High-power and high-efficiency operation of 1.3 µm-wavelength InP-based photonic-crystal surface-emitting lasers with metal reflector.

We demonstrate high-output-power and high-efficiency operation of 1.3-µm-wavelength InP-based photonic-crystal surface-emitting lasers (PCSELs). By introducing a metal reflector and adjusting the phase of the reflected light via optimization of the thickness of the p-InP cladding layer, we successfully achieve an output power of approximately 400 mW with the slope efficiency of 0.4 W/A and the wall-plug efficiency of 20% under CW conditions. In addition, this PCSEL exhibits a narrow circular beam with a divergence angle below 1.6° even at high output powers under CW conditions at temperatures from 15°C to 50°C. We have also demonstrated an output power of over 12 W under pulsed conditions at room temperature.

A machine learning model for predicting the lymph node metastasis of early gastric cancer not meeting the endoscopic curability criteria.

BACKGROUND: We developed a machine learning (ML) model to predict the risk of lymph node metastasis (LNM) in patients with early gastric cancer (EGC) who did not meet the existing Japanese endoscopic curability criteria and compared its performance with that of the most common clinical risk scoring system, the eCura system. METHODS: We used data from 4,042 consecutive patients with EGC from 21 institutions who underwent endoscopic submucosal dissection (ESD) and/or surgery between 2010 and 2021. All resected EGCs were histologically confirmed not to satisfy the current Japanese endoscopic curability criteria. Of all patients, 3,506 constituted the training cohort to develop the neural network-based ML model, and 536 constituted the validation cohort. The performance of our ML model, as measured by the area under the receiver operating characteristic curve (AUC), was compared with that of the eCura system in the validation cohort. RESULTS: LNM rates were 14% (503/3,506) and 7% (39/536) in the training and validation cohorts, respectively. The ML model identified patients with LNM with an AUC of 0.83 (95% confidence interval, 0.76-0.89) in the validation cohort, while the eCura system identified patients with LNM with an AUC of 0.77 (95% confidence interval, 0.70-0.85) (P = 0.006, DeLong's test). CONCLUSIONS: Our ML model performed better than the eCura system for predicting LNM risk in patients with EGC who did not meet the existing Japanese endoscopic curability criteria. We developed a neural network-based machine learning model that predicts the risk of lymph node metastasis in patients with early gastric cancer who did not meet the endoscopic curability criteria.

Endoscopic Features of Synchronous Multiple Early Gastric Cancers: Findings from a Nationwide Cohort.

INTRODUCTION: We investigated the factors associated with synchronous multiple early gastric cancers and determined their localization. METHODS: We analyzed 8,191 patients who underwent endoscopic submucosal dissection for early gastric cancers at 33 hospitals in Japan from November 2013 to October 2016. Background factors were compared between single-lesion (n = 7,221) and synchronous multi-lesion cases (n = 970) using univariate and multivariate analyses. We extracted cases with two synchronous lesions (n = 832) and evaluated their localization. RESULTS: Significant independent risk factors for synchronous multiple early gastric cancer were older age (≥75 years old) (odds ratio [OR] = 1.257), male sex (OR = 1.385), severe mucosal atrophy (OR = 1.400), tumor localization in the middle (OR = 1.362) or lower region (OR = 1.404), and submucosal invasion (OR = 1.528 [SM1], 1.488 [SM2]). Depressed macroscopic type (OR = 0.679) and pure undifferentiated histology OR = 0.334) were more common in single early gastric cancers. When one lesion was in the upper region, the other was more frequently located in the lesser curvature of the middle region. When one lesion was in the middle region, the other was more frequently located in the middle region or the lesser curvature of the lower region. When one lesion was in the lower region, the other was more frequently located in the lesser curvature of the middle region or the lower region. CONCLUSION: Factors associated with synchronous multiple early gastric cancer included older age, male sex, severe mucosal atrophy, tumor localization in the middle or lower region, and tumor submucosal invasion. Our findings provide useful information regarding specific areas that should be examined carefully when one lesion is detected.

Association between the Prognostic Nutritional Index and the Occurrence of Immune-Related Adverse Events.

