Usefulness of Technetium-99 m-2-methoxy-isobutyl-isonitrile liver scintigraphy for evaluating disease activity of non-alcoholic fatty liver disease.

AIM: Non-alcoholic steatohepatitis (NASH) is a progressive form of non-alcoholic fatty liver disease (NAFLD). Therefore, it is important to evaluate disease activity and distinguish NASH from simple steatosis in NAFLD. Technetium-99 m-2-methoxy-isobutyl-isonitrile ((99m) Tc-MIBI) is a lipophilic cation designed for myocardial perfusion scintigraphy in the diagnosis of ischemic heart diseases, and its retention reflects mitochondrial function. It was reported that hepatic mitochondrial abnormalities would be an important predictive factor for NASH disease progression. The aim of this study was to examine the clinical usefulness of (99m) Tc-MIBI liver scintigraphy for evaluating disease activity of NAFLD and distinguishing NASH from simple steatosis in patients with NAFLD. METHODS: Twenty-six patients with biopsy-proven NAFLD were enrolled. Clinicolaboratory tests and (99m) Tc-MIBI liver scintigraphy were performed. To evaluate hepatic uptake, regions of interest were set at the liver and heart, and the uptake ratio of the liver to heart (liver/heart ratio) was calculated. RESULTS: All patients with NAFLD were classified into three groups according to the NAFLD activity score: non-NASH (simple steatosis) (n = 4), borderline NASH (n = 11), and NASH (n = 11). Liver/heart ratios were significantly lower in NASH than in simple steatosis (P < 0.05). Moreover, liver/heart ratios were significantly correlated with NAFLD activity scores among the patients (r = -0.413, P < 0.05). CONCLUSIONS: The present study indicates that (99m) Tc-MIBI liver scintigraphy would be a useful non-invasive functional imaging method with which to evaluate disease activity of NAFLD and distinguish NASH from simple steatosis.

Alterations of contralateral thalamic perfusion in neuropathic pain.

Contralateral thalamus, the place of termination of spinothalamic tract, is affected in patients with pain. We employed single photon emission computed tomography (SPECT) to evaluate the thalamic perfusion in patients with spontaneous neuropathic pain. Ten patients with complex regional pain syndrome (CRPS) and eleven radiculopathiy patients were enrolled in this study. Regional cerebral blood flow of thalamus was assessed bilaterally by iodine-123-labelled iodoamphetamine SPECT. To standardize the inter-patient data, we set a contralateral thalamic uptake index (CTUI) for assessing thalamic asymmetry. In one study, we found elevation of CTUI in patients with symptoms of neuropathic pain for less than 12 month, whereas no change was observed in the case of a longer lasting disease. An another study demonstrated decrease of CTUI after pain treatment, even though it was unrelated to the pain intensity prior to treatment. Our SPECT study revealed that neuropathic pain altered thalamic neuronal activity. CTUIs were increased in early stage of the disease but decreased as the disease progressed to the chronic stage. These results suggest that CTUI can be used to improve management of neuropathic pain for proper evaluation of spontaneous pain.

Positron emission tomography/computed tomography: a clinical tool for evaluation of enthesitis in patients with spondyloarthritides.

OBJECTIVE: To evaluate the accuracy of PET/CT using [(18)F]fluorodeoxyglucose (FDG) in determining the presence of enthesitis in patients with SpAs. METHODS: Results of PET/CT scans of eight patients with SpA and seven patients with RA were retrospectively examined, with specific focus on five joints and three entheses. Volume fixation values are expressed as standardized uptake values (SUVs). Data from 20 patients with non-rheumatic (NR) diseases and 20 healthy subjects were also examined if non-specific, false positive findings were possible. We evaluated the clinical utility of PET/CT examinations in SpA, compared with MRI and Ga scintigraphy. RESULTS: Images of PET/CT scans of the shoulder, hip and knee joints revealed that FDG accumulated at the entheses in SpA and in the synovium in RA patients. The maximum SUVs [mean (s.d.)] were statistically higher in SpA patients compared with RA patients at the entheses of lumbar spinous process [4.83 (1.15) vs 1.42 (0.34); P < 0.05, respectively], pubic symphysis [3.93 (0.87) vs 1.35 (0.31); P < 0.05, respectively] and ischial tuberosity [4.76 (1.5) vs 1.35 (0.42); P < 0.05, respectively]. The positive frequencies of lumbar spinous processes and ischial tuberosity evaluated by PET/CT scan in the SpA group were significantly higher than that evaluated by MRI. CONCLUSION: MRI is now widely used to detect bone marrow oedema and enthesitis in patients with SpA. PET/CT scans offer an alternative method to identify enthesitis, and will likely contribute to the early diagnosis of SpA.

