Early Enhancement with Contrast-Enhanced Ultrasonography Relates to the Number of Small-Diameter Neovessels in the Carotid Plaque.

BACKGROUND AND PURPOSE: Intraplaque neovessels (INVs) have been recognized as a major cause of intraplaque hemorrhage and subsequent vulnerability of the carotid plaque. However, the exact mechanisms by which INVs cause intraplaque hemorrhage remain unclear. Various sizes of INVs coexist in carotid plaques pathologically, and we hypothesized that the size of INVs would be associated with carotid plaque histology, particularly in terms of intraplaque hemorrhage. Detection method of INV is important when determining whether carotid plaques are vulnerable, and contrast-enhanced ultrasonography (CEUS) is one of the most useful methods to detect them. The purpose of this study was to examine the relationship between findings from CEUS and vascular pathology obtained by carotid endarterectomy (CEA). We focused on associations between small and large INVs evaluated by CEUS and histologically defined intraplaque hemorrhage. METHODS: Participants comprised 115 patients (mean age, 73.0 ± 7.2 years; 96 men) who underwent preoperative CEUS and underwent CEA. CEUS findings were evaluated as vascular grade at 0 min (Vas-G0) and 10 min (Vas-G10) after contrast injection. Plaques were histologically evaluated quantitatively for the total area of intraplaque hemorrhage, cholesterol, and calcification and the thinnest fibrous cap. Immunohistochemical studies were conducted using anti-CD-34 antibody as a marker for endothelial cells. INVs were divided into two groups depending on diameter: small INVs, <50 µm; and large INVs, ≥50 µm. The numbers of small and large blood vessels in the plaque were quantified histologically. Associations of small and large INVs with CEUS, plaque histology, and clinical findings were assessed by uni- and multivariable analyses. RESULTS: Multivariable analyses indicated that CEUS Vas-G0 was associated with the 4th quartile of the number of small INVs compared with other quartiles, and Vas-G10 was associated with the 4th quartile of the number of large INVs. Histologically, the presence and area of intraplaque hemorrhage were associated with the number of small INVs, while the increased number of large INVs was associated with infrequent plaque disruption and thicker fibrous cap. CONCLUSIONS: Our study showed that early phase enhancement in the CEUS can help identify plaque vulnerability by predicting a larger number of small INVs. This information can also help determine treatment strategies for carotid plaque.

Detection and Differentiation of Dural Arteriovenous Fistulas in the Transverse Sinus/Sigmoid Sinus and Cavernous Sinus Using Carotid Ultrasound: Importance of Evaluation of the Occipital Artery.

OBJECTIVES: Dural arteriovenous fistula (DAVFs) in the transverse sinus (TS)/sigmoid sinus (SS) and cavernous sinus (CS) are observed frequently in the clinic. This study aimed to detect DAVFs with ultrasound and compare carotid ultrasound findings between these conditions. METHODS: We retrospectively reviewed 26 patients with either a TS/SS DAVF or a CS DAVF who were admitted to our hospital for evaluation of DAVFs from 2014 to 2018. The shunt site decision was made by neuroendovascular experts, whereas carotid ultrasound examinations were performed by ultrasound specialists. The flow velocity of the ipsilateral external carotid artery was reviewed in all 26 patients, whereas that of the occipital artery (OA) was examined in 20 patients. Blood flow velocities were compared between the TS/SS DAVF and CS DAVF groups. RESULTS: The study included 18 patients with a TS/SS DAVF (11 women and 7 men; mean age ± SD, 65.3 ± 18.6 years) and 8 patients with a CS DAVF (7 women and 1 man; mean age, 70.4 ± 9.3 years). Evaluations of feeder arteries on cerebral angiography showed that all patients had dural branches from the internal carotid and middle meningeal arteries as feeders of CS DAVFs, whereas the OA was the major feeder source of all TS/SS DAVF cases. The end-diastolic velocity (EDV) of the external carotid artery was significantly higher in patients with a TS/SS DAVF compared with those with a CS DAVF (P = .004). The EDV of the OA was significantly elevated in TS/SS DAVF cases compared with CS DAVF cases (P < .001). CONCLUSIONS: Duplex ultrasound parameters are significantly different between patients with TS/SS and CS DAVFs. An increased EDV of the OA can predict the presence of a TS/SS DAVF.

