Feasibility of Breath-Hold Zero TE Magnetic Resonance Imaging Sequence for Evaluation of Pulmonary Arteriovenous Malformations After Embolotherapy

ABSTRACT

We obtained breath-hold zero TE (ZTE) magnetic resonance imaging for the evaluation of pulmonary arteriovenous malformations before and after embolotherapy. To the best of our knowledge, there have been no reports of ZTE for the entire lung imaging in single breath-hold scan time such as 20 seconds. Breath-hold ZTE magnetic resonance imaging can be a useful technique for magnetic resonance-based follow-up of vascular lung diseases without using contrast media, reducing the undesired artifacts from metallic devices.

Real-World Clinical Efficacy of Antifibrotic Agents for Idiopathic Pulmonary Fibrosis: A Single-Center Retrospective Study in Japan

BACKGROUND

The antifibrotic drugs, nintedanib and pirfenidone, inhibit the decline in forced vital capacity in patients with idiopathic pulmonary fibrosis (IPF). Nintedanib also inhibits the onset of acute exacerbation and reduces the risk of all-cause mortality. However, their effectiveness in real-world practice remains unclear. Our study aimed to investigate the changes in forced vital capacity, survival period, causes of death, and risk factors for mortality in patients with IPF receiving antifibrotic drugs.

METHODS

This retrospective study enrolled Japanese patients who visited Toho University Sakura Medical Center who were diagnosed with IPF and received antifibrotic drugs.

RESULTS

We included 102 patients [mean age ± standard deviation (SD): 71.8 ± 7.5 years], of whom 76 were males. The decline in forced vital capacity (mean ± SD) during the antifibrotic therapy period was - 154 ± 259 mL/year, which was significantly lower than before the antifibrotic therapy period (- 484 ± 589 mL/year; n = 80, p = 0.003). Altogether, 52 deaths were confirmed, and the median survival time from antifibrotic therapy initiation was 38.0 months (95% confidence interval: 25.9-50.1 months). Acute exacerbation accounted for 9.6% of all deaths (95% confidence interval: 1.6-17.6). The decline in forced vital capacity during antifibrotic therapy was a risk factor for mortality.

CONCLUSIONS

In actual clinical practice in Japan, antifibrotic drugs suppressed the gradual decline in forced vital capacity, which is a risk factor for mortality. However, the median survival period remained poor at 38 months.

Ion-pairing assemblies of π-extended anion-responsive organoplatinum complexes

PtII complexes of π-extended dipyrrolyldiketones were synthesized as anion-responsive π-electronic molecules. The dipyrrolyldiketone PtII complexes exhibited red-shifted absorption and photoluminescence properties. In the solid state, [1 + 1]-type anion complexes formed charge-by-charge ion-pairing assemblies when combined with countercations. Detailed theoretical studies of the packing structures revealed favorable interactions between the planar anion complexes and π-electronic cations.

Dosiomics for intensity-modulated radiotherapy in patients with prostate cancer: survival analysis stratified by baseline prostate-specific antigen and Gleason grade group in a 2-institutional retrospective study

OBJECTIVE

This study evaluated the prognostic impact of the quality of dose distribution using dosiomics in patients with prostate cancer, stratified by pretreatment prostate-specific antigen (PSA) levels and Gleason grade (GG) group.

METHODS

A total of 721 patients (Japanese Foundation for Cancer Research [JFCR] cohort: N = 489 and Tokyo Radiation Oncology Clinic [TROC] cohort: N = 232) with localized prostate cancer treated by intensity-modulated radiation therapy were enrolled. Two predictive dosiomic features for biochemical recurrence (BCR) were selected and patients were divided into certain groups stratified by pretreatment PSA levels and GG. Freedom from biochemical failure (FFBF) was estimated using the Kaplan-Meier method based on each dosiomic feature and univariate discrimination was evaluated using the log-rank test. As an exploratory analysis, a dosiomics hazard (DH) score was developed and its prognostic power for BCR was examined.

RESULTS

The dosiomic feature extracted from planning target volume (PTV) significantly distinguished the high- and low-risk groups in patients with PSA levels >10 ng/mL (7-year FFBF: 86.7% vs 76.1%, P < .01), GG 4 (92.2% vs 76.9%, P < .01), and GG 5 (83.1% vs 77.8%, P = .04). The DH score showed significant association with BCR (hazard score: 2.04; 95% confidence interval: 1.38-3.01; P < .001).

CONCLUSION

The quality of planned dose distribution on PTV may affect the prognosis of patients with poor prognostic factors, such as PSA levels >10 ng/mL and higher GGs.

ADVANCES IN KNOWLEDGE

The effects of planned dose distribution on prognosis differ depending on the patient's clinical background.

Enhanced solid-state phosphorescence of organoplatinum π-systems by ion-pairing assembly

Anion binding and ion pairing of dipyrrolyldiketone PtII complexes as anion-responsive π-electronic molecules resulted in photophysical modulations, as observed in solid-state phosphorescence properties. Modifications to arylpyridine ligands in the PtII complexes significantly impacted the assembling behaviour and photophysical properties of anion-free and anion-binding (ion-pairing) forms. The PtII complexes, in the presence of guest anions and their countercations, formed various anion-binding modes and ion-pairing assembled structures depending on constituents and forms (solutions and crystals). The PtII complexes emitted strong phosphorescence in deoxygenated solutions but showed extremely weak phosphorescence in the solid state owing to self-association. In contrast, the solid-state ion-pairing assemblies with tetraalkylammonium cations exhibited enhanced phosphorescence owing to the formation of hydrogen-bonding 1D-chain PtII complexes dispersed by stacking with aliphatic cations. Theoretical studies revealed that the enhanced phosphorescence in the solid-state ion-pairing assembly was attributed to preventing the delocalisation of the electron wavefunction over PtII complexes.

