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.

Idiopathic pneumoperitoneum diagnosed following high-energy motor vehicular trauma:a case report

Intra-abdominal free gas is a finding of extra-intestinal gas in the abdominal cavity on radiography or CT, mainly suggesting gastrointestinal perforation and necessitating emergency surgery. Idiopathic pneumoperitoneum is diagnosed when there is no obvious gastrointestinal perforation, but there is presence of free gas in the abdominal cavity with an unidentifiable cause. Herein, we report a case of idiopathic pneumoperitoneum secondary to high-energy trauma following a car rollover accident. A 95-year-old man was transferred to our clinic after a car-to-car rollover accident. He had abrasions on his right upper arm and left abdomen that appeared to be the result of the accident;however, no other apparent traumatic injuries were noted. There was no pain in the abdomen, and peritoneal irritation symptoms were also not noted. A CT scan showed fine free air. Although idiopathic pneumoperitoneum could not be ruled out, considering the patient's background and the possibility of traumatic small bowel perforation, emergency surgery was performed. A thorough search of the abdominal cavity was performed;however, the surgery was completed without an obvious perforation site. Idiopathic pneumoperitoneum should be considered as a differential disease in cases who have free air on abdominal CT but clinically lack obvious inflammatory reaction findings. J. Med. Invest. 69 : 155-157, February, 2022.

ASO Author Reflections: Impact of the Ratio of the Visceral Fat Area (VFA) to Psoas Muscle Area (PMA) (V/P Ratio) on Survival for Patients with Surgically Resected Esophageal Cancer

PAST: The true impact of co-occurring muscle mass reduction and fat accumulation on patients with surgically resected esophageal cancer (EC) remains controversial. PRESENT: The current study defined reduction in muscle mass and excess body adiposity as the ratio of the visceral fat area (VFA) to the psoas muscle area (V/P ratio) on the same axial computed tomography slice at the third lumbar vertebra (L3). A high V/P ratio was associated with greater age (p = 0.03), higher body mass index (BMI) (p < 0.001), larger VFA (p < 0.001), and increased age-adjusted Charlson comorbidity index (ACCI) (p = 0.005). Multivariate analysis showed a high V/P ratio to be an independent prognostic factor for poor overall survival (OS) of EC patients who underwent surgery (p = 0.003). The prognostic value of the V/P ratio still was significant for EC patients with a BMI lower than 25 kg/m2. FUTURE: A high V/P ratio was an independent prognostic factor for OS of EC patients who underwent surgery, even BMI-defined non-obese EC patients. The V/P ratio as a surrogate marker of relative muscle mass reduction and fat accumulation may have prognostic value for EC patients regardless of body composition differences.

Normal Tissue Complication Probability Model for Acute Radiation Dermatitis in Patients with Head and Neck Cancer Treated with Carbon Ion Radiotherapy

PURPOSE

This study aimed to explore the prognostic factors associated with acute radiation dermatitis (ARD). A normal tissue complication probability (NTCP) model for ARD in patients with head and neck cancer (HNC) treated with carbon ion radiotherapy (CIRT) was developed.

MATERIALS AND METHODS

A total of 187 patients were included in the analysis, and the endpoint was ≥grade 2 ARD. The biological and physical dose-surface parameters associated with ARD were used in the logistic regression model. The mean areas under the receiver operating characteristic curve (AUC) in the internal cross-validation and Akaike's corrected Information Criterion (AICc) were examined for model evaluation and selection. The multivariate logistic regression NTCP models were established based on factors with weak correlation.

RESULTS

Tumour volume, planning target volume to the skin, radiation technique and all dose-surface parameters were significantly associated with ARD (P < 0.05). Models with high performance for grade 2-3 ARD were constructed. The most significant prognostic predictors were S_{40 Gy (relative biological effectiveness, RBE)} and S_{20 Gy} [absolute surface area receiving RBE-weighted dose of 40 Gy (RBE) or physical dose of 20 Gy]. The internal cross-validation-based AUCs for models with S_{40 Gy (RBE)} and S_{20 Gy} were 0.78 and 0.77, respectively. The biological and physical dose-surface parameters had similar performance at various dose levels. However, the performance of the multivariate NTCP models based on two factors was not better than that of the univariate models.