Co-precipitation molecules hemopexin and transferrin may be key molecules for fibrillogenesis in TTR V30M amyloidogenesis.

The disease model of familial amyloidotic polyneuropathy-7.2-hMet30 mice-manifests amyloid deposition that consists of a human amyloidogenic mutant transthyretin (TTR) (TTR V30M). Our previous study found amyloid deposits in 14 of 27 7.2-hMet30 mice at 21-24 months of age. In addition, non-fibrillar TTR deposits were found in amyloid-negative 7.2hMet30 mice. These results suggested that TTR amyloidogenesis required not only mutant TTR but also an additional factor (or factors) as an etiologic molecule. To determine the differences in serum proteome in amyloid-positive and amyloid-negative mice in the 7.2-hMet30 model, we used proteomic analyses and studied serum samples obtained from these mice. Hemopexin (HPX) and transferrin (Tf) were detected in the serum samples from amyloid-positive mice and were also found in amyloid deposits via immunohistochemistry, but serum samples from amyloid-negative mice did not contain HPX and Tf. These two proteins were also not detected in non-fibrillar TTR deposits. In addition, in silico analyses suggested that HPX and Tf facilitate destabilization of TTR secondary structures and misfolding of TTR. These results suggest that HPX and Tf may be associated with TTR amyloidogenesis after fibrillogenesis in vivo.

Intra-Plaque Vessels on Contrast-Enhanced Ultrasound Sonography Predict Carotid Plaque Histology.

BACKGROUND AND PURPOSE: Although the echogenicity of carotid plaques on carotid enhanced ultrasound (CEUS) was reported to correlate with the historological density of intra-plaque neovessels, it is unclear whether the intra-plaque vessel size is associated with carotid plaque vulnerability. We evaluated the relationship of size of intra-plaque vessels on CEUS with carotid plaque histology. METHODS: We prospectively registered patients with carotid stenosis who were hospitalized to receive carotid endarterectomy between 2012 and 2016. CEUS was performed by ultrasound specialists using a 7-MHz linear transducer (GE LOGIQ7; GE Healthcare, Milwaukee, WN, USA). Sonazoid® was used for conducting CEUS. The sizes of microbubbles inside the plaques were scored at 0, 1, 3, and 5 min after the injection of contrast agent, and were categorized according to our defined vascular score (Vas-S; 0: the effect of contrast was not recognized; 1: the microbubbles were visible, but so blurred and vague that their shape could not be recognized; 2: dot or string-like microbubbles with movement, localized in part or the whole site of the plaque). At histological examination, we simplified the modified American Heart Association classification and defined as an atherosclerotic category (Ath-cat; 1: unruptured plaque; 2: ruptured plaque; 3: healed plaque). We then assessed the correlation of Vas-S with Ath-cat, which describes the process of rupture and restoration of carotid plaques. RESULTS: A total of 97 patients were included in this study. A higher Ath-cat was significantly associated with higher Vas-S at any time. Spearman signed-rank test indicated that Vas-S at 1 min was most strongly correlated with Ath-cat (ρ = 0.43, p = 0.001). Receiver operating curve analysis indicated that a Vas-S of 0 at 1 min was significantly associated with an unruptured plaque (area under curve [AUC] 0.72, p = 0.006), while a Vas-S of 2 at 1 min was significantly associated with a healed plaque (AUC 0.72, p = 0.001). CONCLUSION: Vas-S values of 0 and 2 at 1 min indicated unruptured and healed plaques respectively. Thus, a Vas-S of 1 at 1 min is an indicator of a ruptured plaque. The intra-plaque vessel size on CEUS was significantly associated with carotid plaque histology, and may predict the process of plaque rupture and restoration.

