T2*-weighted MR imaging findings of giant cell tumors of bone: radiological-pathological correlation.

PURPOSE: To assess the correlation between T2*-weighted MR imaging and pathological findings of giant cell tumors (GCT) of bone. METHODS: Of the 33 patients with histopathologically proven GCT of bone, 12 were examined using 1.5-T MR imaging, including T2*-weighted imaging, and were included in this study. The imaging and pathological findings of GCTs were compared between GCTs with and without hypointensity on T2*-weighted images (T2* hypointensity). RESULTS: T2* hypointensity was observed in 6 out of 12 (50%) GCTs. Septal formation (83% vs. 17%; p < 0.05) and cystic formation (67% vs. 0%; p < 0.05) on T2-weighted images was significantly more frequent in the GCTs with T2* hypointensity compared with those without T2* hypointensity. Among the six GCTs with T2* hypointensity, a large amount of hemosiderin deposition was pathologically observed in five (83%) cases, whereas small amounts of hemosiderin deposition was seen in one (17%) case. In contrast, among the six GCTs without T2* hypointensity, a small amount of hemosiderin deposition was pathologically observed in all six (100%). CONCLUSION: Half of the GCTs showed T2* hypointensity, which is characteristic of hemosiderin deposition; whereas, the other half did not show T2* hypointensity due to a small amount of hemosiderin deposition.

The feasibility of dedicated breast PET for the assessment of residual tumor after neoadjuvant chemotherapy.

PURPOSE: To evaluate the utility of ring-type dedicated breast positron emission tomography (dbPET) for the detection of the residual tumor after neoadjuvant chemotherapy (NAC). MATERIALS AND METHODS: This prospective study included 27 women with histologically proven breast cancer over a 37-month period. All patients underwent ring-type dbPET followed by whole-body PET-CT (WBPET) for preoperative tumor evaluation and re-staging after NAC. The maximum standardized uptake value (SUVmax) of the tumor lesion and the degree of confidence for the presence of the residual tumor were compared between pathological complete response (pCR) and non-pCR tumors. The sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) for the detection of a non-pCR tumor were compared between dbPET and WBPET. RESULTS: On dbPET, SUVmax was significantly higher in non-pCR than in pCR tumors (P = 0.030). The sensitivity for the detection of a non-pCR tumor was significantly higher with dbPET than with WBPET (84.2% vs 26.3%, P = 0.001). In the qualitative analysis, the sensitivity for the detection of a non-pCR tumor was also significantly higher with dbPET than with WBPET (57.9% vs 21.1%, P = 0.016). CONCLUSION: The dbPET can provide more sensitive detection of residual tumor after NAC than can WBPET.

11C-methionine positron emission tomography for target delineation of recurrent glioblastoma in re-irradiation planning.

AIM: To define the optimal margin on MRI scans in the re-radiation planning of recurrent glioblastoma using methionine positron emission tomography (MET-PET). BACKGROUND: It would be very useful if the optimal margin on MRI to cover the uptake area on MET-PET is known. MATERIALS AND METHODS: CT, MRI, and MET-PET were performed separately over the course of 2 weeks. Among the MRI scans, we used the contrast-enhanced T1-weighted images (Gd-MRI) and T2-weighted images (T2-MRI). The Gd-MRI-based clinical target volume (CTV) (CTV-Gd) and the T2-MRI-based CTV (CTV-T2) were defined as the contrast-enhanced area on Gd-MRI and the high intensity area on T2-MRI, respectively. We defined CTV x mm (x = 5, 10, 15, 20) as x mm outside the CTV. MET-PET-based CTV (CTV-MPET) was defined as the area of accumulation of MET-PET. We calculated the sensitivity and specificity of CTV-Gd and CTV-T2 following comparison with CTV-MPET, which served as the gold standard in this study. RESULTS: The sensitivity of CTV-T2 5 mm (98%) was significantly higher than CTV-T2 (87%), and there was no significant difference in the sensitivity between CTV-T2 5 mm and CTV T2 10, 15, or 20 mm. The sensitivity of CTV-Gd 20 mm (97%) was lower than that of CTV-T2 5 mm (98%). CONCLUSIONS: A margin of at least 5 mm around the high intensity area on T2-MRI is necessary in the target volume delineation of recurrent glioblastoma for the coverage of MET-PET findings in re-radiation therapy planning.