CONCLUSIONS

NTCP models for ARD may provide a basis for the development of individualised treatment strategies and reduce the incidence of severe ARD in patients with HNC receiving CIRT. Furthermore, biological and physical dose-surface parameter-based models are comparable. However, further validation with more evaluation parameters is warranted.

Impact of the Ratio of Visceral Fat Area (VFA) to Psoas Muscle Area (PMA) (V/P Ratio) on Survival for Surgically Resected Esophageal Cancer

BACKGROUND

The synergic effects of muscle mass reduction with excess body adiposity in surgically resected esophageal cancer (EC) patients remains controversial, especially in non-obese patients.

METHODS

One hundred and six patients with EC who underwent surgery between 2006 and 2014 were included in this study. Reduction in muscle mass and excess body adiposity were defined as the ratio of visceral fat area (VFA) to psoas muscle area (PMA) (V/P ratio) on the same axial computed tomography (CT) slice at the third lumbar vertebra (L3).

RESULTS

A high V/P ratio was associated with greater age (p = 0.03), higher body mass index (BMI) (p < 0.001), higher VFA (p < 0.001), and increased age-adjusted Charlson comorbidity index (ACCI) (p = 0.005). Multivariate analysis revealed a high V/P ratio to be an independent prognostic factor for poor overall survival (OS) in EC patients who underwent surgery (p = 0.003). The prognostic value of the V/P ratio was still significant in EC patients with a BMI < 25.

CONCLUSIONS

A high V/P ratio was associated with poor survival in surgically resected EC patients, even in non-obese patients. The V/P ratio as a surrogate marker of relative muscle mass reduction and fat accumulation may have prognostic value in EC patients regardless of body composition differences.

Experimental investigation of supertransmission for an intrinsic localized mode in a cyclic nonlinear transmission line

In this experimental study of the nonlinear loss mechanism between traveling localized excitation and the underlying extended normal mode spectrum for a 1D lattice, three types of cyclic, electric, nonlinear transmission lines (NLTLs) are used. They are nonlinear capacitive, inductive, and capacitive+inductive NLTLs. To maintain a robust, steady-state traveling intrinsic localized mode (ILM), a traveling wave driver is used. The ILM loses energy because of a resonance between it and the extended NLTL modes. A wake field excitation is detected directly from ILM velocity experiments by the decrease in ILM speed and by the observation of the wake. Its properties are quantified via a two-dimensional Fourier map in the frequency-wavenumber domain, determined from the measured spatial-time voltage pattern. Simulations support and extend these experimental findings. We find for the capacitive+inductive NLTL configuration, when the two nonlinear terms are theoretically balanced, the wake excitation is calculated to become very small, giving rise to supertransmission over an extended driving frequency range.

A case of spontaneous esophageal submucosal hematoma

A 78-year-old man visited a nearby hospital owing to chest pain triggered by vomiting. As computed tomography revealed suspected esophageal perforation, he was referred to our hospital. Upper gastrointestinal endoscopy showed blood coagula extending from the middle intra-thoracic to the esophago-cardiac junction (ECJ), and it was diagnosed as an esophageal submucosal hematoma. Conservative therapy was initiated by fasting and discontinuing oral anticoagulants. The lesion was monitored by upper gastrointestinal endoscopy. On day 12 of the symptom appearance, the hematoma had completely disappeared and on day 22, the patient was discharged from the hospital. In most cases, esophageal submucosal hematoma has a favorable course with preservative treatment. Esophageal submucosal hematoma should be considered as one of the differential diagnoses for chest pain triggered by vomiting.

