Prediction of malignant glioma grades using contrast-enhanced T1-weighted and T2-weighted magnetic resonance images based on a radiomic analysis

We conducted a feasibility study to predict malignant glioma grades via radiomic analysis using contrast-enhanced T1-weighted magnetic resonance images (CE-T1WIs) and T2-weighted magnetic resonance images (T2WIs). We proposed a framework and applied it to CE-T1WIs and T2WIs (with tumor region data) acquired preoperatively from 157 patients with malignant glioma (grade III: 55, grade IV: 102) as the primary dataset and 67 patients with malignant glioma (grade III: 22, grade IV: 45) as the validation dataset. Radiomic features such as size/shape, intensity, histogram, and texture features were extracted from the tumor regions on the CE-T1WIs and T2WIs. The Wilcoxon–Mann–Whitney (WMW) test and least absolute shrinkage and selection operator logistic regression (LASSO-LR) were employed to select the radiomic features. Various machine learning (ML) algorithms were used to construct prediction models for the malignant glioma grades using the selected radiomic features. Leave-one-out cross-validation (LOOCV) was implemented to evaluate the performance of the prediction models in the primary dataset. The selected radiomic features for all folds in the LOOCV of the primary dataset were used to perform an independent validation. As evaluation indices, accuracies, sensitivities, specificities, and values for the area under receiver operating characteristic curve (or simply the area under the curve (AUC)) for all prediction models were calculated. The mean AUC value for all prediction models constructed by the ML algorithms in the LOOCV of the primary dataset was 0.902 ± 0.024 (95% CI (confidence interval), 0.873–0.932). In the independent validation, the mean AUC value for all prediction models was 0.747 ± 0.034 (95% CI, 0.705–0.790). The results of this study suggest that the malignant glioma grades could be sufficiently and easily predicted by preparing the CE-T1WIs, T2WIs, and tumor delineations for each patient. Our proposed framework may be an effective tool for preoperatively grading malignant gliomas

硝子体手術後に網膜静脈分枝閉塞症を来したタモキシフェン内服患者の1例

タモキシフェンは主に乳癌治療薬として使用されているが,眼副作用の報告は非常に少ない.今回,タモキシフェン内服患者における,硝子体手術後に発症した網膜静脈分岐閉塞症(branch retinal vein occlusion,以下BRVO)の1例を経験したので報告する.症例は51歳女性,乳癌の術後1日量20mgのタモキシフェンによるアジュバント療法を受けていた.2年後に左眼の黄斑円孔が発見され硝子体手術を行った.後部硝子体剥離を起こしている際にアーケード血管から出血を認めたため出血部位の圧迫及び眼内灌流圧を上げることで止血を行った.術翌日には黄斑円孔の閉鎖が確認されたが,術後15日目に出血部位を閉塞起点とするBRVOを認めた.視力は左矯正0.7pと術前と比べほぼ変わりはなかったが,光干渉断層計で黄斑浮腫を認めたためベバシズマブ硝子体内投与を行った.同時にタモキシフェンによる副作用を疑い,内服を中止した.タモキシフェンの眼副作用として,BRVOも念頭におく必要がある.Tamoxifen is often used for treating breast cancer. However, tamoxifen-induced ocular complications are very rare. We will report on a case of branch retinal vein occlusion (BRVO) associated with tamoxifen use. A fifty-one year old female was receiving peroral tamoxifen with daily doses of 20 mg following surgery for breast cancer. A macular hole was detected in her left eye two years later and vitreous surgery was performed. It was observed that there was bleeding from the inferior arcade vessels after inducing the posterior vitreous detachment. Hemostasis of the vein was performed by raising the intraocular perfusion pressure and by compression of the bleeding site. The macular hole was closed on a postoperative day. A fundus examination revealed that the left branch retinal vein occlusion started bleeding fifteen days after the surgery. There was almost no change compared with preoperative visual acuity, but optical coherence tomography (OCT) showed a macular edema. Therefore, intravitreal injections of bevacizumab and tamoxifen therapy were discontinued. Although BRVO is rare, ophthalmologists should be alerted to this type of ocular side effect

Characterization of Human Induced Pluripotent Stem Cell-Derived Retinal Pigment Epithelium Cell Sheets Aiming for Clinical Application

Age-related macular degeneration (AMD) causes severe visual impairment due in part to age-dependent impairment of retinal pigment epithelium (RPE). It has been suggested that autologous human induced pluripotent stem cells (hiPSCs) may represent a useful cell source for the generation of graft RPE. We generated hiPSC-derived RPE (hiPSC-RPE) cell sheets optimized to meet clinical use requirements, including quality, quantity, consistency, and safety. These cell sheets are generated as a monolayer of cells without any artificial scaffolds, express typical RPE markers, form tight junctions that exhibit polarized secretion of growth factors, and show phagocytotic ability and gene-expression patterns similar to those of native RPE. Additionally, upon transplantation, autologous nonhuman primate iPSC-RPE cell sheets showed no immune rejection or tumor formation. These results suggest that autologous hiPSC-RPE cell sheets may serve as a useful form of graft for use in tissue replacement therapy for AMD

Solitary mediastinal lymph node metastasis of hepatocellular carcinoma: MR imaging findings.

A 65-year-old man with multiple hepatocellular carcinomas in the liver with type C viral hepatitis had a solitary mediastinal lymph node metastasis in the right paratracheal to tracheobronchial region. Surgical resection for the mediastinal metastasis was undertaken based on magnetic resonance (MR) imaging findings, suggesting its radicality. We assess the MR imaging findings and presumable pathways of lymphatic metastasis from the liver to mediastinal lymph nodes in this report.A 65-year-old man with multiple hepatocellular carcinomas in the liver with type C viral hepatitis had a solitary mediastinal lymph node metastasis in the right paratracheal to tracheobronchial region. Surgical resection for the mediastinal metastasis was undertaken based on magnetic resonance (MR) imaging findings, suggesting its radicality. We assess the MR imaging findings and presumable pathways of lymphatic metastasis from the liver to mediastinal lymph nodes in this report