Clinical course of the bony lesion of single-system single-site Langerhans cell histiocytosis - Is appropriate follow-up sufficient treatment?

BACKGROUND: Langerhans cell histiocytosis (LCH) is categorized into three types, which include single-system single-site (SS-s), single-system multiple-site (SS-m) and multisystem (MS). The most commonly affected site in LCH is bone, and the bony lesion of SS-s LCH has a good prognosis. The bony lesion of SS-s LCH has been thought to regress spontaneously. Although treatments such as curettage, direct injection of corticosteroids, and chemotherapy have been performed, regular follow-up is the first line of treatment for the bony lesion of SS-s LCH. For preventing orthopedic sequelae, strict and appropriate follow-up should be performed, but the appropriate period and method of follow-up has not yet been established. METHODS: In the present study, we retrospectively analyzed a series of 7 cases of patients with SS-s LCH with a bony lesion treated in the Department of Orthopedic Surgery at Kagoshima University Hospital (Kagoshima, Japan) from 2006 to 2015. RESULTS: The bony lesion regressed spontaneously in all patients. Factors such as location, size, preoperative C-reactive protein (CRP) value, standardized uptake (SUV) value of positron emission tomography (PET), age, sex and direct steroid injection were not related to the clinical course. Temporary expansion of the lesion occurred in 3 patients and a temporary worsening of pain occurred in 1 patient during the follow-up period. These events occurred within 6 weeks after biopsy. CONCLUSION: Careful follow-up and the use of an appropriate orthosis can lead to a good clinical course for the bony lesion of SS-s LCH. Future research should seek to determine the appropriate follow-up period.

Evaluation of the Time-Dependent Changes and the Vulnerability of Carotid Plaques Using Contrast-Enhanced Carotid Ultrasonography.

BACKGROUND: The association of carotid plaque enhancement on contrast-enhanced carotid ultrasound (CEUS) and plaque vulnerability evaluated by magnetic resonance imaging (MRI) was to be determined. MATERIALS AND METHODS: The 103 patients underwent CEUS from May 2013 until June 2016. CEUS images of the carotid plaque were obtained offline. Plaque images obtained at 1, 3, 5, and 10 minutes were compared with the reference image, defined as the image obtained at 0 minute. Plaque brightness was assessed using the gray-scale median during contrast enhancement (GSM-C). Plaque vulnerability was evaluated using T1- and T2-weighted MRI and Volume ISotropic TSE Acquisition (VISTA), with a VISTA cutoff value for the plaque muscle ratio (PMR) of 1.5. Time-dependent changes in the GSM-C were evaluated, and those between 0 and 1 minute were compared with the PMR values determined on MRI. FINDINGS: GSM-C decreased significantly over time, from 32.0 at 0 minute to 28.0 at 1 minute, 25.0 at 3 minutes, and 19.0 at 10 minutes. The greater the increase in the changes in the GSM-C from 0 to 1 minute, the more significant the association with a PMR higher than the median on T1 (GSM-C: 0 minute: 29.0, 1 minute: 24.0, P = .015), a PMR less than or equal to the median on T2 (0 min: 35.0, 1 min: 28.0, P = .003), and a PMR more than 1.5 determined on VISTA (GSM-C: 0 minute: 29.0, 1 minute: 24.0, P = .005). CONCLUSIONS: Early changes in the GSM-C evaluated with CEUS indicate significant plaque vulnerability on MRI.

Incidence, risk factors, and dose-volume relationship of radiation-induced rib fracture after carbon ion radiotherapy for lung cancer.