Cytoplasmic localization of connexin 26 suppresses transition of β‐catenin into the nucleus in intestinal‐ and mix‐type gastric cancer

Background

Methods

Results

Conclusions

Salvage thoracoscopic esophagectomy after carbon-ion radiotherapy in a patient with esophageal squamous cell carcinoma: a case report

Background

Carbon-ion radiotherapy (CIRT) for esophageal cancer has been receiving significant attention given its high local control rates and minimal damage to normal tissues. However, the efficacy and safety of salvage surgery after CIRT for esophageal cancer remain unclear. We report the case of a patient who underwent salvage thoracoscopic surgery after CIRT.

Case presentation

A 51-year-old woman underwent upper gastrointestinal endoscopy and a type 0-IIa + 0-IIc esophageal squamous cell carcinoma located 27–29 cm from the patient’s incisors, classified as clinical stage I (T1bN0M0), was detected. She received CIRT (50.4 Gy [relative biological effectiveness, RBE]/12 fr) for localized esophageal cancer and achieved complete remission after 4 months. Six years after CIRT, follow-up endoscopic examination demonstrated a type 0-IIa + 0-IIc tumor in the previously treated area. In addition, a type 0-IIa lesion located 20–22 cm from the incisors was found. We diagnosed localized ESCC, classified as clinical stage I (T1bN0M0). Salvage thoracoscopic surgery was performed in the prone position with five access ports. Although the esophagus tightly adhered to the thoracic descending aorta and left main bronchus with severe fibrosis, the esophagus could be separated from the surrounding organs with careful forceps manipulation. The operation time and blood loss were 8 h 45 min and 253 mL, respectively. The patient was discharged from our hospital 17 days after the salvage surgery without any complications. Pathological findings revealed two squamous cell carcinomas. Both tumors were localized in the lamina propria mucosa, and lymph node metastasis was not detected. The tumors were diagnosed as pathological stage IA (pT1aN0M0) according to the TNM criteria. Moreover, pathological examinations showed severe fibrosis of the previously irradiated tissues compared to the normal esophagus located outside of the irradiation field. Following the surgery, the patient had no recurrence for 1 year and 6 months.

Conclusions

Thoracoscopic radical esophagectomy can be performed as salvage surgery. Careful and discreet surgery is integral to perform salvage surgery after CIRT since CIRT may cause severe adhesions and fibrosis in the irradiated field.

Integrated anatomical practice combining cadaver dissection and matched cadaver CT data processing and analysis

PURPOSE

With the increasing significance of diagnostic imaging in clinical practice, long-term anatomical education and training is required to ensure that students can reliably distinguish anatomical structures and interpret images. To improve students' motivation and prospects for learning imaging anatomy, we developed an integrated anatomical practice program combining cadaveric dissection with cadaver CT data processing and analysis during undergraduate students' dissection courses.

METHODS

Workstations imported with post-mortem CT data of dissected cadavers and various forms of clinical CT/MRI data were set in the dissection room. Medical students had free access to the imaging data during cadaver dissection, and they were challenged to process and analyze the data for submission of voluntary imaging reports on their topics of interest. Finally, we surveyed the integrated anatomical education of 481 medical students.

RESULTS

The positive response rate to the integrated anatomical practice was 74.9%, and 79.4% of the students answered that this form of practice offered a suitable introduction to anatomical imaging. The usefulness of this approach in understanding the 2- to 3D arrangement of the human body and enhancing interest in anatomy was also confirmed. The submission rate of voluntary imaging reports also increased annually and is currently 97.4%.

CONCLUSION

Our integrated anatomical practice only allowed students to actively browse CT images and facilitated imaging processing and analysis of their region of interest. This practice may improve students' long-term ability to analyze images and deepen their understanding. A competitive imaging contest may help improve students' motivation when they begin learning imaging anatomy.

Coexistence of superficial carcinogenesis of resident epithelium besides neuroendocrine neoplasm of the digestive tract

Background & Aims

Mixed neuroendocrine–non‐neuroendocrine neoplasm (MiNEN) is a rare neuroendocrine neoplasm (NEN) comprising dual neuroendocrine and non‐neuroendocrine components. Although the coexistence pattern of neuroendocrine and non‐neuroendocrine components in definitive MiNEN is thought to overlap, there may be a coexistent pattern of both components, such as superficial carcinoma adjacent to NEN. The present study evaluated the histopathological findings of the coexistence pattern of superficial carcinomas adjacent to NENs in the esophagogastrointestinal tract.

