Delayed Stent Infection after Deployment of a Carotid Dual Layer Stent in Dialysis Cases.

Objective: Infection after carotid artery stenting (CAS) is rare. We report two dialysis cases of delayed stent infection associated with a carotid dual-layer stent (DLS), which occurred several months after deployment of the stent. Case Presentations: Case 1: A 74-year-old man receiving dialysis underwent CAS with DLS. Three months after CAS, the patient developed a high fever, neck pain, and neck swelling. Neck CT and carotid ultrasonography (CUS) indicated an abscess around the inserted DLS. The patient was treated with antibiotic agents and fully recovered. Case 2: A 73-year-old man receiving dialysis underwent CAS with DLS. Two months after CAS, this patient also developed a high fever, neck pain, and neck swelling. Contrast-enhanced neck CT indicated inflammatory effusion with an abscess and a giant infectious pseudoaneurysm. Endovascular stent graft reconstruction was employed urgently under antibiotic therapy to prevent its rupture. However, intracranial hemorrhage occurred postoperatively and left hemiparesis remained. Conclusion: Delayed carotid stent infection is a rare but severe complication. The use of a DLS might be avoided during CAS for dialysis cases.

Regulation of Chloride Channels by Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitor-Induced α-Defensin 5.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are used to treat non-small cell lung cancer with EGFR mutations. However, first-generation erlotinib and second-generation afatinib often cause diarrhea, which may develop because of the association between EGFR-TKIs and the chloride channel or abnormalities in the intestinal microbiota due to disruption of the intestinal immune system. As reports on the effects of EGFR-TKIs on intestinal immunity are lacking, we aimed to determine whether the intestinal immune system is involved in the molecular effects of EGFR-TKIs on chloride channels using Caco-2 cells. Initially, we evaluated the association of chloride channels with α-defensin 5 (DEFA5), a marker of intestinal immunity. Erlotinib and afatinib significantly increased the extracellularly secreted DEFA5 level and autophagy-related 16-like 1 and X-box binding protein 1 transcript levels, indicative of enhanced granule exocytosis. Conversely, intracellular DEFA5 and Toll-like receptor 4 protein expression and tumor necrosis factor-α transcript levels decreased significantly, suggesting that Toll-like receptor 4 suppression repressed DEFA5 production. Furthermore, among the chloride channels, DEFA5 was found to significantly increase the transcript levels of cystic fibrosis transmembrane conductance regulators. These results indicate that DEFA5 plays a significant role in the mechanism of chloride channel-mediated diarrhea induced by EGFR-TKIs. Therefore, we successfully elucidated the potential host action of DEFA5 in cancer therapy for the first time.

Chronic Limb-Threatening Ischemia is a Residual Bleeding Risk Factor among Patients with Lower Extremity Artery Disease.

AIM: Lower-extremity artery disease (LEAD) is a high-risk factor for bleeding. However, the specific risk factors for bleeding in patients with LEAD remain unclear. We aimed to identify risk factors for bleeding in patients with LEAD after endovascular treatment (EVT). METHODS: This multicenter, retrospective, observational study included 732 consecutive patients with LEAD who underwent EVT between January 2018 and December 2019. Patient characteristics, laboratory data, target lesions, and medications were compared between patients with and without chronic limb-threatening ischemia (CLTI). Predictive bleeding risk factors were explored using Cox regression analysis with differential models. RESULTS: In model 1, a body mass index (BMI) ＜18.5 kg/m2, prior heart failure, high bleeding risk, use of single antiplatelet therapy (SAPT) plus warfarin, and CLTI were predictive bleeding risk factors (hazard ratio [HR] 2.05; 95% confidence interval [CI] 1.13-3.52; p＜0.01; HR 2.15; 95% CI 1.28-3.55; p＜0.01; HR 3.40; 95% CI 1.28-3.55; p＜0.01; HR 2.05; 95% CI 1.33-5.84; p＜0.01; respectively). In model 2, a BMI ＜18.5 kg/m2, prior heart failure, anemia (＜11 g/dL), low platelet count (＜10*104/µL), chronic kidney disease, use of single antiplatelet therapy (SAPT) plus warfarin, and CLTI were independent risk factors for bleeding (model 2: HR 2.05; 95% CI 1.12-3.56; p=0.02; HR 2.35; 95% CI 1.39-3.90; p＜0.01; HR 2.71; 95% CI 1.64-4.50; p＜0.01; HR 2.66; 95% CI 1.00-5.89; p=0.05; HR 2.47; 95% CI 1.25-5.45; p＜0.01; HR 2.79; 95% CI 1.24-5.63; p=0.01; respectively) Conclusions: CLTI is a residual and predictive risk factor for bleeding in patients with LEAD. We have to pay attention to the bleeding events of patients with CLTI after EVT during follow-up.

