Safety and Efficacy of Single-Fraction Carbon-Ion Radiotherapy for Early-Stage Lung Cancer with Interstitial Pneumonia

Patients with lung cancer complicated by interstitial pneumonia (IP) often lose treatment options early owing to acute exacerbation of IP concerns. Carbon-ion radiotherapy (CIRT) can provide superior tumor control and low toxicity at high dose concentrations. We conducted a retrospective analysis of the efficacy and tolerability of a single-fraction CIRT using 50 Gy for IP-complicated lung cancer. The study included 50 consecutive patients treated between April 2013 and September 2022, whose clinical stage of lung cancer (UICC 7th edition) was 1A:1B:2A:2B = 32:13:4:1. Of these, 32 (64%) showed usual interstitial pneumonia patterns. With a median follow-up of 23.5 months, the 3-year overall survival (OS), cause-specific survival, and local control rates were 45.0, 75.4, and 77.8%, respectively. The median lung V5 and V20 were 10.0 and 5.2%, respectively (mean lung dose, 2.6 Gy). The lung dose, especially lung V20, showed a strong association with OS (p = 0.0012). Grade ≥ 2 pneumonia was present in six patients (13%), including two (4%) with suspected grade 5. CIRT can provide a relatively safe and curative treatment for patients with IP-complicated lung cancer. However, IP increases the risk of severe radiation pneumonitis, and further studies are required to assess the appropriate indications.

Clinical Trials of Carbon Ion Radiotherapy for Early-Stage Breast Cancer

PURPOSE/OBJECTIVE(S)

Our institute conducted a clinical trial of curative partial breast irradiation using carbon ion radiotherapy (CIRT) to patients with stage 0 and I breast cancer since 2013. The purpose of this report is to evaluate treatment outcomes up to now.

MATERIALS/METHODS

To date, we have conducted three clinical trials and one advanced medical treatment (NIRS 9404 Comprehensive Research). The first study (UMIN000010848: commonly known as Breast I trial) was 4-split irradiation for stage I low-risk patients aged 60 years or older, and the next clinical study (UMIN000029478: commonly known as Breast II trial) was for Tis-1N0M0 cases of 2 cm or less. On the other hand, 4-split irradiation using standard adjuvant drug therapy according to risk combined with whole breast irradiation by X-ray, the latest clinical trial (UMIN000046859: commonly known as Breast III trial) is a single irradiation for Tis-1N0M0 patients aged 50 years or older. be. In each phase I, the dose increase test was performed, and in phase II, treatment was performed with the recommended dose determined in phase I. Advanced medical care was provided in parallel with breast I for stage I breast cancer that was difficult or rejected to participate in breast I trial.

RESULTS

By January 2023, 60 cases were enrolled. A total of 19 were enrolled In Breast I, 7 in Phase I, 12 in Phase II of the recommended dose of 60.0 Gy (RBE). A total of 14 were enrolled in the 9404 Comprehensive Research. A total of 17 were enrolled In Breast II, 5 cases in Phase I, 12 cases in Phase II of recommended dose 60.0 Gy (RBE). A total of 10 were enrolled in Breast III, 6 cases in Phase I, and 4 in Phase II of recommended dose 50.0 Gy (RBE). As acute adverse events, grade 2 of acute radiation dermatitis were observed in 1 case, grade 1 of acute radiation dermatitis was observed in 31 cases, and grade 1 of mastitis was observed in 6 cases. As a late adverse event, grade 3 of pneumonia of unknown causality were observed in one case, but there were no other problematic adverse events, and breast cosmetic outcome was excellent in all cases. Tumor disappearance after CIRT took 3 to 24 months. Local recurrence and axillary lymph node metastasis were observed in one high-risk case of advanced medical treatment who refused any other therapy. Two cases had ipsilateral intramammary metachronous breast cancer with different subtypes. To date, no other recurrences or metastases have been observed.

CONCLUSION

CIRT for early-stage breast cancer is expected to be effective with mild adverse events, and it is considered meaningful to continue research.

Dual-Energy Computed Tomography-Based Iodine Concentration Estimation for Evaluating Choroidal Malignant Melanoma Response to Treatment: Optimization and Primary Validation

Contrast-enhanced imaging for choroidal malignant melanoma (CMM) is mostly limited to detecting metastatic tumors, possibly due to difficulties in fixing the eye position. We aimed to (1) validate the appropriateness of estimating iodine concentration based on dual-energy computed tomography (DECT) for CMM and optimize the calculation parameters for estimation, and (2) perform a primary clinical validation by assessing the ability of this technique to show changes in CMM after charged-particle radiation therapy. The accuracy of the optimized estimate (eIC_optimized) was compared to an estimate obtained by commercial software (eIC_commercial) by determining the difference from the ground truth. Then, eIC_optimized, tumor volume, and CT values (80 kVp, 140 kVp, and synthesized 120 kVp) were measured at pre-treatment and 3 months and 1.5−2 years after treatment. The difference from the ground truth was significantly smaller in eIC_optimized than in eIC_commercial (p < 0.01). Tumor volume, CT values, and eIC_optimized all decreased significantly at 1.5−2 years after treatment, but only eIC_commercial showed a significant reduction at 3 months after treatment (p < 0.01). eIC_optimized can quantify contrast enhancement in primary CMM lesions and has high sensitivity for detecting the response to charged-particle radiation therapy, making it potentially useful for treatment monitoring.

The Utility of a Convolutional Neural Network for Generating a Myelin Volume Index Map from Rapid Simultaneous Relaxometry Imaging

Purpose:

A current algorithm to obtain a synthetic myelin volume fraction map (SyMVF) from rapid simultaneous relaxometry imaging (RSRI) has a potential problem, that it does not incorporate information from surrounding pixels. The purpose of this study was to develop a method that utilizes a convolutional neural network (CNN) to overcome this problem.

Methods:

RSRI and magnetization transfer images from 20 healthy volunteers were included. A CNN was trained to reconstruct RSRI-related metric maps into a myelin volume-related index (generated myelin volume index: GenMVI) map using the MVI map calculated from magnetization transfer images (MTMVI) as reference. The SyMVF and GenMVI maps were statistically compared by testing how well they correlated with the MTMVI map. The correlations were evaluated based on: (i) averaged values obtained from 164 atlas-based ROIs, and (ii) pixel-based comparison for ROIs defined in four different tissue types (cortical and subcortical gray matter, white matter, and whole brain).