Methods

From 2000 to 2019, 35 serial NEN resections of the esophagus (n = 9), stomach (n = 3), and large intestine (n = 23), respectively, were performed at Gunma University Hospital. Borderline areas between NEN and resident superficial epithelium were observed in the 35 serial NEN cases as well as two additional cases from affiliated hospitals.

Results

Among the 35 serial NEN samples, squamous cell carcinomatous/dysplastic components were identified 77.8% (7/9 cases) of esophageal NENs, and adenocarcinomatous areas were seen in 66.7% (2/3 cases) of gastric NENs and 26% (6/23 cases) of colorectal NENs. Thus, all superficial carcinomatous components adjacent to NENs were observed as squamous cell carcinoma/dysplasia in esophagus and adenocarcinoma in stomach and large intestine, which showed histological characteristics as the resident epithelial pattern in each organ.

Conclusions

These findings suggested a potential “paratransformation” or “bystander effect” in resident epithelium by NENs. Thus, “bystander carcinogenesis” could be a pathogenic mechanism of resident epithelium transformation adjacent to NENs in the esophagogastrointestinal tract.

Safety verification of carbon-ion radiotherapy for patients with cardiac implantable electronic devices (CIEDs)

According to guidelines, carbon-ion beam therapy is considered to carry a high safety risk for patients with cardiac implantable electronic devices (CIEDs), although the actual impacts remain unclear. In this study, we investigated the safety of carbon-ion beam therapy in patients with CIEDs. Patients with CIEDs who underwent carbon-ion therapy at Gunma University Heavy Ion Medical Center between June 2010 and December 2019 were identified and investigated for abnormalities in the operation of their CIEDs, such as oversensing and resetting during irradiation, and abnormalities in operation after treatment. In addition, the risk of irradiation from carbon-ion beam therapy was evaluated by model simulations. Twenty patients (22 sites) with CIEDs were identified, 19 with pacemakers and one with an implantable cardioverter-defibrillator (ICD). Treatments were completed without any problems, except for one case in which the treatment was discontinued because of worsening of the primary disease. Monte Carlo simulation indicated that the carbon beam irradiation produced neutrons at a constant and high level in the irradiation field. Nevertheless, with the distances between the CIEDs and the irradiation fields in the analyzed cases, the quantity of neutrons at the CIEDs was lower than that within the irradiation. Although carbon-ion beam therapy can be safely administered to patients with CIEDs, it is advisable to perform the therapy with sufficient preparation and backup devices because of the risks involved.

Computed tomographic features of portal vein thrombosis in two cats with splenosystemic shunts

Two spayed female cats presented with hepatic encephalopathy due to hyperammonaemia. On abdominal ultrasound, concurrent portal vein thrombosis and splenosystemic shunts were suspected in both cats. Computed tomographic angiography clearly detected thrombi as non-contrast enhancing intraluminal structures in the main portal vein of both cats. Additionally, splenorenal shunts were revealed in both cats. Follow-up computed tomographic angiography for portal vein thrombosis was performed in both cats, only one of whom received anticoagulant therapy. In the untreated cat, portal vein thrombosis had progressed with the development of an aberrant tortuous vessel. In the cat treated with low-molecular-weight heparin, the thrombus progressively decreased in size and disappeared on follow-up diagnostic imaging. Computed tomographic angiography might be useful for the diagnosis and follow-up of portal vein thrombosis in cats.

Clinical features as potential prognostic factors in patients treated with nivolumab for highly pretreated metastatic gastric cancer: a multicenter retrospective study

BACKGROUND

Although nivolumab (anti-programmed cell death-1 antibody) is a promising approach for advanced gastric cancer (AGC), the response rate remains limited. The aim of this multicenter retrospective study was to determine if clinical features could serve as prognostic factors of the efficacy of nivolumab in patients with AGC.

