Masatoyo Nakajo

FDG PET/CT and diffusion-weighted imaging for breast cancer: prognostic value of maximum standardized uptake values and apparent diffusion coefficient values of the primary lesion

PurposeTo correlate both primary lesion 18F-fluorodeoxyglucose (FDG) maximum standardized uptake value (SUVmax) and diffusion-weighted imaging (DWI) apparent diffusion coefficient (ADC) with clinicopathological prognostic factors and compare the prognostic value of these indexes in breast cancer.MethodsThe study population consisted of 44 patients with 44 breast cancers visible on both preoperative FDG PET/CT and DWI images. The breast cancers included 9 ductal carcinoma in situ (DCIS) and 35 invasive ductal carcinomas (IDC). The relationships between both SUVmax and ADC and clinicopathological prognostic factors were evaluated by univariate and multivariate regression analysis and the degree of correlation was determined by Spearman’s rank test. The patients were divided into a better prognosis group (n = 24) and a worse prognosis group (n = 20) based upon invasiveness (DCIS or IDC) and upon their prognostic group (good, moderate or poor) determined from the modified Nottingham prognostic index. Their prognostic values were examined by receiver operating characteristic analysis.ResultsBoth SUVmax and ADC were significantly associated (p<0.05) with histological grade (independently), nodal status and vascular invasion. Significant associations were also noted between SUVmax and tumour size (independently), oestrogen receptor status and human epidermal growth factor receptor-2 status, and between ADC and invasiveness. SUVmax and ADC were negatively correlated (ρ=−0.486, p = 0.001) and positively and negatively associated with increasing of histological grade, respectively. The threshold values for predicting a worse prognosis were ≥4.2 for SUVmax (with a sensitivity, specificity and accuracy of 80%, 75% and 77%, respectively) and ≤0.98 for ADC (with a sensitivity, specificity and accuracy of 90%, 67% and 77%, respectively).ConclusionSUVmax and ADC correlated with several of pathological prognostic factors and both indexes may have the same potential for predicting the prognosis of breast cancer.

FDG PET/CT and diffusion-weighted imaging of head and neck squamous cell carcinoma: comparison of prognostic significance between primary tumor standardized uptake value and apparent diffusion coefficient.

Purpose: To compare primary tumor 18F-fluorodeoxyglucose (FDG) maximum standardized uptake value (SUVmax) and diffusion-weighted imaging (DWI) apparent diffusion coefficient (ADC) obtained in the same patients with head and neck squamous cell carcinoma (HNSCC) to clarify the prognostic significance of both indexes. Materials and Methods: The study population comprised 26 patients with HNSCC visible on both pretreatment FDG PET/CT and DWI. Correlation between SUVmax and ADC (b values; 0 and 800 seconds/mm2) was analyzed by the Spearmans rank test. Disease-free survival (DFS) was calculated by the Kaplan-Meier method. Prognostic significance was assessed by the long-rank test and Cox proportional hazards analysis. Results: SUVmax and ADC correlated significantly and negatively (&rgr; = −0.566, P = 0.005). High (>12.1) SUVmax (P < 0.001), low (⩽0.88) ADC (P = 0.009), high (T3–4) T stage (P = 0.030), and high (N2–3) N stage (P = 0.007) were significant in predicting poor 2-year DFS. The accuracy for predicting disease events was 81% (21/26) for SUVmax (>12.1) and 73% (19/26) for ADC(⩽0.88) without significant difference between them (P = 0.52). Disease event hazards ratios for significant unadjusted SUVmax (P = 0.015) and ADC (P = 0.039) remained significant when adjusted for other dichotomized clinical covariates (SUVmax; P = 0.009–0.039, ADC; P = 0.017–0.037) except SUVmax for ADC and ADC for SUVmax and T stage. Conclusion: These results suggest that pretreatment primary tumor SUVmax and ADC correlate significantly and negatively and both may have similar potential to predict DFS or disease events of HNSCC.

FDG PET and PET/CT monitoring of autoimmune pancreatitis associated with extrapancreatic autoimmune disease.

