PubMed Health⌕ Search

Biomedical subjects

Alan J Fischman

Publications and source records attributed to Alan J Fischman.

78 records · Page 5Linked to original sources
PubMedDate not supplied

Improved radiologic staging of lung cancer with 2-[18F]-fluoro-2-deoxy-D-glucose-positron emission tomography and computed tomography registration.

PURPOSE: To determine if volumetric nonlinear registration or registration of thoracic computed tomography (CT) and 2-[18F]-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) datasets changes the detection of mediastinal and hilar nodal disease in patients undergoing staging for lung cancer and if it has any impact on radiologic lung cancer staging. METHOD: Computer-based image registration was performed on 45 clinical thoracic helical CT and FDG-PET scans of patients with lung cancer who were staged by mediastinoscopy and/or thoracotomy. Thoracic CT, FDG-PET, and registration datasets were each interpreted by 2 readers for the presence of metastatic nodal disease and were staged independently of each other. Results were compared with surgical pathologic findings. RESULTS: One hundred and thirty lymph node stations in the mediastinum and hila were evaluated each on CT, PET, and registration datasets. Sensitivity, specificity, positive predictive value, and negative predictive value, respectively, for detecting metastatic nodal disease for CT were 74%, 78%, 55%, 88%; for PET with CT side by side, 59% to 76%, 77% to 89%, 48% to 68%, and 84% to 91%; and for CT-PET registration, 71% to 76%, 89% to 96%, 70% to 86%, and 90% to 91%. Registration images were significantly more sensitive in detecting nodal disease over PET for 1 reader (P = 0.0156) and were more specific than PET (P = 0.0107 and 0.0017) in identifying the absence of mediastinal disease for both readers. Registration was significantly more accurate for staging when compared with PET for both readers (P = 0.002 and 0.035). CONCLUSION: Registration of CT and FDG-PET datasets significantly improved the specificity of detecting metastatic disease. In addition, registration improved the radiologic staging of lung cancer patients when compared with CT or FDG-PET alone.

Adult↗
PubMedDate not supplied

Fluorodeoxyglucose positron emission tomography pattern of pulmonary lymphangitic carcinomatosis.

OBJECTIVE: The purpose of this study was to evaluate the F-fluorodeoxyglucose (FDG) positron emission tomography (PET) uptake in pulmonary lymphangitic carcinomatosis identified on computed tomography (CT) in patients with lung cancer. METHODS: This was a retrospective analysis of F-FDG PET images in 7 patients (4 male and 3 female, mean age: 56.6 +/- 6.6 years) with lung cancer with a CT-based diagnosis of lymphangitic carcinomatosis. The F-FDG PET scans in a group of 7 patients (4 male and 3 female, mean age: 42.1 +/- 5.66 years) with normal chest CT scans served as a control group. Mean standardized uptake values (SUVs) were calculated based on average tumor uptake, initial injected activity, and body weight. RESULTS: The intensity of F-FDG uptake in diseased lung is significantly greater than in corresponding normal contralateral lung or in the lungs of normal controls (P = 0.003). The ratio of the SUV of lung with lymphangitic carcinomatosis to corresponding contralateral normal lung was significantly increased (P = 0.006), and the ratio of the SUV of mediastinal blood pool to lung with lymphangitic carcinomatosis was significantly decreased (P = 0.0002). CONCLUSION: There is diffuse increased FDG uptake in the lung corresponding to the CT pattern of lymphangitic carcinomatosis.

Adult↗
PubMedDate not supplied

Photosensitizer delivery to vulnerable atherosclerotic plaque: comparison of macrophage-targeted conjugate versus free chlorin(e6).

We have previously shown that a conjugate (MA-ce6) between maleylated serum albumin and the photosensitizer chlorin(e6) (ce6) is targeted in vitro to macrophages via class A scavenger receptors. We now report on the ability of this conjugate to localize in macrophage-rich atherosclerotic plaques in vivo. Both the conjugate and the free photosensitizer ce6 are studied after injection into New Zealand White rabbits that are rendered atherosclerotic by a combination of aortic endothelial injury and cholesterol feeding into normal rabbits. Rabbits are sacrificed at 6 and 24 h after injection and intravascular fluorescence spectroscopy is carried out by fiber-based fluorimetry in intact blood-filled arteries. Surface spectrofluorimetry of numbered excised aortic segments together with injured and normal iliac arteries is carried out, and quantified ce6 content by subsequent extraction and quantitative fluorescence determination of the arterial segments and also of nontarget organs. There is good agreement between the various techniques for quantifying ce6 localization, and high contrast between arteries from atherosclerotic and normal rabbits is obtained. Fluorescence correlates with the highest burden of plaque in the aorta and the injured iliac artery. The highest accumulation in plaques is obtained using MA-ce6 at 24 h. Free ce6 gives better accumulation at 6 h compared to 24 h. The liver, spleen, lung, and gall bladder have the highest uptake in nontarget organs. Macrophage-targeted photosensitizer conjugates may have applications in both detecting and treating inflamed vulnerable plaque.

Animals↗
PubMedDate not supplied

Pearls and pitfalls in interpretation of abdominal and pelvic PET-CT.

The interpretation of images obtained in the abdomen and pelvis can be challenging, and the coregistration of positron emission tomographic (PET) and computed tomographic (CT) scans may be especially valuable in the evaluation of these anatomic areas. PET-CT represents a major technologic advance, consisting of generally complementary modalities whose combined strength tends to overcome their respective weaknesses. However, this combined functional-structural imaging approach raises a number of controversial questions and presents some unique interpretative challenges. Accurate PET-CT scan interpretation requires awareness of the various pitfalls associated with the imaging components, both individually and in combination. The results of recent PET-CT studies have been very encouraging, but larger prospective studies will be needed to establish optimal hybrid scanning protocols. Applying sound imaging principles, paying attention to detail, and staying abreast of advances in this exciting new modality are necessary for harnessing the full diagnostic power of abdominopelvic PET-CT.

Abdomen↗
PubMedDate not supplied

Correlation of FDG-PET interpretation with survival in a cohort of glioma patients.

Adult supratentorial gliomas continue to be one of the most challenging diagnostic and therapeutic problems for the neuro-oncologist. Despite a variety of therapeutic approaches, local control and survival rates remain disappointingly low, largely due to a relative inability to localize diffusely infiltrating glial tumor cells. FDG PET provides a relatively noninvasive method for studying glucose metabolism in normal and pathologic brain tissues. In order to assess the usefulness of FDG PET in a prospective cohort of patients, a group of 31 glial tumor patients underwent serial FDG PET scans at specified evaluation time points: initial or perioperative scan; scan following completion of radiation or chemotherapy; scan(s) at 3-month follow-up intervals until last follow-up exam or death. FDG PET score categories were established to provide a visual and clinically useful means for assessing tumor progression and response to treatment. Both progression-free and overall actuarial survival were determined. There were a total of 137 scans interpreted, on a semi-quantitative basis, by two board-certified radiologists. Patients with high FDG PET scores were more likely to progress clinically and demonstrated lower overall actuarial survival times and revealed statistically significant correlations with other determinants of survival (p < 0.05, Kaplan Meier). Further prospective studies on an expanded patient population are necessary in order to define the role of FDG PET, compared with conventional magnetic resonance imaging (MRI) and computed tomography (CT), in the evaluation and care of patients with malignant gliomas.

Adult↗