METHODS

Fifty-eight patients with AGC who were treated with nivolumab as a third or later line from October 2017 to December 2018 at any of five clinical sites were enrolled in the study. The correlation between the best overall response and clinical features was investigated. Overall survival and progression-free survival after initiation of nivolumab were calculated and clinical features that could be predictors of the prognosis were sought.

RESULTS

The disease control rate (DCR) for nivolumab was 36.2% and was significantly correlated with performance status (p = 0.021), metastasis to one organ (p = 0.006), and grade 2 or higher immune-related adverse events (p = 0.027). There was also a significant association between response to nivolumab and ability to receive subsequent chemotherapy (p = 0.022). In the analysis of overall survival, the following variables were identified as being significantly associated with a poor outcome: Eastern Cooperative Oncology Group performance status ≥1, prior treatment with trastuzumab, no immune-related adverse events, lack of a response to nivolumab, and inability to receive subsequent chemotherapy.

CONCLUSION

The findings of this study suggest that nivolumab may be ineffective for AGC in patients with poor performance status and those with a history of treatment with trastuzumab.

The potential for reducing alcohol consumption to prevent esophageal cancer morbidity in Asian heavy drinkers: a systematic review and meta-analysis

Alcohol consumption is a major risk factor for esophageal cancer. In Asia, heavy drinkers are considered to have a higher risk of esophageal cancer than nondrinkers and light drinkers. However, no study has shown an association between alcohol reduction and the morbidity of esophageal cancer in Asian heavy drinkers. Therefore, this study investigated the significance of reducing alcohol consumption to prevent esophageal cancer in Asian heavy drinkers by conducting a systematic review and meta-analysis. The MEDLINE (PubMed) and ICHUSHI (Japana Centra Revuo Medicina) databases were searched from January 1995 to December 2020. The hazard ratio (HR) and 95% confidence interval (CI) were calculated using a random-effects model. I² statistics were used to detect heterogeneity. This study included 21 articles in the qualitative synthesis. Light drinkers and heavy drinkers were categorized based on alcohol consumption amount as ≤ 25 ethanol g/day and ≥ 66 ethanol g/day, respectively, as described in many previous studies, and five cohort studies were eligible for this meta-analysis. The HR of esophageal cancer among heavy drinkers versus nondrinkers was 4.18 (95% CI 2.34-7.47, I² = 74%). On the other hand, the HR of esophageal cancer among light drinkers was 1.82 compared with nondrinkers (95% CI 1.57-2.10, I² = 0%). Heavy drinkers have a higher esophageal cancer incidence than light drinkers and nondrinker. It is possible that alcohol reduction may decrease the risk of esophageal cancer in Asian heavy drinkers.

Current status of surgical treatment of Boerhaave's syndrome

BACKGROUND

Surgical treatment is usually required for Boerhaave's syndrome (post-emetic esophageal perforation), and the technique should be chosen based on the local infection status and patient's general condition. This study was performed to examine the current status of surgical treatment of Boerhaave's syndrome in Japan.

METHODS

Ninety-five patients with Boerhaave's syndrome who underwent surgical treatment from January 2010 to December 2015, obtained from a national survey were retrospectively analyzed. The details of each surgical treatment and the type of treatment performed according to the patients' characteristics were examined.

RESULTS

Primary closure was performed in 75 (78.9%) patients, T-tube insertion in 15 (15.8%), and esophagectomy in 5 (5.3%). The length of the postoperative stay was significantly shorter in patients who underwent primary closure (p = 0.0011). Esophagectomy tended to be performed more often in patients with a long perforation and was performed significantly more often in patients with a high C-reactive protein concentration (p = 0.0118). The postoperative hospital stay was significantly longer in patients with leakage of the primary closure site (p < 0.0001). As a result, leakage of the primary closure site was significantly correlated with a long duration from symptom onset to patient presentation (p = 0.042), diagnostic imaging of the intrathoracic perforation (p = 0.013), and abscess formation in the mediastinal cavity (p = 0.006).