Zero Echo Time Magnetic Resonance Imaging; Techniques and Clinical Utility in Musculoskeletal System

Zero echo time (ZTE) sequence is recent advanced magnetic resonance technique that utilizes ultrafast readouts to capture signals from short-T2 tissues. This sequence enables T2- and T2* weighted imaging of tissues with short intrinsic relaxation times by using an extremely short TE, and are increasingly used in the musculoskeletal system. We review the imaging physics of these sequences, practical limitations, and image reconstruction, and then discuss the clinical utilities in various disorders of the musculoskeletal system. ZTE can be readily incorporated into the clinical workflow, and is a promising technique to avoid unnecessary radiation exposure, cost, and time-consuming by computed tomography in some cases. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 1.

Prediction of Tumor PD-L1 Expression in Resectable Non-Small Cell Lung Cancer by Machine Learning Models Based on Clinical and Radiological Features: Performance Comparison With Preoperative Biopsy

OBJECTIVE

We investigated if PD-L1 expression can be predicted by machine learning using clinical and imaging features.

METHODS

We included 117 patients with c-stage I/II non-small cell lung cancer who underwent radical resection. A total of 3951 radiomic features were extracted by defining the tumor (within tumor contour), rim (contour ±3 mm) and exterior (contour +10 mm) on preoperative contrast computed tomography. After feature selection by Boruta algorithm, prediction models of tumor PD-L1 expression (22C3: ≥1%, <1%) of resected specimens were constructed using Random Forest: radiomics, clinical, and combined models. Their performance was evaluated by 5-fold cross-validation, and AUCs were compared using Delong test. Next, study groups were categorized as patients without biopsy (training set), and those with biopsy (test set). Predictive ability of biopsy was compared to each prediction model.

RESULTS

Of 117 patients (66 ± 10 years old, 48% male), 33 (28.2%) had PD-L1≥1%. Mean AUC of PD-L1≥1% for the validation set in radiomics, clinical, and combined models were 0.80, 0.80, and 0.83 (P = .32 vs. clinical model), respectively. The diagnosis of malignancy was made in 22 of 38 (58%) patients with attempted biopsies, and PD-L1 was measurable in 19 of 38 (50%) patients. Diagnostic accuracies of PD-L1≥1% from 19 determinable biopsies and 38 all attempted biopsies were 0.68 and 0.34, respectively. These were out performed by machine learning: 0.71, 0.71, and 0.74 for radiomics, clinical, and combined models, respectively.

CONCLUSIONS

Our machine learning could be an adjunctive tool in estimating PD-L1 expression prior to neoadjuvant treatment, particularly when PD-L1 is indeterminable with biopsy.

A Nomogram Based on Pretreatment Radiomics and Dosiomics Features for Predicting Overall Survival for Esophageal Squamous Cell Cancer: Multi-Institutional Study

PURPOSE/OBJECTIVE(S)

The current study aims to propose a nomogram-based 2- and 3-years survival prediction model for esophageal squamous cell carcinoma treated by definitive radiotherapy using pretreatment computed tomography (CT), positron emission tomography (FDG PET) radiomic features and dosiomics features in addition to the common clinical factors using multi-institution data.

MATERIALS/METHODS

Data of 112 patients from one institution and 28 patients from the other institution were retrospectively collected. Radiomics and dosiomics features were extracted using five segmentations on CT and PET images and dose distribution. The least absolute shrinkage and selection operator (LASSO) with logistic regression was used to select radiomics and dosiomics features by calculating the radiomics and dosiomics scores (Rad-score and Dos-score), respectively, in the training model. The predictive clinical factors, Rad-score, and Dos-score were identified to develop a nomogram model.

RESULTS

We extracted 15219 features from the radiomics and dosiomics analysis. By LASSO Cox regression analysis, 13 CT-based radiomics features, 11 PET-based radiomics features, and 19 dosiomics features were selected. Clinical factors of T-stage, N-stage, and clinical stage were selected as significant prognostic factors by univariate Cox regression analysis. A predictive nomogram for prognosis in was established using these factors. In the external validation cohort, the C-index of the combined model of CT-based radiomics, PET-based radiomics, and dosiomics features with clinical factors were 0.74, 0.82, and 0.92, respectively. Moreover, we divided the cohort into high-risk and low-risk groups using the median nomogram score. Significant differences in overall survival (OS) in the combine model of CT-based radiomics, PET-based radiomics, and dosiomics features with clinical factors were observed between the high-risk and low-risk groups (P = 0.019, P = 0.038, and 0.014, respectively).

CONCLUSION

The current study established and validated 2- and 3-year survival prediction models based on radiomics and dosiomics features with clinical factors. The prediction model with dosiomics analysis could better predict OS than CT- and PET-based radiomics analysis in esophageal cancer patients treated with radiotherapy.

Laryngo-Esophageal Dysfunction Free Survival of Chemoradiation for Cervical Esophageal Cancer

PURPOSE/OBJECTIVE(S)

Chemoradiotherapy is often the treatment of choice for cervical esophageal cancer due to the invasiveness of surgery. However, toxicity after chemoradiotherapy often affects the quality of life related to swallowing and speech. This study evaluated laryngoesophageal dysfunction-free survival (LEDFS) in patients with cervical esophageal cancer, which has recently been used in head and neck cancer.