Treatment outcomes and late toxicities of intensity-modulated radiation therapy for 1091 Japanese patients with localized prostate cancer.

AIM: This study aimed to evaluate the treatment result of intensity-modulated radiation therapy (IMRT) in a large number of Japanese patients with prostate cancer. BACKGROUND: A total of 1091 patients with localized prostate cancer were recruited between March 2006 and July 2014. The patients were stratified into low- (n = 205 [18.8%]), intermediate- (n = 450 [41.2%]), high- (n = 345 [31.6%]), and very high-risk (n = 91 [8.3%]) groups according to the National Comprehensive Cancer Network classification. All patients were irradiated via IMRT at a dose of 74-78 Gy with or without androgen-deprivation therapy. The mean follow-up period was 50 months (range, 2-120 months). RESULTS: The biochemical failure-free rate (BFFR), the clinical failure-free rate, and the overall survival rate at the 5-year follow-up for all patients was 91.3%, 96.2%, and 99.1%, respectively. In univariate analysis, the prostate-specific antigen (PSA) levels (≤20 vs. >20 ng/ml) were significantly correlated with BFFR. A trend toward higher BFFR was noted in patients with a Gleason score (GS) of ≤7 than in patients with GS ≥8. In multivariate analysis, only PSA (≤20 vs. >20 ng/ml) was significantly correlated with BFFR. The cumulative incidence rate of gastrointestinal and genitourinary toxicity (≥grade 2) at the 5-year follow-up was 11.4% and 4.3%, respectively. CONCLUSIONS: The findings of this study indicate that IMRT is well tolerated and is associated with both good long-term tumor control and excellent outcomes in patients with localized prostate cancer.

Utility of 111In-Cl3 scintigraphy for differentiating bone marrow reconversion.

Indium chloride (111In-Cl3) scintigraphy has been used to evaluate various hematological diseases for many years. However, there have been few reports on patients with bone marrow reconversion showing high uptake in 111In-Cl3 scintigraphy. Herein, we report a case of a 68-year-old man with esophageal cancer who underwent 18F-FDG PET/CT for staging of the disease. 18F-FDG PET/CT demonstrated high uptake in the first lumbar vertebral body, which was difficult to distinguish bone metastasis and bone marrow reconversion. 111In-Cl3 scintigraphy demonstrated specific findings with high uptake in the lesion, indicating bone marrow hyperplasia or reconversion.

Does intensity-modulated radiation therapy (IMRT) alter prostate size? Magnetic resonance imaging evaluation of patients undergoing IMRT alone.

AIM: To assess the changes in prostate size in patients with prostate cancer undergoing intensity-modulated radiation therapy (IMRT). BACKGROUND: The effect of size change produced by IMRT is not well known. MATERIALS AND METHODS: We enrolled 72 patients who received IMRT alone without androgen-deprivation therapy and underwent magnetic resonance imaging (MRI) examination before and after IMRT. The diameter of the entire prostate in the anterior-posterior (P-AP) and left-right (P-LR) directions was measured. The transitional zone diameter in the anterior-posterior (T-AP) and left-right (T-LR) directions was also measured. RESULTS: The average relative P-AP values at 3, 6, 12, 24, and 36 months after IMRT compared to the pre-IMRT value were 0.94, 0.90, 0.89, 0.89, and 0.90, respectively; the average relative P-LR values were 0.93, 0.92, 0.91, 0.91, and 0.90, respectively. The average P-AP and P-LR decreased by approximately 10% during the 12 months post-IMRT, and remained unchanged thereafter. The average relative T-AP values at 3, 6, 12, 24, and 36 months after IMRT compared to the pre-IMRT value were 0.93, 0.88, 0.91, 0.87, and 0.89, respectively; the average relative T-LR values were 0.96, 0.90, 0.91, 0.87, and 0.88, respectively. The average T-AP and T-LR also decreased by approximately 10% during the 12 months post-IMRT, and remained unchanged thereafter. At 12 months after IMRT, the average relative T-AP was significantly lower in patients with recurrence than in those without recurrence. CONCLUSIONS: The average prostate diameter decreased by approximately 10% during the 12 months after IMRT; thereafter remained unchanged.