Results:

For atlas-based ROIs, the overall correlation with the MTMVI map was higher for the GenMVI map than for the SyMVF map. In the pixel-based comparison, correlation with the MTMVI map was stronger for the GenMVI map than for the SyMVF map, and the difference in the distribution for the volunteers was significant (Wilcoxon sign-rank test, P < 0.001) in all tissue types.

Conclusion:

The proposed method is useful, as it can incorporate more specific information about local tissue properties than the existing method. However, clinical validation is necessary.

A clinical study of curative partial breast irradiation for stage I breast cancer using carbon ion radiotherapy

Background and purpose

Our institute initiated carbon ion radiotherapy research for patients with stage I breast cancer in April 2013. The purpose of this article is to evaluate the treatment outcome of cases treated outside clinical trial up to May 2020.

Materials and methods

Eligibility criteria of the patients were having untreated stage I breast cancer and being unsuitable for operation for physical or mental reasons. The irradiated volume was defined as the gross tumor including intraductal components. The dose escalation study was initially conducted four times a week for a total of 52.8 Gy [relative biological efficacy (RBE)]. After confirming that adverse effects were within acceptable range, the total dose was increased to 60.0 Gy (RBE).

Results

Between April 2013 and November 2015, 14 cases were treated. The median follow up period was 61 months. No adverse toxicities were observed except for grade 1 acute skin reaction in 10 cases. The time required from carbonion radiotherapy to tumor disappearance was 3 months in 1 case, 6 months in 3 cases, 12 months in 4 cases, and 24 months in 5 cases. The third case developed local recurrence 6 months after radiotherapy. Twelve patients with luminal subtype received 5-year endocrine therapy. Thirteen of 14 tumors have been maintaining complete response with excellent cosmetic results.

Conclusions

The time from carbon ion radiotherapy to tumor disappearance was longer than expected, but complete tumor disappearance was observed except for one high-grade case. With careful patient selection, carbonion radiotherapy in patients with stage I breast cancer is deemed effective and safe, and further research is recommended.

Impact of diabetes mellitus on the early phase arterial healing after drug-eluting stent implantation: a multicenter coronary angioscopic study

Background

Diabetes mellitus (DM) is a strong risk factor for major cardiac and cerebrovascular events. In particular, coronary artery disease with DM is often complicated with complex lesions. Drug-eluting stents (DES) are mainly used for these lesions, and dual-antiplatelet therapy (DAPT) has been used to prevent stent thrombosis. Early arterial healing after DES implantation may enable short DAPT strategy. However, the impact of DM on the arterial healing in the early phase has not been elucidated to date.

Purpose

We evaluated the arterial healing in the early phase after DES implantation using coronary angioscopy (CAS) and compared the findings between DM and non-DM patients.

Methods

This study was a multicenter retrospective observational study. We analyzed CAS findings of 337 lesions from 270 patients which were evaluated 3 to 5 months after DES implantation. Patients were divided into two groups: DM (149 lesions in 118 patients) versus non-DM groups (188 lesions in 152 patients). We assessed neointimal coverage (NIC) grades (maximum, minimum and dominant), thrombus adhesion and maximum yellow color of plaque underneath the stent. NIC was graded as follows: grade 0, stent struts were not covered; grade 1, stent struts were covered by thin layer; grade 2, stent struts were buried under neointima. Yellow color was graded as follows: grade 0, white; grade 1, light yellow; grade 2, yellow; grade 3, intensive yellow.

Results

Minimum NIC coverage grade was lower in DM group than in non-DM group (P=0.002, Figure), while maximum and dominant NIC coverage grades were similar between them (P=0.94 and P=0.59, respectively). Thrombus adhesion (44.3% versus 38.8%, P=0.32) and maximum yellow color grade (P=0.78) were also similar between DM and non-DM groups. Even after the adjustment by the confounding factors such as follow-up duration and primary disease of acute coronary syndrome, DM was an independent factor predicting grade 0 of minimum NIC (odds ratio [OR] 1.83 [95% confidence interval 1.11–3.03], P=0.019).

Conclusion

DM patients showed less covered struts than non-DM patients 3 to 5 months after DES implantation, suggesting that the recent ultra-short DAPT strategy might not be easily applicable to DM patients.

Minimum neointimal coverage grade

Funding Acknowledgement

Type of funding source: None

The Utility of Applying Various Image Preprocessing Strategies to Reduce the Ambiguity in Deep Learning-based Clinical Image Diagnosis

PURPOSE

A general problem of machine-learning algorithms based on the convolutional neural network (CNN) technique is that the reason for the output judgement is unclear. The purpose of this study was to introduce a strategy that may facilitate better understanding of how and why a specific judgement was made by the algorithm. The strategy is to preprocess the input image data in different ways to highlight the most important aspects of the images for reaching the output judgement.

MATERIALS AND METHODS

T2-weighted brain image series falling into two age-ranges were used. Classifying each series into one of the two age-ranges was the given task for the CNN model. The images from each series were preprocessed in five different ways to generate five different image sets: (1) subimages from the inner area of the brain, (2) subimages from the periphery of the brain, (3-5) subimages of brain parenchyma, gray matter area, and white matter area, respectively, extracted from the subimages of (2). The CNN model was trained and tested in five different ways using one of these image sets. The network architecture and all the parameters for training and testing remained unchanged.

RESULTS

The judgement accuracy achieved by training was different when the image set used for training was different. Some of the differences was statistically significant. The judgement accuracy decreased significantly when either extra-parenchymal or gray matter area was removed from the periphery of the brain (P < 0.05).

CONCLUSION

The proposed strategy may help visualize what features of the images were important for the algorithm to reach correct judgement, helping humans to understand how and why a particular judgement was made by a CNN.

An African pygmy hedgehog adenovirus 1 (AhAdV-1) outbreak in an African pygmy hedgehog (Atelerix albiventris) colony in Japan

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A novel adenovirus outbreak occurred in a colony of African pygmy hedgehogs (APHs).

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An African pygmy hedgehog adenovirus 1 (AhAdV-1) infection was confirmed in 13 APHs.

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AhAdV-1 was isolated from one APH.

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Five APHs died during the outbreak and AhAdV-1 can cause fatal pneumonia in a case.