We report a series of FDG PET findings of a 69-year-old male patient with autoimmune pancreatitis (AIP) associated with extrapancreatic disease. The first FDG PET revealed diffuse uptake of FDG in AIP and retroperitoneal fibrosis (RF). The second FDG PET after cessation of steroid treatment indicated subsiding of disease activity in AIP, continuous disease activity in RF, and new extrapancreatic lesions, including enlargement of a right salivary gland, nephritis, and lymphadenopathy. The last FDG PET under steroid treatment revealed reduced FDG uptake in the above abnormal FDG uptake lesions. A series of these FDG PET findings suggest the usefulness of FDG PET for the diagnosis and monitoring of AIP associated with extrapancreatic autoimmune diseases.

Intrapancreatic accessory spleen: case report

Abstract. We report a rare case of intrapancreatic accessory spleen which radiologically mimicked a pancreatic hypervascular tumor. The diagnosis of an intrapancreatic accessory spleen should be considered when a pancreatic mass has the CT densities and/or MR signal intensities similar to those of the spleen, with and without contrast medium.

18F -fluorodeoxyglucose positron emission tomography features of idiopathic retroperitoneal fibrosis

Objective: To evaluate the 18F-fluorodeoxyglucose (FDG) uptake features of idiopathic retroperitoneal fibrosis (IRF). Methods: 18F-Fluorodeoxyglucose positron emission tomographic (PET) or PET/computed tomographic findings were retrospectively reviewed in 6 patients with IRF. FDG PET or PET/computed tomography was performed 1 and 2 hours after FDG injection. The FDG level was scored using a 4-point scale, and the intensity of FDG uptake was quantified using the maximum standardized uptake value (SUVmax). Results: In the 1-hours images, intense FDG uptake by IRF was observed in 5 patients before steroid treatment, but no abnormal uptake was noted in 1 patient receiving steroid treatment. The SUVmax in IRF increased from a mean ± SD of 6.0 ± 1.2 (range, 4.9-7.6) to 7.6 ± 1.1 (range, 5.9-8.2) for all 4 patients who underwent 1 and 2 hours dual-time point imaging. Abnormal uptake was also noted in the mediastinum and the pancreas in 1 and 2 patients, and the diagnoses of mediastinal fibrosis and autoimmune pancreatitis were made, respectively. The SUVmax was stable or increased in the 3 lesions of mediastinal fibrosis and autoimmune pancreatitis. Conclusion: FDG PET may be a reliable means of evaluating disease activity and the extent of IRF, but dual-time point imaging may not be useful to differentiate malignancy from IRF.

Multidetector-row CT findings of colonic perforation: direct visualization of ruptured colonic wall

Background: We examined the findings of contrast-enhanced multidetector-row computed tomography (MD-CT) in patients with colonic perforation.Methods: Abdominal contrast-enhanced MD-CT findings in six patients with colonic perforation were reviewed retrospectively. Patients (three men and three women) were 74 to 88 years old (mean age = 78 years). Colonic perforation was confirmed by surgery. CT findings were correlated with surgical and pathologic findings.Result: The site of colonic perforation was suggested by the following combination of CT findings: free air, dirty mass, dirty fat sign, extraluminal fluid collection, bowel wall thickening, and interruption of colonic wall. The ruptured colonic wall was directly visualized in four cases (67%).Conclusion: Abdominal contrast-enhanced MD-CT may improve the accuracy of diagnosis and localization of colonic perforation.

18FDG PET for grading malignancy in thymic epithelial tumors: Significant differences in 18FDG uptake and expression of glucose transporter-1 and hexokinase II between low and high-risk tumors: Preliminary study