Cross-sectional and longitudinal studies of three-dimensional stereotactic surface projection SPECT analysis in Parkinson's disease.

Although dementia is increasingly recognized as a common feature in Parkinson's disease (PD), its pathological substrate remains unknown. We conducted cross-sectional and longitudinal brain perfusion SPECT analyses to explore changes during the course of developing dementia in PD. Fifty-five patients originally diagnosed with PD were imaged in the cross-sectional study. Twenty-one of these, nine without dementia and 12 with dementia (PDD), were included in the longitudinal study to observe perfusion changes during the course of their disease. Data were analyzed using three-dimensional stereotactic surface projection SPECT analysis. The UK Parkinson's Disease Society Brain Bank criteria were used to diagnose PD and the revised criteria for the clinical diagnosis of dementia with Lewy bodies for PDD. The cross-sectional study showed that patients with PDD had significantly reduced perfusion in the right posterior cingulate, the right precuneus and the left posterior cingulate area. In the longitudinal study, significantly reduced perfusion was observed in the left anterior frontal gyrus in PD without dementia, and in the right inferior parietal lobule in those that developed PDD. We suggest that a relationship exists between developing dementia in PDD and reduced perfusion in the posterior parietal area.

Phase I study of a new radiosensitizer containing hydrogen peroxide and sodium hyaluronate for topical tumor injection: a new enzyme-targeting radiosensitization treatment, Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, Type II (KORTUC II).

Using a currently employed linear accelerator, our intent was to inactivate peroxidase/catalase in tumor tissue by the application of hydrogen peroxide, which is degraded to produce oxygen, thus re-oxygenizing the tumor tissue. In this way, we can convert radioresistant tumors into radiosensitive ones. On the basis of this strategy, we previously developed a new enzyme-targeting radiosensitization treatment named KORTUC I, which remarkably enhances the radiotherapeutic effect on various types of superficially exposed and locally advanced malignant neoplasms. Based on our clinical experience using KORTUC I, we also developed a new radiosensitizer containing hydrogen peroxide and sodium hyaluronate for injection into various types of tumors that are not superficially exposed (KORTUC II; described herein). KORTUC II was approved by our local ethics committee for advanced skin cancer, including malignant melanoma, bone/soft tissue malignant neoplasms, breast cancer, and metastatic lymph nodes. A maximum of 6 ml of the agent was injected into tumor tissue one to two times per week under ultrasonographic guidance, just prior to each administration of radiation therapy. Eleven patients, including seven with breast cancer, were enrolled in the KORTUC II trial upon fully informed consent. KORTUC II was well tolerated, with a minimum of adverse effects. Nine of the 11 patients showed a complete response (CR), and no severe complications occurred in any of the 11 patients. This new enzyme-targeting radiosensitization treatment may be indicated for various types of locally advanced neoplasms, including soft tissue neoplasms and breast cancers.

Three-dimensional stereotactic surface projection SPECT analysis in Parkinson's disease with and without dementia.