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AhAdV-1 should be monitored as a potential cause of emerging infections in APHs.

An African pygmy hedgehog adenovirus 1 (AhAdV-1) outbreak in a colony of 24 African pygmy hedgehogs (APHs) with a case of fatal pneumonia occurred in Japan. Thirteen out of a colony of 15 APHs with respiratory symptoms were diagnosed with AhAdV-1 infection based on the detection of AhAdV-1 genome in throat/nasal swabs and further one APH was diagnosed on isolation of the virus. Five infected APHs died during the outbreak and AhAdV-1 caused severe pneumonia and death in one case. After the outbreak, persistent AhAdV-1 infection was suggested in one surviving APH. AhAdV-1 is a novel adenovirus and is suspected to be an emerging pathogen.

Reference region extraction by clustering for the pharmacokinetic analysis of dynamic contrast-enhanced MRI in prostate cancer

PURPOSE

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) measures changes in the concentration of an administered contrast agent to quantitatively evaluate blood circulation in a tumor or normal tissues. This method uses a pharmacokinetic analysis based on the time course of a reference region, such as muscle, rather than arterial input function. However, it is difficult to manually define a homogeneous reference region. In the present study, we developed a method for automatic extraction of the reference region using a clustering algorithm based on a time course pattern for DCE-MRI studies of patients with prostate cancer.

METHODS

Two feature values related to the shape of the time course were extracted from the time course of all voxels in the DCE-MRI images. Each voxel value of T1-weighted images acquired before administration were also added as anatomical data. Using this three-dimensional feature vector, all voxels were segmented into five clusters by the Gaussian mixture model, and one of these clusters that included the gluteus muscle was selected as the reference region.

RESULTS

Each region of arterial vessel, muscle, and fat was segmented as a different cluster from the tumor and normal tissues in the prostate. In the extracted reference region, other tissue elements including scattered fat and blood vessels were removed from the muscle region.

CONCLUSIONS

Our proposed method can automatically extract the reference region using the clustering algorithm with three types of features based on the time course pattern and anatomical data. This method may be useful for evaluating tumor circulatory function in DCE-MRI studies.

Intra- and inter-operator reproducibility of US point shear-wave elastography in various organs: evaluation in phantoms and healthy volunteers

PURPOSE

This study was conducted in order to assess the intra- and interoperator reproducibility of shear-wave speed (SWS) measurement on elasticity phantoms and healthy volunteers using ultrasound-based point shear-wave elastography.

MATERIALS AND METHODS

This study was approved by the institutional review board. Two operators measured the SWS of five elasticity phantoms and seven organs (thyroid, lymph node, muscle, spleen, kidney, pancreas, and liver) of 30 healthy volunteers with 1.0-4.5 MHz convex (4C1) and 4.0-9.0 MHz linear (9L4) transducers. The phantom measurements were repeated ten times, while the volunteer measurements were performed five times each. Intra- and interoperator reproducibility was assessed. Interoperator reproducibility was also evaluated with the 95% Bland-Altman limits of agreement (LOA).

RESULTS

In phantoms, all intraclass correlation coefficients (ICCs) were above 0.90 and the 95% LOA between the two operators were less than ± 18%. In volunteers, intraoperator ICCs were > 0.75 for all regions except the pancreas. Interoperator ICC was above 0.75 for the right lobe of the liver (depth 4 cm) and the kidney, but the 95% LOA was less than ± 25% only for the liver.

CONCLUSION

Although excellent in phantoms, interoperator reproducibility was insufficient for all regions in the volunteers other than the right hepatic lobe at a depth of 4 cm. Clinicians should be aware of the 95% LOA when using SWS in patients.

KEY POINTS

• Our phantom study indicated a high reproducibility for shear-wave speed (SWS) measurements with point shear-wave elastography (pSWE). • In volunteers, intraoperator reproducibility was generally high, but the interoperator reproducibility was not high enough except for the right hepatic lobe at 4 cm depth. • To evaluate interoperator reproducibility, the 95% limits of agreement (LOA) between operators should be considered in addition to the intraclass correlation coefficient (ICC).

Numerical Simulation Based on Individual Voxel Phantoms for a Sophisticated Evaluation of Internal Doses Mainly From 131I in Highly Exposed Workers Involved in the TEPCO Fukushima Daiichi NPP Accident

As a response to the Tokyo Electric Power Company's Fukushima Daiichi nuclear power plant accident in 2011, seven TEPCO workers whose exposure doses were expected to be >250 mSv (a tentative dose limit stipulated by the Japanese central authority) attended Japan's National Institute for Radiological Sciences for additional internal dose measurements. The National Institute for Radiological Sciences examination revealed that these workers' internal doses came mainly from their intake of the radionuclide I during emergency operations. In this study, we performed numerical simulations based on individual volume-pixel (voxel) phantoms of six of the seven workers for a more sophisticated evaluation of their internal doses, taking into account the individual thyroid size and other specific parameters. The voxel phantoms were created from magnetic resonance imaging scan images. As a result, the individual thyroid volumes ranged from 6.5 to 28.2 cm and were considerably smaller than the reference value (~20 cm) adopted in the International Commission on Radiation Protection's dosimetric model for four of the six subjects. Compared to the original estimates of the thyroid absorbed dose, our preliminary evaluation revealed values that were increased by approximately 3-fold or decreased by 30% at maximum. A wide difference in the individual thyroid size would be one of the significant modifiers in the current dose estimation of subjects of the ongoing epidemiological study project. The present simulations also provided evidence that the direct thyroid measurements by the National Institute for Radiological Sciences to determine the workers' I thyroid contents were sufficiently accurate.

Prospective clinical trial of 12-fraction carbon-ion radiotherapy for primary renal cell carcinoma

The aims of this study were to clarify the safety and efficacy of 12-fraction carbon-ion radiotherapy (CIRT) for primary renal cell carcinoma (RCC) and to confirm the recommended dose in a prospective clinical trial.

This clinical trial was planned as a non-randomized, open-label, single-center phase I/II study of CIRT monotherapy. The incidence of acute adverse events was the primary endpoint. Dose-limiting toxicities (DLTs) were defined as grade ≥3 skin, gastrointestinal tract, or urologic adverse events.