MATERIALS/METHODS

We analyzed 59 patients with cervical esophageal cancer without distant metastases other than supraclavicular lymph node metastases who received radical chemoradiotherapy with 5-fluorouracilplus platinum between 2002 and 2018. Loco-regional control (LRC), overall survival (OS), LEDFS, metachronous esophageal cancer incidence rates, and late toxicities were evaluated. LEDFS events were defined as death, local recurrence, total or partial laryngectomy, tracheostomy for more than 2 years, and feeding tube use for more than 2 years, as recommended by the Larynx Preservation Consensus Panel. The Kaplan-Meier method was used to calculate survival rates. The generalized Wilcoxon test was used to compare the two groups. The Common Terminology Criteria for Adverse Events v5.0 was used to assess toxicities.

RESULTS

The median age was 66 years (range, 38-83). There were 13 women and 46 men. Stage I, II, III, IVA, and IVB disease according to UICC 8th staging were 15, 9, 9, 10, and 16 patients, respectively. 22 received conventional radiotherapy and 37 received volumetric modulated arc therapy. The median total irradiation dose was 66 Gy. Platinum plus 5-fluorouracil chemotherapy was administered to all patients. The median follow-up for survivors was 87.5 months. The 5-year LRC, OS, and LEDFS rates were 54.2%, 48.9%, and 41.9%, respectively. The prognostic factors for OS were performance status (PS), hypopharyngeal extension, and clinical stage in univariate analysis and only clinical stage (hazard ratio [HR] 3.87, 95% Confidence interval [CI]: 1.52-9.87, p<0.01) in multivariate analysis; the prognostic factors for LEDFS were PS, hypopharyngeal extension and clinical stage in univariate analysis and hypopharyngeal extension (HR 2.38, 95% CI: 1.12-5.03, p = 0.02) and clinical stage (HR 4.07, 95% CI: 1.48-11.06, p<0.02) in multivariate analysis. Metachronous esophageal cancer was observed in 28.6% of patients at 5 years. As severe late toxicities, grade 3 pneumonitis, esophageal stricture, esophageal fistula, laryngeal stricture, and laryngeal edema were observed in 1 (2%), 1 (2%) and 4 (7%), 1 (2%) and 1 (2%), respectively. Grade 2 hypothyroidism was observed in 31 (53%) patients.

CONCLUSION

Chemoradiation for cervical esophageal cancer showed good results. The prognostic factors for LEDFS were pharyngeal extension and clinical stage. Late esophageal and laryngeal toxicity, hypothyroidism, and metachronous esophageal cancer should be noted.

Impact of the G8 Score on Treatment Strategies and Outcome in Definitive Radiotherapy for the Elderly Esophageal Cancer Patients

PURPOSE/OBJECTIVE(S)

Although chemoradiotherapy (CRT) is widely used as a curative treatment for esophageal cancer, it is often difficult to perform standard CRT for the elderly in the real world. This study aimed to investigate the impact of the Geriatric 8 (G8) score on treatment strategies and outcome in definitive radiotherapy (RT) for elderly esophageal cancer patients.

MATERIALS/METHODS

We analyzed 81 esophageal cancer patients aged ≥65 years who received definitive RT between 2018 and 2021. The G8 score was acquired at the first visit to the radiation oncology department. The treatment strategy was decided by a multi-disciplinary conference, and the G8 score was not used to determine the treatment strategy. Standard treatment (standard CRT) was defined as RT with elective nodal irradiation and a total dose ≥50 Gy, and chemotherapy with two cycles of platinum (70 mg/m2) and 5FU (700 mg/m2 for 4 days) concurrently. The Kaplan-Meier method was used to generate actual survival curves. The Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 was used to assess toxicities. The Mann-Whitney U test was used to compare the two groups, and statistical significance was set at p<0.05. The Receiver Operating Characteristic (ROC) curve was used to calculate the cutoff value.

RESULTS

The Median follow-up time was 30 months (range: 8-51) for survivors. The mean G8 scores by treatment strategy were 13.9 (range: 9-17) for standard CRT group (n = 26), 12.1 (range: 7-16) for reduced CRT group (n = 30), and 9.7 (range: 4.5-14) for RT alone group (n = 25). G8 score was significantly higher for standard CRT (p = 0.017) and significantly lower for RT alone (p<0.01). The cut-off value of the G8 score for standard treatment, calculated by the ROC curve, was 12.5 points. In the non-standard treatment group, the cut-off value of the G8 score for RT alone, calculated by the ROC curve, was 10.5 points. The 2-year overall survival (OS) rates for standard CRT, reduced CRT and RT alone were 74%, 71% and 35%, respectively, and significantly lower in RT alone (p<0.001). The 2-years OS rates for G8 score >10.5 points and ≤10.5 points were 69% and 48%, respectively (p = 0.039). Grade 3 or higher acute toxicities were observed in 33 patients (41%); 14 (54%) in standard CRT, 17 (57%) in reduced CRT and 2 (8%) in RT alone. Grade 5 acute toxicity was not observed. G8 scores tended to be higher in the patients with grade 3 or higher acute toxicities, but the difference was not statistically significant (p = 0.057). Grade 3 or higher late toxicities were observed in 7 patients.