Validation of the Usefulness of the Diameter Reduction, Spiral Shape, Flow Impairment, or Adverse Morphology Classification System in Real-World Clinical Practice.

AIM: The accuracy of the DISFORM (diameter reduction, spiral shape, flow impairment, or adverse morphology) classification system has not been validated. METHODS: This retrospective multicenter observational study enrolled 288 consecutive patients with lower extremity artery disease who underwent endovascular therapy with drug-coated balloons for femoropopliteal lesions between January 2018 and December 2021. Patients were classified into DISFORM I-IV groups. Primary patency (PP) and freedom from clinically driven target lesion revascularization (CD-TLR) at 12 months, and recurrence predictors at 12 months were investigated. RESULTS: In total, 183, 66, 11, and 28 patients were classified into DISFORM I, II, III, and IV groups, respectively. In the DISFORM I, II, III, and IV groups, the PP rates were 75.3%, 91.1%, 87.5%, and 50.0%, respectively, and freedom from CD-TLR rates were 86.0%, 91.6%, 88.9%, and 76.7%, respectively, at 12 months. In the DISFORM I-III and IV groups, the PP rates were 79.4% and 50.0%, respectively, and freedom from CD-TLR rates were 87.5% and 76.7%, respectively, at 12 months. Multivariate analysis showed that chronic limb-threatening ischemia, DISFORM IV, and Lutonix™ use were independent predictors of PP loss at 12 months. CONCLUSION: DISFORM IV had a lower PP rate than DISFORM I-III in midterm phase.

Demonstration of differential ventricular overdrive pacing during long RP' supraventricular tachycardia.

We described the differential ventricular overdrive pacing during long RP' supraventricular tachycardia and discussed about its response leading to the dianosis.

Impact of antimicrobial stewardship implementation on the antibiotic use and susceptibility in a Japanese long-term care hospital.

BACKGROUND: Antimicrobial use (AMU) is closely related to the emergence of antimicrobial-resistant (AMR) bacteria. Meanwhile, long-term care hospitals (LTCHs) have been pointed out to be important reservoirs for AMR. However, evidence illustrating the association between AMU and AMR in LTCHs is lacking compared to that of acute care hospitals. METHODS: We evaluated the impact of an antimicrobial stewardship (AS) program implementation, in a LTCH on AMU and antibiotic susceptibility between three periods: the pre-AS-period (pre-AS); the first period after AS implementation (post-AS 1), in which initiated recommendation the blood culture collection and definitive therapy by AS team; and the second period (post-AS 2), implementation of a balanced use of antibiotics was added. RESULTS: After the AS implementation, a significant increase in the number of blood cultures collected was observed. Conversely, the AMU of piperacillin-tazobactam (PIPC/TAZ), which has activity against Pseudomonas aeruginosa, was increased and occupied 43.0% of all injectable AMU in post-AS 1 compared with that in pre-AS (35.5%). In the post-AS 2 period, we analyzed the %AUD and recommended hospital-wide PIPC/TAZ sparing; this resulted in the significant reduction in %AUD of PIPC/TAZ, which was associated with improved susceptibility of P. aeruginosa to PIPC/TAZ. CONCLUSIONS: These results suggest that AS programs aimed at implementing antibiotic sparing may lead to improve AMR, highlighting the necessity of correcting overuse of a single class of antibiotics and usefulness of AMU monitoring in the LTCH setting.