We investigated regional cerebral blood flow (rCBF) using three-dimensional stereotactic surface projection (3D-SSP) analysis in 30 patients initially diagnosed as Parkinson's disease (PD), and compared differences in rCBF between patients with and without PD-related manifestations. 3D-SSP analysis of cerebral perfusion was performed by use of a control database. Compared to age-matched controls, there were multiple hypoperfusion areas in cases where the original diagnosis was PD. Temporal bases showed the lowest perfusion; frontal bases and medial parietal lobes the second; visual cortices the third; and parietal association areas exhibited the fourth lowest. During the clinical course, 10 of the patients suffered dementia, 9 had fluctuating cognition, and 19 experienced repeated visual hallucinations. Significant negative correlations were observed between dementia and the bilateral posterior cingulate area, and among fluctuating cognition and bilateral medial parietal lobes, parietal association areas, and dorsal occipital lobes. Repeated visual hallucinations did not show any correlation with any region of interest. We concluded that multiple hypoperfusion areas were observed in the 3D-SSP SPECT analysis. Although the presence of dementia showed a significant relationship with the bilateral posterior cingulate areas, perfusion in the frontal bases, temporal bases, or parietal lobes was markedly more reduced than that seen in the bilateral posterior cingulate areas.

CYP17 polymorphism as a risk factor of tamoxifen-induced hepatic steatosis in breast cancer patients.

Oral administration of tamoxifen, an endocrine therapy for breast cancer, often induces hepatic steatosis (THS, tamoxifen-induced hepatic steatosis) as a complication, which can progress to non-alcoholic steatohepatitis (NASH). The development of this complication is strongly associated with three clinical risk factors; specifically, insulin resistance, central obesity, and hypertriglyceridemia, however a genetic predisposition to THS has yet to be investigated. The aim of this study is to determine whether genetic polymorphism of the P450c17alpha enzyme coded for by the CYP17 gene, responsible for regulating serum estrogen, has an association with THS. After obtaining informed consent from 180 eligible breast cancer patients treated with tamoxifen, DNA was collected and analyzed by restriction fragment length polymorphism assay and classified into alleles defined as A1 and A2. The absence or presence and extent of THS was evaluated by calculating the liver/spleen (L/S) ratio based on Hounsfield units with a CT scanner. Administration of tamoxifen led to THS (L/S ratio <0.9) in 57 (31.7%) of 180 patients while the remaining 123 (68.3%) patients did not develop THS. A significant difference in the distribution of CYP17 genotypes was observed between patients who developed THS and those who did not (P=0.021). A significantly higher frequency of the A2 allele was seen in the THS group (odds ratio, 1.90; 95% confidence interval, 1.21-2.99). Our study provides the first evidence that CYP17 polymorphism participates in the development of THS, and sheds light on the genetic causes of this side effect and genetic differences between tamoxifen-treated individuals.

In vivo imaging of hepatic fatty acid metabolism in patients with nonalcoholic steatohepatitis using semiquantative (123)I-BMIPP liver scan.

Recent progress of studies in NASH displays multi-disciplinary characters of the pathogeneses. Despite these advances, the strategic use of imaging modalities such as CT, US, and MRI, remains a relatively low priority in clinical situations, because these can only visualize the presence of fatty infiltration to the hepatic parenchyma, impossible to figure out the dynamic function of NASH liver. Morphological alteration such as CT value, MR signal intensity and echo-grade do not distinguish NASH from simple fatty liver. In this presentation, from a radiologic viewpoint, we show the feasibility of in vivo fatty acid imaging with (123)I-beta-methyl-p-iodophenyl-pentadecanoic acid (BMIPP). BMIPP is an (123)I labeled fatty acid analog for imaging damaged myocardium, using conventional nuclear imaging equipment. Under normal conditions, the energy source for myocardial utilization is dependent on the beta-oxidation of fatty acids. For energy production in ischemic myocardium, the drastic switch from reduced beta-oxidation of fatty acids to glucose metabolism is well known. BMIPP can detect the area of reduced fatty acids metabolism on myocardial imaging and the data can be converted into semiquantitative analysis. Therefore, we speculate that the use of BMIPP to in vivo hepatic imaging in NASH could highlight a lot of matters of NASH. Details of this presentation include: (1) Hepatic imaging with BMIPP; (2) Clearance of BMIPP from NASH liver; (3) semiquantitative analysis of hepatic BMIPP clearance and clinical features of NASH; (4) Profiles of NASH categorized by BMIPP imaging and (5) Preliminary data of BMIPP clearance in patients with Tamoxifen-induced NASH. The core of our stance in this presentation is searching for valuable advice on clinical use of BMIPP in patients with NASH from specialists in the field of HEPATOLOGY.