BACKGROUND: The purpose of this study was to assess the incidence, risk factors, and dose-volume relationship of radiation-induced rib fracture (RIRF) after carbon ion radiotherapy for lung cancer. MATERIAL AND METHODS: Fifty-seven ribs of 18 patients with peripheral stage I non-small cell lung cancer treated with carbon ion radiotherapy were analyzed on rib fracture. The patients were treated at a total dose of 52.8 Gy [relative biologic effectiveness (RBE)] or 60.0 Gy (RBE) in 4 fractions and were followed at least six months. Patient characteristics and dosimetric parameters were analyzed for associations with RIRF. RESULTS: Eighteen patients and 57 ribs were included in this study. The median length of follow-up was 36.5 months. RIRF was observed in seven (39%) of the 18 patients, and in 11 (19%) of 57 ribs. Only one patient developed symptomatic fracture. The distance from the ribs to the tumor site was significantly shorter in fractured ribs than in non-fractured ribs (1.4 ± 0.3 cm vs. 2.5 ± 0.3 cm). Receiver operating characteristic curve analysis showed that [Formula: see text] as a cut-off value for discriminating RIRF had the largest area under the curve (AUC =0.78). Comparison of the two-year cumulative incidence of RIRF among two groups as determined by cut-off values, yielded the following result: 53% vs. 4% [[Formula: see text], ≥ 38.2 Gy (RBE) or less]. Results from the two groups were significantly different (p < 0.05). CONCLUSION: The crude incidence of RIRF after carbon ion radiotherapy was 39% but incidence of symptomatic fracture was low. The [Formula: see text] as cut-off values may be helpful for discriminating the risk of RIRF.

Giant Cell Tumor of the Distal Phalanx of the Fourth Toe: A Case Report.

Giant cell tumor of the bone is a benign, but locally aggressive, primary bone tumor of unknown origin. It most commonly occurs in the long bones and is only rarely found in the phalangeal bones, such as the distal phalanx of the foot. In our review of English-language published studies, only 4 other cases of giant cell tumor involving the distal phalangeal bone of the foot had been reported to date. We report a case of giant cell tumor arising in the distal phalanx of the fourth toe in a 28-year-old female. Although bisphosphonate therapy was administered, the tumor showed highly aggressive behavior with ulceration of the overlying skin, and the patient underwent phalangeal amputation 1.5 months after diagnosis.

Differentiation of lipoma and atypical lipomatous tumor by a scoring system: implication of increased vascularity on pathogenesis of liposarcoma.

BACKGROUND: Well-differentiated liposarcoma (WDL)/atypical lipomatous tumor (ALT) is considered a low-grade malignancy that rarely metastasizes but should be carefully followed because recurrence or dedifferentiation may occur. It is recognized that WDL and ALT are essentially synonymous, describing lesions that are identical both morphologically and karyotypically, and that site-specific variations in behavior relate only to surgical resectability. Preoperative differential diagnosis between lipoma and ALT has been well studied because their clinical and image characteristics are very similar. We evaluated the factors that may differentiate ALTs from lipomas, and validated a tentative scoring system for the diagnosis of the 2 tumor types. METHODS: Forty-eight lipomas and 12 ALTs were included. The mean age, location and depth of the tumor as well as the compartment were not significantly different between the 2 groups. To evaluate the vascularity of the tumors, the average number of intratumoral vessels on pathological sections was calculated and compared between cases of lipoma and ALT. RESULTS: The tumor size was significantly larger in ALT cases than in lipoma cases (P < 0.001). Magnetic resonance imaging (MRI) revealed septal structures in 91.6% of ALTs, whereas 20.8% of lipomas showed septa. Contrast enhancement in MRI was found significantly more often in ALTs (81.2%) than in lipomas (18.8%) (P < 0.001). We created a "ALT score" to discriminate between lipoma and ALT (0-6 points). ALT cases gave significantly higher point values (average 5.1 points) than lipoma cases (average 1.7 points) (P < 0.001). We found a significantly increased number of vessels in cases of ALT than in cases of lipoma (P = 0.001). CONCLUSIONS: Our ALT score may help surgeons to differentiate a suspected ALT from a lipoma and could recommend a marginal resection in cases of suspected ALT. Increased intratumoral vascularity in ALT is reflected in the MRI findings and may play a key role in the acquisition of a malignant phenotype in adipocytic tumors.