Complete atrioventricular block following internal electrical cardioversion during atrial fibrillation ablation.

BACKGROUND: Complete atrioventricular block (C-AVB) following internal electrical cardioversion (IEC) during atrial fibrillation (AF) ablation has not been fully investigated. We aimed to determine the prevalence and predictors of C-AVB following IEC during AF ablation. METHODS: C-AVB (non-conducted sinus impulse after IEC) and ventricular pause (VP) (the interval between IEC and the QRS complex) following the first attempt of IEC, and baseline electrocardiographic parameters were investigated in patients who underwent first-time AF ablation. RESULTS: We investigated the first attempt of IEC in 124 patients (mean age:70 ± 11 years, 81 men, 99 non-paroxysmal AF). AF was terminated in 109/124 (88%) patients, with a VP of 1590 [1014-2208] (maximum, 8780) ms. Transient C-AVB following IEC occurred in 14/109 (13%) patients. The VP was longer in patients with transient C-AVB than in those without transient C-AVB (2418 [1693-4425] vs. 1530 [876-2083] ms, p = 0.002). In multivariate analysis, the left atrial diameter (Odds ratio [OR]:1.21; 95% confidence interval (95%CI):1.06-1.39; p = 0.005) and preexisting intraventricular conduction abnormality (OR:9.22; 95%CI:1.60-53.3; p = 0.013) were predictors of transient C-AVB following IEC. CONCLUSION: Left atrial diameter and preexisting intraventricular conduction abnormalities were predictors of transient C-AVB following IEC during AF ablation.

Effects of preceding antiplatelet agents on severity of ischemic stroke in patients with a history of stroke.

INTRODUCTION: Antiplatelet agents are effective for secondary prevention of ischemic stroke and can reduce the severity of first-ever ischemic stroke. However, it is uncertain if prophylactic antiplatelet therapy reduces the severity of recurrent ischemic stroke. The aim of this study was to determine the effect of preceding antiplatelet treatment on the severity of thrombotic stroke (TS) in patients with a prior history of stroke. METHODS: From a prospective hospital registry of 1338 consecutive patients with acute ischemic stroke, we identified patients with a prior history of stroke who were admitted for cardioembolic stroke (CE); TS including large-artery atherosclerosis, small vessel occlusion, and branch atheromatous disease; or other cause or cryptogenic stroke (OCS). Cases in each subtype were categorized based on preceding medication: antiplatelet agents (AP) and none (N). Severity of stroke (National Institutes of Health Stroke Scale: NIHSS) on admission was compared between AP and N cases. RESULTS: The total cohort of 252 patients included 83 with CE, 102 with TS, and 67 with OCS. After excluding those with prior anticoagulants, the median NIHSS on admission was lower in AP cases than in N cases (3 vs. 5, p = 0.002). In multivariate analysis, preceding AP treatment was independently associated with minor stroke (NIHSS ≤4) on admission in CE group (OR 8.48, 95% CI 1.71-62.9, p = 0.008) and TS group (OR 4.24, 95% CI 1.44-13.4, p = 0.009). CONCLUSION: Preceding antiplatelet treatment in patients with a prior history of stroke may reduce the severity of subsequent thrombotic and cardiogenic stroke.

Breaking away from an endemic state of multidrug-resistant Pseudomonas aeruginosa by daily sink disinfection.

The detection rate of multidrug-resistant Pseudomonas aeruginosa in patients admitted to 2 wards and the intensive care unit decreased from 20.3% (129 of 636 isolates) to 4.2% (37 of 889 isolates) after the start of disinfection of hand washing sinks using alkyl diaminoethylglycine hydrochloride.

Predictors of recurrence based on intravascular ultrasound findings after Eluvia placement in symptomatic peripheral arterial disease: A retrospective study.