CONCLUSION

Our results suggest that there is an association between the G8 score and clinicians' treatment decisions. Although RT alone could be safely performed even in patients with low G8 scores, administration of chemotherapy strongly affected prognosis. These results suggest the importance of developing less toxic systemic therapy regimens for patients with low G8 scores.

Predictive Modeling of Radiation Pneumonitis Induced by Chemoradiotherapy for Locally Advanced Non-Small Cell Lung Cancer Using Radiomics and Clinical Features

PURPOSE/OBJECTIVE(S)

The purpose of this study is to establish a prediction model for the development of grade 2 or higher radiation pneumonitis (RP) using radiomics analysis of pretreatment CT images, PET images, and dose distribution, in addition to clinical factors, in patients with locally advanced non-small cell lung cancer (NSCLC) treated with radical chemoradiotherapy.

MATERIALS/METHODS

We retrospectively evaluated 128 cases of locally advanced NSCLC treated with radical radiotherapy at our institution from 2008 to 2021. Clinical factors included age, sex, performance status (PS), KL-6, smoking history, histological type, clinical stage, and total radiation dose. Radiomics analysis was performed by analyzing treatment planning CT images, PET images, and dose distribution, and Rad-score (Radiomics-score) was calculated for the extracted features using Lasso-Cox regression. Rad-score (Radiomics-score) was calculated by Lasso-Cox regression for the extracted features. Risk factors were selected by univariate/multivariate analysis of clinical factors and Rad-score. Three models for predicting RP were developed from the identified risk factors using Nomogram: Clinical, Rad-score, and Combined model. The model was evaluated using area under the curve (AUC) based on receiver operating characteristic (ROC) curves and concordance index (C-index). RP was evaluated using the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. The cumulative incidence of Grade 2 or higher RP was evaluated using the Kaplan-Meier method.

RESULTS

Of the 128 cases, grade 2 or higher RP was observed in 50 cases (39%). Regarding clinical factors, gender, smoking status, and histology were selected as significant predictors of RP. Lasso-Cox analysis of radiomics features selected 11 features from CT images, 7 features from PET images, and 16 features from dose distribution as predictors of RP, yielding a total of 34 factors. The combined model (C-index: 0.96, AUC: 0.92) showed the best discrimination performance compared to the clinical model (C-index: 0.73, AUC: 0.56) and the Rad-score model (C-index: 0.87, AUC: 0.92). Risk classification using the combined model showed that the 1-year cumulative incidence of grade 2 or higher RP was 65% in the high-risk group, significantly higher than 15% in the low-risk group (p<0.001).

CONCLUSION

The combined model with Rad-score and clinical factors can predict grade 2 or higher RP in NSCLC patients with high accuracy.

Modifications of peripheral perfusion in patients with vasopressor-dependent septic shock treated with polymyxin B-direct hemoperfusion

Abnormal peripheral perfusion (PP) worsens the prognosis of patients with septic shock. Polymyxin B-direct hemoperfusion (PMX-DHP) increases blood pressure and reduces vasopressor doses. However, the modification of PP following administration of PMX-DHP in patients with vasopressor-dependent septic shock have not yet been elucidated. A retrospective exploratory observational study was conducted in patients with septic shock treated with PMX-DHP. Pulse-amplitude index (PAI), vasoactive inotropic score (VIS), and cumulative fluid balance data were extracted at PMX-DHP initiation (T0) and after 24 (T24) and 48 (T48) h. Changes in these data were analyzed in all patients and two subgroups (abnormal PP [PAI < 1] and normal PP [PAI ≥ 1]) based on the PAI at PMX-DHP initiation. Overall, 122 patients (abnormal PP group, n = 67; normal PP group, n = 55) were evaluated. Overall and in the abnormal PP group, PAI increased significantly at T24 and T48 compared with that at T0, with a significant decrease in VIS. Cumulative 24-h fluid balance after PMX-DHP initiation was significantly higher in the abnormal PP group. PMX-DHP may be an effective intervention to improve PP in patients with abnormal PP; however, caution should be exercised as fluid requirements may differ from that of patients with normal PP.

Detection of EGFR mutations in early-stage lung adenocarcinoma by machine learning-based radiomics

Background

We hypothesized that epidermal growth factor receptor (EGFR) mutations could be detected in early-stage lung adenocarcinoma using radiomics.

Methods

This retrospective study included consecutive patients with clinical stage I/II lung adenocarcinoma who underwent curative-intent pulmonary resection from March-December 2016. Using preoperative enhanced chest computed tomography, 3,951 radiomic features were extracted in total from the tumor (area within the tumor boundary), tumor rim (area within ±3 mm of the tumor boundary), and tumor exterior (area between +10 mm outside the tumor and tumor boundary). A machine learning-based radiomics model was constructed to detect EGFR mutations. The combined model incorporated both radiomic and clinical features (gender and smoking history). The performance was validated with five-fold cross-validation and evaluated using the mean area under the curve (AUC).

Results

Of 99 patients (mean age, 66±11 years; female, 66.6%; clinical stage I/II, 89.9%/10.1%), EGFR mutations in the surgical specimen were detected in 46 (46.5%). A median of 4 (range, 2 to 8) radiomic features was selected for each validation session. The mean AUCs in the radiomics and combined models were 0.75 and 0.83, respectively. The two top-ranked features in the combined model were the radiomic features extracted from the tumor exterior and the tumor, indicating a higher impact of radiomic features over relevant clinical features.