Giant cell tumor of the clavicle: report of a case in a rare location with consideration of surgical method.

BACKGROUND: Most bone tumors that occur in the clavicle are malignant. A few giant cell tumors (GCTs) of the clavicle have been reported; however, the most appropriate operative method for this tumor has never been discussed. CASE PRESENTATION: A 54-year-old man noticed enlargement of the proximal aspect of the right clavicle. A plain X-ray revealed lytic change and ballooning of the proximal end of the right clavicle. The tumor was isointense on T1-weighted magnetic resonance images and showed a mixture of low- and high-intensity areas on T2-weighted images without extension to the surrounding soft tissues. Bone scintigraphy showed strong accumulation (normal/tumor ratio, 2.31), and positron emission tomography revealed strong uptake of fluorine-18-2-fluoro-2-deoxy-d-glucose (SUVmax, 6.0) in the proximal part of the right clavicle. Because we could not completely exclude malignancy, an open biopsy was performed. Pathologically, the tumor comprised mononuclear stromal cells and multinuclear giant cells, resulting in a diagnosis of a GCT of the bone. Although curettage may be considered for such lesions (Campanacci grade II), we chose resection to minimize the chance of recurrence. The tumor was resected en-bloc with the proximal half of the clavicle. No postoperative shoulder disproportion was observed, and full range of motion of the right shoulder was maintained. The patient was satisfied with the surgical outcome (Musculoskeletal Tumor Society score of 96 %). He returned to his original job as a land and house investigator without any signs of recurrence for 1 year after surgery. CONCLUSIONS: Although GCT of the bone rarely occurs in the clavicle, the typical X-ray findings demonstrated in the present case are helpful for a correct diagnosis. Although en-bloc resection without reconstruction is appropriate for GCTs in expendable bones, there has been much discussion about shoulder function after total claviculectomy. Considering the importance of the function of the clavicle, which is to support the scapula through the acromioclavicular joint, we preserved the muscle attachments of the deltoid, trapezius, and pectoralis major. Because both the oncological and functional outcomes were satisfactory, we recommend preservation of as much of the clavicle as possible in patients with clavicular bone tumors.

Doppler ultrasound for diagnosis of soft tissue sarcoma: efficacy of ultrasound-based screening score.

BACKGROUND: The utility of ultrasound imaging in the screening of soft-part tumours (SPTs) has been reported. We classified SPTs according to their blood flow pattern on Doppler ultrasound and re-evaluated the efficacy of this imaging modality as a screening method. Additionally, we combined Doppler ultrasound with several values to improve the diagnostic efficacy and to establish a new diagnostic tool. PATIENTS AND METHODS: This study included 189 cases of pathologically confirmed SPTs (122 cases of benign disease including SPTs and tumour-like lesions and 67 cases of malignant SPTs). Ultrasound imaging included evaluation of vascularity by colour Doppler. We established a scoring system to more effectively differentiate malignant from benign SPTs (ultrasound-based sarcoma screening [USS] score). RESULTS: The mean scores in the benign and malignant groups were 1.47 ± 0.93 and 3.42 ± 1.30, respectively. Patients with malignant masses showed significantly higher USS scores than did those with benign masses (p < 1 × 10(-10)). The area under the curve was 0.88 by receiver operating characteristic (ROC) analysis. Based on the cut-off value (3 points) calculated by ROC curve analysis, the sensitivity and specificity for a diagnosis of malignant SPT was 85.1% and 86.9%, respectively. CONCLUSIONS: Assessment of vascularity by Doppler ultrasound alone is insufficient for differentiation between benign and malignant SPTs. Preoperative diagnosis of most SPTs is possible by combining our USS score with characteristic clinical and magnetic resonance imaging findings.

