Takuro Isoda

Diagnostic and Prognostic Value of Pretreatment SUV in 18F-FDG/PET in Breast Cancer: Comparison with Apparent Diffusion Coefficient from Diffusion-Weighted MR Imaging

In oncology, the apparent diffusion coefficient (ADC) measured by diffusion-weighted MR imaging (DWI) and the standardized uptake value (SUV) from 18F-FDG PET have similar clinical applications. The purpose of this study was to assess the correlation between the ADC and SUV and compare their potential in the diagnosis and prediction of prognosis in breast tumors. Methods: Seventy-nine female patients (age range, 19–69 y; average, 49.1 y) with 83 pathologically proven breast tumors were recruited. The diagnoses consisted of 70 malignant breast tumors (65 cases of invasive ductal carcinoma, 1 of medullary carcinoma, 1 of mucinous carcinoma, 1 of squamous cell carcinoma, and 2 of micropapillary carcinoma) and 13 benign breast tumors (4 cases of fibroadenoma, 4 of mastopathy, 3 of adenosis with atypia, and 2 of benign phyllodes tumor). All patients underwent mammary gland MR imaging with DWI and 18F-FDG PET within a 2-wk interval. The patients’ ADCs and SUVs were measured within the tumor by DWI and 18F-FDG PET, respectively. For the malignant tumors, we evaluated the relationships among ADC, SUV, histopathologic appearance, and long-term prognosis. Results: A significant difference (P < 0.05) was observed in both parameters (ADC and SUV) between the benign and malignant breast tumors, and the difference was more significant when we introduced a new parameter, SUV/ADC. There was a weak inverse correlation between ADC and SUV (r = −0.36; P = 0.06) among the total tumors; however, this correlation was not significant within the group of malignant tumors. High SUV was found to correlate with larger tumor size, higher nuclear grade, and the triple-negative hormonal receptor profile. High ADC was revealed to be correlated with negative progesterone receptor and positive human epidermal growth factor receptor 2 profile. Higher SUVs also showed a correlation with poor prognosis. No correlation was seen between ADC and prognosis. Conclusion: Both SUV and ADC are helpful parameters in differentiating benign from malignant breast tumors. The use of SUV and ADC in combination may help in the diagnosis because of their inverse relationship. High preoperative SUV was associated with poor prognosis, but the contribution of ADC to prognosis prediction was small.

Pulmonary tumor thrombotic microangiopathy: FDG-PET/CT findings.

Pulmonary tumor thrombotic microangiopathy (PTTM) is histopathologically characterized by proliferation of intimal myofibroblasts in the small pulmonary arterioles, induced by tumor microemboli. Patients develop rapidly progressive and severe cardiopulmonary failure, and the clinical course of this disease is fatal. Conventional radiologic findings are often minimal or nonspecific, making diagnosis difficult before death. We report 2-(F-18)-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) images of PTTM, which illustrate the characteristic findings of this clinical entity. FDG-PET can be helpful for the diagnosis of PTTM.

Prediction of outcome with FDG-PET in definitive chemoradiotherapy for esophageal cancer

The purpose of this study was to assess the efficacy of 18F-fluoro-2-deoxy-glucose uptake positron emission tomography (FDG-PET) for the prediction of outcome in definitive chemoradiotherapy (CRT) for esophageal cancer. We enrolled 56 patients with esophageal cancer treated with definitive CRT and examined by FDG-PET before treatment. We examined the correlation of the maximum standardized uptake value (SUVmax) in FDG-PET of the primary tumor with overall survival (OS), progression-free survival (PFS), local control (LC) and response of the primary tumor. After definitive CRT, 30 patients had a clinical complete response (CR), making the CR rate 54%. For all 56 patients, the 2-year OS rate, PFS rate and LC rates were 64%, 38% and 51%, respectively. We divided the patients into two groups according to SUVmax: SUVmax < 10 (low-SUV) and ≥10 (high-SUV). The 2-year OS rates in the low- and high-SUV groups were 100% and 41%, the PFS rates were 73% and 19%, the LC rates were 71% and 39%, and the CR rates were 100% and 32%, respectively. A univariate analysis revealed significant differences between the low- and high-SUV group in OS, PFS, LC and response (P = 0.0005, 0.0002, 0.048, and <0.0001, respectively). SUVmax and T stage were significantly associated with OS, PFS, LC and response. A multivariate analysis showed significant differences between the SUVmax <10 and ≥10 groups in overall survival and response (P < 0.05). Our result suggests that the SUVmax in FDG-PET of the primary tumor before treatment may have prognostic value for esophageal cancer.