PURPOSE To evaluate (18)F-fluorodeoxyglucose (FDG) uptake to predict the malignant nature and analyze the correlation between FDG uptake and expression of glucose transporter 1 (Glut-1) and hexokinase II (HK-II) in thymic epithelial tumors. MATERIALS AND METHODS Eleven patients with a thymic epithelial tumor who underwent FDG PET/CT before therapy were reviewed. The thymic tumors were classified by the WHO histological classification and Masaoka clinical staging. Comparison of maximum standardized uptake value (SUV(max)) of the lesion was made between the low-risk (Type A, AB and B1) and high-risk {Type B2, B3 and C (thymic cancer)} groups and among clinical stages. Expression of Glut-1 and HK-II was analyzed immunohistochemically. RESULTS All 11 tumors showed FDG uptake visually. SUV(max) was significantly higher in the high-risk group (n=5, 5.24 ± 2.44) than the low-risk group (n=6, 3.05 ± 0.55) (P=0.008). Staining scores of both Glut-1 and HK-II were significantly higher in the high-risk group than in the low-risk group (Glut1: P=0.034 and HK-II: P=0.036). There were no significant differences in SUV(max) (P=0.11), Glut-1 (P=0.35) and HK-II scores (P=0.29) among clinical stages. SUV(max) was significantly correlated to each of the staining scores of Glut-1 (ρ=0.68, P=0.031) and HK-II (ρ=0.72, P=0.024). CONCLUSION These preliminary results support the previously published view that SUV(max) may be useful to predict the malignant nature of thymic epitherial tumors and suggest that the degree of FDG uptake in the thymic epitherial tumors is closely related to the amount of Glut-1 and HK-II in the tumor.

LOCALIZATION OF INSULINOMAS: Comparison of conventional arterial stimulation with venous sampling (ASVS) and superselective ASVS

Purpose: To examine the value of superselective arterial stimulation venous sampling (ASVS) to localize insulinomas. Material and Methods: Superselective ASVS (SS-ASVS) was performed in 9 patients with insulinoma. Injection of secretagogue (calcium gluconate: 0.01 mEq Ca++/kg) was performed into the gastroduodenal, splenic (proximal and distal), and superior mesenteric arteries in 9 patients and additionally into the dorsal pancreatic artery in 6 patients. Sampling from the hepatic vein was performed to measure serum insulin concentrations at 30, 60 and 120 s after each injection of secretagogue into these arteries. SS-ASVS results were correlated with surgical findings, compared to those of conventional ASVS. Results: Insulinomas were correctly localized to the head, body or tail of the pancreas by SS-ASVS in 8 patients (89%). Conventional ASVS detected insulinomas in 7 patients (78%), although it could not distinguish whether the insulinoma was located in the pancreatic body or tail in 4 of the 7 patients. There were eight-fold or more increases in serum insulin levels in hepatic venous samples related to the artery supplying the tumor in 8 patients. Localization of the insulinomas was verified at surgery in all patients. Conclusion: SS-ASVS is a useful method for detailed evaluation of overproduction of insulin from pancreatic insulinomas and their localization. When the pancreatic insulinoma is situated in the pancreatic body or tail, the localization is more accurately made by SS-ASVS than by conventional ASVS.

18F-FDG PET/CT findings of a right subphrenic foreign-body granuioma

We report a case of an 85-year-old woman with a foreign-body granuioma which accumulated18F-fluorodeoxyglucose (FDG). Unenhanced computed tomography showed a hyperdense mass with a hypodense rim in the right subphrenic space. FDG PET/CT images showed intense FDG uptake in the hypodense rim and little FDG uptake in the center of the mass, showing a ring-shaped appearance. The fusion imaging of FDG PET/CT represented the metabolic features of the foreign-body granuioma. When a ring-shaped FDG uptake is noted in the abdomen of a patient with a history of abdominal surgery, a foreign-body granuioma should be included in the differential diagnosis.

FDG PET findings of chronic myeloid leukemia in the chronic phase before and after treatment.

We report 2 patients with chronic myeloid leukemia in the chronic phase showing diffusely increased F-18 fluorodeoxyglucose (FDG) uptake in the bone marrow before treatment. Follow-up FDG positron emission tomography (PET) scans were performed in a patient after cessation of treatment and in the other under treatment. Both FDG PET findings showed reduced FDG uptake in the bone marrow. A series of these FDG PET findings suggest the usefulness of FDG PET for the diagnosis and monitoring of chronic myeloid leukemia after treatment.