Publications (4)2.78 Total impact
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ABSTRACT: Peritoneal lymphomatosis is uncommon, but when encountered is associated with aggressive histological subtypes of high-grade lymphoma, such as small-cell, large-cell, mixed large and small cell, non-cleaved, lymphoblastic Burkitt-like, and diffuse large B cell lymphomas. The CT findings of peritoneal lymphomatosis are linear or nodular peritoneal thickening, retroperitoneal lymphadenopathy, omental and mesenteric involvement with streak-like infiltrations or a bulky mass, bowel wall thickening, hepatosplenomegaly, and ascites. The authors report the first FDG PET/CT images of diffuse large B-cell lymphoma of small bowel origin associated with peritoneal lymphomatosis in a 69-year-old man. The lesions demonstrated intense FDG uptake in PET/CT images. KeywordsPeritoneal lymphomatosis-Lymphoma-FDG-PET04/2012; 44(2):159-160.
Article: Usefulness of Bremsstrahlung Images after Intra-arterial Y-90 Resin Microphere Radioembolization for Hepatic Tumors[show abstract] [hide abstract]
ABSTRACT: PurposeY-90 resin microsphere radioembolization is used to treat inoperable hepatic tumors. After injection of Y-90 resin microsphere, the only method to visualize the distribution of Y-90 is the scintigraphic imaging of bremsstrahlung radiation. The purpose of this study was to evaluate the characteristics and usefulness of bremsstrahlung imaging in Y-90 resin microsphere treatment. MethodsTwenty patients (22 administrations) underwent intra-arterial Y-90 resin microsphere treatment. For pre-treatment planning, images of Tc-99m albumin macroaggregate (MAA) arterial injection and hepatic contrast angiography were obtained. Post-treatment bremsstrahlung images were taken and compared with pre-treatment images. The extrahepatic activity was evaluated on bremsstrahlung images. To correlate the size and vascularity of the tumors with tumor visualization on bremsstrahlung images, the individual tumors were grouped according to visualization on each image and compared with one another by size and tumor-to-normal ratio. ResultsAll post-therapeutic bremsstrahlung images showed similar contours of the liver with pre-treatment angiography. No extrahepatic activity was seen in all cases. The visualized tumors on bremsstrahlung images were significantly larger than the non-visualized tumors. Tumor-to-normal ratios of the visualized tumors on bremsstrahlung images were significantly higher than those of the non-visualized tumors. ConclusionsBremsstrahlung images after intra-arterial Y-90 resin microsphere treatment are useful in evaluating the intrahepatic distribution of radioisotope and detecting possible extrahepatic activity. KeywordsY-90–microsphere–Radioembolization–Bremsstrahlung–Hepatocellular carcinoma–Liver malignancy04/2012; 45(1):59-67.
Article: Radiation Safety Issues in Y-90 Microsphere Selective Hepatic Radioembolization Therapy: Possible Radiation Exposure from the Patients[show abstract] [hide abstract]
ABSTRACT: PurposeThe purpose of this study was to estimate the possible external radiation dose to other individuals from patients treated with Y-90 resin microspheres for unresectable hepatocellular carcinoma. MethodsWe designed the study prospectively to estimate the possible radiation dose to other individuals from patients who had been treated with Y-90 microspheres for unresectable hepatocellular carcinoma. We estimated the total effective dose equivalent (TEDE) using two methods: ‘theoretical’ TEDEs according to the administered activity and ‘measured’ TEDE based on the ‘measured’ ambient radiation exposure rate. We compared the results from each method to determine when we can release patients from confinement at the earliest time complying with the patient release criteria. ResultsA total of 20 administrations of Y-90 resin microspheres were done in 18 patients. The average administered activity was 1.2 ± 0.77 (0.28–2.97) GBq. The ‘theoretical’ TEDEs were in the range of 0.8–10 μSv. The ‘measured’ TEDEs were in the range of 2.31–185 μSv. The measured TEDEs tend to be higher than the theoretical TEDEs. The values of theoretical and measured TEDE were both far less than 1mSv, the upper limit at which the licensee can release a patient without any written documents. ConclusionThe effective dose equivalent caused by the Y-90 microsphere administered patient is very low. It is safe in terms of radiation safety to the other individuals when Y-90 microsphere radioembolization therapy is done with dose less than 3GBq. Because the measured TEDE tends to be higher than the theoretical TEDE, it is recommended to use ‘measured’ TEDE for determining patient release. KeywordsRadiation safety-Y-90 microsphere-Selective hepatic radio-embolization therapy-Liver tumor-Hepatocellular carcinoma04/2012; 44(4):252-260.
Article: Diagnostic value of CT density in patients with diffusely increased FDG uptake in the thyroid gland on PET/CT images.[show abstract] [hide abstract]
ABSTRACT: The purpose of this article is to determine the diagnostic significance of thyroid density as determined by CT in patients with a diffuse hypermetabolic thyroid on PET/CT images. One hundred twelve patients were enrolled in this study, and all underwent PET/CT and a thyroid function test between August 2007 and December 2008. The 56 study patients enrolled had visible (18)F-FDG uptake in the thyroid, whereas the 56 control subjects had no visible FDG uptake. Maximum standardized uptake values (SUV(max)), Hounsfield units, thyroid-stimulating hormone levels, free thyroxine levels, and visual assessments of thyroid CT densities (grades 0-2) were evaluated. Analyses were performed to identify variables that differed between patients and control subjects and to examine relationships between Hounsfield unit and SUV(max) values, free thyroxine level, or thyroid-stimulating hormone level. Mean Hounsfield unit and SUV(max) values were significantly different between the two groups (p < 0.001), and SUV(max) values were found to be significantly different between grades. Free thyroxine and thyroid-stimulating hormone levels were also significantly different between thyroid density grades 0 and 2 (p < 0.001). A strongly negative relationship was found between Hounsfield units and SUV(max) values (r = 0.75), whereas Hounsfield units were found to be weakly correlated with free thyroxine level (r = 0.36) and thyroid-stimulating hormone level (r = -0.33). CT density is closely related to FDG uptake, and low CT density coupled with high FDG uptake suggests a change in thyroid tissue composition and is probably helpful for assessing the disease process and thyroid function of patients whose thyroid show diffuse FDG uptake on FDG PET/CT.American Journal of Roentgenology 07/2010; 195(1):223-8. · 2.78 Impact Factor