Background and Aims: Polymer-coated drug-eluting stents (Eluvia) have shown favorable clinical outcomes in real-world registries. There are no reports on recurrent predictors after Eluvia placement based on intravascular ultrasound (IVUS) findings. Methods: We analyzed clinical data from the ASIGARU PAD registry, a retrospective, multicenter, observational study that enrolled patients who underwent endovascular therapy for superficial femoral and proximal popliteal arteries lesions using Eluvia or drug-coated balloon. The primary outcome was the identification of recurrent predictors, including IVUS parameters at 12 months. The rate of target lesion recurrence was also assessed. Results: IVUS images were obtained in 54 of 65 cases. Seven recurrent cases (13.0%) were observed within 12 months. The random survival forest method presented eight predictive variables of recurrence: Clinical Frailty Scale (CFS), distal stent edge area, distal plaque burden, age, sex, distal external elastic membrane (EEM) area, minimum stent area (MSA), and distal lumen area. Furthermore, the partial dependence plot showed that frailty (CFS ≥ 6), smaller distal stent edge area, higher and lower distal plaque burden, older and younger age, female sex, smaller distal EEM area, smaller MSA, and smaller and larger distal lumen area predicted recurrence after Eluvia placement within 12 months. Conclusion: CFS, distal stent edge area, distal plaque burden, age, sex, distal EEM area, MSA, and distal lumen area were significant recurrent predictors after Eluvia placement.

Clinical Outcomes Based on High Bleeding Risk in Patients With Lower Extremity Peripheral Artery Disease Who Have Undergone Endovascular Therapy.

PURPOSE: Endovascular therapies (EVTs) for symptomatic lower extremity peripheral artery disease (PAD) are efficient and minimally invasive. However, patients with PAD tend to have high bleeding risk (HBR), and there are limited data regarding the HBR for patients with PAD after EVT. In this study, we investigated the prevalence and severity of HBR, as well as its association with clinical outcomes in the patients with PAD who underwent EVT. MATERIALS AND METHODS: The Academic Research Consortium for High Bleeding Risk (ARC-HBR) criteria were applied to 732 consecutive patients with lower extremity PAD post-EVT to assess the prevalence of HBR, and its association with major bleeding events, all-cause mortality, and ischemic events. The ARC-HBR scores (1 point for each major criterion and 0.5 points for each minor criterion) were obtained and the patients were divided into four groups (score: 0-0.5; low risk, score: 1-1.5; moderate risk, score: 2-2.5; high risk, and score: ≥3; very high risk) according to the score. Major bleeding events were defined as Bleeding Academic Research Consortium type-3 or type-5 bleeding, and ischemic events were defined as the composite of myocardial infarction, ischemic stroke, and acute limb ischemia within 2 years. RESULTS: High bleeding risk occurred in 78.8% of the patients. Major bleeding events, all-cause mortality, and ischemic events occurred in 9.7%, 18.7%, and 6.4% of the study cohort, respectively, within 2 years. During the follow-up period, major bleeding events significantly increased with the ARC-HBR score. The severity of the ARC-HBR score was significantly associated with an increased risk of major bleeding events (high risk: adjusted hazard ratio [HR] 5.62; 95% confidence interval [CI]: [1.28, 24.62]; p=0.022; very high risk: adjusted HR: 10.37; 95% CI: [2.32, 46.30]; p=0.002). All-cause mortality and ischemic events also significantly increased with higher ARC-HBR score. CONCLUSIONS: High bleeding risk patients with lower extremity PAD can be at a high risk of bleeding events, mortality, and ischemic events after EVT. The ARC-HBR criteria and its associated scores can successfully stratify HBR patients and assess the bleeding risk in patients with lower extremity PAD who undergo EVT. CLINICAL IMPACT: Endovascular therapies (EVTs) for symptomatic lower extremity peripheral artery disease (PAD) are efficient and minimally invasive. However, patients with PAD tend to have high bleeding risk (HBR), and there are limited data regarding the HBR for patients with PAD after EVT. Post EVT, most of the patients with PAD were classified as having HBR using the Academic Research Consortium for HBR (ARC-HBR) criteria and the rate of bleeding events as well as mortality and ischemic events within 2 years increased as the ARC-HBR score increased in this retrospective study of 732 participants. HBR patients with PAD can be at high risk of not only bleeding events but also mortality and ischemic events in the mid-term. The ARC-HBR criteria and its associated scores can successfully stratify HBR patients and assess the bleeding risk in patients with PAD who underwent EVT.

