaluation of cervical lymph node metastasis in oral cavity squamous cell cancers (SCCs) and to determine the SUV-max values in differentiating reactive and metastatic lymph nodes as a supportive parameter. In this study, 23 patients were included who were diagnosed with oral cavity SCC and treated with surgery between 2006 and 2013 in our department. All the patients were scanned with PET-CT during the pretreatment evaluation. Detailed pretreatment PET-CT (retention sites and SUV-max values) and histopathological examination results were obtained. SPSS 17.0 software package was used for statistical analysis of the data. Categorical measurement was summarized as number and percentage and continuous measurements as mean and standard deviation (median and minimum-maximum where necessary). Chi-square test or Fisher's test were used in the comparison of categorical variables. Compliance of methods was assessed by Kappa coefficient analysis. In this study, the advantages of PET-CT were determined by the calculation of sensitivity and specificity values with histopathological examination results considered as the gold standard, and SUV-max value was assessed by examining the area under the ROC curve. In all tests, the level of statistical significance was accepted as 0.05. The threshold value for SUV-max depending on the data of the histopathological examination and results of PET-CT of the 23 patients was 2.50. The reliability of this threshold was determined as AUC=0.819. In demonstrating neck metastasis in patients with cancer of the oral cavity, PET-CT has a sensitivity of 89% and specificity of 98%. Compliance between the histopathological examination and PET-CT for metastatic cervical lymph nodes was determined to be 0.416 by kappa coefficient analysis. There was FDG uptake on PET-CT in the cervical lymph node regions of all patients with metastatic cervical lymph nodes. There were no metastases in any of the patients with no FDG retention. The sensitivity and specificity of PET-CT in determining cervical lymph node metastasis were 89% and 98%, respectively, with a threshold SUV-max value considered as 2.50 in patients with FDG retention.

18F-FDG PET-CT as a supplement to CT/MRI for detection of nodal metastasis in hypopharyngeal SCC with palpably negative neck.

To determine the diagnostic value of (18) F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) compared with CT or magnetic resonance (MR) imaging for the detection of nodal metastasis in patients with hypopharyngeal squamous cell carcinoma (SCC) with palpably negative neck and to assess the role of PET-CT as a supplement to CT/MR. Retrospective analysis. A total of 39 patients with palpably negative neck (36 men and 3 women; average age 65.4 years) underwent tumor resection and neck dissection as primary treatment. All patients were preoperatively evaluated with PET-CT and CT and/or MR, and imaging data were retrospectively reviewed. The diagnostic performance of PET-CT, CT/MR, and a combination of PET-CT and CT/MR was assessed using histopathologic results as a gold standard. Twenty (51.3%) of the 39 patients were found to have neck metastases. On a level-based analysis, the sensitivity of PET-CT, CT/MR, and combined interpretation of PET-CT and CT/MR was 65.7%, 57.1%, and 65.7%, respectively, but without statistical significance. Of the six patients who showed false negative neck findings based on CT/MR in addition to palpation, four cases were still missed with additional PET-CT. The addition of PET-CT examination to anatomic imaging involving CT and MR did not provide additional benefit for the preoperative evaluation of cervical nodal metastasis in patients with hypopharyngeal SCC with nonpalpable neck, yielding insufficient data to spare elective neck dissection.

DIAGNOSTIC ROLE OF FLUORINE-18 (18F) FLUORODEOXYGLUCOSE POSITRON EMISSION TOMOGRAPHY COMPUTED TOMOGRAPHY IN DETECTING RECURRENT DISEASE IN PATIENTS WITH COLORECTAL CANCER AND ELEVATED CARCINOEMBRYONIC ANTIGEN.

Early detection of recurrence is an important factor for long term survival of patients with colorectal cancer. Measurement of serum levels of carcinoembryonic antigen has been commonly used in the postoperative surveillance of colorectal cancer. The purpose of this study was to evaluate the ability of positron emission tomography-computed tomography to detect pathological substrate of elevated serum carcinoembryonic antigen in patients with colorectal cancer. The patients with colorectal cancer who underwent curative surgical resection and/ or chemotherapy, who were found in our database, were analyzed retrospectively. Forty-eight 18F-fluorodeoxyglucose positron emission tomography-computed tomography studies including 45 patients (14 women, 31 men; mean age: 62.93 years) with elevated serum, carcinoembryonic antigen levels, which had been performed between January 2011 and January 2014, were evaluated. Serum levels of carcinoembryonic antigen were measured within 3 months after positron emission tomography-computed tomography examination. Final diagnosis of recurrence was made by histopathological findings, radiology studies or clinical follow-up. Recurrences were diagnosed in 37 patients, the prevalence being 77.1%. Liver metastases were found in 18 patients, abdominal, pelvic and/or mediastinal lymph nodes were positive in 19 patients, 11 patients had loco regional recurrences and 4 patients had pulmonary metastasis, and bone metastases were found in one patient. One patient was diagnosed with metastasis in scar tissue. The overall sensitivity and specificity of positron emission tomography-computed tomography was 90.24% and 71.42%, respectively. The positive and negative predictive values were 94.87% and 55.56%, respectively. 18F-fluorodeoxyglucose positron emission tomography-computed tomography is a powerful tool that could be used in determining colorectal cancer recurrence in patients with elevated carcinoembryonic antigen levels and could have an important clinical impact on the management in patients with suspected recurrent colorectal cancer.

