Added value of 18-F-FDG-PET/CT in patients with pancreatic cancer: Initial observation

Purpose: The goal of the study was to highlight the added value of 18-F-FDG PET/CT over isolated CT to depict pancreatic tumors, distant metastases, monitor response to treatment and its usefulness in distinguishing fibrosis from residual/recurrence, thus direct biopsy to sites more likely to yield representative tumor tissue. Patients and methods: This study included 20 patients for which 18-F-PET/CT scans were performed. A case based analysis was performed in detailed manner for lesions on CT and fused images of 18-F-PET/CT. Statistical analysis including specificity, Sensitivity, negative predictive value (NPV) and positive predictive value (PPV) of each of these modalities was performed. A final diagnosis of metastasis was confirmed by further clinical and radiological workup. Results: PET/CT has 100% sensitivity, 88.9% specificity, 91.7% PPV, 100% NPV and 95% accuracy compared to 77.8% sensitivity and 54.5% specificity, 58.3% PPV, 75% NPV and 65% accuracy for CT in diagnosis and monitoring treatment response. Conclusion: Combined 18-F FDG PET/CT significantly improves the sensitivity and specificity of isolated CT for depicting pancreatic tumors, distant metastases, monitor response to treatment distinguishing fibrosis from residual/recurrence

Fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography: A diagnostic imaging modality in renal cancer patients

Purpose: The aim of this study is to clarify the role of 18-F-FDG PET/CT over CT alone in the detection of primary, recurrent and metastatic disease in renal cancers patients. Patients and methods: In this study; 18-F-PET/CT scans were performed for 25 patients (19 males and 6 females) with renal cancer. A patient-based analysis was performed in a dedicated manner to pick up lesions on CT, PET and PET/CT fused images. Statistical analysis was calculated. A final diagnosis of disease extent was affirmed by clinical, radiologic workup and histopathological correlation. Results: PET/CT has 100% sensitivity, 93% specificity, 100% PPV, 91% NPV and 96% accuracy; compared to 100% sensitivity and 70% specificity, 83% PPV, 100% NPV and 88% accuracy for CT in diagnosis of primary, recurrent and metastatic disease in renal cancer. Conclusion: Incorporated 18-F FDG PET/CT is a very versatile and accurate imaging technique for renal cancers. It significantly improves the accuracy and predictive values over CT alone for detection of primary, recurrent and metastatic disease in renal cancer thus change the treatment decision

Can fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography detect hepatocellular carcinoma and its extrahepatic metastases?

Aims: The point of this research is to investigate the potential role of (18-F-FDG/PET) in the identification of hepatocellular carcinoma (HCC) and its metastases. Patients and method: The present study was performed on 22 patients (15 newly diagnosed, 7 previously treated).18F-FDG was injected IV 1 h before the scan. Non-contrast-enhanced CT was performed trailed by PET in the same session. PET/CT scans were performed on (Philips Gemini-NM system). The whole study took around 20–30 min. Results: PET/CT revealed increased local liver tumor 18-F-FDG uptake in 13/17 of those patients (6 solitary uptakes and 7 multi-nodular uptakes). Primary tumor SUV max. extended from 3 to 11 (mean 6.1) and liver tumor background ratio (TBR) varied from 0.4 to 3 (mean 2.05). 18-F-FDG PET/CT showed extrahepatic metastasis in 6 newly diagnosed patients. It also showed local tumor recurrence in 4 treated patients; 3 of them with no metastasis and 1 previously treated patient had local recurrence and distant metastasis. PET/CT has 76.5% sensitivity, 60% specificity, 86.7% PPV, 42.9% NPV and 59% accuracy in defining HCC and its extrahepatic metastases. Conclusion: This study affirms the achievability of 18-F-FDG PET/CT for identification of primary HCC and its extrahepatic metastases. Keywords: PET/CT, Liver, Hepatocellular carcinom

Diagnostic value of positron emission tomography/computed tomography (PET/CT) in detection of peritoneal carcinomatosis

Abstract Background The diagnosis of peritoneal carcinomatosis is challenging and can be difficult to detect with imaging, especially the detection of small-sized peritoneal lesions. The presence of peritoneal neoplastic spread alters tumour staging and is one of the most significant prognostic indicators in several malignancies, and the purpose of this study was to highlight the diagnostic value of PET/CT in detection of peritoneal carcinomatosis in patients with malignant neoplastic disease. Results PET/CT has 76.2% sensitivity, 88.9% specificity, 94.1% PPV, 61.5% NPV and 80% accuracy in detection of peritoneal carcinomatosis. Different patterns of FDG uptake of peritoneal carcinomatosis were found such as focal nodular uptake, diffuse abdominal uptake and liver surface focal or diffuse uptake. From all these different patterns, focal nodular uptake was the most frequent pattern. The best cut-off value of SUVmax was 5 for diagnosis. Conclusions The study affirms the significant role of PET/CT in the diagnosis of peritoneal carcinomatosis and its important value in the staging, management and follow-up of patients with secondary peritoneal malignancies, especially in case of unavailable or inappropriate peritoneal biopsy. Therefore, PET/CT could help reduce the number of laparotomies and a better selection of patients who are candidates for adjuvant chemotherapy

Added values of diffusion weighted imaging, Dynamic contrast enhancement and opposed phase MRI in evaluation of bony lesions around the knee & ankle joints

Background: Magnetic resonance imaging (MRI) represents the most advanced imaging technique in diagnosis of bone tumors being more sensitive in assessing bone marrow changes and extent of tumors compared to CT and plain X-ray. The distinction between malignant and benign neoplasms is mandatory for appropriate therapeutic choices and planning. MRI has the upper hand in the assessment of such tumors due to its brilliant soft tissue discrimination. The use of multiparametric MRI techniques increase accuracy of discrimination between malignant and benign lesions. Results: This prospective study included 34 patients; 16 males and 18 females with musculoskeletal complaint around the knee & ankle joints. Their age ranged from 10 to 65 years (mean age was 26.65 ± 17.23 years). The cut off value of ADC for bony lesions (by ROC curve) was ≤ 1 to be considered malignant. At this cut off point; the sensitivity of ADC to detect malignant and to exclude benign lesions was 83.3 % and the specificity was 86.4 %. The cut off value for SIR for bony lesions (by ROC curve) was ≥ 0.89 to be considered malignant.&nbsp

Fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography as a diagnostic tool in therapeutic evaluation of lymphoma after completion of therapy

Purpose: This study aimed at assessment of the role of (PET/CT) in lymphoma after completion of therapy to differentiate post-treatment fibrosis from residual viable tumor and being familiar with the limitations and interpretative pitfalls of PET/CT. Method and materials: The present study was performed on 50 patients(27 males and 23 females).18F-FDG was injected IV one hour before performing the study. Contrast enhanced CT was performed followed by PET. Results: After the end of therapy; PET/CT revealed (38%) of cases showed a partial regression, (28%) of cases showed a progressive disease, (22%) of cases with complete metabolic disease remission, (8%) of cases showed a stationary disease and the remaining (4%) of cases showed mixed response to therapy. CT only agreed with PET/CT in 76% of the cases. Some physiologic uptake often occurs after treatment in (4%) of patients. PET/CT has 100% sensitivity,68.75 % specificity, 87.17% PPV, 100% NPV and 90% accuracy in treatment response of lymphoma; compared to 94.1% sensitivity and 50% specificity, 80% PPV, 80% NPV and 80% accuracy for CECT. Conclusion: PET/CT is a multimodality technique that can accurately monitor the treatment response of lymphoma. It can differentiate residual mass containing viable tumor from post treatment fibrosis