Conclusions

Radiomic features, including those in the peri-tumoral area, may help detect EGFR mutations in lung adenocarcinomas in preoperative settings. This non-invasive image-based technology could help guide future precision neoadjuvant therapy.

Intensity-modulated radiation therapy for intermediate-risk prostate cancer: does ADT still have an impact in the dose-escalated external beam radiation therapy era?

BACKGROUND

This study aimed to investigate the effect of androgen deprivation therapy (ADT) on the survival of intermediate-risk prostate cancer (IR-PCA) patients treated with dose-escalated external beam radiation therapy (DE-EBRT), and to determine the group that will benefit from ADT.

METHODS

We analysed 620 IR-PCA patients treated with DE-EBRT at two institutions. Variables were adjusted using the stabilised inverse probability of treatment weighting method (sIPTW) between radiation therapy (RT) and RT plus ADT groups. Biochemical relapse-free survival (bRFS) rate and overall survival (OS) rate were compared using Kaplan-Meier analysis and log-rank test. Cox proportional hazard analysis (CPH) was conducted to detect unfavorable risk factors.

RESULTS

This study included 405 patients; with 217 and 188 patients in the RT and RT plus ADT groups, respectively. The prescribed radiation dose was 78 Gy in 39 fractions. The median follow-up time was 82.0 months. After sIPTW-adjustment, 214.3 and 189.7 patients were assigned to the RT and RT plus ADT groups, respectively. The 7-year bRFS and OS were 89.3% and 94.6% in RT group and 92.3% and 91.0% in RT plus ADT group, respectively. Before and after sIPTW adjustment, no statistically significant differences were found in these endpoints between treatment groups. Multivariate CPH for bRFS revealed Gleason score (GS) 4 + 3 as an unfavorable risk factor, and ADT improved biochemical control of them.

CONCLUSION

ADT may not always be effective in all Japanese IR-PCA patients treated with DE-EBRT, but it can improve biochemical control in patients with GS 4 + 3.

Targeted deletion of ecto-5'-nucleotidase results in retention of inosine monophosphate content in postmortem muscle of medaka (Oryzias latipes)

Inosine monophosphate (IMP) is an important indicator of meat freshness and contributes to its umami taste. An attractive strategy for enhancing umami is to suppress the IMP-degrading activity and increase the IMP content in the skeletal muscle through genome editing technology using the CRISPR-Cas9 system. However, the molecular mechanisms underlying IMP degradation remain unclear. We cloned two ecto-5'-nucleotidase genes, designated as ecto-5'-nucleotidase-a (nt5ea) and ecto-5'-nucleotidase-b (nt5eb), from medaka (Oryzias latipes), a vertebrate model organism. Expression analysis using embryos showed that nt5ea or nt5eb overexpression remarkably upregulated IMP degradation, and that the IMP-degrading activity was higher in Nt5ea than in Nt5eb. Furthermore, we established frame-shifted or large deletion (lacking nt5ea or nt5eb locus) mutant strains and assayed the effects of gene disruptions on the amount of IMP in skeletal muscle. The nt5ea-deficient medaka showed considerable higher levels of IMP at 48 h postmortem than did the wild-type fish. The nt5eb mutants also exhibited higher IMP contents than that in the wild types, but the increase was less than that in the nt5ea mutants. Our results demonstrated that nt5e is an important regulator of IMP levels in skeletal muscle and that its loss of function was effective in maintaining IMP content.

Dosimetric comparison between three-dimensional conformal radiotherapy followed by electron beam boost and volumetric modulated arc therapy using concomitant boost for the heart and cardiac segments in patients with left-sided breast cancer at risk for radiation-induced cardiac toxicity

PURPOSE

We aimed to compare dosimetric parameters between three-dimensional conformal radiation therapy followed by electron beam boost (3D-CRT + EB) and volumetric modulated arc therapy using simultaneous integrated boost (SIB-VMAT) in left-sided breast cancer patients.

METHODS

This study included 57 patients with left-sided breast cancer who underwent SIB-VMAT. All patients had a computed tomography-based maximum heart distance of ≥ 1 cm and were prescribed a dose of 42.56 Gy/16 fractions to the planning target volume and a concomitant-boosted target dose of 53.2 Gy or 51.2 Gy. The 3D-CRT + EB plan was retrospectively created for the purpose of comparison using tangential fields with field-in-field technique followed by electron beam irradiation.

RESULTS

The doses to the clinical target volume significantly improved in the SIB-VMAT plans. All dosimetric parameters for the left anterior descending coronary artery (LAD) and LAD middle position (LAD mid) in the SIB-VMAT plans were significantly lower than those for 3D-CRT + EB plans (P < 0.01), while the doses to the heart, lung, contralateral breast and non-target tissue were decreased in the 3D-CRT + EB plans compared with those in the SIB-VMAT plans (e.g., 1.9 Gy vs. 2.9 Gy; P < 0.001 for the mean dose of heart).

CONCLUSIONS

SIB-VMAT significantly improved the dose to the target while reducing the doses to the LAD and LAD mid, whereas 3D-CRT + EB significantly decreased the doses to the heart and other organs at risk in patients with left-sided breast cancer at risk for radiation-induced coronary artery disease.