Misjudgement of gefitinib efficacy in patients with central non-small-cell lung cancer due to obstructive atelectasis caused by stereotactic radiotherapy.

Stereotactic body radiation therapy (SBRT) has been reported to be safe and effective for the treatment of central lung cancer, with mostly tolerable early complications. In this study, we report the development of severe obstructive atelectasis as a late complication in two patients with central lung cancer who received SBRT. This obstructive atelectasis interrupted the evaluation of efficacy of the subsequent gefitinib treatment for non-small-cell lung cancer (NSCLC). The two patients received a total dose of 40 Gy encompassing the planning target volume in 10 fractions (5 fractions/week) at 4 Gy per fraction at the central lesions. Obstructive atelectasis occurred when the patients received subsequent gefitinib treatment. Follow-up reviews or positron emission tomography-computed tomography examination of the two patients confirmed that obstructive atelectasis was actually caused by radiotherapy rather than disease progression. Misjudgement of the cause of ostructive atelectasis in one of the cases resulted in premature termination of gefitinib. Therefore, it is crucial to accurately determine the cause of late complications in NSCLC patients receiving sequential SBRT and gefitinib.

Ectopic liver: Different manifestations, one solution

Developmental abnormalities are rare in the liver. This study presents two case reports of ectopic liver. The first case was a 31-year-old male with clinical indication for laparoscopic appendectomy. Laparoscopy identified a perforated appendix and an unknown tumorous lesion in the ligamentum hepato umbilicalis. The patient underwent a laparoscopic appendectomy, intraoperative lavage of the peritoneal cavity, and extirpation of the lesion in the ligamentum hepato umbilicalis. Histopathological examination of the excised tumor revealed that it comprised liver tissue with fibrinous changes. The tumor was completely separate from the liver with no connection. It was classified as an ectopic liver. No further therapy was required. The second case was a 59-year-old male with a tumor on the upper pole of the spleen, incidentally diagnosed in an ultrasound examination. The biopsy raised suspicion of hepatocellular carcinoma. A positron emission tomography-computed tomography examination revealed accumulation of F-18 fluorodeoxyglucose only in the tumor. The patient underwent a splenectomy with a resection and reconstruction of diaphragm. After the hepatocellular carcinoma was confirmed, adjuvant therapy (sorafenib) was initialized. The operations and postoperative recoveries were uncomplicated in both cases. Despite the low incidence of ectopic liver and rare complications, it is necessary to maintain awareness of this possibility. The potential malignancy risk for ectopic liver tissue is the basis for radical surgical removal. Therapy for hepatocellular carcinoma in an ectopic liver follows the same guidelines as those followed for treating the "mother" liver.

Infected prosthetic dialysis arteriovenous grafts: a single dialysis center study.

The prosthetic arteriovenous grafts (AVG) being used increasingly to create hemodialysis access are prone to infections that pose potentially life-threatening infectious and bleeding complications, as well as loss of dialysis access. In this study, we identified the bacteriologic agents of infected AVGs by site swab, blood culture, and prosthesis cultures, and to evaluate the role of microbiological findings in the management of the infection. We focused on 51 patients with 53 AVGs operated on in our clinic from January 2006 to December 2009. An infected AVG was identified by clinical, ultrasound, and microbiological findings. Sensitivity to antibiotics was determined for all bacterial strains. Isolates were identified by pulsed-field gel electrophoresis (PFGE) of bacterial DNA. In a few cases, positron emission tomography-computed tomography (PET-CT) examination was performed. Strains of Staphylococcus spp., especially S. aureus, were the most frequent cause of infected AVG. All S. aureus strains were sensitive to methicillin. With the exception of a single case, isolates obtained simultaneously from the skin site and the vascular prosthesis were identical genetically. Our results suggest that bacterial infectious agents detected in site swab, blood, or graft culture confirm a suspicion of AVG infection. A PET-CT examination can provide confirmation. The combination of microbiologic and radionuclide findings can improve the management of the AVG infection, but surgery remains essential.

Impact of PET‐CT on Primary Staging and Response Control on Multimodal Treatment of Esophageal Cancer