CONCLUSIONS

Selection of an appropriate surgical procedure may contribute to reduced mortality rates in patients with esophageal rupture. With regard to primary closure, it is necessary to understand that leaks are likely to occur in patients with a long duration from symptom onset to presentation or with severe intrathoracic/mediastinal inflammation, and to select an appropriate surgical procedure in consideration of the degree of invasiveness and QOL.

A Nationwide Survey on Digestive Reconstruction Following Pharyngolaryngectomy With Total Esophagectomy: A Multicenter Retrospective Study in Japan

AIM

Digestive reconstruction after pharyngolaryngectomy with total esophagectomy (PLTE) remains challenging, with the optimal method remaining unclear. The current study aimed to clarify the short-term outcomes after PLTE and determine the optimal digestive reconstruction method.

METHODS

Based on a nationwide survey of 151 patients who underwent PLTE, outcomes of digestive reconstruction methods are described.

RESULTS

Among digestive reconstruction methods, a simple gastric tube was most frequently used (37.1%), followed by gastric tube combined with free graft transfer (FGT) (35.1%), gastric tube with microvascular anastomosis (22.5%), and other procedures (5.3%). Intraoperative evaluation of microcirculation (IOEM) was utilized in 29 patients (19.2%). Among the included patients, 66.9% developed any-grade complications, 41.0% developed severe complications, and 23.8% developed digestive reconstruction-related complications (DRRCs; leakage or necrosis). Reoperation within 30 days for any complications and DRRCs was required in 13.9% and 8.6% of the patients, respectively. Mortality within 90 days was observed in 4.6%. Among the three major methods, gastric tube combined with FGT promoted the least DRRCs in the gastric tube (P = .005), although the overall incidence of DRRCs was comparable. The use of IOEM was significantly associated with a reduction of severe DRRCs (P = .005).

CONCLUSIONS

Pharyngolaryngectomy with total esophagectomy is a high-risk surgery significantly associated with the occurrence of postoperative morbidity and mortality. Nonetheless, the addition of FGT can help prevent gastric tip complications, while IOEM can be an effective method for improving outcomes.

64Cu-ATSM Predicts Efficacy of Carbon Ion Radiotherapy Associated with Cellular Antioxidant Capacity

Simple Summary

Carbon ion radiotherapy is an emerging cancer treatment modality that has a greater therapeutic window than conventional photon radiotherapy. To maximize the efficacy of this extremely scarce medical resource, it is important to identify predictive biomarkers of higher carbon ion relative biological effectiveness (RBE) over photons. Here we show that the carbon ion RBE in human cancer cells correlates with the cellular uptake of ⁶⁴Cu(II)-diacetyl-bis(N4-methylthiosemicarbazone) (⁶⁴Cu-ATSM), a potential radioligand that reflects an over-reduced intracellular environment. High RBE/⁶⁴Cu-ATSM cells show greater steady-state levels of antioxidant proteins and increased capacity to scavenge reactive oxygen species in response to X-rays than low RBE/⁶⁴Cu-ATSM counterparts. These data suggest that the cellular antioxidant activity is a possible determinant of carbon ion RBE predictable by ⁶⁴Cu-ATSM uptake.

Abstract

Carbon ion radiotherapy is an emerging cancer treatment modality that has a greater therapeutic window than conventional photon radiotherapy. To maximize the efficacy of this extremely scarce medical resource, it is important to identify predictive biomarkers of higher carbon ion relative biological effectiveness (RBE) over photons. We addressed this issue by focusing on cellular antioxidant capacity and investigated ⁶⁴Cu(II)-diacetyl-bis(N4-methylthiosemicarbazone) (⁶⁴Cu-ATSM), a potential radioligand that reflects an over-reduced intracellular environment. We found that the carbon ion RBE correlated with ⁶⁴Cu-ATSM uptake both in vitro and in vivo. High RBE/⁶⁴Cu-ATSM cells showed greater steady-state levels of antioxidant proteins and increased capacity to scavenge reactive oxygen species in response to X-rays than low RBE/⁶⁴Cu-ATSM counterparts; this upregulation of antioxidant systems was associated with downregulation of TCA cycle intermediates. Furthermore, inhibition of nuclear factor erythroid 2-related factor 2 (Nrf2) sensitized high RBE/⁶⁴Cu-ATSM cells to X-rays, thereby reducing RBE values to levels comparable to those in low RBE/⁶⁴Cu-ATSM cells. These data suggest that the cellular activity of Nrf2-driven antioxidant systems is a possible determinant of carbon ion RBE predictable by ⁶⁴Cu-ATSM uptake. These new findings highlight the potential clinical utility of ⁶⁴Cu-ATSM imaging to identify high RBE tumors that will benefit from carbon ion radiotherapy.