Metastasis of osteosarcoma to the trapezius muscle: a case report.

Metastasis of a primary osteosarcoma to the muscles is extremely rare. As there have been few reported cases, the necessity of surgical treatment for such metastatic lesions remains controversial. We present the case of a primary osteosarcoma with development of a solitary metastasis to the trapezius muscle during chemotherapy for pulmonary metastasis. The patient was a 51-year-old man diagnosed with osteosarcoma of the right tibia. After undergoing chemotherapy and femoral amputation, he developed pulmonary metastasis. Chemotherapy was reinitiated, however, after approximately 1 year a palpable tumor was identified in the patient's right shoulder. This tumor grew and was associated with pain in the right shoulder. It was surgically removed 3 years after the re-initiation of chemotherapy. The pathological diagnosis was osteosarcoma with metastasis to the trapezius muscle. Although the patient died of respiratory failure due to pulmonary metastasis 14 months after resection of the metastatic lesion in the trapezius muscle, no new extrapulmonary metastasis was observed after the resection.

[Carotid Ultrasound].

Carotid ultrasound is used to noninvasively assess the structure of the carotid wall as well as flow velocity of the common carotid, internal carotid, and vertebral arteries. The intima-media thickness and carotid plaque evaluated by carotid ultrasound enables us to assess the degree of patients' atherosclerotic change. They have been reported to be closely associated with atherosclerotic risk factors and future cardiovascular events. Furthermore, carotid ultrasound allows us to evaluate large artery atherosclerosis and its flow velocity, which provides information on the cause of acute ischemic stroke. Regarding the comparison of ultrasound findings of carotid plaque with its pathology, plaque with calcification shows the highest echogenicity, with fibrous carotid plaque showing the second highest. On the other hand, atheromatous plaque and that with hemorrhage in it show the lowest echogenicity, indicating the vulnerability of plaques. Furthermore, carotid plaque with ulceration or mobility leads to the occurrence of ischemic stroke.

Three-dimensional and multienergy gamma-ray simultaneous imaging by using a Si/CdTe Compton camera.

PURPOSE: To develop a silicon (Si) and cadmium telluride (CdTe) imaging Compton camera for biomedical application on the basis of technologies used for astrophysical observation and to test its capacity to perform three-dimensional (3D) imaging. MATERIALS AND METHODS: All animal experiments were performed according to the Animal Care and Experimentation Committee (Gunma University, Maebashi, Japan). Flourine 18 fluorodeoxyglucose (FDG), iodine 131 ((131)I) methylnorcholestenol, and gallium 67 ((67)Ga) citrate, separately compacted into micro tubes, were inserted subcutaneously into a Wistar rat, and the distribution of the radioisotope compounds was determined with 3D imaging by using the Compton camera after the rat was sacrificed (ex vivo model). In a separate experiment, indium 111((111)In) chloride and (131)I-methylnorcholestenol were injected into a rat intravenously, and copper 64 ((64)Cu) chloride was administered into the stomach orally just before imaging. The isotope distributions were determined with 3D imaging after sacrifice by means of the list-mode-expectation-maximizing-maximum-likelihood method. RESULTS: The Si/CdTe Compton camera demonstrated its 3D multinuclear imaging capability by separating out the distributions of FDG, (131)I-methylnorcholestenol, and (67)Ga-citrate clearly in a test-tube-implanted ex vivo model. In the more physiologic model with tail vein injection prior to sacrifice, the distributions of (131)I-methylnorcholestenol and (64)Cu-chloride were demonstrated with 3D imaging, and the difference in distribution of the two isotopes was successfully imaged although the accumulation on the image of (111)In-chloride was difficult to visualize because of blurring at the low-energy region. CONCLUSION: The Si/CdTe Compton camera clearly resolved the distribution of multiple isotopes in 3D imaging and simultaneously in the ex vivo model.