The predictive value of positron emission tomography-computed tomography (PET-CT) in primary staging and response control in patients with esophageal carcinoma (EC) is under discussion. In the present study initial staging and metabolic response of PET-CT was correlated with tumor regression and survival in patients with multimodal treatment of EC. The authors conducted a retrospective analysis on a prospective database for 83 patients with EC (42 squamous cell, 39 adenocarcinoma, 2 anaplastic carcinoma) undergoing PET-CT for primary staging. Twenty-four of the patients underwent primary esophagectomy, 9 had palliative treatment, and 50 neoadjuvant radiochemotherapy (cisplatin, 5-fluorouracil; 50.4 Gy). The PET-CT study was repeated 6 weeks after induction of chemotherapy and compared with endoscopic ultrasound (EUS). For response control, the metabolic response (tumor standardized uptake value [SUV] reduction) was correlated with histopathologic (ypT0-4) and histomorphologic response (tumor regression) and survival. At primary staging 81 of 83 EC (97.5%) showed an increased SUV uptake correlating with the EUS tumor stage. Suspicious lymph nodes were detected in 51 (61.4%) patients by PET-CT and 66 (79.5%) were detected by EUS. Fifteen patients had additional findings on PET-CT examination leading to a change in therapy in 9 patients (10.3%). Of 50 patients receiving a second PET-CT study, a SUV reduction >50% correlated with major histomorphologic response (tumor regression grade 4, <10% vital tumor cells) and histopathologic response (ypT0 ypN0). Furthermore, these patients showed a significantly increased survival (33.1 ± 3.5 months) compared to non-responders (21.7 ± 3.3 months; p = 0.02) and patients after primary surgery (29 ± 3.2 months; p = 0.05). The present study shows that PET-CT is a valuable tool for primary staging and response control in multimodal treatment of patients with EC.

Impact of F-18 Fluorodeoxyglucose Positron Emission Tomography–Computed Tomography on Oncologic Patient Management: First 2 Years' Experience at a Single Canadian Cancer Center

Purpose The purpose of this study was to assess the influence of positron emission tomography–computed tomography (PET-CT) results on patient management from a single Canadian oncology center during its first 2 years of operation. Methods A total of 3,779 consecutive patients, 18 years of age and older, who were referred for PET-CT imaging at the British Columbia Cancer Agency between July 1, 2005 and June 30, 2007, were included in this analysis. Results were tabulated from a standard questionnaire, which was given to referring physicians following completion of their patient's PET-CT study. Results From July 1, 2005 to June 30, 2007, 3,779 consecutive fluoro-2-deoxyglucose PET-CT examinations were performed in patients aged 18 years or older. A total of 3,429 referring-physician surveys (90.7%) were returned. The results of the PET-CT study resulted in a change in treatment decision in 49.8% of the studies and resulted in improved decision making in 83.2% of the studies. Conclusion This series demonstrated that the results from PET-CT studies performed at a single Canadian oncology center during the first 2 years of its operation altered patient management in 50% of cases and resulted in improved decision making in the majority of cases.

Pediatric Positron Emission Tomography–Computed Tomography Protocol Considerations

Pediatric body oncology positron emission tomography-computed tomography studies require special considerations for optimal diagnostic performance while limiting radiation exposure to young patients. Differences from routine adult procedures include the patient preparation phase, radiopharmaceutical dose, computed tomography acquisition parameters, and approach to computed tomography contrast materials and imaging sequence. Attention to these differences define the best practice for positron emission tomography-computed tomography examinations of children with cancer contributing to optimal care of these patients.

Protocol Considerations for Positron Emission Tomography–Computed Tomography of the Abdomen and Pelvis

New developments in positron emission tomography-computed tomography (PET-CT) have included the introduction of scanners with multidetector 16- to 64-row CT that allow thin-section essentially isotropic imaging datasets to be acquired rapidly in multiple time phases. "Diagnostic quality" CT with both oral and intravenous enhancement is now routinely possible in PET-CT and allows greater potential for the accurate diagnosis and staging of the full range of cancers involving the abdomen and pelvis. This article explores the considerations for more tailored, specific tumor-related protocols for PET-CT in the abdomen and pelvis, with emphasis on the use and value of fully optimized CT as part of an integrated PET-CT examination.

Positron-emission tomography and computed tomography of cystic pancreatic masses

To investigate the sensitivity and specificity of computed tomography (CT), positron-emission tomography (PET), and both methods in combination, for determining whether cystic pancreatic tumours are malignant. We retrospectively identified all patients with cystic pancreatic tumours who underwent separate PET and contrast-enhanced CT examinations within a 1-month interval. Tumours were classified as benign or malignant on CT (two radiologists, independently), PET [a reported standardized uptake value (SUV) of 2.5 was taken as the cut-off between benign and malignant], and with PET and CT images together (two radiologists, in consensus). Readers were blinded to pathological and other radiological findings. Mean patient age and lesion size were compared between benign and malignant groups using Student's t-test. For CT findings, odds ratios (OR) and confidence intervals (CI) were calculated using multivariate logistic regression models. For CT, PET, and the combined images, sensitivities and specificities were calculated, and compared between groups using Fisher's exact test. Thirty patients were identified. The best CT predictor of malignancy was size; mean diameter was 2.3 cm (benign) and 4.1 cm (malignant) (p<0.01); OR was 2.80 (95% CI, 1.26-6.20). Sensitivities of CT, PET and combined PET/CT images were 67-71, 57, and 86%, respectively. PET/CT was more sensitive than PET (p<0.01) or CT (p<0.01) alone. Specificities of CT, PET, and combined PET/CT images were 87-90, 65, and 91%, respectively. PET/CT was more specific than PET (p<0.01) but not CT (p>0.05). The sensitivity and specificity of combined PET and CT images is comparable with or superior to either CT or PET alone in determining malignancy in cystic pancreatic lesions.