The added value of PET/Ce-CT/DW-MRI fusion in assessment of hepatic focal lesions: PET/Ce-CT/DW-MRI fusion in hepatic focal lesion.

INTRODUCTION: The liver hosts a variety of benign and malignant tumors. Accurate diagnosis can be challenging in certain cases, especially in patients with a history of malignancy or in those with underlying liver pathology, such as cirrhosis. OBJECTIVES: To evaluate the added clinical value of multi-modality liver imaging utilizing PET/Ce-CT/DW-MRI for characterization of hepatic focal lesions (HFL) and compare it with each diagnostic modality when interpreted alone. METHODS: The study included 35 patients with HFL. They were 7 females & 28 males; their age ranged from 41 to 78years, all patients underwent PET/Ce-CT and DW-MRI scans. Ce-CT, PET and DW-MR images were reviewed independently, and then combined PET/Ce-CT, PET/DW-MRI and PET/Ce-CT/DW-MRI scans were analyzed. The results were correlated with histopathology or clinical/imaging follow-up. RESULTS: The 35 patients had 98 focal lesions. Fifty-three lesions were finally diagnosed as primary hepatocellular carcinoma, 18 lesions were metastases, 7 lesions were lymphoma and 20 lesions were benign. On a patient based analysis; the sensitivity, specificity, PPV, NPV and accuracy were 100%, 67%, 94%, 100% and 94% for PET/Ce-CT compared to 97%, 83%, 97%, 83% and 94 % for DW-MRI, respectively. Combined PET/Ce-CT/DW-MR scans raise those parameters up to 100%. On a lesion based analysis; the sensitivity, specificity, PPV, NPV and accuracy were 94%, 75%, 94%, 75%, 90% for PET/Ce-CT compared to 94%, 95%, 99%, 97% and 94 % for DW-MRI, respectively. All these parameters were 100 % with PET/Ce-CT/DW-MRI. CONCLUSIONS: The addition of DW-MRI to PET/Ce-CT is valuable in the characterization of hepatic focal lesions.

The value of combined assessment of vertebral fractures with 99mTc MDP scintigraphy and MRI in selecting and planning percutaneous vertebroplasty.

BACKGROUND: Percutaneous vertebroplasty is a minimally invasive radiological procedure intended for relieving painful vertebral fractures. Suitability depends largely on fracture age, with acute osteoporotic fractures being most appropriate. Selection and planning usually involves either Tc MDP scintigraphy or MRI. There is evidence indicating that either modality is predictive of response to vertebroplasty, but there is limited evidence promoting their combined use. AIM: The aim of the study was to establish the degree of concordance between MRI and Tc MDP scintigraphy in vertebral fracture assessment. MATERIALS AND METHODS: Our institution routinely uses both MRI and Tc MDP scintigraphy in vertebroplasty planning. This retrospective analysis included 39 patients, with a total of 73 vertebral fractures, all treated with vertebroplasty. The fractures were classified according to fracture age, aetiology and intermodality concordance. RESULTS: The overall concordance between MRI and Tc MDP scintigraphy was 63%. Almost twice as many fractures classified as 'acute/ subacute' on MRI were so classified on Tc MDP scintigraphy. CONCLUSION: Using MRI without Tc MDP scintigraphy, 48.2% of the potentially suitable vertebroplasty targets (37% of the total vertebral lesions) would likely have been overlooked. Clearly, Tc MDP scintigraphy and MRI provide different but complementary information on vertebral fractures, and these results support the use of dual-modality assessment in vertebroplasty selection and planning.

Prognostic value of p27 in follicular thyroid carcinoma and its relation to radioactive iodine response: does it aid in the modification of risk stratification?