Patient-Derived Training Simulator for Image-Guided Adaptive Brachytherapy of Locally Advanced Cervical Cancers: Development and Initial Use.

Image-guided adaptive brachytherapy (IGABT) using intracavitary and interstitial (IC/IS) techniques plays a pivotal role in definitive radiotherapy for locally advanced cervical cancers. However, the training opportunities for interstitial needle application are limited, preventing this technique from becoming widespread. This study aimed to develop a training simulator for IC/IS brachytherapy. The simulator consists of a soft silicone tumor phantom and acrylic tube mimicking the vagina; it has high visibility because of translucent materials and is compatible with computed tomography (CT) and magnetic resonance imaging (MRI). A patient harboring a typical bulky and irregular-shaped cervical tumor was selected from 495 in-house IGABT-treated candidates, and a tumor phantom (68 × 49 × 45 mm) modeled on this patient was produced from three-dimensional real-scale measurements of the MRI-based high-risk clinical target volume at first brachytherapy. In trial use by two physicians with different levels of IGABT skills, a Fletcher-Suit Asian Pacific applicator, and a Venezia applicator with interstitial needles were nicely applied to the simulator, facilitating successful creation of CT-based treatment plans consistent with clinical practice. Thus, the training simulator can be useful for the training of IC/IS brachytherapy, and warrants further research employing a greater number of phantoms and practitioners to verify its educational value.

Implementation of a rapid response system at an isolated radiotherapy facility through simulation training.

A rapid response system is required in a radiotherapy department for patients experiencing a critical event when access to an emergency department is poor due to geographic location and the patient is immobilised with a fixation device. We, therefore, rebuilt the response system and tested it through onsite simulations. A multidisciplinary core group was created and onsite simulations were conducted using a Plan-Do-Study-Act cycle. We identified the important characteristics of our facility, including its distance from the emergency department; the presence of many staff with little direct contact with patients; the treatment room environment and patient fixation with radiotherapy equipment. We also examined processes in each phase of the emergency response: detecting an emergency, calling the medical emergency team (MET), MET transportation to the site and on-site response and patient transportation to the emergency department. The protocol was modified, and equipment was updated. On-site simulations were held with and without explanation of the protocol and training scenario in advance. The time for the MET to arrive at the site during a 2017 simulation prior to the present project was 7 min, whereas the time to arrive after the first simulation session was shortened to 5 min and was then shortened further to 4 min in the second session, despite no prior explanation of the situation. A multidisciplinary project for emergency response with on-site simulations was conducted at an isolated radiation facility. A carefully planned emergency response is important not only in heavy ion therapy facilities but also in other departments and facilities that do not have easy access to hospital emergency departments.

Single-cell genotyping of phytoplankton from ocean water by gel-based cell manipulation.

A comprehensive understanding of phytoplankton diversity is valuable for assessing an environment of interest as phytoplankton are primary producers in various aquatic food webs. Microscopic analyses are useful for diversity assessment based on characteristic cell morphologies. However, phylogenetic classification based solely on morphology requires an extremely high level of expertise. The genetic approach is another option for evaluating phytoplankton diversity; however, it cannot reveal morphological information. To integrate these two approaches, an original technology was developed, that is referred to as microcavity array (MCA)/gel-based cell manipulation (GCM). The model experiments using monocultures of various phytoplankton indicated that the efficiencies of cell recovery and isolation of single-cell plankton were dependent on cell size and shape. Cells with widths larger than the cavity width showed high level of recovery and isolation efficiency. Subsequent whole-genome amplification (WGA) of isolated single-cell plankton provided a sufficient amount (≈30 µg) of WGA products for genetic analyses. Furthermore, it is showed that MCA/GCM could directly analyze phytoplankton in ocean water obtained from Suruga Bay, Japan, without any cumbersome pretreatment. These results indicate that MCA/GCM technology is a powerful tool for elucidating the phytoplankton diversity in marine environment.