Removal of Migrated Vascular Closure Device Plug Material From the Popliteal Artery Using the Bi-Directional Approach "Push Balloon Into Vessel and Close Embolus From Retrograde Site (PINCER)" Technique: A Case Report.

Vascular closure devices (VCDs) are widely used to achieve rapid hemostasis after percutaneous intervention via the common femoral artery (CFA), with well-established efficacy and safety. Although VCD-related artery occlusion is rare, it can be critical. A 72-year-old female underwent endovascular therapy (EVT) for stent occlusion in the left superficial femoral artery through a 7-Fr guiding sheath from the right CFA. After the procedure, an acute right popliteal artery (POP-A) occlusion, associated with the EXOSEAL VCD plug, occurred. The plug material was successfully removed using a bidirectional approach. The migration plug was blocked to prevent distal vessel migration and pushed gently to close the antegrade system, using an over-the-wire balloon from the retrograde site. We named this the "Push balloon INto vessel and Close Embolus from Retrograde site" (PINCER) technique. Finally, the plug was successfully removed using biopsy forceps. Acute limb ischemia (ALI) caused by EXOSEAL is a rare condition. Removal of the emboli by EVT is clinically significant because it is minimally invasive. However, it is sometimes difficult to remove the embolus using only antegrade approach; thus, the bidirectional approach using the PINCER technique can be effective in these situations.

Association between High Bleeding Risk and 2-Year Mortality in Patients with Chronic Limb-Threatening Ischemia.

AIM: Patients with chronic limb-threatening ischemia (CLTI) have a high bleeding risk (HBR) and mortality rate. The 2-year life expectancy is an important factor in deciding the appropriate treatment strategy. This study aimed to assess the influence of HBR on the prognosis of patients with CLTI. METHODS: A total of 259 patients with CLTI who underwent endovascular therapy (EVT) (mean age, 76.2 years; male, 62.9%) between January 2018 and December 2019 were evaluated. The Academic Research Consortium for HBR (ARC-HBR) criteria were applied to each patient, and the ARC-HBR scores were calculated. The cut-off score for predicting all-cause mortality within two years was derived using a survival classification and regression tree (CART) model. Causes of death and the association between ARC-HBR scores and major bleeding events within two years were also investigated. RESULTS: Based on the CART model, patients were divided into three groups (low HBR score 0-1.0, 48 patients; moderate HBR score 1.5-3.0, 176 patients; and high HBR score ≥ 3.5, 35 patients). During the study period, 82 patients (39.6%) died due to cardiac (n=23) and non-cardiac causes (n=59). All-cause mortality increased significantly with increasing ARC-HBR scores. Cox multivariate analysis revealed a significant association between high ARC-HBR scores and the risk of all-cause mortality within two years. Major bleeding events increased significantly with increasing ARC-HBR scores. CONCLUSIONS: The ARC-HBR score could predict 2-year mortality in patients with CLTI who underwent EVT. Thus, this score can help determine the best revascularization strategy for patients with CLTI.

Revisiting exit block after entrance block: Investigation of ablation index-guided pulmonary vein isolation.