Based on the eligibility criteria, 8 patients with primary RCC, including 3 medically inoperable patients and 5 patients with tumors >4 cm, were enrolled. Of the 8 patients, 5 were treated with 66 Gy (relative biological effectiveness [RBE]), and subsequently, the dose was escalated to 72 Gy (RBE) for the remaining 3 patients. The median follow-up time was 43.1 months. No DLTs were observed at any dose level though the end of follow-up. Although 1 patient died of pneumonia 3 months after CIRT, which was determined to be unrelated to CIRT, no grade 3 or higher adverse events were observed, and both local control and cancer-specific survival rates were 100%.

In conclusion, the safety and efficacy of CIRT hypofractionation using 12-fractions for the treatment of eligible RCC patients, including those with inoperable or tumor size >4 cm, were confirmed in this prospective trial, and a recommended dose of 72 Gy (RBE) was established.

Updated long-term outcomes after carbon-ion radiotherapy for primary renal cell carcinoma

Long‐term oncological outcomes for primary renal cell carcinoma (RCC) treated with carbon‐ion radiotherapy (CIRT) are poorly understood. Patients with primary RCC were treated with 12 or 16‐fraction CIRT at The Hospital of the National Institute of Radiological Sciences outside of clinical trials. Outcome data were pooled and retrospectively analyzed for toxicity, local control, and disease‐free, cancer‐specific, and overall survival. From 1997 to 2014, 19 RCC patients (11 with T1aN0M0, 4 with T1bN0M0, and 4 with inoperable advanced stage [T4N0M0, T3aN1M0, and T1aN0M1]) were treated with CIRT and followed up for a median of 6.6 (range, 0.7‐16.5) years; 9 of these patients were inoperable because of comorbidities or advanced‐stage disease. Diagnoses were confirmed by imaging in 11 patients and by biopsy in the remaining 8. In 4 of 5 patients with definitive renal comorbidities, including diabetic nephropathy, sclerotic kidney or solitary kidney pre‐CIRT progressed to grade 4 chronic kidney disease (CKD). In contrast, the remaining 14 patients without definitive renal comorbidities did not progress to grade 3 or higher CKD. Furthermore, although 1 case of grade 4 dermatitis was observed, there were no other grade 3 or higher non‐renal adverse events. Local control rate, and disease‐free, cancer‐specific, and overall survival rates at 5 years of all 19 patients were 94.1%, 68.9%, 100%, and 89.2%, respectively. This updated retrospective analysis based on long‐term follow‐up data suggests that CIRT is a safe treatment for primary RCC patients without definitive renal comorbidities pre‐CIRT, and yield favorable treatment outcomes, even in inoperable cases.

Comparison of passive and scanning irradiation methods for carbon-ion radiotherapy for breast cancer

The dose distribution of passive and scanning irradiation for carbon-ion radiotherapy for breast cancer was compared in order to determine the preferred treatment method. Eleven Japanese patients who received carbon-ion radiotherapy for breast cancer were retrospectively analyzed. The original clinical plans were used for the passive irradiation method, while the plans for the scanning irradiation method were more recently made. Statistical analysis suggested that there was no significant difference in superiority in terms of dose distribution between the passive and scanning irradiation methods. The present study found that the scanning irradiation method was not always superior to the passive method, despite a previous study having reported the superiority of scanning irradiation. The present result is considered to arise from characteristics of breast cancer treatment, such as the simplicity of the organ at risk and the shallow depth point of the target from the skin. It is noteworthy that the present study suggests that the passive irradiation method can provide better dose distribution, depending on the case.

Molecular epidemiological survey and phylogenetic analysis of bovine influenza D virus in Japan

The influenza D virus, a new member of the Orthomyxoviridae family, is predominantly found in cattle. Although viral pathology and clinical disease in cattle appear mild, this virus plays an important role as a trigger of bovine respiratory disease (BRD). BRD is a costly illness worldwide. Thus, epidemiological surveys of the influenza D virus are necessary. Here, we conducted a molecular epidemiological survey for the influenza D virus in healthy and respiratory-diseased cattle in Japan. We found that 2.1% (8/377) of the cattle were infected with influenza D. The cattle with and without respiratory symptoms had approximately equal amounts of the virus. A full-genome sequence analysis revealed that the influenza D virus that was isolated in Japan formed an individual cluster that was distinct from the strains found in other countries. These results suggest that this virus might have evolved uniquely in Japan over a long period of time and that the viral pathology of Japanese strains might be different from the strains found in other countries. Continuous surveillance is required to determine the importance of this virus and to characterize its evolution.

Exploring the self-mode locking and vortex structures of nonplanar elliptical modes in selectively end-pumped Nd:YVO4 lasers: manifestation of large fractional orbital angular momentum

An end-pumped Nd:YVO₄ laser under selective pumping is used to excite lasing modes with transverse patterns performed to exhibit the characteristics of multiple spots arranged on elliptical features near degenerate cavities. The spatial distribution of elliptical lasing modes is clearly revealed to be localized on the nonplanar ray orbits, so-called nonplanar elliptical modes, which possess large fractional orbital angular momentum. Moreover, temporal dynamics for the output emission of nonplanar elliptical modes are verified to obtain self-mode-locked operation. We further numerically manifest not only the influence of radial-asymmetry distributions on the vortex structures of nonplanar elliptical modes, but also the vector field of transverse lasing modes altered with twisting phase structures in the propagation direction.

Measuring shear-wave speed with point shear-wave elastography and MR elastography: a phantom study

OBJECTIVES

To compare shear-wave speed (SWS) measured by ultrasound-based point shear-wave elastography (pSWE) and MR elastography (MRE) on phantoms with a known shear modulus, and to assess method validity and variability.

METHODS

5 homogeneous phantoms of different stiffnesses were made. Shear modulus was measured by a rheometer, and this value was used as the standard. 10 SWS measurements were obtained at 4 different depths with 1.0-4.5 MHz convex (4C1) and 4.0-9.0 MHz linear (9L4) transducers using pSWE. MRE was carried out once per phantom, and SWSs at 5 different depths were obtained. These SWSs were then compared with those from a rheometer using linear regression analyses.

RESULTS

SWSs obtained with both pSWE as well as MRE had a strong correlation with those obtained by a rheometer (R²>0.97). The relative difference in SWS between the procedures was from -25.2% to 25.6% for all phantoms, and from -8.1% to 6.9% when the softest and hardest phantoms were excluded. Depth dependency was noted in the 9L4 transducer of pSWE and MRE.