High-power laser experiment forming a supercritical collisionless shock in a magnetized uniform plasma at rest

We present an experimental method to generate quasiperpendicular supercritical magnetized collisionless shocks. In our experiment, ambient nitrogen (N) plasma is at rest and well magnetized, and it has uniform mass density. The plasma is pushed by laser-driven ablation aluminum (Al) plasma. Streaked optical pyrometry and spatially resolved laser collective Thomson scattering clarify structures of plasma density and temperatures, which are compared with one-dimensional particle-in-cell simulations. It is indicated that just after the laser irradiation, the Al plasma is magnetized by a self-generated Biermann battery field, and the plasma slaps the incident N plasma. The compressed external field in the N plasma reflects N ions, leading to counterstreaming magnetized N flows. Namely, we identify the edge of the reflected N ions. Such interacting plasmas form a magnetized collisionless shock.

Successful treatment of severe adrenaline-resistant anaphylactic shock with glucagon in a patient taking a beta-blocker: a case report

Background

The efficacy of glucagon for adrenaline-resistant anaphylactic shock in patients taking β-blockers is controversial. However, understanding the efficacy of glucagon is important because adrenaline-resistant anaphylactic shock is fatal. We present a case of severe adrenaline-resistant anaphylactic shock in a patient taking a β-blocker, and glucagon was effective in improving hemodynamics.

Case presentation

An 88-year-old woman with severe aortic stenosis and taking a selective β-1 blocker underwent transcatheter aortic valve implantation under general anesthesia. Postoperatively, she received 100 mg sugammadex, but 2 min later developed severe hypotension and bronchospasm. Suspecting anaphylactic shock, we intervened by administering adrenaline, fluid loading, and an increased noradrenaline dose. Consequently, the bronchospasm improved, but her blood pressure only increased minimally. Therefore, we administered 1 mg glucagon intravenously, and the hypotension resolved immediately.

Conclusions

Glucagon may improve hemodynamics in adrenaline-resistant anaphylactic shock patients taking β-blockers; however, its efficacy must be further evaluated in more cases.

Relationship between vancomycin-associated nephrotoxicity and the number of combined nephrotoxic agents

Vancomycin is associated with nephrotoxicity; however, the influence of the number of combined nephrotoxic agents on the incidence of vancomycin nephrotoxicity has not been clarified. We investigated patient backgrounds in 148 inpatients who received vancomycin treatment. The patients were divided into nephrotoxicity (n=35) and non-nephrotoxicity (n=113) groups. A comparison of the patient backgrounds in the two groups revealed significant differences in weight, changes in serum creatinine before vancomycin administration, blood urea nitrogen to serum creatinine ratio, length of vancomycin therapy, vancomycin trough concentration, and number of combined nephrotoxic agents. Multiple logistic regression analysis using these six factors as autonomous variables showed that the highest vancomycin trough concentration (odds ratio, 1.080; 95% confidence interval, 1.030-1.140; p = 0.003) and the number of combined nephrotoxic agents (odds ratio, 1.590; 95% confidence interval, 1.120-2.260; p = 0.010) were significantly related to nephrotoxicity.

Impact of Proteinuria and Low eGFR on Lifetime Risk of Cardiovascular Disease Death: A Pooled Analysis of Data From the Evidence for Cardiovascular Prevention From Observational Cohorts in Japan Study

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): H20–Junkankitou [Seishuu]–Ippan–013; H23–Junkankitou [Seishuu]–Ippan–005; H26-Junkankitou [Seisaku]-Ippan-001; H29–Junkankitou–Ippan–003 and 20FA1002

OnBehalf

EPOCH-JAPAN

Introduction

Absolute risk of Lifetime risk (LTR) is useful estimate for risk communication compared with short term risk or relative risk especially for young people. Proteinuria is leading cause of end-stage kidney disease (ESKD) and independent risk factor for cardiovascular disease (CVD). Although nonproteinuric renal disease is global burden of ESKD, it has been poorly focused. To date, there have been no reports of impact of proteinuria and low eGFR on LTR with the outcome of CVD death in Asian population.

Purpose

We aimed to estimate LTR of CVD death stratified by the status of proteinuria and low eGFR.

Methods

We used modified Kaplan-Meier approach to estimate the remaining lifetime risk of cardiovascular death based on EPOCH-JAPAN(Evidence for Cardiovascular Prevention From Observational Cohorts in Japan) database. LTR was estimated at each index age starting from 40 years for those with proteinuria and without proteinuria stratified by low eGFR, which is defined as eGFR &lt;60 ml/min/1.73 m². Participants were classified into three groups, which were those with proteinuria (Proteinuria (+)), those without proteinuria with low eGFR (Proteinuria (-)/Low eGFR (+)), those without proteinuria without low eGFR (Proteinuria (-)/Low eGFR (-)).

Results

A total of 47,292 participants from 9 cohorts was included in the analysis. Mean follow-up period was 14.6 years with 690,463 person years and total CVD death was 1,075 in men and 1,193 in women. The LTRs at the index age of 40 years were as follows: 17.7% (95% confidence interval: 15.4 – 19.0%) in Proteinuria (-)/Low eGFR (-) group, 26.2% (20.2 – 31.1%) in Proteinuria (-)/low eGFR (+) group, 24.5% (15.1 – 29.3%) in Proteinuria (+) group for men; 15.3%(13.7 – 16.5%), 29.9%(14.7 – 46.8%) , 28.3%(19.4 – 34.7%) for women.

Conclusions

We observed that those without proteinuria with low eGFR have equivalently high LTR with those with proteinuria. These results indicate that even in the absence of proteinuria, low eGFR has high impact on LTR. Lifestyle modification from young age is necessary to prevent from renal dysfunction.