Immune-related adverse events (irAEs) affect all organs and are associated with various symptoms. The identification of biomarkers that can predict irAEs may be particularly clinically useful. This study aimed to investigate whether the prognostic nutritional index (PNI) before the initiation of immune checkpoint inhibitor (ICI) treatment can predict the occurrence of irAEs. We conducted a survey of 111 patients with cancer who were receiving ICI fixed-dose monotherapy at Saga University Hospital from the time each ICI became available until January 2020. We compared the PNI between the patients with and without irAE expression, established a cutoff value for PNI associated with the development of irAEs, and investigated the incidence of irAEs and progression-free survival (PFS) in groups divided by the cutoff value. Patients with irAEs had significantly higher PNI than did those without, and there was a significant association between PNI and irAEs after adjusting for potential factors (odds ratio, 1.12; 95% confidence interval, 1.03-1.21). In addition, PNI ≥44.2 was associated with a significantly higher incidence of irAEs (75.0% vs. 35.2%, p = 0.0001) and significantly longer PFS than PNI <44.2 (p = 0.025). In conclusion, pretreatment PNI may be associated with the risk of developing irAEs in patients with advanced recurrent solid tumors. When the PNI is ≥44.2, patient management is important for avoiding serious AEs because while the treatment may be effective, the occurrence of irAEs is a concern.

Efficacy and Safety of Re-administration of Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitor (EGFR-TKI) After EGFR-TKI-Induced Interstitial Lung Disease (CS-Lung-005).

PURPOSE: This study investigated the safety and efficacy of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) re-administration after recovery from EGFR-TKI-induced interstitial lung disease (ILD). METHODS: This multicenter retrospective study collected data from consecutive advanced NSCLC patients who underwent EGFR-TKI re-administration after recovery from EGFR-TKI-induced ILD. RESULTS: Fifty-eight patients were registered. The grades of initial TKI-induced ILD were grade 1 to 4. TKIs used for re-administration were erlotinib for 15 patients, osimertinib for 15, gefitinib for 14, afatinib for 13 patients, and dacomitinib for 1 patient. ILD recurred in 13 patients (22.4%), comprising 3 patients with grade 1, 6 patients with grade 2, and 4 patients with grade 3. No significant associations were found between ILD recurrence and age, smoking history, performance status, time from initial ILD to TKI re-administration, or concomitant corticosteroid use. However, the incidence of ILD recurrence was high in cases of repeated use of gefitinib or erlotinib or first time use of osimertinib at TKI re-administration. The ILD recurrence rate was lowest in patients treated with first time use of gefitinib (8%) or erlotinib (8%), followed by patients treated with repeated use of osimertinib (9%). The response rate, median progression-free survival by TKI re-administration, and median overall survival were 55%, 9.6 and 84.8 months, respectively. CONCLUSION: This study showed that EGFR-TKI re-administration is a feasible and effective treatment for patients who recovered from EGFR-TKI-induced ILD. Our results indicate that re-administration of EGFR-TKI is an important option for long-term prognosis after recovery from EGFR-TKI-induced ILD.

[Ascending Colon Cancer with Radical Resection after Stent Reimplantation Due to Colonic Stent Obstruction for Palliation-A Case Report].

Since the insurance coverage of colorectal stents for bowel obstruction due to colorectal cancer in 2012, the use of colorectal stenting for palliation has rapidly spread. We report a case of ascending colon cancer in which a colorectal stent was placed for palliation, but the stent was reimplanted due to obstruction, followed by radical resection. The patient was a 92- year-old woman who was brought to the emergency room at the age of 90 years with repeated vomiting and abdominal pain, and was diagnosed as colorectal cancer ileus caused by ascending colon cancer, and a colorectal stent was inserted. She received palliative care and had been asymptomatic for 1 year and 3 months, but due to in-stent stenosis, she had bowel obstruction and sent to emergency room, and another stent was installed. The patient had a good course, but 4 months after the second stenting, she was concerned about restenosis and referred to the department of surgery, then performed a radical resection. The indication for colorectal stents for palliative purposes should be considered on a case-by- case basis, including ADL, stage of the disease, and prognosis.