Efficacy and safety of octreotide for the treatment of congenital hyperinsulinism: a prospective, open-label clinical trial and an observational study in Japan using a nationwide registry.

Octreotide, a long-acting somatostatin analog, has been used for treating hypoglycemia caused by congenital hyperinsulinism (CHI). However, octreotide has not been evaluated in clinical trials and has not been approved in any developed country. We aimed to test the efficacy and safety of octreotide for diazoxide-unresponsive CHI through a combination of a single-arm, open-label clinical trial (SCORCH study) and an observational study to collect data on the clinical course of patients treated off-label in Japan (SCORCH registry). In the SCORCH study, 5 patients were stabilized (blood glucose > 45 mg/dL) by hypertonic glucose infusion, and treated by continuous subcutaneous octreotide infusion at a dose of 5-25 µg/kg/day. Continuous blood glucose monitoring was performed between -24 and +48 hours. In 3 patients, a clinically meaningful rise in blood glucose was achieved and therapy was continued. The glucose infusion was gradually decreased and stopped after 5, 11, and 174 days, respectively. In one case, remission of CHI was reached after 606 days and octreotide was discontinued. The SCORCH registry included 19 diazoxide-unresponsive patients treated by subcutaneous octreotide, by continuous infusion or multiple daily injections. Of the 17 patients treated with hypertonic glucose infusion, the infusion rate was reduced after 4 weeks to less than 50% in 11 patients (64.7%) and stopped in 9 (52.9%). During the combined observation period of 695.4 patient-months in both studies, no severe adverse events related to octreotide were observed. In conclusion, subcutaneous octreotide injection was effective and well tolerated in the majority of patients with diazoxide-unresponsive CHI.

Focal form of congenital hyperinsulinism clearly detectable by contrast-enhanced computed tomography imaging.

The focal form of congenital hyperinsulinism (CHI) is characterized by a cluster of abnormal insulin-oversecreting ß cells within a restricted area of the pancreas. Although identification of the focal lesion is very important in the management of CHI, it has been reported that imaging studies, including computed tomography (CT), magnetic resonance imaging (MRI) scans, or angiography, are not helpful in identifying the focal lesion. Currently, fluorine-18-L-dihydroxyphenylalanine positron emission tomography ((18)F-DOPA PET) is believed to be the only imaging modality that can identify the focal lesions. In this report, however, we present a case of a 7-month-old girl with the focal form of CHI, caused by a loss-of-function mutation in the ABCC8 gene, whose lesion was clearly visible as a hyperenhancing nodule on contrast-enhanced CT and dynamic MRI imaging.

18-F fluorodeoxyglucose uptake in positron emission tomography as a pathological grade predictor for renal clear cell carcinomas.

OBJECTIVES: To evaluate the usefulness of Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18-F FDG-PET/CT) in the prediction of Fuhrman pathological grades of renal clear cell carcinoma (cRCC). METHODS: This retrospective study was approved by our institutional review board, and written informed consent was waived. Thirty-one patients with pathologically proven cRCC underwent 18-F FDG-PET/CT for tumour staging. Maximum standardized uptake value of cRCC (tumour SUVmax) and mean SUV of the liver and spleen (liver and spleen SUVmean) were measured by two independent observers. Tumour SUVmax, tumour-to-liver SUV ratio, and tumour-to-spleen SUV ratio were correlated with the pathological grades. RESULTS: Logistic analysis demonstrated that only the tumour-to-liver SUV ratio was a significant parameter for differentiating high-grade (Fuhrman grades 3 and 4) tumours from low-grade (Fuhrman grades 1 and 2) tumours (P = 0.007 and 0.010 for observers 1 and 2, respectively). Sensitivity, specificity, and positive and negative predictive values for detecting tumours of Fuhrman grades 3 and 4 were 64, 100, 100, and 77%, respectively, for observer 1, and 79, 88, 85, and 83%, respectively, for observer 2. CONCLUSIONS: The tumour-to-liver SUV ratio with 18-F FDG-PET/CT appeared to be a valuable imaging biomarker in the prediction of high-grade cRCC. KEY POINTS: • Tumour SUV max was correlated with the Fuhrman grades. • High-grade tumours have significantly higher SUV max than low-grade tumours. • Tumour-to-liver SUV ratio is useful in the prediction of high-grade cRCC.