CONCLUSIONS

SWSs from pSWE and MRE showed a good correlation with a rheometer-determined SWS. Although based on phantom studies, SWSs obtained with these methods are not always equivalent, the measurement can be thought of as reliable and these SWSs were reasonably close to each other for the middle range of stiffness within the measurable range.

Activation of c-Jun N-terminal kinase by Akabane virus is required for apoptosis

Akabane virus (AKAV) belongs to the Simbu serogroup of the genus Orthobunyavirus in the family Bunyaviridae. It has been shown that AKAV induces apoptosis in mammalian cells. It is necessary to understand the signaling pathways involved in AKAV-induced apoptosis to further elucidate the molecular virology of AKAV. c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) are mediators of apoptosis; therefore, we investigated the roles of JNK and p38 MAPK cascades in AKAV-infected cells. We found that JNK and p38 MAPK as well as their downstream substrates, c-Jun and heat shock protein 27 (HSP27), were phosphorylated in response to AKAV infection. A JNK inhibitor (SP600125) inhibited AKAV-mediated apoptosis whereas a p38 MAPK inhibitor (SB203580) did not. We conclude that AKAV infection activates the JNK and p38 MAPK signaling pathways, and the JNK cascade plays a crucial role in AKAV-induced apoptosis in vitro.

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JNK and p38 MAPK were phosphorylated in response to Akabane virus infection.

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Downstream substrates, c-Jun and heat shock protein 27, were also phosphorylated by viral infection.

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JNK inhibitor (SP600125) inhibited AKAV-mediated apoptosis whereas a p38 MAPK inhibitor (SB203580) did not.

Calcium supplementation in salt-dependent hypertension

To clarify the mechanism of the antihypertensive effect of oral Ca loading, we studied the effect of Ca supplementation on salt-induced blood pressure elevations in patients with essential hypertension and DOCA-salt hypertensive rats. When the diet was changed from low to high salt (300 mEq/day), the percent increase in mean blood pressure was smaller (p less than 0.01) in the Ca-supplemented (2,160 mg/day) patients than in the Ca-restricted (250 mg/day) ones. Oral Ca loading resulted in a smaller weight gain, a greater urinary sodium excretion, and an increase in red cell Mg. In the experimental study, high Ca (4% CaCl2) intake attenuated the blood pressure elevation in DOCA-salt-treated rats, accompanied with an increase in urinary sodium excretion, with the resultant attenuation in intra- and extracellular sodium retention. The decrease in catecholamine contents of hearts was improved, and a higher survival rate was observed in Ca-supplemented DOCA-salt rats. The results suggest that Ca supplementation may prevent a rise in BP in salt-dependent hypertension by inducing natriuresis with the resultant attenuation in sodium retention. The altered intracellular Mg level in hypertensive patients and the normalization of enhanced sympathetic nervous activity in DOCA-salt rats may, in part, be involved in its mechanism.

The role of mitochondria-derived reactive oxygen species in the pathogenesis of non-steroidal anti-inflammatory drug-induced small intestinal injury

Non-steroidal anti-inflammatory drugs (NSAIDs) have been implemented in clinical settings for a long time for their anti-inflammatory effects. With the number of NSAID users increasing, gastroenterological physicians and researchers have worked hard to prevent and treat NSAID-induced gastric mucosal injury, an effort that has for the large part being successful. However, the struggle against NSAID-induced mucosal damage has taken on a new urgency due to the discovery of NSAID-induced small intestinal mucosal injury. Although the main mechanism by which NSAIDs induce small intestinal mucosal injury has been thought to depend on the inhibitory effect of NSAIDs on cyclooxygenase (COX) activity, recent studies have revealed the importance of mitochondria-derived reactive oxygen species (ROS) production, which occurs independently of COX-inhibition. ROS production is an especially important factor in the increase of small intestinal epithelial cell permeability, an early stage in the process of small intestinal mucosal injury. By clarifying the precise mechanism, together with its clinical features using novel endoscopy, effective strategies for preventing NSAID-induced small intestinal damage, especially targeting mitochondria-derived ROS production, may be developed.

First experience of carbon-ion radiotherapy for early breast cancer

Breast cancer is increasingly being detected at earlier stages, and partial breast irradiation for patients with low-risk-group tumor has come to be applied in the US and Europe as an alternative to whole-breast irradiation. Based on those experiences, some institutes have tried using particle beams for partial breast irradiation for postoperative or radical intent for early breast cancer, but technical difficulties have hindered its progress. The National Institute of Radiological Sciences has been preparing for carbon-ion radiotherapy (C-ion RT) with radical intent for stage I breast cancer since 2011, and we carried out the first treatment in April 2013. In this case report, we explain our first experience of C-ion RT as a treatment procedure for breast tumor and present the radiation techniques and preliminary treatment results as a reference for other institutes trying to perform the same kind of treatment.

Relationship between diffusion-weighted magnetic resonance imaging and histological tumor grading of hepatocellular carcinoma

BACKGROUND

Intrahepatic and extrahepatic recurrence remains a significant problem for hepatocellular carcinoma (HCC). The aim of this study was to determine the usefulness of diffusion-weighted magnetic resonance imaging (DWI) for histological tumor grading and preoperative prediction of early HCC recurrence within 6 months of operation.

METHODS

A total of 44 patients who had undergone hepatic resection for HCC (50 nodules) were reviewed retrospectively. DWI was performed within 30 days before hepatectomy, and apparent diffusion coefficients (ADCs) were measured using 2 methods: mean ADC and minimum-spot ADC. Relationships between ADCs and histological differentiation and between ADCs and early recurrence of HCC were analyzed.

RESULTS

Mean ADC was significantly lower in poorly differentiated HCC (n=18, 1.07±0.15×10(-3) mm2/s) than in moderately differentiated HCC (n=29, 1.29±0.21×10(-3) mm2/s; P<.05). Minimum-spot ADC was significantly lower in poorly differentiated HCC (n=18, 0.69±0.19×10(-3) mm2/s) than in well-differentiated HCC (n=3, 1.15±0.10×10(-3) mm2; P<.01) or in moderately differentiated HCC (n=29, 0.98±0.18×10(-3) mm2/s; P<.0001). Of 34 patients who were able to be observed for >6 months after resection, 9 showed early recurrence. Minimum-spot ADC was significantly lower in patients with early recurrence (n=9, 0.64±0.24×10(-3) mm2/s) than in patients without early recurrence (n=25, 0.88±0.19×10(-3) mm2/s; P<.05). On multivariate analysis, minimum-spot ADC was a significant risk factor for early recurrence (P<.05).