INTRODUCTION: Unidirectional block, left atrium to pulmonary vein (LA-PV) entrance block without PV-LA exit block, has not been fully investigated in the setting of ablation index (AI)-guided pulmonary vein (PV) isolation (PVI). The aim of this study was to investigate unidirectional blocks during AI-guided PVI. METHODS: After achieving entrance block, exit block was evaluated by pacing from the catheter placed in the PV. Local PV musculature capture without conduction to the LA was necessary to prove exit block. RESULTS: In total, 441 PVs (including nine left common PVs) from 113 consecutive patients (mean age: 71 ± 12 years, 77 men, 61 paroxysmal atrial fibrillation cases) who underwent initial AI-guided PVI for atrial fibrillation were studied. Entrance block was achieved in all PVs. of the 247/441 (56%) PVs showing local PV musculature capture, 5/247 (2.0%) showed unidirectional blocks. Three of the five PVs (left superior and inferior PVs in one patient; right superior PV in another patient) showed LA-PV reconnection, requiring additional ablation to achieve bidirectional block during the procedure. Two of the five PVs (left superior and inferior PVs in one patient) showed LA-PV reconnection, and thereafter, LA-PV conduction became blocked again spontaneously, leading to bidirectional block without further ablation during the procedure. CONCLUSION: AI-guided PVI presented a low prevalence of unidirectional block (2%), using entrance block alone as the endpoint of PVI could therefore be justified.

Two-year clinical outcomes and predictors of restenosis following the use of polymer-coated paclitaxel-eluting stents or drug-coated balloons in patients with femoropopliteal artery disease.

We aimed to assess the clinical performance and risk factors for patency loss within 2 years following the use of polymer-coated paclitaxel-eluting stents (PC-PESs) and drug-coated balloons (DCBs) in patients with lower extremity artery disease. Multi-center registry data from 151 patients (65 and 86 treated with PC-PES and DCB, respectively) were retrospectively investigated. Two-year primary patency (PP) and clinically driven target lesion revascularization (CD-TLR) were evaluated using Kaplan-Meier analysis. Predictors of restenosis within 2 years of the procedures were analyzed using the random survival forest method. The consistent predictors of restenosis within 1 and 2 years were assessed and validated using Kaplan-Meier analysis. Two-year PP was 77.2 and 57.2% (log rank p = 0.047) and freedom from CD-TLR was 84.4 and 84.8% in the PC-PES and DCB groups, respectively (log rank p = 0.89). In the DCB group, most of the patients (n = 77, 89.5%) were treated with high-dose DCB. Consistent predictors of restenosis were lower vessel diameter and severity of Clinical Frailty Scale in the PC-PES group, and severity of peripheral artery calcification scoring system grade, severity of post dissection pattern, and smaller vessel diameter in the DCB group. The validation analysis revealed that patients with consistent predictors had significantly worse PP values than that of those without in the PC-PES (87.9% vs. 55.3%, log rank p = 0.003) and DCB groups (75.9% vs. 35.2%, log rank p = 0.001). The 2-year PP of DCBs was lower than that of PC-PESs. A smaller vessel diameter could predict restenosis in both devices. Vessel calcification and dissection should be considered when using DCB to ensure longer term patency.

Fifteen-Fraction Radiosurgery Followed by Reduced-Dose Whole-Brain Irradiation With a Total Biologically Effective Dose of >90-100 Gy for a Locally Invasive Brain Metastasis From Lung Adenocarcinoma With a High Dissemination Potential.

A deep-seated, locally infiltrative 5.8-cm brain metastasis (BM) involving the ventricular wall and optic radiation is deemed unamenable for a safe total resection, while preventing tumor seeding. Meanwhile, radiotherapeutic management alone for such a BM close to the brainstem is also challenging. We describe such a BM (gross tumor volume [GTV] 40.3 cm3) from lung adenocarcinoma (LAC), located in the left temporo-occipital lobes, with extensive invasion to the tentorium cerebelli and a high potential for dissemination. The BM was treated with 15-fraction(s) (fr) stereotactic radiosurgery (SRS) followed by whole-brain irradiation (WBI) at 27 Gy/15 fr with a 19-day interval. During the SRS, the solid component away from the tentorium showed obvious shrinkage. The cumulative biologically effective doses (BEDs) of the minimum and D99% of the GTV were ≥92.3 Gy and ≥102.6 Gy, respectively, where the BED was based on the linear-quadratic formula at an alpha/beta ratio of 10 (BED10). Despite a maximum response with nearly complete regression at 7.5 months, local tumor regrowth near the tentorial incisura became gradually apparent from 11.2 to 19.3 months. Salvage re-SRS with 53 Gy/10 fr specific to these lesions resulted in obvious regression at 5.8 months. However, radiation injury concomitant with triventriculomegaly progressed from 7.9 to 13.9 months, eventually leading to meningeal dissemination and patient mortality at 34.6 months. This case demonstrates that a BED10 ≥90-100 Gy in 30 fr to the GTV boundary with a more than two-week interval without combined systemic therapy is insufficient for achieving complete local tumor eradication of a 40-cc LAC-BM. Shorter treatment duration with a steeper dose gradient outside and inside the GTV in the SRS or a volumetric modulated arc-based SRS combined with simultaneously integrated WBI may improve efficacy and safety.