[A Case of Refractory Lymphorrhea after Laparoscopic Distal Gastrectomy].

An 84-year-old man with gastric cancer, cT2N0M0, cStage Ⅰ underwent laparoscopic distal gastrectomy, D1+dissection, and Roux-en-Y reconstruction. We started enteral nutrition on the second postoperative day, but milky drainage appeared from the drain on the fifth postoperative day. The triglyceride in the ascites was markedly elevated, and it was diagnosed as a lymphorrhea. Neither conservative treatment nor lymphangiography were successful. We decided to perform surgical intervention because the lymphorrhea did not improve for about 1 month after gastrectomy. At laparotomy, we detected the lymphatic ducts using enteral nutrition of fat formulas during surgery and successfully closed the lymphatic ducts by suturing and ligation on the 38th postoperative day. Prolonged lymphorrhea causes extreme deterioration of the patient's general condition. Prolonged total parenteral nutrition also increases the risk of infection. It is important to perform surgical treatment for intractable lymphorrhea that does not improve with conservative treatment without hesitation.

Radiocontrast Medium-Induced Kounis Syndrome in a Dialysis Patient: A Case Report.

Kounis syndrome is defined as the concurrence of acute coronary syndrome and a condition related to mast cell activation, including anaphylaxis and anaphylactoid. A 58-year-old male hemodialysis patient underwent enhanced computed tomography (CT) using the radiocontrast medium, iopamidol for investigation of a kidney tumor. Two minutes after the administration of iopamidol, he developed respiratory symptoms and chest pain. Five minutes after that, disturbed consciousness and low blood pressure were observed. On the other hand, he did not demonstrate urticaria and swelling of the skin. A 12-lead electrocardiogram (ECG) and echocardiogram suggested the presence of cardiac ischemia. Therefore, he was diagnosed with Kounis syndrome caused by radiocontrast media. Eighteen minutes after this, he received an intramuscular injection of adrenaline (0.3 mg), and his vital signs stabilized and his ECG, echocardiogram, and symptoms improved. Without undergoing emergency coronary angiography (CAG), he was hospitalized and closely monitored. The next day, his symptoms had not worsened, and he underwent hemodialysis at his local hospital. The allergen radiocontrast media could be injurious and not sufficiently excreted if administrated for patients on weekly hemodialysis with radiocontrast medium-induced Kounis syndrome manifesting; hence, indication for emergency CAG in radiocontrast medium-induced Kounis syndrome should be cautiously evaluated by close observation.

Deciphering the association between biopsy-confirmed systemic small vessel vasculitis and Epstein-Barr virus-positive polymorphic B-cell lymphoproliferation.

The Epstein-Barr virus (EBV) is associated with various lymphoproliferative disorders (LPD). Additionally, EBV infection has correlated with diverse autoimmune diseases. However, the association between EBV and systemic small vessel vasculitis (SVV) remains controversial. Here, we report a case of SVV with pauci-immune glomerulonephritis accompanied by an EBV-positive polymorphic B-cell LPD, not otherwise specified. The intricate distinction between EBV-positive B-cell LPD and SVV was difficult, as both diseases demonstrated similar clinical presentations. Lymph node and kidney biopsies facilitated the accurate diagnosis of these two conditions. The administration of high-dose prednisolone, combined with rituximab, proved efficacious, with no instances of relapse over the subsequent 2-year period. This case indicates an association between EBV-positive B-cell LPD and SVV. The diligent execution of biopsies is a crucial diagnostic and interpretive strategy, generating precise comprehension of this condition and guiding its appropriate therapeutic management.

Comparison of percutaneous ablation and hepatectomy for liver metastasis: A single center retrospective study.

