Abstract 2382: Three-dimensional spatial phenotyping of cellular landscapes in the bone microenvironment of spontaneous metastases

Metastasis to distant organs is the major cause of cancer-related deaths, and bone is the most frequent destination of metastasis in many cancers. Recent studies have shown that the bone microenvironment, not only permits, but augments cancer cells’ invasion and spread within tissue. Recent evidence also suggests that NG2+ cells participate in the initiation of bone metastasis and enhance proliferation and migration via cell-to-cell interactions and often co-localize with early disseminated tumor cells (DTCs). Hence, we developed an imageomics framework to measure and model three-dimensional (3D) spatial relationships within the bone microenvironment using whole slide confocal imaging.

To investigate the progression of DTCs, we delivered Lewis Lung Carcinoma (LLC1) GFP+ cancer cells to hind limb bones through intra-iliac artery injection. We did not observe immunogenic rejection of the cells or loss of markers during tumor progression. We performed whole slide confocal imaging to reconstruct high, single-cell resolution, 3D images of femur bones using NG2-creER;ROSA26-LoxP-TdTomato mice. This allowed us to detect and localize single spontaneous DTCs and NG2+ cells within the overall structure of the bone using anti-RFP and anti-GFP fluorescent markers.

To quantify 3D spatial relationships in the bone microenvironment, cell positions were labeled within the image by setting a channel-specific minimum intensity threshold to remove background noise and weakly-stained objects, followed by removing all objects measuring <10 μm in more than one dimension. The remaining markers for DTCs were evaluated manually. DTCs were identified based on 3D shape, size, heterogeneity of stain markers, and absence of non-specific staining, while the coordinates (x,y,z) of each DTC were recorded. NG2+ cell positions were determined automatically; a black-hat transformation is used to remove background noise and enhance contrast, followed by thresholding to segment NG2+ cells. For segmented objects within the volume range of an expected cell (5-20 μm radius), the centroid coordinates of the resulting objects were recorded.

To evaluate the spatial relationships in the stationary point patterns (SPPs) generated from the DTC and NG2+ staining, we implemented a 3D Ripley’s cross-K function to indicate spatial clustering or dispersion within and between SPPs to quantitatively evaluate spatial relationships at various distances and statistically compare against random distributions.

We have developed an imageomics framework for 3D spatial relationships of different cells within the bone microenvironment using whole slide confocal imaging. Our framework can accurately assess the relationship between the two groups and evaluate additional elements within the bone microenvironment, and potentially other cancer-affected organ systems.

Citation Format: Daniel S. Kermany, Weijie Zhang, Jianting Sheng, Matthew Vasquez, Xiang Zhang, Stephen T. Wong. Three-dimensional spatial phenotyping of cellular landscapes in the bone microenvironment of spontaneous metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2382.

The effects of temporary intraocular pressure spikes after intravitreal dexamethasone implantation on the retinal nerve fiber layer

Background and objective: The dexamethasone (DEX) implant is known to cause temporary intraocular pressure (IOP) spikes after implantation. The purpose of this study is to determine if IOP spikes after DEX implant cause significant thinning in the retinal nerve fiber layer (RNFL).

Study design, patients, and methods: A total of 306 charts were reviewed with 48 and 21 patients meeting inclusion criteria for the cross-sectional and prospective groups, respectively. Cross-sectional inclusion criteria: IOP spike ≥22 mmHg up to 16 weeks after DEX implant, DEX implant in only 1 eye per patient, and spectral-domain optical coherence tomography (OCT) RNFL imaging of both eyes ≥3 months after IOP spike. Prospective inclusion criteria: OCT RNFL performed within 1 year prior to DEX implantation, IOP spike ≥22 mmHg up to 16 weeks after DEX implant, and OCT RNFL performed ≥3 months after IOP spike. The average RNFL thickness in the contralateral eye was used as the control in the cross-sectional group. Institutional review board approval was obtained.

Results: In the cross-sectional group, there was no statistically significant difference in the mean RNFL thicknesses in the treated vs untreated eyes (80.4±15.5 μm and 82.6±15.8 μm, respectively; P=0.33) regardless of treatment diagnosis, magnitude of IOP spike, or history of glaucoma. In the prospective group, mean RNFL thicknesses before and after IOP spikes ≥22 mmHg were similar (78.0±14.8 μm and 75.6±13.6 μm, respectively; P=0.13).

Conclusion and relevance: Temporary elevation of IOP after DEX implantation when treated with topical IOP lowering drops does not appear to lead to a meaningful change in RNFL thickness.

Appointment Compliance in Patients With Diabetic Macular Edema and Exudative Macular Degeneration

BACKGROUND AND OBJECTIVE

The purpose of this study is to compare cancellation and no-show rates in patients with diabetic macular edema (DME) and exudative macular degeneration (wet AMD).

PATIENTS AND METHODS

An anonymous survey was sent to 1,726 retina specialists inquiring as to the number of appointments their patients with DME and wet AMD attended, cancelled, or did not show up for in 2014 and 2015.

RESULTS

Data were obtained on 109,599 appointments. Patients with DME in the U.S. had a 1.591-times increased odds of cancelling or no-showing to their appointments than patients with wet AMD (P < .0001). Patients with DME in Europe had a 1.918-times increased odds of cancelling or no showing to their appointments than patients with wet AMD (P < .0001).

CONCLUSION

Patients with DME in the U.S. and Europe cancelled and no-showed to their appointments significantly more often than patients with wet AMD. These findings can be taken into consideration when establishing treatment plans for patients with DME. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:186-190.].

Identifying Medical Diagnoses and Treatable Diseases by Image-Based Deep Learning

The implementation of clinical-decision support algorithms for medical imaging faces challenges with reliability and interpretability. Here, we establish a diagnostic tool based on a deep-learning framework for the screening of patients with common treatable blinding retinal diseases. Our framework utilizes transfer learning, which trains a neural network with a fraction of the data of conventional approaches. Applying this approach to a dataset of optical coherence tomography images, we demonstrate performance comparable to that of human experts in classifying age-related macular degeneration and diabetic macular edema. We also provide a more transparent and interpretable diagnosis by highlighting the regions recognized by the neural network. We further demonstrate the general applicability of our AI system for diagnosis of pediatric pneumonia using chest X-ray images. This tool may ultimately aid in expediting the diagnosis and referral of these treatable conditions, thereby facilitating earlier treatment, resulting in improved clinical outcomes. VIDEO ABSTRACT.

Clinical applications of retinal gene therapies

Retinal degenerative diseases are a major cause of blindness. Retinal gene therapy is a trail-blazer in the human gene therapy field, leading to the first FDA approved gene therapy product for a human genetic disease. The application of Clustered Regularly Interspaced Short Palindromic Repeat/Cas9 (CRISPR/Cas9)-mediated gene editing technology is transforming the delivery of gene therapy. We review the history, present, and future prospects of retinal gene therapy.

Diabetic macular edema: it is more than just VEGF

Diabetic macular edema is a serious visual complication of diabetic retinopathy. This article reviews the history of previous and current therapies, including laser therapy, anti-vascular endothelial growth factor agents, and corticosteroids, that have been used to treat this condition. In addition, it proposes new ways to use them in combination in order to decrease treatment burden and potentially address other causes besides vascular endothelial growth factor for diabetic macular edema.