CONCLUSION

Quantitative measurement of ADC of HCC with magnetic resonance diffusion weighted imaging is a promising functional imaging tool in the prediction of histological grade and early recurrence before treatment.

Dual-frequency picosecond optical parametric generator pumped by a Nd-doped vanadate bounce laser

Dual-frequency MHz-repetition 1.5-μm optical parametric generation is demonstrated from a tandem system pumped by a picosecond Nd:YVO₄ bounce laser. An average power of 1.0 W is obtained over the range 1571-1630 nm, corresponding to an optical-optical conversion efficiency and slope efficiency of 16% and 23%, respectively. Terahertz-wave with a frequency of 3.2 THz is also generated from the system in combination with an organic nonlinear DAST crystal.

Inhibition of Bach1 ameliorates indomethacin-induced intestinal injury in mice

BTB and CNC homolog 1 (Bach1) is a transcriptional repressor of heme oxygenase-1 (HO-1). It plays an important role in the feedback regulation of HO-1 expression, which protects cells from various insults including oxidative stress and inflammatory cytokines. However, the role of Bach1 in intestinal inflammation remains unclear. In this study, the role of Bach1 in intestinal mucosal injury was elucidated using 8-week-old female C57BL/6 (wild-type) and homozygous Bach1-deficient C57BL/6 mice. Intestinal mucosal injuries induced by a single subcutaneous administration of indomethacin were evaluated macroscopically, histologically, and biochemically. Mucosal protein content and chemokine mRNA levels were determined by real-time PCR. Our results showed that the indomethacin-induced intestinal injury was remarkably improved in Bach1-deficient mice. Histological examination showed that the area of injured lesion was decreased in Bach1-deficient mice compared to wild-type mice. Administration of indomethacin induced expression of inflammatory chemokines such as KC, MIP1alpha and MCP1, which was suppressed in Bach1-deficient mice. Myeloperoxidase activity in the intestinal mucosa was also significantly decreased in Bach1-deficient mice. Additionally, Bach1 deficiency enhanced immunopositivity of HO-1 in the intestinal mucosa after indomethacin administration. Disruption of the Bach1 gene thus caused inhibition of mucosal injury, indicating that inhibition of Bach1 may be a novel therapeutic strategy for treating indomethacin-induced intestinal injury.

Sub-100 W picosecond output from a phase-conjugate Nd:YVO4 bounce amplifier

We demonstrated >80 W picosecond output at a pulse repetition frequency of 100 MHz from a dual Nd:YVO(4) amplifier laser system consisting of a phase-conjugate Nd:YVO(4) bounce amplifier combined with a second diode-side-pumped Nd:YVO(4) bounce amplifier. The output exhibited high quality spatial form with M(2) < 1.8 and a pulse duration (FWHM) of 9.2 ps. A peak power of >7.4 MW with an average power of 78.5 W was also achieved at a pulse repetition frequency of 1.0 MHz.

Splenic volume measurements on computed tomography utilizing automatically contouring software and its relationship with age, gender, and anthropometric parameters

OBJECTIVE

The present research was conducted to establish the normal splenic volume in adults using a novel and fast technique. The relationship between splenic volume and age, gender, and anthropometric parameters was also examined.

MATERIALS AND METHODS

The splenic volume was measured in 230 consecutive patients who underwent computed tomography (CT) scans for various indications. Patients with conditions that have known effect on the spleen size were not included in this study. A new technique using volumetric software to automatically contour the spleen in each CT slice and quickly calculate splenic volume was employed. Inter- and intra-observer variability were also examined.

RESULTS

The average splenic volume of all the subjects was 127.4+/-62.9 cm(3), ranging from 22 to 417 cm(3). The splenic volume (S) correlated with age (A) (r=-0.33, p<0.0001), body weight (W) (r=0.35, p<0.0001), body mass index (r=0.24, p<0.0001) and body surface area (BSA) (r=0.31, p<0.0001). The age-adjusted splenic volume index correlated with gender (p=0.0089). The formulae S=W[6.47A(-0.31)] and S=BSA[278A(-0.36)] were derived and can be used to estimate the splenic volume. Inter- and intra-observer variability were 6.4+/-9.8% and 2.8+/-3.5% respectively.

CONCLUSION

Of the anthropometric parameters, the splenic volume was most closely linked to body weight. The automatically contouring software as well as formulae can be used to obtain the volume of the spleen in regular practice.

Combination immunotherapy with radiation and CpG-based tumor vaccination for the eradication of radio- and immuno-resistant lung carcinoma cells

Unmethylated cytosine-phosphorothioate-guanine containing oligodeoxynucleotides (CpG-ODN) is known as a ligand of toll-like receptor 9 (TLR9), which selectively activates type-1 immunity. We have already reported that the vaccination of tumor-bearing mice with liposome-CpG coencapsulated with model-tumor antigen, ovalbumin (OVA) (CpG + OVA-liposome) caused complete cure of the mice bearing OVA-expressing EG-7 lymphoma cells. However, the same therapy was not effective to eradicate Lewis lung carcinoma (LLC)-OVA-carcinoma. To overcome the refractoriness of LLC-OVA, we tried the combination therapy of radiation with CpG-based tumor vaccination. When LLC-OVA-carcinoma intradermally (i.d.) injected into C57BL/6 became palpable (7-8 mm), the mice were irradiated twice with a dose of 14 Gy at intervals of 24 h. After the second radiation, CpG + OVA-liposome was i.d. administered near the draining lymph node (DLN) of the tumor mass. The tumor growth of mice treated with radiation plus CpG + OVA-liposome was greatly inhibited and approximately 60% of mice treated were completely cured. Moreover, the combined therapy with radiation and CpG + OVA-liposome allowed the augmented induction of OVA-tetramer(+) LLC-OVA-specific cytotoxic T lymphocyte (CTL) in DLN of tumor-bearing mice. These results indicate that the combined therapy of radiation with CpG-based tumor vaccine is a useful strategy to eradicate intractable carcinoma.