Intraosseous schwannoma of the ilium.

We presented a 27-year-old male diagnosed with intraosseous schwannoma of the ilium. Computed tomographic images revealed a well-demarcated, lobulated, expansile, osteolytic lesion in the right supraacetabular region of the ilium. In addition, an intratumoral punctate calcification and a sclerotic rim were observed. T2-weighted magnetic resonance (MR) images demonstrated a heterogeneously hyperintense lesion with a hypointense rim. Major parts of the lesion, excluding some central areas, were enhanced on gadolinium-enhanced MR images. Pathological examination revealed an intraosseous schwannoma. Our findings indicate that intraosseous schwannoma should be considered when images demonstrate a well-demarcated, lobulated, expansile, osteolytic lesion with a sclerotic rim.

Congenital hyperinsulinism: global and Japanese perspectives.

Over the past 20 years, there has been remarkable progress in the diagnosis and treatment of congenital hyperinsulinism (CHI). These advances have been supported by the understanding of the molecular mechanism and the development of diagnostic modalities to identify the focal form of ATP-sensitive potassium channel CHI. Many patients with diazoxide-unresponsive focal CHI have been cured by partial pancreatectomy without developing postsurgical diabetes mellitus. Important novel findings on the genetic basis of the other forms of CHI have also been obtained, and several novel medical treatments have been explored. However, the management of patients with CHI is still far from ideal. First, state-of-the-art treatment is not widely available worldwide. Second, it appears that the management strategy needs to be adjusted according to the patient's ethnic group. Third, optimal management of patients with the diazoxide-unresponsive, diffuse form of CHI is still insufficient and requires further improvement. In this review, we describe the current landscape of this disorder, discuss the racial disparity of CHI using Japanese patients as an example, and briefly note unanswered questions and unmet needs that should be addressed in the near future.

Efficacy and safety of long-term, continuous subcutaneous octreotide infusion for patients with different subtypes of KATP-channel hyperinsulinism.

OBJECTIVE: To evaluate the efficacy of long-term, continuous, subcutaneous octreotide infusion for congenital hyperinsulinism caused by mutations in the KATP-channel genes, KCNJ11 and ABCC8. PATIENTS: Fifteen Japanese patients with diazoxide-unresponsive, KATP-channel hyperinsulinism. METHODS: Molecular diagnoses were made by sequencing and multiple ligation-dependent probe amplification analysis. In patients with paternally inherited, monoallelic mutations, 18F-DOPA PET scans were performed to determine the location of the lesion. The patients were treated with continuous, subcutaneous octreotide infusion at a dosage of up to 25 µg/kg/day, using an insulin pump to maintain blood glucose levels higher than 3.33 mmol/l. Additional treatments (IV glucose, glucagon or enteral feeding) were administered as needed. The efficacy of the treatment was assessed in patients who received octreotide for 4 months to 5.9 years. RESULTS: Three patients had biallelic mutations, and 12 had monoallelic, paternally inherited mutations. Four patients with monoallelic mutations showed diffuse 18F-DOPA uptake, whereas seven patients showed focal uptake. Octreotide was effective in all the patients. The patients with biallelic mutations required a higher dosage (17-25 µg/kg/day), and two patients required additional treatments. By contrast, the patients with monoallelic mutations required a lower dosage (0.5-21 µg/kg/day) irrespective of the PET results and mostly without additional treatments. Treatment was discontinued in three patients at 2.5, 3.3 and 5.9 years of age, without psychomotor delay. Except for growth deceleration at a higher dosage, no significant adverse effects were noted. CONCLUSIONS: Long-term, continuous, subcutaneous octreotide infusion is a feasible alternative to surgery especially for patients with monoallelic KATP-channel mutations.

Is "black geode" sign a characteristic MRI finding for extracranial schwannomas?