Detection of Residual Lymph Node Metastases in High-risk Papillary Thyroid Cancer Patients Receiving Adjuvant I-131 Therapy: The Usefulness of F-18 Fdg Pet/ct

Objective: The aims of this retrospective study were to evaluate the incidence of residual lymph node (LN) metastases in high-risk papillary thyroid cancer (PTC) patients receiving adjuvant I-131 therapy, especially in those without I-131 accumulation, and to evaluate the clinical usefulness of F-18 FDG PET/CT to detect those lesions. Methods: The 37 PTC patients receiving adjuvant I-131 therapy were retrospectively evaluated. We examined the incidence of residual LN metastasis and compared the accumulation of F-18 FDG and I-131 in those lesions, and compared the serum thyroglobulin (Tg) levels between patients with and without residual LN metastases. Result: A total of 33 lesions were diagnosed as residual LN metastases in 9 patients. FDG accumulated in all of the lesions, but 19 lesions (57.6%) of them had no I-131 accumulation. The SUVmax was significantly higher in lesions without I-131 accumulation than in lesions with I-131 accumulation (6.6 ± 2.8 vs. 4.2 ± 1.8; P = 0.007). The serum Tg levels were significantly higher in patients with residual LN metastases than in patients without it (709.9 ± 1470.8 vs. 25.6 ± 37.1 ng/mL; P = 0.005). The incidence of residual LN metastasis was significantly higher in patients with a detectable serum Tg level than in patients without it (35.0% vs. 0%, P = 0.03). Conclusion: These results indicate that the residual LN metastasis was relatively common in high-risk PTC patients receiving adjuvant I-131 therapy whose serum Tg levels remained detectable, and those lesions often had no I-131 accumulation. FDG-PET/CT would be recommended for PTC patients with detectable serum Tg levels to detect residual LN metastases.

Abnormality in Wnt signaling is causatively associated with oxidative stress-induced intestinal tumorigenesis in MUTYH-null mice

MUTYH is a DNA glycosylase that excises adenine paired with 8-oxoguanine to prevent mutagenesis in mammals. Biallelic germline mutations of MUTYH have been found in patients predisposed to a recessive form of familial adenomatous polyposis (MAP: MUTYH-associated polyposis). We previously reported that Mutyh-deficient mice showed a high susceptibility to spontaneous and oxidative stress-induced intestinal adenoma/carcinoma. Here, we performed mutation analysis of the tumor-associated genes including Apc, Ctnnb1, Kras and Trp53 in the intestinal tumors of Mutyh-deficient mice. In the 62 tumors, we identified 25 mutations in Apc of 18 tumors and 36 mutations in Ctnnb1 of 36 tumors. Altogether, 54 out of the 62 tumors (87.1%) had a mutation in either Apc or Ctnnb1; no tumor displayed mutations simultaneously in the both genes. Similar to MAP, 60 out of 61 mutations (98.3%) were identified as G:C to T:A transversions of which 85% occurred at either AGAA or TGAA sequences. Immunohistochemical analyses revealed the accumulation of β-catenin in the nuclei of tumors. No mutation was found in either Kras or Trp53 in the tumors. These results indicate that the uncontrolled activation of Wnt signaling pathway is causatively associated with oxidative stress-induced intestinal tumorigenesis in the Mutyh-deficient mice.

Diagnostic and prognostic values of FDG-PET in patients with non-small cell lung cancer

PURPOSE The aim of this study was to address the efficacy of 2-[F-18]-Fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in the staging of non-small cell lung cancer (NSCLC) and in prognostic prediction in patients with NSCLC. METHODS Forty-four patients (26 males, 18 females) were analyzed. RESULTS Accurate staging was obtained by addition of FDG-PET. Multivariate analysis indicated that the standardized uptake value of the primary tumor was the most significant prognostic factor for disease-free survival (P=.0073). CONCLUSION FDG-PET is useful for the diagnosis of NSCLC and for prognostic prediction in patients with NSCLC.