Usefulness of arterial spin labeling in the evaluation for dural arteriovenous fistula of the craniocervical junction

In the diagnosis of an intracranial dural arteriovenous fistula (DAVF), arterial spin labeling (ASL), a sequence of magnetic resonance imaging (MRI) to depict high-blood-flow intracranial lesions, has been reported as a useful and noninvasive tool, not only to predict the presence of cortical venous drainage and draining veins, but also to confirm persistent obliteration after treatment. However, such utility of ASL has not been reported in DAVF of the craniocervical junction (CCJDAVF) because of the rarity of this disease and uncertainty in the acquisition of precise images.

We report a case of CCJDAVF presenting with myelopathy. Preoperative ASL images showed an abnormal high-intensity signal in the craniocervical junction, consistent with the anterior spinal vein and draining veins, which were also identified by digital subtraction angiography. After successful surgical treatment for the disease, MRI and 4-dimensional computed tomography angiography (4DCTA) confirmed complete disappearance of CCJDAVF. The ASL images also showed no abnormal intensity signal. The patient was followed-up using ASL, and no recurrence of high-intensity signal was observed.

As repetitive image examination is mandatory in the follow-up of a patient with DAVF to exclude recurrence, ASL is highly beneficial because of the unnecessity of an exogenous contrast medium and high credibility to depict the disease. The craniocervical junction may be out of the field of view in routine MRI. Special attention must be paid to setting the field of view and post labeling delay (PLD) to obtain precise images of ASL in CCJDAVF.

[Does Surgeons' Experience Affect the Surgical Outcomes of Total Arch Replacement?]

OBJECTIVES

Total arch replacement( TAR) is used to be a complicated and quite invasive aortic procedure. To perform TAR safely and effectively under all circumstances, we have constructed standardization of the procedures of TAR. The aim of this study is to analyze the impact of surgeons' experience on surgical outcome of TAR to evaluate our standardization.

METHODS

From January 2008 to December 2020, 346 consecutive patients (mean age 73.6±10.2) underwent elective TAR through a median sternotomy at our institute. TAR was performed by three types of surgeon classified by their experience( A:over 20 years, B:15~20 years, C:under 15 years). The surgical outcomes were examined. Our standard approach include( 1) meticulous selection of arterial cannulation site and type of arterial cannula;(2) antegrade selective cerebral perfusion;(3) maintenance of minimal tympanic temperature between 20 ℃ and 23 ℃;(4) early rewarming just after distal anastomosis;(5) maintaining fluid balance below 1,000 ml during cardiopulmonary bypass.

RESULTS

The operative cases were 227 in A, 86 in B and 33 in C. Surgeon A operated more complicated TAR with higher operative risk compared with B and C. The hospital mortality and major complication rate was not significant difference among surgeons( hospital mortality A:3.5%, B:2.3%, C:3.0%). Multivariate analysis showed the surgeons' experience was not associated with hospital mortality and major complications. Long-term outcomes were also compatible among three groups.

CONCLUSIONS

Our standardization for TAR seemed to be an useful approach to eliminate the impact of surgeon experience on surgical outcomes if the type of surgeon was appropriately selected according to the level of operative difficulty.

Topological metastability supported by thermal fluctuation upon formation of chiral soliton lattice in [Formula: see text]

Topological magnetic structure possesses topological stability characteristics that make it robust against disturbances which are a big advantage for data processing or storage devices of spintronics; nonetheless, such characteristics have been rarely clarified. This paper focused on the formation of chiral soliton lattice (CSL), a one-dimensional topological magnetic structure, and provides a discussion of its topological stability and influence of thermal fluctuation. Herein, CSL responses against change of temperature and applied magnetic field were investigated via small-angle resonant soft X-ray scattering in chromium niobium sulfide ([Formula: see text]). CSL transformation relative to the applied magnetic field demonstrated a clear agreement with the theoretical prediction of the sine-Gordon model. Further, there were apparent differences in the process of chiral soliton creation and annihilation, discussed from the viewpoint of competing between thermal fluctuation and the topological metastability.

Radiomics Approach Outperforms Diameter Criteria for Predicting Pathological Lateral Lymph Node Metastasis After Neoadjuvant (Chemo)Radiotherapy in Advanced Low Rectal Cancer

BACKGROUND

Advanced low rectal cancer has a non-negligible risk of lateral pelvic lymph node (LPLN) metastasis (LPLNM) and lateral local recurrence (LR) after neoadjuvant (chemo)radiotherapy and total mesorectal excision. LPLN dissection (LPLND) reduces LR but increases postoperative complications and sexual/urinary dysfunction.

OBJECTIVE

The aim of this study was to develop a new radiomics-based prediction model for LPLNM in patients with rectal cancer.

METHODS

A total of 247 patients with rectal cancer and enlarged LPLNs treated by (chemo)radiotherapy and LPLND were enrolled in this retrospective, multicenter study. LPLN radiomic features were extracted from pretreatment portal venous-phase computed tomography images. A radiomics score of LPLN was constructed based on the least absolute shrinkage and selection operator regression in a primary cohort of 175 patients. Model performance was assessed in terms of discrimination, calibration, and decision curve analysis, and was externally validated in 72 patients.

RESULTS

The radiomics score showed significantly better discrimination compared with pretreatment short-axis diameter measurements in both the primary (area under the curve [AUC] 0.91 vs. 0.83, p = 0.0015) and validation (AUC 0.90 vs. 0.80, p = 0.0298) cohorts. Decision curve analysis also indicated the superiority of the radiomics score. In a subanalysis of patients with a short-axis diameter ≥ 7 mm, the radiomics nomogram, incorporating the radiomics score and LPLN shrinkage to ≤ 4 mm, had better discrimination compared with a model incorporating only LPLN shrinkage in both cohorts.