Visualisation of Range Shortening in Carbon Ion Beams and Washout of Positron Emitter: First-in-Human Report

BACKGROUND/AIM

Auto-activation positron emission tomography (AAPET) is one of the most promising methods to verify beam range in carbon ion radiotherapy (C-ion RT). We aimed to confirm this for the first time in a clinical setting by performing AAPET in a patient with pancreatic cancer previously receiving coil embolisation of hepatic artery pseudoaneurysm.

MATERIALS AND METHODS

A 70-year-old pancreatic head cancer patient was treated with C-ion RT on a clinical dose of 4.6 Gy (RBE), followed by AAPET, to verify beam ranges in C-ion RT.

RESULTS

Positron emission tomography (PET) revealed low positron emitter concentrations at the distal side of the internal metals and in the aorta compared to the dose distribution of the treatment plan, indicating range shortening by internal metals in C-ion beams and positron emitter transportation by biofluids.

CONCLUSION

AAPET may detect range shortening by internal metals in the trajectory and washout of intravascular positron emitter compared to plan dose distribution.

Robust Angle Selection in Particle Therapy

The popularity of particle radiotherapy has grown exponentially over recent years owing to the marked advantage of the depth–dose curve and its unique biological property. However, particle therapy is sensitive to changes in anatomical structure, and the dose distribution may deteriorate. In particle therapy, robust beam angle selection plays a crucial role in mitigating inter- and intrafractional variation, including daily patient setup uncertainties and tumor motion. With the development of a rotating gantry, angle optimization has gained increasing attention. Currently, several studies use the variation in the water equivalent thickness to quantify anatomical changes during treatment. This method seems helpful in determining better beam angles and improving the robustness of planning. Therefore, this review will discuss and summarize the robust beam angles at different tumor sites in particle radiotherapy.

Isolation of Rhodococcus equi from the gastrointestinal contents of earthworms (family Megascolecidae)

Rhodococcus equi was isolated from the gastrointestinal contents of earthworms (family Megascolecidae) and their surrounding soil collected from pastures of two horse-breeding farms in Aomori Prefecture, outdoor pig pens, forest in Towada campus, orange groves and forest where wild boars (Sus scrofa) are established in Tanabe, Wakayama Prefecture. The number of R. equi in the lower gastrointestinal contents of 23 earthworms collected from our campus was significantly larger than that of the upper gastrointestinal content. The mean numbers of R. equi from the gastrointestinal contents of earthworms collected from the various places were 2·3-fold to 39·7-fold more than those of the surrounding soil samples. In all, 1771 isolates from the earthworms and 489 isolates from the soil samples were tested for the presence of vapA and vapB genes using polymerase chain reaction. At the horse-breeding farm N, 9 of the 109 isolates (8·3%) from the earthworms and 7 of the 106 isolates (6·6%) from the soil samples were positive for the vapA gene. At the University's forest, one of the 250 isolates (0·4%) from the gastrointestinal contents of the earthworm was positive for the vapB gene. These results revealed that R. equi can be found in significant quantities in the gastrointestinal contents of earthworms, suggesting that they act as an accumulator of R. equi in the soil environment and as a source or reservoir of animal infection.