PURPOSE: To evaluate whether the "black geode" sign is a characteristic magnetic resonance imaging (MRI) finding for extracranial schwannomas. MATERIALS AND METHODS: Forty-three patients with pathologically confirmed extracranial schwannomas underwent preoperative gadolinium-enhanced MRI. The black geode sign was defined as the appearance of enhanced outer and inner rings. MR images were retrospectively reviewed for size, configuration, and signal intensity of the lesions in addition to the presence of the black geode sign. RESULTS: Gadolinium-enhanced T1-weighted images revealed the black geode sign in seven of 43 patients (16%). The thickness of inner rings (mean 0.6 cm, range 0.3-0.8 cm) was significantly greater than that of outer rings (mean 0.2 cm, range 0.1-0.3 cm) (P < 0.01). While outer rings were circular or elliptical in shape with smooth contours, inner rings had a lobular configuration with irregular thickness and contours. The degrees of enhancement were significantly stronger with inner rings than with outer rings (P < 0.01). In histopathological correlation of five patients who underwent total excision, inner and outer rings corresponded to peridegenerative areas and fibrous capsules, respectively. CONCLUSION: The black geode sign may be fairly specific to extracranial schwannomas on gadolinium-enhanced MR images.

Congenital hyperinsulinism in an infant with paternal uniparental disomy on chromosome 11p15: few clinical features suggestive of Beckwith-Wiedemann syndrome.

Beckwith-Wiedemann syndrome (BWS) is the most common congenital overgrowth syndrome involving tumor predisposition. BWS is caused by various epigenetic or genetic alterations that disrupt the imprinted genes on chromosome 11p15.5 and the clinical findings of BWS are highly variable. Hyperinsulinemic hypoglycemia is reported in about half of all babies with BWS. We identified an infant with diazoxide-unresponsive congenital hyperinsulinism (HI) without any apparent clinical features suggestive of BWS, but diagnosed BWS by molecular testing. The patient developed severe hyperinsulinemic hypoglycemia within a few hours after birth, with macrosomia and mild hydronephrosis. We excluded mutations in the K(ATP) channel genes on chromosome 11p15.1, but found a rare homozygous single nucleotide polymorphism (SNP) of ABCC8. Parental SNP pattern suggested paternal uniparetal disomy in this region. By microsatellite marker analysis on chromosome 11p15, we could diagnose BWS due to the mosaic of paternal uniparental disomy. Our case suggests that some HI of unknown genetic etiology could involve undiagnosed BWS with no apparent clinical features, which might be diagnosed only by molecular testing.

Impact of [11C]methionine positron emission tomography for target definition of glioblastoma multiforme in radiation therapy planning.

PURPOSE: The purpose of this work was to define the optimal margins for gadolinium-enhanced T(1)-weighted magnetic resonance imaging (Gd-MRI) and T(2)-weighted MRI (T(2)-MRI) for delineating target volumes in planning radiation therapy for postoperative patients with newly diagnosed glioblastoma multiforme (GBM) by comparison to carbon-11-labeled methionine positron emission tomography ([(11)C]MET-PET) findings. METHODS AND MATERIALS: Computed tomography (CT), MRI, and [(11)C]MET-PET were separately performed for radiation therapy planning for 32 patients newly diagnosed with GBM within 2 weeks after undergoing surgery. The extent of Gd-MRI (Gd-enhanced clinical target volume [CTV-Gd]) uptake and that of T(2)-MRI of the CTV (CTV-T(2)) were compared with the extent of [(11)C]MET-PET (CTV--[(11)C]MET-PET) uptake by using CT--MRI or CT--[(11)C]MET-PET fusion imaging. We defined CTV-Gd (x mm) and CTV-T(2) (x mm) as the x-mm margins (where x = 0, 2, 5, 10, and 20 mm) outside the CTV-Gd and the CTV-T(2), respectively. We evaluated the relationship between CTV-Gd (x mm) and CTV-- [(11)C]MET-PET and the relationship between CTV-T(2) (x mm) and CTV-- [(11)C]MET-PET. RESULTS: The sensitivity of CTV-Gd (20 mm) (86.4%) was significantly higher than that of the other CTV-Gd. The sensitivity of CTV-T(2) (20 mm) (96.4%) was significantly higher than that of the other CTV-T(2) (x = 0, 2, 5, 10 mm). The highest sensitivity and lowest specificity was found with CTV-T(2) (x = 20 mm). CONCLUSIONS: It is necessary to use a margin of at least 2 cm for CTV-T(2) for the initial target planning of radiation therapy. However, there is a limit to this setting in defining the optimal margin for Gd-MRI and T(2)-MRI for the precise delineation of target volumes in radiation therapy planning for postoperative patients with GBM.