Three-dimensional intrafractional motion of breast during tangential breast irradiation monitored with high-sampling frequency using a real-time tumor-tracking radiotherapy system

PURPOSE

To evaluate the three-dimensional intrafraction motion of the breast during tangential breast irradiation using a real-time tracking radiotherapy (RT) system with a high-sampling frequency.

METHODS AND MATERIALS

A total of 17 patients with breast cancer who had received breast conservation RT were included in this study. A 2.0-mm gold marker was placed on the skin near the nipple of the breast for RT. A fluoroscopic real-time tumor-tracking RT system was used to monitor the marker. The range of motion of each patient was calculated in three directions.

RESULTS

The mean +/- standard deviation of the range of respiratory motion was 1.0 +/- 0.6 mm (median, 0.9; 95% confidence interval [CI] of the marker position, 0.4-2.6), 1.3 +/- 0.5 mm (median, 1.1; 95% CI, 0.5-2.5), and 2.6 +/- 1.4 (median, 2.3; 95% CI, 1.0-6.9) for the right-left, craniocaudal, and anteroposterior direction, respectively. No correlation was found between the range of motion and the body mass index or respiratory function. The mean +/- standard deviation of the absolute value of the baseline shift in the right-left, craniocaudal, and anteroposterior direction was 0.2 +/- 0.2 mm (range, 0.0-0.8 mm), 0.3 +/- 0.2 mm (range, 0.0-0.7 mm), and 0.8 +/- 0.7 mm (range, 0.1-1.8 mm), respectively.

CONCLUSION

Both the range of motion and the baseline shift were within a few millimeters in each direction. As long as the conventional wedge-pair technique and the proper immobilization are used, the intrafraction three-dimensional change in the breast surface did not much influence the dose distribution.

Power scaling of a pico-second Nd:YVO(4) master-oscillator power amplifier with a phase-conjugate mirror

We investigated design issues for the power scaling of a pico-second Nd:YVO(4) master-oscillator power amplifier system with a photorefractive phase-conjugate mirror by using standard beam propagation analysis. We also demonstrated a 25 W diffraction-limited pico-second output. A corresponding extraction efficiency of 31 % was achieved.

Identification and analysis of MHC class II DRB1 (Patr-DRB1) alleles in chimpanzees

The MHC-DRB1 gene is known to display the most extensive allelic polymorphisms among MHC class II genes. We attempted the selective identification of chimpanzee (Pan troglodytes) DRB1 (Patr-DRB1) alleles using the polymerase chain reaction (PCR) technique in three steps: first, we performed Patr-DRB1*02 lineage-specific 8-kb PCR for *02 lineage detection in each chimpanzee; second, we performed 620-bp PCR for amplification of full-length exon 2; and finally, we carried out an insert check using the pattern of microsatellite repeat length variability. In the genomic DNA of 23 chimpanzees, nine Patr-DRB1 alleles containing two new alleles were detected. Our approach provides a relatively effective method of identifying Patr-DRB1 alleles in individual chimpanzees and should also contribute to our understanding of the features of MHC molecules in non-human primates.

Sequence analysis of the MHC class II DPB1 gene in chimpanzees (Pan troglodytes)

The diversity of the MHC class II region in non-human primates is a focus of biomedical research because this region plays a crucial role in the recognition of antigens in the immune system. In particular, the chimpanzee [Pan troglodytes (Patr)], which belongs to the superfamily Hominoidea, has been used as a human model for the study of diseases such as human hepatitis C virus (HCV), human hepatitis B virus (HBV) and human immunodeficiency virus (HIV) infections, to which only humans and chimpanzees are susceptible. In the present study, polymorphisms of the MHC-DPB1 gene (Patr-DPB1) in a chimpanzee colony in Japan were examined using a stepwise polymerase chain reaction (PCR) technique. In order to design a suitable primer pair which would amplify exon 2 of the Patr-DPB1 gene, a fragment of approximately 8 kb from exon 1 to exon 3 was amplified from chimpanzee genomic DNA. After designing a 500-bp primer pair at the 3' region of intron 1 and the 5' region of intron 2, analysis of DPB1 exon 2 alleles of each chimpanzee was carried out. Twenty-two chimpanzees were used in our study, and we identified seven alleles by sequence analysis on the Patr-DPB1 gene, including one new allele. The obtained nucleotide sequence patterns suggest that Patr-DPB1 alleles emerge by genetic variations such as the exchange of sequence motifs and the accumulation of point mutations.

Physiologic change in flow velocity and direction of dural venous sinuses with respiration: MR venography and flow analysis

BACKGROUND AND PURPOSE

Blood flow of the internal jugular vein and intracranial venous sinuses is affected by respiratory state. The purpose of this study was to clarify the changes in flow velocity and direction and signal intensities of sigmoid sinuses on phase-contrast (PC) MR images obtained with regular breathing and with deep inspiratory breath holding.

METHODS

One hundred seven subjects without venous sinus abnormality were studied. Coronal 2D PC MR venography and axial 2D PC images with peripheral pulse gating were acquired with a 1.5-T MR unit, during regular breathing and deep inspiratory breath holding. The signal intensity changes of bilateral sigmoid sinuses on MR venograms and the changes of flow velocity and direction on the axial 2D PC images were analyzed.

RESULTS

Breath holding decreased signal intensities of the right and left sigmoid sinuses on MR venograms in 57 (53.3%) and 36 (33.6%) subjects, respectively. Increased signal intensity was observed in 12 (11.2%) and 33 (30.8%) subjects, respectively. In the flow analysis, retrograde flow was detected at the left sigmoid sinus in four subjects (3.7%) during regular breathing, which was normalized by breath holding. Flow velocities of the right and left sigmoid sinuses decreased during breath holding in 92 (86.0%) and 70 (65.4%) subjects, and increased in 15 (14.0%) and 37 (34.6%) subjects, respectively.

CONCLUSION

The signal intensities of sigmoid sinuses were affected by breath holding in about 2/3 of the subjects. Breath-holding maneuver can be used to increase blood flow and signal intensities of dural venous sinuses on PC MR venograms.