Robotic Radiosurgical Boost After Whole-Brain Radiotherapy for 12 Brain Metastases: En Bloc Consecutive Irradiation With Comprehensively Optimized Single Plan for Eight Lesions Totaling 118 cc.

General radiotherapeutic management for >10 brain metastases (BMs) totaling >100 cm3, including multiple large lesions (>10-30 cm3) in close proximity, demonstrated limited efficacy and/or safety. We describe a case of 12 BMs, summating 122.2 cm3, including a 39.6 cm3 maximum lesion and adjacent ones. The patient had an 8.1-year treatment history for recurrent/metastatic breast cancer refractory to endocrine and chemotherapy. BMs were treated with conventional whole-brain radiotherapy (WBRT) with 30 Gy/10 fractions (fr), followed by an immediate stereotactic radiosurgery (SRS) boost with 27 Gy/5 fr (52-64% isodoses) which covers the gross tumor boundaries of selected eight lesions (total 118.4 cm3). The SRS dose was defined to ensure the cumulative biologically effective dose (BED10) of just ≥80 Gy while minimizing the risk of radiation injury. The SRS was performed using a CyberKnife (CK) robotic system (Accuray Incorporated, Sunnyvale, California, United States) with a variable-sized collimator (10-40 mm), for which en bloc consecutive irradiation, using 215 beams based on a comprehensively optimized single plan (path), was adopted. The treatment time per fraction was ≤45 min (mean 5.6 min per lesion). Afterward, BMs demonstrated remarkable regression over six months, causing the total residual visible lesions of 12.6 cm3 (10.3%) at 11.4 months, despite the absence of obvious lesion shrinkage during the radiotherapy. WBRT, followed by an immediate 5-fr SRS boost with a total BED10 of 80 Gy to large and/or culprit lesions, can be an efficacious and safe treatment option for multiple BMs, totaling >120 cm3. En bloc consecutive irradiation with a single path provides overwhelmingly more efficient delivery for treating multiple lesions using CK in terms of irradiation time and comprehensive reduction of normal brain dose compared to individual planning. Volumetric-modulated arc-based >10-fr SRS with simultaneously integrated reduced-dose WBRT may be an alternative to further enhance efficacy and safety.

Stereotactic radiotherapy for ventricular tachycardia: A study protocol.

Background: Currently, the standard curative treatment for ventricular tachycardia (VT) and ventricular fibrillation (VF) is radiofrequency catheter ablation. However, when the VT circuit is deep in the myocardium, the catheter may not be delivered, and a new, minimally invasive treatment using different energies is desired. Methods: This is a protocol paper for a feasibility study designed to provide stereotactic radiotherapy for refractory VT not cured by catheter ablation after at least one catheter ablation. The primary end point is to evaluate the short-term safety of this treatment and the secondary endpoint is to evaluate its efficacy as assessed by the reduction in VT episode. Cyberknife M6 radiosurgery system will be used for treatment, and the prescribed dose to the target will be 25Gy in one fraction. The study will be conducted on three patients. Conclusion: Since catheter ablation is the only treatment option for VT that is covered by insurance in Japan, there is currently no other treatment for VT/VF that cannot be cured by catheter ablation. We hope that this feasibility study will provide hope for patients who are currently under the stress of ICD activation. Trial registration: The study has been registered in the Japan Registry of Clinical Trials (jRCTs042230030).