Lasting 18F-DOPA PET uptake after clinical remission of the focal form of congenital hyperinsulinism.

BACKGROUND: Positron emission tomography (PET) using (18)F-DOPA is a useful tool for detecting the focal forms of congenital hyperinsulinism. (18)F-DOPA is taken up by aromatic L-amino acid decarboxylase in pancreatic ß-cells. However, the role of this enzyme in insulin secretion is unknown. SUBJECTS AND METHODS: A Japanese boy who presented with symptomatic hyperinsulinemic hypoglycemia at the age of 2 days and spontaneous resolution at 1 year and 10 months was subjected to mutational analysis and repeated (18)F-DOPA PET scans. RESULTS: Mutational analysis revealed a paternally inherited monoallelic mutation, c.4186G>T (p.D1396Y), in the ABCC8 gene, and an (18)F-DOPA PET scan revealed focal uptake in the body of the pancreas. The patient was successfully treated with frequent feeding. A follow-up PET scan revealed virtually identical uptake to that observed previously. However, in the arterial stimulation-venous sampling procedure, no significant insulin release was observed. He was placed on a normal diet, and no hypoglycemia recurrence was observed. CONCLUSION: This case demonstrates two important findings. Firstly, the uptake of (18)F-DOPA does not correlate with the insulin-secreting capacity of the lesion. Secondly, clinical remission could be a functional process not necessarily accompanied by the apoptotic death of abnormal ß-cells.

Diagnostic accuracy of [¹8F]-fluoro-L-dihydroxyphenylalanine positron emission tomography scan for persistent congenital hyperinsulinism in Japan.

OBJECTIVE: We aimed to elucidate the accuracy and limitations of [(18)F]-fluoro-L-dihydroxyphenylalanine ([(18) F]DOPA) positron emission tomography (PET) for Japanese patients with congenital hyperinsulinism. Although [(18)F]DOPA PET is reported to be useful for precisely localizing the focal form of congenital hyperinsulinism, previous reports are mostly from European and North American centres. PATIENTS: Seventeen Japanese infants with congenital hyperinsulinism. MEASUREMENTS: [(18)F]DOPA PET studies were carried out, and the results were assessed by simple inspection or by a quantitative measurement termed the 'Pancreas Percentage', which expresses the uptake of the head, body or tail of the pancreas as a percentage of the total maximum standardized uptake value of the whole pancreas. The results were compared with those of other studies, including genetic analysis and histology. RESULTS: By simple inspection, when a single focal uptake was obtained, the localization and histology were correct in all cases that underwent pancreatectomy. However, the overall results were consistent with the molecular diagnosis and histology in only 7/17 and 6/12 patients, respectively. The inaccuracy of PET studies by inspection was because of elevated background uptake that mimicked a diffuse or multifocal appearance. The accuracy improved substantially using the Pancreas Percentage; it was consistent with the molecular diagnosis and histology in 10/17 and 9/12 patients, respectively. CONCLUSIONS: In contrast to the results of previous reports, [(18)F]DOPA PET appears to be less efficient for diagnosing Japanese patients with congenital hyperinsulinism. However, the diagnostic accuracy is substantially improved when this technique is combined with the Pancreas Percentage.

CT of the pancreas: comparison of anatomic structure depiction, image quality, and radiation exposure between 320-detector volumetric images and 64-detector helical images.