Overexpression of homeobox gene HOXD3 induces coordinate expression of metastasis-related genes in human lung cancer cells

Homeobox-containing genes are expressed in spatiotemporal fashion during embryogenesis and act as master transcription-regulating factors which control the expression of a variety of genes involved in morphogenesis. They are also expressed in a tissue-specific manner in normal adult tissues and appear to give cells spatial information in the maintenance of their architectural integrity. We transfected a HOXD3 class I homeobox-containing gene into human lung cancer A549 cells and investigated alterations in gene expressions and phenotypes related to the maintenance of tissue architecture in HOXD3-overexpressing A549 cells. In the HOXD3-overexpressing cell lines, expression of E-cadherin was lost and plakoglobin was strongly repressed, whereas integrin alpha3 and beta3 were up-regulated and N-cadherin and integrin alpha4 were newly expressed. Compared with parental and control transfectant lines, the HOXD3-overexpressing cell lines showed highly motile and invasive activity. Blocking experiments using anti-integrin beta1 and beta3 suggested that the increased haptotaxis of the HOXD3-overexpressing cells to vitronectin resulted from increased expression and activation of integrin alphavbeta3, and that overexpression of the HOXD3 gene converted the integrin beta1-dependent haptotaxis to fibronectin into both integrin beta1- and beta3-dependent one. HOXD3 overexpression increased production of matrix-degrative enzymes including matrix metalloproteinase-2 and urokinase-plasminogen activator. When the tumor cells were intravenously injected into the tail veins of nude mice, HOXD3 transfectants formed a significantly large number of metastatic foci in lungs compared with the control transfectants. These findings suggest that HOXD3 can act as a metastasis-promoting gene in human lung cancer A549 cells.

Thermal conductivity of a self-frequency-doubling laser crystal measured by use of optical methods

We present a new all-optical technique to measure the thermal conductivity of laser crystals. This technique can be used for crystals that are too small for direct measurement of thermal conductivity. We used this technique to measure the thermal conductivities of Nd:LYAB, with the result of 44 +/- 6% compared with that of Nd:YAG thermal conductivity.

Wavelet compression on detection of brain lesions with magnetic resonance imaging

The purpose of this report is to assess clinically acceptable compression ratios on the detection of brain lesions at magnetic resonance imaging (MRI). Four consecutive T2-weighted and the corresponding T1-weighted images obtained in 20 patients were studied for 109 anatomic sites including 50 with lesions and 59 without lesions. The images were obtained on a 1.5-T MR unit with a pixel size of 0.9 to 1.2 x 0.47 mm and a section thickness of 5 mm. The image data were compressed by wavelet-based algorithm at ratios of 20:1, 40:1, and 60:1. Three radiologists reviewed these images on an interactive workstation and rated the presence or absence of a lesion with a 50 point scale for each anatomic site. The authors also evaluated the influence of pixel size on the quality of image compression. At receiver operating characteristic (ROC) analysis, no statistically significant difference was detected at a compression ratio of 20:1. A significant difference was observed with 40:1 compressed images for one reader (P = .023), and with 60:1 for all readers (P = .001 to .012). A root mean squared error (RMSE) was higher in 0.94- x 0.94-mm pixel size images than in 0.94- x 0.47-mm pixel size images at any compression ratio, indicating compression tolerance is lower for the larger pixel size images. The RMSE, subjective image quality, and error images of 10:1 compressed 0.94- x 0.94-mm pixel size images were comparable with those of 20:1 compressed 0.94- x 0.47-mm pixel size images. Wavelet compression can be acceptable clinically at ratios as high as 20:1 for brain MR images when a pixel size at image acquisition is around 1.0 x 0.5 mm, and as high as 10:1 for those with a pixel size around 1.0 x 1.0 mm.

Tunable phase conjugation by intracavity degenerate four-wave mixing in an injection-seeded solid dye laser

We demonstrate efficient degenerate four-wave mixing in a laser injection-seeded solid dye laser. Phase-conjugate energy of as much as 140 times the total energy injected externally into the phase conjugator was extracted. Moreover, efficient phase-conjugate energy was obtained in the broad wavelength region from 558 to 567 nm.

The role of radiotherapy in treating squamous cell carcinoma of the external auditory canal, especially in early stages of disease

PURPOSE

Our intent was to investigate the role of radiotherapy in treating external auditory canal squamous cell carcinoma, especially in early stages of disease.

MATERIALS AND METHODS

The treatment results for 20 patients treated between 1980 and 1998 were retrospectively analyzed. Radiotherapy was used as an initial treatment without surgery in eight patients and with surgery in 12 patients. The patients treated by radiotherapy alone received 65 Gy in 26 fractions over 6.5 weeks. The patients treated with radiotherapy perioperatively received 30-75 Gy in 12-30 fractions. The follow-up period for survivors including patients died of intercurrent disease ranged from 7 to 205 months (mean: 71 months).

RESULTS

The 5-year survival rate calculated by the Kaplan-Meier method for all patients was 59%. According to Stell classification (Laryncol. Otol. 99 (1985) 847), the 5-year survival rates for eight patients with T1 disease and eight with T2 disease were 100 and 38%, respectively. In the eight patients with T1 disease, disease control was 100%. Local control with hearing preservation was achieved in five patients with T1 disease by radiotherapy alone. No late complications related to radiotherapy were observed.

CONCLUSIONS

A precise diagnosis of the disease in terms of whether or not it has invaded the bone is important in order to predict the treatment outcome. Radiotherapy with or without surgery is the treatment of choice for patients with T1-stage disease. Surgery with radiotherapy is recommended as standard care for tumors with bony invasion.

Highly efficient degenerate four-wave mixing with multipass geometries in a polymer laser dye saturable amplifier

We demonstrate the use of highly efficient degenerate four-wave mixing for phase conjugation with multipass geometries in a polymer laser dye saturable amplifier. Phase-conjugate energy reflectivity of as much as 20,000% with a four-pass geometry in the longitudinally pumped polymer dye was obtained at 564 nm.

Tunable, visible phase conjugator with a saturable-amplifier polymer laser dye

We present the first report to the best of our knowledge of highly efficient phase conjugation in a laser-pumped polymer-dye saturable amplifier. Phase-conjugate reflectivity of as much as 210% at 560 nm has been obtained. Moreover, efficient reflectivity has been obtained in the broad wavelength region from 556 to 567 nm.