Diagnostic utility of intravoxel incoherent motion mr imaging in differentiating primary central nervous system lymphoma from glioblastoma multiforme

To evaluate the diagnostic performance of intravoxel incoherent motion (IVIM) MR imaging and 18F‐fluorodeoxyglucose positron emission tomography (FDG‐PET) in differentiating primary central nervous system lymphoma (PCNSL) from glioblastoma multiforme (GBM).

Nabothian cyst a predominant cause of false-positive iodine uptake in uterus: comparison of SPECT/CT and pelvic MRI.

Purpose Many cases of unexpected radioiodine uptake have been reported, including physiological uptake in healthy tissue and in both benign and malignant nonthyroidal lesions. However, iodine uptake in the uterus has not been well assessed. In this article, we systemically analyzed iodine uptake in the uterus and identified the site in which uptake occurred. Materials and Methods Seventy-six female patients who underwent SPECT/CT from neck to pelvis were included in this study; 5 patients with uterine uptake received pelvic MRI. Iodine uptake in the uterus was diagnosed with SPECT/CT and compared with the findings of the MRI. Serum TSH level, administered dose of iodine-131 and number of radioiodine therapies were compared between the 2 groups with and without iodine uptake in the uterus. Results Twenty (26.3%) of 76 patients showed iodine uptake in the uterine cervix on SPECT/CT. It was difficult to distinguish the uptake in the uterus from that in the urinary bladder or rectum using only planar images. The patients with the uterine uptake were younger than those without (median age, 46.5 vs. 62, P = 0.011). There were no significant differences in serum TSH level, administered dose of iodine-131, or number of radioiodine therapies between the 2 groups. In all instances of the 5 patients who underwent pelvic MRI, iodine uptake in the uteri was located in nabothian cysts. Conclusion Iodine uptake in the uterus is frequently found if pelvic SPECT/CT is performed. Nabothian cysts are a predominant cause of iodine uptake in the uterine cervix.

Three-dimensional fractal analysis of 99m Tc-MAA SPECT images in chronic thromboembolic pulmonary hypertension for evaluation of response to balloon pulmonary angioplasty: Association with pulmonary arterial pressure

Objective Balloon pulmonary angioplasty (BPA) is used for inoperable chronic thromboembolic pulmonary hypertension (CTEPH), but its effect cannot be evaluated noninvasively. We devised a noninvasive quantitative index of response to BPA using three-dimensional fractal analysis (3D-FA) of technetium-99m-macroaggregated albumin (99mTc-MAA) single-photon emission computed tomography (SPECT). Patients and methods Forty CTEPH patients who underwent pulmonary perfusion scintigraphy and mean pulmonary arterial pressure (mPAP) measurement by right heart catheterization before and after BPA were studied. The total uptake volume (TUV) in bilateral lungs was determined from maximum intensity projection 99mTc-MAA SPECT images. Fractal dimension was assessed by 3D-FA. Parameters were compared before and after BPA, and between patients with post-BPA mPAP more than 30 mmHg and less than or equal to 30 mmHg. Receiver operating characteristic analysis was carried out. Results BPA significantly improved TUV (595±204–885±214 ml, P<0.001) and reduced the laterality of uptake (238±147–135±131 ml, P<0.001). Patients with poor therapeutic response (post-BPA mPAP≥30 mmHg, n=16) showed a significantly smaller TUV increase (P=0.044) and a significantly greater post-BPA fractal dimension (P<0.001) than the low-mPAP group. Fractal dimension correlated with mPAP values before and after BPA (P=0.013 and 0.001, respectively). A post-BPA fractal dimension threshold of 2.4 distinguished between BPA success and failure with 75% sensitivity, 79% specificity, 78% accuracy, and area under the curve of 0.85. Conclusion 3D-FA using 99mTc-MAA SPECT pulmonary perfusion scintigraphy enables a noninvasive evaluation of the response of CTEPH patients to BPA.

PET/CT findings in acute gastric anisakiasis.

Acute gastric anisakiasis is caused by the consumption of raw or undercooked fish containing Anisakis larvae. Although several reports have demonstrated the CT features of acute gastric anisakiasis, little is known about the FDG PET/CT findings. We report a 59-year-old woman who underwent FDG PET/CT and was finally diagnosed as having acute gastric anisakiasis. The PET/CT demonstrated focal FDG accumulation in the fornix of the gastric wall and lymph nodes in the lesser curvature and paraaortic regions.