CYP17 polymorphism and tamoxifen-induced hepatic steatosis.

Hepatic steatosis is a frequent complication, which sometimes develops nonalcoholic steatohepatitis (NASH), in breast cancer patients treated with tamoxifen, a potent antagonist of estrogen. Recently we reported the impairment of fatty acid beta-oxidation and the enhancing fatty infiltration to hepatocytes in aromatase deficiency (ArKO) mice as the estrogen deficiency models. This experimental observation let us speculate strong link between estrogen and hepatic steatosis. In this study, we investigated whether a polymorphism in the cytochrome P450c17alpha gene (CYP17), which is associated with circulating estrogen levels, influences the development of tamoxifen-induced hepatic steatosis. This consecutive study included 180 breast cancer patients undergoing tamoxifen treatment. Genomic DNA extracted from the peripheral blood of each patient was analyzed by restriction fragment length polymorphism (defined as the A1 and A2 alleles). The extent of hepatic steatosis was assessed by computed tomography (CT) as the liver/spleen (L/S) ratio. While receiving adjuvant tamoxifen, 57 of 180 patients developed hepatic steatosis (L/S ratio <0.9) without obvious changes in body mass index (BMI). We observed a significant association between the A2/A2 genotype and the development of hepatic steatosis compared with the A1/A1 genotype [odds ratio (OR), 3.60; 95% confidence interval (C.I.)=1.42-9.10]. The A1/A2 genotype was at an intermediately increased risk of hepatic steatosis (OR, 2.24; 95% C.I.=0.99-5.08). The presence of the A2 allele possibly increased the progression of hepatic steatosis with a gene dosage effect (P=0.06). Our results suggest that functional polymorphism in CYP17 may be involved in determining susceptibility of tamoxifen-induced hepatic steatosis.

Utility of initial MRI for predicting extent of residual disease after neoadjuvant chemotherapy: analysis of 70 breast cancer patients.

This study was performed to evaluate the utility of initial MRI in predicting the extent of residual disease following neoadjuvant chemotherapy (NAC). The study population consisted of 70 patients with breast cancer (unilateral, n=69; bilateral, n=1) (mean age 51 years) who underwent magnetic resonance imaging (MRI) with gadolinium enhancement both before and after NAC. Basic NAC was comprised of cyclophosphamide, pirarubicin, and 5-fluorouracil. MRI features were compared with pathological diagnosis following surgery. MRI features of breast cancer before NAC were classified as either solitary nodular (SN) (n=33) (47%), or multiple nodular and/or unlocalized dendritic (MN/UD) (n=38) (53%). MRI typing was independent of NAC in 68 tumors (SN, n=32; MN/UD, n=36) (96%, p<0.0001). All except one of the 33 SN tumors (97%) displayed negative margins. In addition, 5 of the 33 SN tumors (15%) displayed pathological complete response (pCR). Conversely, all 5 requiring total glandectomy due to wide infiltration and all except one of the 17 (94%) displaying positive margins necessitating extended resection were classified as MN/UD. Only SN-type tumors on initial MRI have the possibility of pCR after NAC. MN/UD tumors could possess margins necessitating expanded excision or total glandectomy. Morphological concepts based on MRI can prove useful in surgical planning and predicting the extent of residual disease after NAC.

Single-photon agents for tumor imaging: 201Tl, 99mTc-MIBI, and 99mTc-tetrofosmin.

This review aims at fostering comprehension and knowledge not only for expert physicians who can skillfully handle various techniques for tumor imaging but also for young practitioners in the field of nuclear medicine. As image processing software and hardware become smaller, faster and better, SPECT will adapt and incorporate these advances. A principal advantage of SPECT over PET is the more widespread availability of the equipment and lower cost for the introduction of the system in community-based facilities. Moreover, SPECT has become less dependent on a limited number of acknowledged experts for its interpretation owing to a variety of handy computer tools for imaging analyses. The increasing use of PET in tumor imaging is not necessarily proportional to the decline of SPECT. General physicians' attention to SPECT technology would also increase more by evoking their interest in "tracer imaging."