AIM: To investigate the current treatment for liver metastasis and clarify the indications for percutaneous thermal ablation for liver metastasis. METHODS: Ninety-two patients were enrolled and retrospectively analyzed. The patients underwent hepatectomy and/or percutaneous thermal ablation for liver metastases between January 2012 and December 2018. Twenty-six patients who underwent ablation treatment and seven patients who underwent both ablation and hepatectomy were included in the ablation treatment group (group A). We compared these patients with 59 patients who underwent hepatectomy only (group H). Subgroup analyses were performed between ablation (group AC) for colorectal liver metastasis and hepatectomy (group HC) for colorectal liver metastasis in 17 and 53 patients, respectively. RESULTS: The percentage of liver metastases other than colorectal cancer in group A was higher than that in the group H. Maximum tumor size in group A was significantly smaller than that in group H. Similarly, the patients in group AC were significantly older and demonstrated higher total bilirubin, lower serum albumin, and lower platelet counts than those in group HC. Overall survival was poorer in the AC group than that in the HC group. However, no differences were observed at metastasis ≤2 cm in size. CONCLUSIONS: Percutaneous thermal ablation was performed for many cancer types than hepatectomy. It is performed in elderly patients. We suggested that ablation for colorectal liver metastasis sized ≤2 cm is a suitable indication.

High incidence of lung cancer death after curative endoscopic submucosal dissection for superficial esophageal squamous cell carcinoma.

BACKGROUND AND AIM: Following treatment of superficial esophageal squamous cell carcinoma (ESCC), surveillance for a second primary malignancy (SPM) is necessary. However, detailed evidence regarding the timing and prognosis of SPMs is insufficient. We aimed to clarify the details of SPMs and their effects on patient outcomes. METHODS: This retrospective, multicenter study involved 11 hospitals. Patients with superficial ESCC curatively resected using endoscopic submucosal dissection between May 2005 and December 2012, were included in this study. RESULTS: The 5-year survival rate of 187 patients was 92.6% during a median follow-up duration of 96.8 months. Thirty-one patients died, 14 of whom died of SPMs. Compared to patients with SPMs detectable by esophagogastroduodenoscopy (EGD), patients with SPMs detectable only by modalities other than EGD had a significantly higher mortality rate (p < 0.001). Patients with second primary lung cancer (LC) had a high mortality rate (56.3%). Univariate and multivariate analyses showed that multiple Lugol-voiding lesions (LVLs) tended to be associated with SPMs (p = 0.077, hazard ratio [HR] 4.43, 95% confidence interval [CI]: 0.91-6.50), and metachronous ESCC was an independent risk factor for the incidence of second primary LC (p = 0.037, HR 3.51, 95% CI: 1.08-11.41). CONCLUSIONS: SPMs that cannot be detected by EGD, such as LC, must be considered after the curative resection of ESCC. We suggest strict screening by both EGD and computed tomography for patients with multiple LVLs or metachronous ESCC to detect SPMs in their early stages.

A novel artificial intelligence-based endoscopic ultrasonography diagnostic system for diagnosing the invasion depth of early gastric cancer.

BACKGROUND: We developed an artificial intelligence (AI)-based endoscopic ultrasonography (EUS) system for diagnosing the invasion depth of early gastric cancer (EGC), and we evaluated the performance of this system. METHODS: A total of 8280 EUS images from 559 EGC cases were collected from 11 institutions. Within this dataset, 3451 images (285 cases) from one institution were used as a development dataset. The AI model consisted of segmentation and classification steps, followed by the CycleGAN method to bridge differences in EUS images captured by different equipment. AI model performance was evaluated using an internal validation dataset collected from the same institution as the development dataset (1726 images, 135 cases). External validation was conducted using images collected from the other 10 institutions (3103 images, 139 cases). RESULTS: The area under the curve (AUC) of the AI model in the internal validation dataset was 0.870 (95% CI: 0.796-0.944). Regarding diagnostic performance, the accuracy/sensitivity/specificity values of the AI model, experts (n = 6), and nonexperts (n = 8) were 82.2/63.4/90.4%, 81.9/66.3/88.7%, and 68.3/60.9/71.5%, respectively. The AUC of the AI model in the external validation dataset was 0.815 (95% CI: 0.743-0.886). The accuracy/sensitivity/specificity values of the AI model (74.1/73.1/75.0%) and the real-time diagnoses of experts (75.5/79.1/72.2%) in the external validation dataset were comparable. CONCLUSIONS: Our AI model demonstrated a diagnostic performance equivalent to that of experts.