Relationship between oral mucositis and the oral bacterial count in patients with head and neck cancer undergoing carbon ion radiotherapy: A prospective study.

BACKGROUND AND PURPOSE: Acute adverse events, such as oral mucositis, can affect treatment success in patients undergoing head and neck radiotherapy. In this study, we aimed to identify the relationship between oral mucositis and oral bacterial counts during carbon ion radiotherapy (C-ion RT) in patients with head and neck cancer. MATERIALS AND METHODS: This prospective study included patients with head and neck tumors treated with C-ion RT between 2017 and 2019. C-ion RT consisted of treatment at 57.6, 64.0, or 70.4 Gy (relative biological effectiveness) in 16 fractions. Bacterial counts in the saliva and the back of the tongue were measured using a rapid oral bacteria quantification system. The relationship between the oral bacterial count and oral mucositis was subsequently analyzed. RESULTS: In total, 46 patients were included in the analysis. The bacterial count in the saliva gradually increased from the commencement of C-ion RT and peaked at 16 fractions. Bacterial counts at the back of the tongue were already high at the beginning of C-ion RT; however, they decreased with continued treatment, peaked at 16 fractions, and subsequently decreased again. Patients with bacterial counts exceeding the mean before C-ion RT (high-count group) did not experience more severe mucositis than those with counts below the mean (low-count group). However, patients in the high-count group tended to experience faster-onset mucositis and slower healing than those in the low-count group. CONCLUSION: Bacterial counts may aid in the development of clinical strategies for C-ion RT-induced oral mucositis.

Rectovaginal fistula in a cervical cancer patient treated with sequential radiotherapy and bevacizumab: A dose-volume analysis.

Bevacizumab is a monoclonal antibody against vascular endothelial growth factor that exerts antitumor effect by preventing tumor angiogenesis. Gastrointestinal fistula is a common side effect of bevacizumab in combination with radiotherapy. This case of rectovaginal fistula indicates that the side effect may be unpredictable by the conventional dose-volume parameters for the rectum.

Association of carotid ultrasonography with perioperative stroke after thoracic aortic aneurysm treatment: a retrospective study.

PURPOSE: The purpose of this study was to verify whether carotid ultrasonography (CUS) findings could be associated with the occurrence of perioperative stroke after thoracic aortic aneurysm (TAA) treatment. METHODS: Patients with TAAs who were treated by either total arch replacement or thoracic endovascular aortic repair (TEVAR) were retrospectively enrolled. Left subclavian artery (LSA) embolization and bypass surgery of the left common carotid artery (CCA) to the LSA before TEVAR were additionally performed for some patients. CUS was performed before TAA treatment to evaluate carotid atherosclerosis and flow velocities of bilateral cervical arteries. After dividing patients into those with and without perioperative stroke, their background, atherosclerotic risk factors, history of stroke, TAA location and size, treatment procedures, and CUS parameters were compared between the two groups. RESULTS: Of the 60 patients (18 women, 42 men; mean age 73.5 ± 10.2 years) with TAA, four (7.5%) developed perioperative stroke. There were no significant differences in the patients' characteristics and their TAAs between those with and without perioperative stroke. For the CUS parameters, end-diastolic velocity (EDV) of bilateral CCAs was significantly decreased in perioperative stroke patients (with vs without stroke; right: 9.2 ± 1.8 vs. 14.5 ± 4.6 cm/s, P = 0.025, left: 9.1 ± 0.3 vs. 15.0 ± 4.5 cm/s, P = 0.012), whereas the resistance index (RI) of bilateral CCAs was significantly elevated (right: 0.76 vs. 0.87, P = 0.008, left: 0.76 vs. 0.87, P < 0.001). CONCLUSIONS: Lower EDV and higher RI of bilateral CCAs were significantly associated with perioperative stroke after TAA treatment. Thus, CUS findings may help predict the occurrence of perioperative stroke.