CT profile curves of peripheral pulmonary adenocarcinoma of the lung: correlations with Noguchi type.

PURPOSE: To evaluate the ability to identify early adenocarcinomas (Noguchi types A/B) from peripheral lung adenocarcinomas of less than 20 mm in diameter based on CT profile curves. MATERIALS AND METHODS: High resolution CT (HRCT) of 33 patients with peripheral lung adenocarcinoma less than 20 mm in diameter were reviewed retrospectively. CT attenuation values were measured using profile curves. Maximum and minimum CT values among profile curves of tumors were correlated with pathological diagnosis based on Noguchi type. RESULTS: As adenocarcinoma type worsened, CT values increased in both minimum and maximum values for the central portion of the tumor, although maximum values did not differ between type C and types D/E/F. Maximum CT values were significantly higher for type B than for type A (p = 0.0029). Minimum CT values were significantly lower for type B than for C (p = 0.0022). In both maximum and minimum CT values, significant differences existed between Noguchi types A/B and all other Noguchi types (p < 0.0001, p < 0.0001) and between types A/B and type C (p = 0.0013, p = 0.0003). CONCLUSION: CT profile curves are relatively simple to derive and offer a consistent method of differentiating Noguchi types A/B from type C and from types C/D/E/F.

Quantitative study of the difference in pulmonary perfusion in different respiratory phases in healthy volunteers.

OBJECTIVE: The purpose of this study is to investigate the physiological pulmonary perfusion pattern in different respiratory phases by calculating the normalized volume center of perfusion intensity. METHODS: Four nonsmoking volunteers underwent single photon emission computed tomography (SPECT) of maximum inspiration and expiration after the injection of Tc-99m-MAA in each respiratory phase at a week's interval. Quantitative analysis by calculating the normalized volume center of perfusion intensity was performed. RESULTS: Quantitative measurement of the normalized volume center of perfusion intensity showed that the percentage averages of ventrodorsal (Y) shift in maximum respiration were 16% (left) and 15% (right) in the upper part, 15% (left) and 14% (right) in the middle part, 17% (left) and 18% (right) in the lower part, 18% (left) and 16% (right) in each total lung. These readings indicated that the normalized center of pulmonary perfusion activity at maximum expiration moved in the ventral direction in contrast to that at maximum inspiration. In horizontal (X) and craniocaudal (Z) directions, the shift in the normalized center of pulmonary perfusion activity at maximum expiration indicated no agreement in movement direction. CONCLUSION: The normalized center of the pulmonary perfusion activity in maximum expiration moved in the ventral direction compared to that in maximum inspiration. This phenomenon might be caused by the increase in physiological intrathoracic pressure and by a definite reserve of pulmonary perfusion.

Scintigraphic prediction of response to chemotherapy in patients with breast cancer: Technetium 99m-tetrofosmin and thallium-201 dual single photon emission computed tomography.

We have investigated the usefulness of dual-isotope single photon emission computed tomography (SPECT) for predicting the response to chemotherapy in patients with breast cancer. Twenty-five patients with breast cancer were analyzed by SPECT using both 99m-technetium-tetrofosmin (99mTc-TF) and 201-thallium-chloride (201Tl). The relationship between response to chemotherapy and retention of each tracer was analyzed. 99mTc-TF retention was significantly higher in responders (42.0+/-37.9) than in non-responders (-11.3+/-34.6) (p=0.003). Ten of 13 patients (76.9%) with high 99mTc-TF retention (>15%) showed good response to chemotherapy, whereas 11 of 12 patients (91.7%) with low 99mTc-TF retention (<15%) did not respond to the therapy. The overall predictability to the response to chemotherapy was 84.0%. 201Tl retention (responders, 47.5+/-60.2% vs. non-responders, 55.8+/-45.0%; p=0.443) was not useful in therapeutic prediction, but was required to identify the lesion on the SPECT image. This is the first report to find that dual-isotope SPECT using 99mTc-TF and 201Tl is useful in predicting the response to chemotherapy in patients with breast cancer. Low 99mTc-TF retention is a strong predictor of therapeutic resistance, and high 99mTc-TF retention suggests a favorable response to chemotherapy.