The presurgical controlling nutritional status (CONUT) score is independently associated with severe peristomal skin disorders: a single-center retrospective cohort study

While nutritional interventions may potentially lower the risk of peristomal skin disorders (PSDs) and their exacerbation, no previous studies have evaluated the relationship between PSDs and nutritional status using the Controlling Nutritional Status (CONUT) score. The purpose of this study was to assess the impact of preoperative nutritional status on stoma health, and determine risk factors for postoperative PSDs, including severe PSDs. A retrospective analysis was performed of 116 consecutive patients with rectal cancer who underwent radical surgery with ileostomy or colostomy creation. PSDs were diagnosed in 32 patients (27.6%); including 10 cases (8.7%) that were defined as severe based on the ABCD-stoma score. Multivariable logistic regression showed that smoking (odds ratio [OR] 3.451, 95% confidence interval [CI] 1.240–9.607, p = 0.018) and ileostomy (OR 3.287, 95% CI 1.278–8.458, p = 0.014) were independent risk factors for PSDs. A separate multivariable logistic regression analysis of risk factors for severe PSDs, found that the only independent risk factor was the CONUT score (OR 10.040, 95% CI 1.191–84.651, p = 0.034). Severe PSDs are associated with preoperative nutritional disorders, as determined by the CONUT score. Furthermore, nutritional disorders may increase the severity of PSDs, regardless of the stoma type.

Fibrin/fibrinogen Degradation Products Are Associated With Tumor Stage and Prognosis in Patients Undergoing Resection of Esophageal Cancer

BACKGROUND/AIM

To investigate the significance of preoperative fibrin/fibrinogen degradation products (FDP) in patients with esophageal cancer (EC), we examined the association between the preoperative FDP level and clinicopathological features in patients with EC who underwent McKeown esophagectomy with gastric tube reconstruction without neoadjuvant therapy.

PATIENTS AND METHODS

Ninety patients with EC who underwent surgery between 2006 and 2014 were included in this study. We investigated the association of FDP levels with clinicopathological features and prognosis.

RESULTS

Multivariate analysis revealed increased FDP level and pathological tumor depth to be independent prognostic factors for overall survival (OS) (p=0.008 and p=0.002, respectively). In addition, FDP levels were significantly positively associated with more advanced pathological TNM stage as a continuous variable (p for trend=0.002).

CONCLUSION

The preoperative FDP level was associated with a poor prognosis and was an independent prognostic factor for the OS of EC patients who underwent esophagectomy. Furthermore, the tumor stage-related increase in FDP indicated that a high FDP level is associated with tumor progression in patients with EC.

Chest Pain after Endoscopic Submucosal Dissection for Esophageal Cancer: The Simple and Clinically Useful Surrogate Marker for Transmural Thermal Injury by Electrocoagulation

BACKGROUND

Endoscopic submucosal dissection (ESD) of early esophageal cancer (EC) is becoming more widespread. Post-ESD coagulation syndrome (CS) has been proposed as temporary inflammatory signs that occur during the post-ESD period caused by transmural thermal injury by electrocoagulation. This retrospective study aimed to evaluate the association between chest pain and abnormal levels of inflammatory markers during the post-esophageal ESD period. We also investigate the clinical importance of chest pain to define the post-esophageal ESD CS.

METHODS

We examined 42 patients with thoracic EC who underwent ESD.

RESULTS

The incidence of chest pain after esophageal ESD is 35.7% and associated with elevation of WBC count on postoperative day 1 (WBC day 1) (p = 0.022). Multivariate logistic regression analysis using the procedure-related factors revealed that WBC day 1 was an independent predictive factor for chest pain (p = 0.034). The elevation of WBC count is associated with the resected esophageal circumference (p for trend = 0.018), specimen size (p = 0.031), and procedural time (p = 0.004). The incidence of post-esophageal ESD CS was estimated ranging from 11.9 to 54.8% using previously reported criteria.

CONCLUSIONS

The incidence of chest pain after ESD was only associated with postoperative elevation of WBC day 1. In considering the elevation of WBC count associated with procedure-related factors, chest pain possibly reflected transmural thermal injury by electrocoagulation during ESD. Post-esophageal ESD chest pain is a simple and clinically useful surrogate marker for transmural thermal injury and is a vital sign of post-esophageal ESD CS.