PURPOSE: To prospectively compare 320-detector volumetric and 64-detector helical computed tomographic (CT) images of the pancreas for depiction of anatomic structures, image noise, and radiation exposure. MATERIALS AND METHODS: This study was approved by the institutional review board, and written informed consent was obtained. A total of 154 patients (85 men, 69 women; age range, 26-85 years; mean age, 67 years) who underwent biphasic (arterial and pancreatic phase) contrast material-enhanced CT performed with a 320-detector scanner were randomized into two groups: the 320-detector group and the 64-detector group. Biphasic transaxial multiplanar reformatted images and volume-rendered CT angiograms were obtained. CT numbers in the abdominal aorta, pancreas, and abdominal wall fat tissue; signal-to-noise ratio (SNR); and dose-length product (DLP) were compared. In addition, image quality and focal lesion depiction (n = 35) were qualitatively determined in the two groups. Unpaired t and Mann-Whitney tests were used for quantitative and qualitative assessment, respectively. RESULTS: No significant difference in CT numbers of the abdominal aorta and pancreas was noted between the two groups. Mean DLP was 43% lower in the 320-detector group (675.4 mGy·cm) than in the 64-detector group (1187.8 mGy·cm) (P < .001). SNR of the abdominal aorta, pancreas, and abdominal wall fat on biphasic images was significantly lower in the 320-detector group than in the 64-detector group (P < .001). Image quality was acceptable in both groups and was slightly better in the 64-detector group for pancreatic phase axial images (P = .02) and arterial phase multiplanar reformatted images (P < .01). No significant difference was found in the depiction of pancreatic parenchyma, main pancreatic duct, focal pancreatic lesions, splanchnic arteries, or most of the small splanchnic arterial branches. CONCLUSION: A 320-detector CT scan facilitates fast volumetric contrast-enhanced CT of the entire pancreas with acceptable image quality, even though SNR was significantly lower at 320-detector volumetric scanning.

Molecular and clinical analysis of Japanese patients with persistent congenital hyperinsulinism: predominance of paternally inherited monoallelic mutations in the KATP channel genes.

BACKGROUND: Preoperative identification of the focal form of congenital hyperinsulinism is important for avoiding unnecessary subtotal pancreatectomy. However, neither the incidence nor the histological spectrum of the disease is known for Japanese patients. AIMS: The aim of the study was to elucidate the molecular and histological spectrum of congenital hyperinsulinism in Japan. SUBJECTS: Thirty-six Japanese infants with persistent congenital hyperinsulinism were included in the study. METHODS: All exons of the ATP-sensitive potassium channel (K(ATP) channel) genes (KCNJ11 and ABCC8), the GCK gene, and exons 6 and 7 and 10-12 of the GLUD1 gene were amplified from genomic DNA and directly sequenced. In patients with K(ATP) channel mutations, the parental origin of each mutation was determined, and the results were compared with the histological findings of surgically treated patients. In one of the patients with scattered lesions, islets were sampled by laser capture microdissection for mutational analysis. RESULTS: Mutations were identified in 24 patients (66.7%): five in GLUD1 and 19 in the K(ATP) channel genes. Sixteen had a paternally derived, monoallelic K(ATP) channel mutation predictive of the focal form. In 10 patients who underwent pancreatectomy, the molecular diagnosis correctly predicted the histology, more accurately than [18F]-3,4-dihydroxyphenylalanine positron emission tomography scans. Three patients showed focal lesions that occupied larger areas of the pancreas. Preferential loss of the maternal allele was observed in these islets. CONCLUSION: The majority of the Japanese patients with K(ATP) channel hyperinsulinism (84.2%) demonstrated paternally inherited monoallelic mutations that accurately predicted the presence of the focal form.

Target definition by C11-methionine-PET for the radiotherapy of brain metastases.

PURPOSE: To evaluate the ability of 11C-methionine positron emission tomography (MET-PET) to delineate target volumes for brain metastases and to investigate to what extent tumor growth is presented by magnetic resonance imaging (MRI) and MET-PET. MATERIALS AND METHODS: Three observers undertook target definition in 19 patients with 95 brain metastases by MRI and MET-PET images. MRI gross target volume (GTV) (GTV-MRI) was defined as the contrast-enhanced area on gadolinium-enhanced T1-weighted MRI. MET-PET GTV (GTV-PET) was defined as the area of an accumulation of MET-PET apparently higher than that of normal tissue on MET-PET images. The size of occupation ratio was determined using the following equation: SOR (%) of MET are within x mm margin outside GTV-MRI = the volume of the GTV-PET within x mm outside the GTV-MRI/the volume of the GTV-PET. RESULTS: For GTV-MRI volumes of 0.5 mL, GTV-PET volumes were larger than GTV-MRI volumes and a significant correlation was found between these variables by linear regression. For all tumor sizes and tumor characteristics, a 2-mm margin outside the GTV-MRI significantly improved the coverage of the GTV-PET. CONCLUSIONS: Although there were some limitations in our study associated with spatial resolution, blurring effect, and image registrations with PET images, MET-PET was supposed to have a potential as a promising tool for the precise delineation of target volumes in radiotherapy planning for brain metastases.