INTRODUCTION: Follicular thyroid carcinoma (FTC) is the second most common type of thyroid cancer. Genetic studies have demonstrated that the loss of expression and function of Cdk inhibitor p27 leads to the development of multiple-organ hyperplasia and malignancy, including thyroid carcinoma. AIM OF WORK: (1) To assess the prognostic value of the quantitative expression of p27 in correlation with clinicopathologic prognostic indicators in FTC. (2) To explore its predictive value in the assessment of response to radioactive I-131 therapy in metastatic FTC patients. MATERIALS AND METHODS: This retrospective study was conducted on 43 histopathologically confirmed FTC patients referred to the nuclear medicine department, National Cancer Institute, Cairo University between July 2001 and December 2010, for radioactive I-131 therapy. Clinicopathologic parameters, details of radioactive I-131 therapy and its outcome, and a serial follow-up serum thyroglobulin levels and I-131 whole body scan were obtained from their medical records. Quantitative expression of p27 using immunostaining was analyzed using paraffin blocks of thyroidectomy specimens in all patients. RESULTS: With respect to clinicopathologic characteristics, p27 expression was found to be significantly lower in patients with vascular invasion (P=0.024) and in patients with an advanced-stage disease (P=0.048). A significant difference was detected between the risk stratification and the quantitative expression of p27. A statistically significant difference was obtained with respect to immunohistochemical expression of p27 between the metastatic and nonmetastatic patients as well as age, growth characteristics, tumor size, vascular invasion, and extrathyroidal extension. Despite the observed trend in patients with a low p27 expression, to have a worse response to iodine therapy, and a poor overall survival, the point of statistical significance could not be reached. CONCLUSIONS: In this preliminary study, p27 quantitative expression appeared to provide a complementary valuable predictor with other prognostic variables for risk stratification in FTC patients. Response to I-131 therapy in FTC in relation to p27 expression should be thoroughly investigated including large-scale studies and more homogenous risk groups.

¹8F-Fluorodeoxyglucose positron emission tomography/computed tomography finds answers in cancer patients with increasing tumor markers and negative or equivocal conventional imaging modalities.

BACKGROUND: The increase in tumor markers with negative or equivocal conventional imaging modalities represents a serious dilemma in the follow-up of previously treated cancer patients. Positron emission tomography/computed tomography (PET/CT) has emerged as a useful tool in oncological imaging in staging and restaging of most cancers. OBJECTIVE: This study explored the potential role of ¹8F-fluorodeoxyglucose (FDG) PET/CT in the detection and localization of tumor recurrence in cancer patients with increasing serum tumor markers and negative or equivocal conventional imaging modalities. MATERIALS AND METHODS: This prospective study was conducted on 105 previously diagnosed and treated cancer patients with different pathologies. All patients were referred for ¹8F-FDG PET/CT scans because of increasing tumor markers with negative or equivocal conventional imaging modalities. All patients underwent whole-body ¹8F-FDG PET/CT scans. The findings were confirmed by clinical and/or radiological follow-up of at least 12 months and histopathologically whenever possible. RESULTS: PET/CT detected recurrence and/or metastases in 90 patients (85.7%), including 17 recurrences, 50 metastases, and 23 recurrences and metastases. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET/CT scans were 95.7, 100, 100, 73.3, and 96.2%, respectively. These parameters were 95, 100, 100, 69, and 95% for PET scans alone and were 91.5, 100, 100, 57.9, and 92.3% for CT scans alone. CONCLUSION: ¹8F-FDG PET/CT is a powerful diagnostic tool in restaging of cancer patients. In most cases, PET/CT provides accurate results and helps resolve the clinical dilemma encountered in oncological patients with increasing serum tumor markers and negative or equivocal findings in conventional imaging modalities.

Impact of histopathology of non-neoplastic thyroid tissue on ablation outcome in patients with papillary thyroid cancer.

OBJECTIVE: To assess the impact of histopathology of non-neoplastic thyroid tissue on ablation outcome in patients with papillary thyroid cancer (PTC). METHODS: The study included 124 patients referred for I-131 ablation therapy after total thyroidectomy for unifocal nonmetastatic PTC. All patients received 100 mCi of I-131 ablation dose. Follow-up whole body scan (WBS) and estimation of serum thyroglobulin level were carried out 6-9 months after ablation therapy and results were divided into complete or incomplete ablation. RESULTS: Incomplete ablation was found in 66.6% (12 of 18), 64% (16 of 25), 39.1% (nine of 23), 30% (six of 20), 33% (six of 18), and 20% (four of 20) in patients with PTC in a background of Hashimoto's thyroiditis, lymphocytic thyroiditis, colloid nodular goiter, nodular hyperplasia, multinodular goiter, and normal thyroid tissue, respectively. Patients with Hashimoto's thyroiditis and lymphocytic thyroiditis had statistically significant higher failure rate to achieve complete ablation compared with other groups. This significant difference was lacking between different nonautoimmune histopathologies and normal thyroid tissue. For patients with thyroid disorders of autoimmune origin (Hashimoto's thyroiditis and lymphocytic thyroiditis), incomplete ablation was found in 65.1% (28 of 43) versus 34.4% (21 of 61) for all other nonautoimmune histopathologies collectively; the difference was statistically significant. CONCLUSION: Histopathology of non-neoplastic thyroid tissue has a significant impact on ablation outcome in patients with PTC. Patients with a histopathology of non-neoplastic thyroid tissue of autoimmune origin have a significantly lower incidence of successful complete ablation after a single I-131 ablative dose (100 mCi) compared with those with nonautoimmune histopathology or with normal thyroid tissue.