CONCLUSIONS

Radiomics-based prediction modeling provides individualized risk estimation of LPLNM in rectal cancer patients treated with (chemo)radiotherapy, and outperforms measurements of pretreatment LPLN diameter.

Phase I/II study of adding intraperitoneal paclitaxel in patients with pancreatic cancer and peritoneal metastasis

BACKGROUND

Intraperitoneal chemotherapy using paclitaxel is considered an experimental approach for treating peritoneal carcinomatosis. This study aimed to determine the recommended dose, and to evaluate the clinical efficacy and safety, of the combination of intravenous gemcitabine, intravenous nab-paclitaxel and intraperitoneal paclitaxel in patients with pancreatic cancer and peritoneal metastasis.

METHODS

The frequencies of dose-limiting toxicities were evaluated, and the recommended dose was determined in phase I. The primary endpoint of the phase II analysis was overall survival rate at 1 year. Secondary endpoints were antitumour effects, symptom-relieving effects, safety and overall survival.

RESULTS

The recommended doses of intravenous gemcitabine, intravenous nab-paclitaxel and intraperitoneal paclitaxel were 800, 75 and 20 mg/m² respectively. Among 46 patients enrolled in phase II, the median time to treatment failure was 6·0 (range 0-22·6) months. The response and disease control rates were 21 of 43 and 41 of 43 respectively. Ascites disappeared in 12 of 30 patients, and cytology became negative in 18 of 46. The median survival time was 14·5 months, and the 1-year overall survival rate was 61 per cent. Conversion surgery was performed in eight of 46 patients, and those who underwent resection survived significantly longer than those who were not treated surgically (median survival not reached versus 12·4 months). Grade 3-4 haematological toxicities developed in 35 of 46 patients, whereas non-haematological adverse events occurred in seven patients.

CONCLUSION

Adding intraperitoneal paclitaxel had clinical efficacy with acceptable tolerability.

Fully automated dose prediction using generative adversarial networks in prostate cancer patients

Purpose

Although dose prediction for intensity modulated radiation therapy (IMRT) has been accomplished by a deep learning approach, delineation of some structures is needed for the prediction. We sought to develop a fully automated dose-generation framework for IMRT of prostate cancer by entering the patient CT datasets without the contour information into a generative adversarial network (GAN) and to compare its prediction performance to a conventional prediction model trained from patient contours.

Methods

We propose a synthetic approach to translate patient CT datasets into a dose distribution for IMRT. The framework requires only paired-images, i.e., patient CT images and corresponding RT-doses. The model was trained from 81 IMRT plans of prostate cancer patients, and then produced the dose distribution for 9 test cases. To compare its prediction performance to that of another trained model, we created a model trained from structure images. Dosimetric parameters for the planning target volume (PTV) and organs at risk (OARs) were calculated from the generated and original dose distributions, and mean differences of dosimetric parameters were compared between the CT-based model and the structure-based model.

Results

The mean differences of all dosimetric parameters except for D_98% and D_95% for PTV were within approximately 2% and 3% of the prescription dose for OARs in the CT-based model, while the differences in the structure-based model were within approximately 1% for PTV and approximately 2% for OARs, with a mean prediction time of 5 seconds per patient.

Conclusions

Accurate and rapid dose prediction was achieved by the learning of patient CT datasets by a GAN-based framework. The CT-based dose prediction could reduce the time required for both the iterative optimization process and the structure contouring, allowing physicians and dosimetrists to focus their expertise on more challenging cases.

[Impact of Aperture Shape Controller on Volumetric Modulated Arc Therapy Treatment Planning for Nasopharyngeal Cancer]

PURPOSE

The aperture shape controller (ASC) decreases the complexity of the multi-leaf collimator (MLC) aperture for volumetric modulated arc therapy (VMAT). The purpose of this study was to evaluate the effect of ASC settings on the VMAT plan quality.

METHOD

First, VMAT plans were created (ASC=off) for three test patterns of The American Association of Physicists in Medicine (AAPM) Task Group 119 (TG-119) and 20 cases of nasopharyngeal cancer. Next, for these VMAT plans, only the ASC settings were changed from very low (complexity reduction: low) to very high (complexity reduction: high) in five steps, and VMAT plans were created respectively. To evaluate the created VMAT plans per each ASC settings, we analyzed the modulation complexity score (MCS_V) and dosimetric parameters for the planning target volume (PTV) and organ at risk (OAR).

RESULT

In three test patterns, there were no major dosimetric differences between the VMAT plans. In nasopharyngeal cancer, the mean MCS_V were 0.413, 0.325, 0.320, 0.307, 0.303, and 0.272 for very high, high, moderate, low, very low, off settings, respectively. Therefore, the most complex MLC aperture was off, followed by very low, low, moderate, high, and very high. In terms of dosimetric parameters, the VMAT plans created using the very high setting showed an increase of D_2% in the PTV and worse OAR sparing than that using other ASC settings. On the other hand, the dosimetric results for the very low to moderate setting obtained similar results to those for the off setting, respectively.

CONCLUSION

The ASC was able to decrease the complexity of the MLC aperture according to the setting level. From very low to moderate settings, a plan equivalent to the off setting could be created in terms of dose parameters.