Left ventricular myocardial ischemia in collagen disease associated with pulmonary hypertension: an evaluation by rest-stress gated SPECT and coronary angiography.

OBJECTIVE: To detect coronary artery disease in asymptomatic patients with systemic lupus erythematosus and scleroderma associated with pulmonary hypertension, and to determine whether it is focal or diffuse ischemia. METHODS: Twenty patients with systemic lupus erythematosus (10 with pulmonary hypertension and 10 without), and 20 patients with scleroderma (10 with pulmonary hypertension and 10 without) were included in this study. Resting ECG, echocardiography, and stress-rest 99mTc sestamibi gated myocardial perfusion imaging were performed for all patients. Patients with ischemia were subjected to coronary angiography to exclude/confirm coronary artery lesions. RESULTS: Myocardial perfusion SPECT showed that seven patients had myocardial ischemia, including three (30%) of 10 with systemic lupus erythematosus and pulmonary hypertension, three (30%) of 10 with scleroderma and pulmonary hypertension, and one (10%) of 10 with systemic lupus erythematosus without pulmonary hypertension. There was a high incidence of positive myocardial perfusion defects among patients with pulmonary hypertension than those without. Normal coronary angiography was found in all patients with ischemia, except for only one patient with scleroderma who had coronary artery stenosis. Significant correlation was found between pulmonary artery diameter obtained by echocardiography and severity of LV myocardial ischemia detected by SPECT (r=0.83). Significant correlation was found between SPECT-detected myocardial ischemia and ECG ST-T segment changes (r=0.82). CONCLUSION: Coronary artery disease is a common association in patients with systemic lupus erythematosus and scleroderma, especially in those with pulmonary hypertension. This may reflect anatomical compression by distended pulmonary artery rather than diffuse ischemia or small vessel disease. It is important to determine the presence of coronary artery disease in these patients, which may be amenable to coronary stenting.

Occult squamous cell carcinoma of the uvula detected by F-18 FDG PET/CT in a case of carcinoma of unknown primary in the head and neck.

Incidence of unknown primary head/neck tumors with metastatic cervical lymphadenopathy at time of diagnosis is approximately 2% to 9%. Detecting site of original disease is challenging. We present a 75-year-old woman with bulky unilateral level 2 and 3 lymphadenopathy. Clinical examination and computed tomography (CT) did not reveal detectable abnormalities except neck-node metastases; biopsy indicated metastatic squamous cell carcinoma (SCC). F-18 FDG PET/CT imaging was performed to detect the primary tumor site, which revealed a small metabolically-avid lesion in uvula, biopsy demonstrated SCC, the origin of metastatic disease. F-18 FDG PET/CT imaging of unknown primary head/neck tumors can have positive impact in identifying small occult primary tumor foci.

Role of Fluorine-18-Fluorodeoxyglucose in the Work-up of Febrile AIDS Patients. Experience with Dual Head Coincidence Imaging.

OBJECTIVE AND METHODS: This study was undertaken to find the role of fluorine-18-fluorodeoxyglucose (F18-FDG) in the diagnostic work-up of febrile Acquired Immune Deficiency Syndrome (AIDS) patients. Forty-seven (42 male and 5 female; mean age = 40.3 years) febrile patients with AIDS underwent imaging with F18-FDG by Dual Head Coincidence Imaging (DHCI). Findings were correlated with other imaging modalities.RESULTS: Our data show good sensitivity for scanning with F18-FDG by DHCI in determining the extent of Castleman's disease, lymphoma, Kaposi's sarcoma (KS), adenocarcinoma, and germ cell carcinoma. Various opportunistic infections also manifest with increased F18-FDG uptake.CONCLUSION: Total-body imaging can be done with F18-FDG with better resolution and a shorter procedure time compared to imaging with Gallium-67 (Ga-67). Furthermore, F18-FDG is more sensitive than Ga-67 for evaluating extent of involvement in various pathologies affecting AIDS patients. The new technology of DHCI is a good alternative for hospitals with no dedicated positron emission tomography (PET) scanner.